TITLE PAGE

ENHANCING SEISMIC RESILIENCE: A COMPARATIVE ANALYSIS

ON THE USE OF LEAD RUBBER BEARING BASE ISOLATORS AND

FLUID VISCOUS DAMPERS ON AN IRREGULAR STRUCTURE

A Capstone Project Proposal

Presented to
The Faculty of the Civil Engineering Department
School of Engineering and Architecture
Saint Louis University
Baguio City

In Partial Fulfillment
Of the Requirements
for the Degree of
Bachelor of Science in Civil Engineering

by:

Engr. Marie Kathlyn De Guzman

Desiree P. Baroña
Harold E. Catanes
Jefferson R. Fernandez
Emmyrald G. Mecos
Ma. Katleen F. Niñalga
Joshua Robert V. Novida
Patricia Denisse N. Racraquin
Ericka F. Timbol
Faye Winslette K. Wakit

November 2023
 Saint Louis University
SCHOOL OF ENGINEERING AND ARCHITECTURE
Civil and Geodetic Engineering Department

INDORSEMENT

This Capstone Project entitled “Enhancing Seismic Resilience: A

Comparative Analysis on The Use Of Lead Rubber Bearing Base
Isolators And Fluid Viscous Dampers on an Irregular Structure”,
prepared and submitted by Desiree P. Baroña, Harold E. Catanes,
Jefferson R. Fernandez, Emmyrald G. Mecos, Ma. Katleen F. Niñalga,
Joshua Robert V. Novida, Patricia Denisse N. Racraquin, Ericka F.
Timbol and Faye Winslette K. Wakit in partial fulfillment of the requirements
for the degree BACHELOR OF SCIENCE IN CIVIL ENGINEERING, has been
examined and hereby recommended for Proposal Defense.

Engr. Marie Kathlyn De Guzman,MSCE

Research Promoter

This Capstone Project entitled “ENHANCING SEISMIC RESILIENCE:

A COMPARATIVE ANALYSIS ON THE USE OF LEAD RUBBER BEARING
BASE ISOLATORS AND FLUID VISCOUS DAMPERS ON AN IRREGULAR
STRUCTURE” prepared and submitted by Desiree P. Baroña, Harold E.
Catanes, Jefferson R. Fernandez, Emmyrald G. Mecos, Ma. Katleen F.
Ninalga, Joshua Robert V. Novida, Patricia Denisse N. Racraquin, Ericka F.
Timbol and Faye Winslette K. Wakit in partial fulfillment of the requirements
for the degree BACHELOR OF SCIENCE IN CIVIL ENGINEERING, has been
examined and recommended for acceptance and approval.

Engr. Janice Kaye Aquino, MSCE, MSMtE Engr. Eleazar Santiago, MSCE
Faculty - Panel Member Faculty, Panel Member

Engr. Lovely L. Rañosa, MAEHP, MSCE

Undergraduate Research Coordinator

TABLE OF CONTENTS
TITLE PAGE i
INDORSEMENT ii
TABLE OF CONTENTS iii
List of Figures v
List of Tables v
CHAPTER 1: THE PROBLEM AND ITS SETTING 1
1.1 Background of the Study 1
1.2 Statement of the Problem 4
1.3 Conceptual and Theoretical Framework 5
1.3.1 Conceptual Framework 5
Fig. 1. Conceptual Framework 5
1.3.1.1 Earthquake Engineering 6
1.3.1.2 Seismic Strengthening Techniques 7
1.3.1.3 Base Isolator 8
Fig.2. Lead Rubber Bearing. 9
1.3.1.3 Damper 9
Fig.3. Fluid Viscous Damper 10
1.3.1.4. Structural Response 10
1.3.2 Theoretical Framework 12
Fig. 4. Theoretical Framework 12
1.4 Scope and Delimitations 15
1.5 Constraints Used in the Study 16
1.5.1. Economic Constraints 16
1.5.2. Environmental Constraints 16
1.5.3. Cultural Constraints 16
1.5.4. Ethical and Professional Constraints 17
1.5.5. Health and Safety Constraints 17
1.5.6. Manufacturability and Sustainability 17
1.5.7. Design Constraints 17
1.5.8. Time Constraints 18
1.6 Significance of the Study 18
1.7 Operational Definition of Terms 20
CHAPTER 2: RESEARCH DESIGN AND METHODOLOGY 22
2.1 Research Design and Methodology 22
Fig. 5. Isometric View of Irregular Structure Frame 23
Fig. 6. Front View of Irregular Structure Frame 23
 Fig. 7. Rear View of Irregular Structure Frame 23
Fig. 8. Side View of Irregular Structure Frame 24
Table 1. Placement of base isolators on the medium-rise building. 25
Table 2. Placement of dampers on the medium-rise building. 26
2.2 Population and Locale 26
2.3 Data Gathering Tools 27
2.4 Data Gathering Procedure 29
Fig. 9. Flowchart of Data Gathering Procedure 29
2.5 Treatment of the Data 30
Eq. 1. ANOVA 31
Eq’n .2. T-Test 32
2.6 Management of Multidisciplinary Environments 33
2.7 Project Management 34
2.7.1 Team Management 34
Table 3: Team Management and Role Distribution 35
2.7.2 Financial Management 36
Table 4: Finance Management for Project Duration 36
2.7.3 Time Management 37
2.7.3.1 Activity Plan Gantt Chart 37
Table 5: Activity Plan Gantt Chart 37
2.7.3.2. Schedule of Outputs 38
Table 6: Schedule of Outputs 38
CHAPTER 3: REVIEW OF RELATED LITERATURE 40
3.1 BUILDINGS CRITICALLY AFFECTED BY SEISMIC ACTIVITY 41
3.1.1. MEDIUM RISE BUILDINGS 41
3.1.2. IRREGULAR BUILDINGS 42
Fig. 10. Vertical Structural Irregularity Diagrams. 43
Fig. 11. Horizontal Irregularities 44
3.2 SEISMIC STRENGTHENING INNOVATIONS 45
3.2.1. DAMPERS 45
3.2.1.1. Fluid Viscous Damper 46
3.2.2. BASE ISOLATORS 47
3.2.2.1. Lead Rubber Bearing 47
3.3 SOFTWARES USED FOR SEISMIC ANALYSIS 48
OVERVIEW OF THE PROPOSED PROJECT 50
APPENDICES 52
 APPENDIX A 52
Fig. 12. Philippines hazard map. 52
APPENDIX B 53
Fig. 13. Hazard Assessment Map and Result of the location of the Dr.
Otto Hahn Building. 53
APPENDIX C 53
Table 7. Most Devastating Earthquakes that Struck the Philippines from
the 1960's to Present 53
BIBLIOGRAPHY 54

List of Figures

Fig. 1. Conceptual Framework 5

Fig.2. Lead Rubber Bearing. 9
Fig.3. Fluid Viscous Damper 10
Fig. 4. Theoretical Framework 12
Fig. 5. Isometric View of Irregular Structure Frame 23
Fig. 6. Front View of Irregular Structure Frame 23
Fig. 7. Rear View of Irregular Structure Frame 23
Fig. 8. Side View of Irregular Structure Frame 24
Fig. 9. Flowchart of Data Gathering Procedure 29
Fig. 10. Vertical Structural Irregularity Diagrams. 43
Fig. 11. Horizontal Irregularities 44
Fig. 12. Philippines hazard map. 52
Fig. 13. Hazard Assessment Map and Result of the location of the Dr. Otto Hahn
Building. 53

List of Tables

Table 1. Placement of base isolators on the medium-rise building. 25

Table 2. Placement of dampers on the medium-rise building. 26
Table 3: Team Management and Role Distribution 35
Table 4: Finance Management for Project Duration 36
Table 5: Activity Plan Gantt Chart 37
Table 6: Schedule of Outputs 38
Table 7. Most Devastating Earthquakes that Struck the Philippines from the 1960's to
Present 53
CHAPTER 1: THE PROBLEM AND ITS SETTING

1.1 Background of the Study

 Structural vulnerabilities to earthquakes were starkly exemplified by the

1990 Luzon Earthquake in the Philippines, commonly referred to as the "Killer

Quake," with a magnitude of 7.8. This seismic event had devastating

consequences, particularly in Baguio, Dagupan, and Cabanatuan, causing

over 2,000 fatalities. Extensive research has been dedicated to understanding

how both regular and irregular geometric designs impact a structure's

susceptibility to seismic forces. Studies, such as the one by Haque et al.

(2016), emphasize that irregularities in modern urban construction, although

common, lead to structural failures during earthquakes. Despite this

vulnerability, buildings often incorporate irregularities for aesthetic and

functional reasons, as noted by Raagavi & Sidhardhan (2021).

The National Structural Code of the Philippines (2015) categorizes

building irregularities into Vertical Structural Irregularities including, Stiffness

Irregularity, Weight Irregularity, Geometric Irregularity, Discontinuity in Vertical

Lateral-Force-Resisting Elements, and Weak Storey Irregularity, and

Horizontal Structural Irregularities, including Torsional Irregularity, Re-entrant

Corner Irregularity, Diaphragm Discontinuity Irregularity, Out-of-Plane Offsets

Irregularity, and Non-Parallel Systems Irregularity. In response to Northern

and Central Luzon seismic activity, enhancing structural stability, particularly

for irregular buildings, has become a critical focus for earthquake resistance.
 The study adapted the Dr. Otto Hahn Building in Saint Louis University

as its building subject. The Dr. Otto Hahn Building was donated by the People

of the Federal Republic of Germany and was built and inaugurated in 1970.

This building is among the many buildings in the Saint Louis University

Campus and which specifically houses the School of Engineering and

Architecture. The Dr. Otto Hahn Building showcases building irregularity in

terms of vertical geometry shown by the presence of a retaining wall in the 3rd

floor to 1st floor as well as the building setbacks due to it being built in a

sloping ground. The said building was previously subjected to earthquakes,

with the killer quake 1990 of magnitude 7.2 as the strongest recorded seismic

event to affect the structure. After the 1990 killer quake that took place in the

city of Baguio, affecting every structure in the municipality including the Dr.

Otto Hahn building at Saint Louis University, it was then retrofitted to increase

its design strength. The columns were increased in size and the damage

acquired by the building due to the earthquake was rehabilitated.

Two extensively researched earthquake-proofing technologies, base

isolators, and dampers, have demonstrated their efficiency in mitigating

earthquake damage. Base isolation systems, designed to extend the lifespan

of fixed base structures, decouple a building's superstructure from the ground

by employing horizontally flexible yet vertically stiff base isolators (Mallah et

al., 2021). These isolators, including elastomeric bearings, high-damping

bearings, lead rubber, and pendulum bearings, provide horizontal and

controlled vertical stiffness. Lead Rubber Bearings (LRB) under elastomeric

bearing, is composed of layered rubber and steel plates that offer strong
vertical load support with minimal distortion (Mishra et al., 2017). Moreover,

applying LRB on vertical irregularity demonstrated greater strength and

seismic performance than the planned irregular building. On the other hand,

according to Ezzaki et al. (2019), dampers such as Fluid Viscous Dampers,

Tuned Mass Dampers, and Retrofitting Dampers are crucial in enhancing the

building and structure stability as these are designed to absorb and dissipate

energy during seismic events or high winds. Specifically, the viscous dampers

reduce seismic responses by allowing fluid flow through a piston hole,

dissipating kinetic energy as heat, thus stabilizing structures during

earthquakes.

In terms of the optimization, in Gluck et al. (1996), a performance cost

function was optimized to select the most suitable configuration of viscous

elastic dampers. Linear design determined constant coefficients for dampers,

focusing on the dominant first mode in high-rise buildings. Meanwhile,

Gurgoze and Muller (1992) presented a numerical method for optimal location

and damping coefficient determination for viscous dampers in multi-degree-of-

freedom systems, contributing to numerical techniques for optimal damper

placement. Wu et al. (1997) also investigated optimal damper placement in

torsional-dependent structures, aiming to minimize rotations and translations.

The transfer function method of the matrix was used to obtain the target

function. They emphasized that excessive damping does not always improve

structural behavior, and optimal placement corresponds to locations of

maximal displacements. Moreover, Takewaki (1997) introduced an optimal

damper placement technique to minimize the sum of transfer function

amplitudes of interstory drifts at the undamped fundamental frequency, with

optimal locations corresponding to areas with maximal interstory drifts. Lastly,

Hahn and Sathiavageeswaran (1992) found that in structures with uniform

floor stiffness, placing dampers on the lower halves of the lower floors is

effective during earthquakes.

Specialized software, such as ETABS, is vital for analyzing and

modeling structures in earthquake-prone areas. Using ETABS for structural

analysis, along with supplementary data, is essential for understanding

reinforced concrete structures. The software's emphasis on the response

spectrum method aids in calculating the components needed to withstand

lateral seismic forces. The Response Spectrum Analysis (RSA) feature,

represented by RX and RY parameters, is pivotal in determining critical

aspects of the structural response. Additionally, ETABS software includes

specific dampers and base isolator devices crucial for influencing the

structure's behavior.

Given the extensive research on base isolators and dampers, this

study aimed to compare Lead Rubber Bearings (LRB) and Fluid Viscous

Dampers (FVR) in a medium-rise irregular structure using ETABS software for

seismic assessment. The goal is to contribute valuable insights to improve

earthquake resilience in Philippine infrastructure.

1.2 Statement of the Problem

Due to the Philippines' location in the Pacific Ring of Fire and its

vulnerability to frequent earthquakes and volcanic eruptions, irregular

structures in the region are most vulnerable. Consequently, the study aimed
to assess and compare the cost-effectiveness of seismic mitigating devices in

withstanding seismic activities and which among them can provide the

greatest resilience and protection for buildings and infrastructure.

The general objective of the study was to compare the effect of the

base isolator and damper on improving the seismic performance of an

irregular medium-rise building. Specifically, it aimed to:

1. Determine the response of an irregular building against earthquake:

a) without base isolator and damper;

b) with base isolator; and

c) with damper

2. Compare the effect of base isolators on the performance of the building

against earthquakes to the building’s performance without base isolators

and dampers.

3. Compare the effect of dampers on the performance of the building against

earthquakes to the building’s performance without base isolators and

dampers.

4. Determine the optimized number of Lead Rubber Bearing Base Isolators

and Fluid Viscous Dampers in terms of safety and economy.

1.3 Conceptual and Theoretical Framework

1.3.1 Conceptual Framework

 Fig. 1. Conceptual Framework
The study used the concept of earthquake engineering and

revolves around two variables: 1) Seismic strengthening techniques and

2) Seismic performance of a medium-rise irregular building. The

independent variable was the seismic strengthening techniques, which

include using a base isolator and damper. The dependent variable was

the seismic performance of a medium-rise irregular building in terms of

the factors: a) base shear, b) story drift, c) story displacement, d) floor

acceleration, and e) torsion.

1.3.1.1 Earthquake Engineering

Earthquake engineering is an interdisciplinary branch that focuses

on studying how structures behave when subjected to earthquakes. This

discipline has evolved into an interdisciplinary subject involving experts

from various fields, such as seismology, structural and geotechnical

engineering, architecture, urban planning, information technology, and

social sciences. In recent years, the earthquake engineering community

has been reevaluating its methods in response to catastrophic

earthquakes that caused extensive damage, loss of life, and property.

 According to Elnashi & Di Sarno (2015), on an annual basis,

approximately 10,000 lives are lost due to earthquakes, and the economic

impact reaches billions of dollars, often constituting a substantial portion

of a country's Gross National Product (GNP). However, most earthquake-

related losses were due to the collapse and damage garnered by civil

engineering structures and the ground that supports them (Villaverde,

2009).

The effects of earthquakes are categorized into two effects: the

direct and indirect effects. The direct effects include firm ground shaking

and fault ruptures crossing long structures or infrastructure networks such

as pipelines or road networks. On the other hand, the indirect effects are

the geotechnical failures caused by the strong ground shaking, such as

liquefaction, lateral spread, earthquake-induced landslides, and tsunamis,

which affects the structures in the geotechnical environment (Sucuoğlu &

Akkar, 2014). Ground shaking causes the most incredible damage to

structures due to the inertial forces in the lateral direction that it induces.

In addition to this, earthquakes are random and oscillatory in nature and

cause structures to deform in opposite directions. When these inertial

forces exceed the lateral resistance of the structures, they will bend

beyond their linear elastic deformation capacity. It results in inelastic

deformity wherein the deformation of the structure's elements will not be

recoverable after the seismic load is removed, causing the structure to

collapse.

Hence, it is necessary to study the behavior of structures under

seismic loads and evaluate their seismic safety in designing structures

that will withstand strong earthquakes. With the proper application of

earthquake engineering principles and techniques, engineers can

minimize the damage caused by earthquakes.

1.3.1.2 Seismic Strengthening Techniques

One method of minimizing the effect of earthquakes on structures

is the installation of seismic mitigation devices such as base isolators and

dampers. The concept of base isolation focuses on separating the

superstructure from its foundation wherein the reduced interaction

between them is expressed by the term “isolation”, while the term “base”

depicts the foundation of the building (Fakih, M. & Halal, J. & Darwich H.

& Damerji, H., 2020). A base isolator consists of members that provide

stiffness under lateral stresses, a damper that controls displacements,

and bearings that permit horizontal movement and is stiff enough to

transfer loads vertically and horizontally (Reddy, Prasad, & Malagavalli,

2021).

On the other hand, Dampers absorb the seismic force, dissipate

the energy in the building, and convert it into a different form of energy,

usually heat (Ezzaki, Stoica, Rece & Legendi, 2019). By absorbing the

seismic force, the movement of the structure will be reduced, thus

preventing it from acquiring heavy damage.

1.3.1.3 Base Isolator

For this study, Lead Rubber Bearing (LRB) base isolators were

used and compared to Fluid Viscous Damper in their effectiveness in

 enhancing the seismic performance of irregular medium-rise buildings. An

LRB Base Isolator is an elastomeric bearing constructed with thick

alternating rubber layers attached to steel shim plates. The function of

this system is a combination of vertical load support, horizontal flexibility,

restoring force, and damping. Also, lead generally has a low yielding point

when its shear stress reaches 10 MPa and is resistant to repeated loads,

allowing itself to renew over time after deformation (Sahoo & Parhi,

2018). The isolator achieves a very high vertical stiffness by layering thin

rubber reinforced by steel shims. However, the rubber also acts as a

spring, making the device soft laterally. LRB also consists of a lead plug

fitted tightly into a preformed hole in an elastomeric bearing, wherein the

lead core provides rigidity under service loads and energy dissipation

under high lateral loads (Mishra & Awchat, 2017). This combination

allows the isolator to move laterally with relatively low stiffness.

Fig.2. Lead Rubber Bearing.

Source: Lead Rubber Bearing. Adapted from Seismic Isolation and Energy Dissipating
Systems in Earthquake Resistant Design, by N. Torunbalci, 2020, from
https://www.researchgate.net/publication/265678859_SEISMIC_ISOLATION_AND_ENERGY_DISSIPA
TING_SYSTEMS_IN_EARTHQUAKE_RESISTANT_DESIGN

1.3.1.3 Damper

The Fluid Viscous Damper (FVD) was utilized in the study, which

works based on the principle of dissipation of energy due to fluid flowing

through orifices (Agrawal & Amjadian, 2022). It will then produce a

damping pressure that creates a force. The FVD consists of a stainless

steel piston, a steel cylinder divided into two chambers by the piston

head, a compressible hydraulic fluid (silicone oil), and an accumulator for

smooth fluid circulation. As the piston moves from left to right or vice

versa, fluid flows from one chamber to another chamber through the

orifice. This fluid movement from the cylinder chamber to the orifice and

vice versa results in energy dissipation because of head loss.

Moreover, adding fluid viscous dampers to a structure can provide

damping as high as 30% of critical and reduce horizontal floor

accelerations and lateral deformations by 50%. It provides a significant

decrease in earthquake excitation. The role of the fluid viscous damper is

to transform mechanical energy caused by earthquakes, winds, or other

structural vibrations into the inner energy of the damping medium. The

dampers use the increasing temperature of the damping medium to store

energy temporarily. The heat is ultimately consumed by natural cooling.

This way, the dampers protect the structure from damage (Kumar et al.,

2016).
 Fig.3. Fluid Viscous Damper
Source: Fluid Viscous Damper.Adapted from Innovative Bridge Design (Second Edition), in
ScienceDirect, by A.K. Agrawal & M. Amjadian, 2022, from
https://www.sciencedirect.com/topics/engineering/viscous-damper

Therefore, both the base isolators and dampers were used to improve the

seismic strength of buildings, specifically irregular structures. The study used

parameters such as base shear, story drift, displacement, floor acceleration,

and torsion in determining the effectiveness of these seismic mitigating

devices.

1.3.1.4. Structural Response

The structural response of a building depends on its configuration,

knowing that an irregular structure has poor seismic performance. According

to Gabor (2016), building configuration is the distribution of seismic forces

within the structure, their relative amplitude, and any critical design

considerations. In the study, assessing each of the responses in an irregular

building was significant as it attracts large seismic forces and induces stress

concentrations. The base shear measures the most significant predicted

lateral stress from seismic activity on the structure's base (Khan, 2017). The

dampers and base isolators were unevenly distributed along the building so

that the braced bays would receive more base shear and less on the

unbraced bays. One study stated that arranging in alternate bays performs

better, and seismic response shows less of its base shear (S & Cheriyath,

2018).

Also, story drift plays a vital role in determining the structural behavior

of an irregular building under seismic loads. It is crucial to control it for the

building's structural stability, architectural integrity, potential damage or

deformations, and even human comfort. Medium to high-rise buildings must

always consider the effect of drift so property and life loss will decrease

(Rahman, Fancy, & Bobby, 2012). It correlates to the displacement of the

building as this drift causes horizontal displacement in medium to high-rise

buildings, influencing how the structural and nonstructural elements move in

response to earthquake and wind loads. The larger the lateral displacements,

the more they cause significant nonstructural and structural damage. The

story displacement occurs at each story level of a building; as the height

increases, the story displacement attains its maximum value (Patil & Bajad,

2021).

In addition, the shaking of the floor incorporates the change in rate of

speed known as acceleration. The potential destruction is determined when

the level of acceleration and duration are combined. Gabor (2016) states that,

typically, a building can withstand less acceleration the longer the seismic

activity duration. A building can resist very high acceleration for a brief period

in proportion to the amount of damping measures, such as the structure's

base isolators and dampers. On the other hand, torsion occurs when uneven

mass distribution causes the center of mass to position outside the geometric

center, generating stress concentrations. The torsion-induced failures are fatal

for multi-story buildings because the torsional behavior of the structure affects

the uniform translational seismic floor movement and causes concentrated

stress, requiring greater structural strength and ductility (Siroya & Patel,

2021). However, a symmetrical arrangement of the masses will produce

balanced stiffness against both directions and maintain tolerable torsion by

utilizing the base isolators and dampers.

Therefore, it is evident that embedding either base isolators or

dampers on an irregular building structure reduces responses when an

earthquake acts on it. These responses are the base shear, story drift,

displacement, floor acceleration, and torsion, mitigated during seismic activity,

resulting in minimal failures and reduced damages.

1.3.1.4. Robust Parameter Design Optimization

Robust Parameter Design is an optimization approach developed by

Genichi Taguchi who is a Japanese engineer who started his professional

career in a telecommunications company. According to Taguchi, robust

design is “a product whose performance is minimally sensitive to factors

causing variability (at the lowest possible cost)”. Robustness is measured by

performance criteria: meeting the specifications, percent of products

scrapped, cost of rework, % defective, and failure rate. The goal of robust

design is to create a set or combination of design parameter values that (a)

fulfill functional requirements and (b) minimize the sensitivity of the design to

variable noise factors.

Taguchi categorized the factors influencing a system into two groups:

control factors and noise factors. Control factors are those that can be readily

adjusted by the experimenter. On the other hand, noise factors are elements

that affect the system but are challenging or impossible for the experimenter

to control.
 Taguchi's philosophy advocates designing systems to produce outputs

precisely at the specified targets or optimal values, rather than merely within

the limits. This proactive stance proves more effective and efficient compared

to reactive methods like sampling inspections. Central to Taguchi's approach

is the quality loss function, which illustrates that any deviation from the target

value results in a quadratic decrease in quality or customer satisfaction. This

function can be mathematically expressed as:

Figure 4. Graphical presentation of Taguchi’s approach

Where y is the performance parameter of the system, m is the target or

nominal value of y, L is the quality loss, and k is a constant.

 The diagram illustrates the variation of the response under two levels

of a noise factor, with response values depicted at two levels of a control

factor (low and high). In Figure (a), where there's no interaction between the

control and noise factors, the response variation remains consistent

regardless of the control factor's settings. In Figure (b), where an interaction

between the control and noise factors exists, it's beneficial to set the control

factor to its low setting, as there's less response variation with changes in the

noise factor at this setting or the system is less sensitive to the noise factor.

1.3.2 Theoretical Framework

Fig.
4. Theoretical Framework
 The research study was grounded in the fundamental principles of

seismic engineering, which encompasses the study of earthquake ground

motion, structural dynamics, and the response of structures to seismic forces.

Also, it utilizes the theories on seismic isolation and damping.

According to Sheikh & Van Engelen (2022), the seismic isolation theory

follows the concept of providing a low-friction interface to decouple the

superstructure from the foundation, allowing the earthquake energy to be

dissipated throughout the structure and the fundamental period of the

structure to be elongated. On the other hand, the principle of damping

encompasses the introduction of damping into a system, often through the

conversion of mechanical energy to thermal energy. This conversion between

energies is called energy dissipation, which is present in base isolation and

damping. The energy dissipation theory is based on the principle of absorbing

or dissipating the energy generated by the earthquake to prevent excessive

deformation and maintain structural stability.

Moreover, in seismic base isolation, the energy transferred to the

superstructure is reduced by decoupling the superstructure and substructure.

In contrast, in passive energy dissipation systems, which include the use of a

damper, seismic energy is dissipated through mechanical devices which may

work on different principles like friction, shear deformations, metallic yielding,

and fluid orifice, and the like (Adithya, Shankarling & Narendra, 2016). The

study will use the principle of Dynamic Analysis, in the form of Response

Spectrum Analysis, to evaluate the effectiveness of these seismic

strengthening devices on the seismic response of the irregular structure. The

principle of dynamic analysis in earthquake engineering involves the

numerical simulation of a structure's response to seismic ground motion. It is

based on the fundamental concept that understanding how structures interact

with dynamic forces during an earthquake is essential for designing

earthquake-resistant structures. Dynamic analysis considers structures' mass,

stiffness, and damping properties to predict their behavior under seismic

loading. This analysis helps assess structural performance, determine

potential vulnerabilities, and refine seismic design and retrofitting strategies

(Losada, Comastri & Franco, 2020).

Additionally, one of the types of Dynamic Analysis is Response

Spectrum Analysis, a widely employed approach in the design of structures.

In essence, RSA simplifies modal analysis, akin to Response History Analysis

(RHA), but leverages the advantages of the response spectrum concept. The

primary objective of this method is to swiftly estimate peak responses without

necessitating the extensive calculations associated with response history

analysis. It is valuable because RSA entails a series of straightforward and

expedient computations instead of time history analysis, which involves

solving complex differential equations over time (Fragiadakis, 2013).

By integrating base isolator and damper on an irregular structure and

analyzing their effects on the structure’s seismic response, the researchers

hypothesized that:

Ho1: LRB base isolators have no significant effect on the seismic

performance of a medium-rise irregular building.

Ho2: Fluid Viscous Dampers have no significant effect on the seismic

performance of a medium-rise irregular building.

1.4 Scope and Delimitations

The research study only included the placement of two types of seismic

strengthening techniques: the first is a lead rubber bearing (LRB) base

isolator, and the second one is a fluid viscous damper (FVD).

The study was limited to conducting seismic assessments on medium-

rise vertically irregular buildings under Zone IV of the Philippines, an area

frequently susceptible to earthquakes and typhoons. In addition, the building

design used in the study was inspired by an existing building in the

Philippines.

The study adhered to earthquake recording guidelines specified in

Section 102 of NSCP 2010 and Section 208 of NSCP 2015 and used a

software called Extended Three-Dimensional Analysis of Building System

(ETABS). The software offers advanced modeling and analysis features,

including response spectrum analysis, pushover analysis, and nonlinear time

history analysis.

This paper intended to demonstrate how an isolation system can be

efficient. It evaluated its effectiveness for medium-rise irregular buildings

regarding seismic response parameters: base shear, story drift, displacement,

floor acceleration, and torsion.

1.5 Constraints Used in the Study

1.5.1. Economic Constraints

 The researchers had a limited budget for the study, which led to a

significant constraint: a lack of funds for license activation tools for

standalone web-activated licenses in ETABS. As a result, the

researchers relied on freely available software downloaded from the

internet.

1.5.2. Environmental Constraints

The researchers focused on environmental factors, specifically

natural seismic events, and considered the International Organization for

Standards or ISO 14001 to ensure compliance with relevant

environmental laws and regulations. It is crucial for manufacturers

dealing with the materials in manufacturing base isolators and dampers.

1.5.3. Cultural Constraints

Considering and respecting the cultural or historical significance of

the structure is crucial. Preserving architectural heritage should be a

priority, necessitating carefully evaluating the seismic mitigating methods

to ensure alignment with the need to conserve the building's historical

integrity. Balancing the implementation of seismic mitigating devices with

the preservation of original design and historical value requires

collaboration with preservation experts, community involvement, and

adherence to regulatory standards.

1.5.4. Ethical and Professional Constraints

The researchers considered the ethical aspects of material sourcing

for base isolators or dampers, including potential environmental and

social impacts. Prioritizing sustainable practices minimizes adverse

effects and upholds social responsibility in our seismic resilience

enhancement study.

1.5.5. Health and Safety Constraints

The researchers abided by the NSCP 2015 and NBCP to ensure

the safety of our building model design. Regular updates to building

codes and standards may also influence the implementation and

acceptance of base isolation and damping technology.

1.5.6. Manufacturability and Sustainability

The researchers prioritized using ecological materials in

manufacturing base isolators and dampers, with a preference for

sustainable sourcing practices wherever feasible. Considering standards

such as ISO 14001 for environmental management was pivotal in our

evaluation, ensuring that the materials align with recognized ecological

responsibility criteria.

1.5.7. Design Constraints

The building used for the research study was the Dr. Otto Hahn

Building in Saint Louis University, a medium-rise private institution. The

study adhered to the provisions outlined in Section 102 of the NBCP and

the specific guidelines stated in Section 208 of the NCSP 2015, essential

to ensuring compliance with mandated seismic safety and construction

standards. In addition, due to the generalized Zone 4 classification,

 researchers lacked specific geological information, resulting in no

particular site for the building.

1.5.8. Time Constraints

The researchers were allocated two semesters to complete the

study. The researchers needed to limit the scope of the study, utilized

efficient research methods, and prioritized tasks to meet the deadlines

within the given timeframe.

1.6 Significance of the Study

This study is of significance to the following:

Future Researchers. They will be able to derive from the study

detailed information on dampers and base isolators and serve as a guide in

selecting the most improved appropriate seismic strategy in irregular

structures.

Structural Engineers. The study will help them make informed

decisions to evaluate and implement the appropriate seismic protection

measures for their projects.

Construction Industry Professionals. They will benefit from

understanding the economic and practical impacts of using base isolators and

dampers in designing irregular structures.

Public Safety and Welfare. This will lessen the risk of fatalities and

injuries by minimizing the long-term financial burden associated with damages

to structural components, post-earthquake reconstruction, and the possibility

of structural failure.

Sustainable Development Goals. This study aimed to achieve the

Sustainable Development Goals (SDG) Number 9 and 11. Sustainable

Development Goal 11 (SDG 11) focuses on making cities and human

settlements inclusive, safe, resilient, and sustainable. Sustainable

Development Goal 9 (SDG 9) focuses on building resilient infrastructure,

promoting inclusive and sustainable industrialization, and fostering innovation.

Students. The students will be able to attain Student Outcomes B, C,

K, and M. Conducting investigations such as analyzing base isolators and

dampers and outlining the parameters needed for the collection will provide

critical insights, unique features and discipline of the seismic strategies, and

entail valid conclusions (SOb). Student Outcome C (SOc) will ensure that the

design solutions used in an irregular structure will yield sustainable practices

and materials by prioritizing environmental resilience. Student Outcome K

(SOk) will help understand the use of the tools in predicting the behavior of

irregular structures under various seismic strategies. For Student Outcome M,

the students will develop a profound understanding of underlying structural

exposures and predict potential failure methods in an irregular structure in

seismic situations.

1.7 Operational Definition of Terms

BASE SHEAR - refers to the total lateral or horizontal force exerted on a

building's foundation or base during an earthquake or other lateral load

conditions.
BUILDING PERFORMANCE - describes the ability of a building to withstand

a seismic event.

ETABS - a 3D integrated software used for civil engineering structural

analysis and design purposes.

FLUID ORIFICING - a process used in fluid dynamics and engineering to

control the flow of fluids (liquids or gases) through a precisely sized opening

called an orifice.

HORIZONTAL DISPLACEMENT - refers to the movement of an object

sideways from its original position, typically along a plane parallel to the

ground or a reference axis.

LATERAL DISPLACEMENT - refers to the sideward movement of an object

perpendicular to its original orientation.

LEAD RUBBER BEARING - a mechanism that allows restricted relative

motion between two components, facilitating rotational or linear movement.

SEISMIC RESPONSE - describes how the structure reacts to seismic forces.

SOFT-STORY BUILDING - a multi-story structure with a weak ground floor

lacking proper structural support, making it vulnerable to lateral forces,

especially during earthquakes. This weakness often stems from open spaces

like storefronts or parking garages on the ground level.

STORY DRIFT - describe the relative horizontal shift between levels in a

multi-story building during lateral events like earthquakes

OPTIMIZATION – a method done to select the most suitable configuration of

dampers and base isolators.

 CHAPTER 2: RESEARCH DESIGN AND METHODOLOGY

2.1 Research Design and Methodology

The comparative approach was used in the study. A comparative

approach involves analyzing issues to identify both differences and

similarities, aiming to highlight unique points as well as commonalities. This

method assisted the researchers in substantiating their perspectives,

revealing deficiencies in past research or regulations, Miri & Shahrok (2019).

This design fitted the study since it focused on the comparison of results of

the lead rubber bearing (LRB) base isolator and fluid viscous damper (FVD)

on a medium-high-rise vertically irregular building.

Moreover, Linear Dynamic Analysis was performed in this study using

the Response Spectrum Analysis. The Response Spectrum Analysis method

is a widely used technique in structural engineering for analyzing the seismic

response of structures. It is a linear analysis method that allows engineers to

estimate the maximum response of a structure to earthquake ground motion

(Fragiadakis, 2021). The Dr. Otto Hahn Building is vertically irregular due to

the presence of a retaining wall on the 3rd floor down to the 1st floor.

Moreover, the building is built on a sloping ground and in this case, the

foundations are placed at two levels. The structure used in the study has 7

floor levels with 3.8 meters spacing between columns and a floor level height
of 3.5 meters. The building has a length of 74 meters and a width of 20.5

meters.
Fig. 5. Isometric View of Irregular Structure Frame

Fig. 6. Front View of Irregular Structure Frame

Fig. 7. Rear View of Irregular Structure Frame

 Fig. 8. Side View of Irregular Structure Frame

The frame plan was modeled using Structural Analysis and Design

Professional (STAAD.Pro), and the seismic performance of the irregular

building will be analyzed using Extended Three-Dimensional Analysis of

Building System (ETABS) software through Response Spectrum Analysis

under Dynamic Analysis, wherein seismic data related to the structure are

needed to perform the analysis. The data include:

a. Occupancy Category: III (Special Occupancy Structures)

b. Importance Factor: 1.00

c. Soil Profile: Sd (Stiff Soil Profile)

d. Seismic Zone: Zone 4 (z=0.4)

e. Basic Seismic-Force Resisting System: Special reinforced

concrete moment resisting frame (R=8.5)

f. Source type: A ( Magnitude 7.2)

The data were derived from the properties of the structure as well as its

location. The factors used are based on these data and are found in the

National Structural Code of the Philippines 2015. On the other hand, some

seismic data were extracted from the HazardHunterPH, a hazard assessment

tool that determines if a location is prone to seismic, volcanic, or

hydrometeorological hazards. From this hazard assessment tool, it was

determined that the location of the building is approximately 7.7 km southeast

of the Tubao Fault and is prone to a magnitude 7.2 earthquake having an

intensity of VIII.

In order to have a fair comparison between LRB Base Isolators and

Fluid Viscous Dampers, optimization was performed to determine the number

of base isolators equivalent to the number of the dampers. A better effect is

achieved if the devices are placed in an optimal position where their number

will be reduced and their efficiency increased (Bogdanovic, A & Rakicevic, Z.,

2019). The placement and number of the LRB base isolators that were

considered in this study can be seen in Appendix D-1 and D-2.

The different placements of the seismic mitigating devices underwent

trial and error, wherein each arrangement of LRB base isolator and FVD were

analyzed per parameter: base shear, displacement, story drift, acceleration,

and torsion.

2.2 Population and Locale

The study's population consisted of medium-rise buildings or structures

that require seismic strengthening. These structures exhibit irregularities in

both vertical and horizontal design and are situated in seismically active

regions or cities where earthquakes pose a significant concern. Seismically

active areas are those where earthquakes occur as a result of various

geological processes. Seismic activity can occur near tectonic plate

boundaries or within the interior of a tectonic plate due to plate movement,

volcanic activity, or other factors.

 The research locale of this study was specified in Zone 4 of the

Philippines, which consists of seismically active regions or places with a

higher seismic risk in the Philippines. During an earthquake, these places are

likely to experience more strong ground shaking. Furthermore, the

researchers selected a mid-rise building with irregular vertical and horizontal

features for their study on infrastructure, integrating base isolators and

dampers. The focus of this research was the Otto Hahn Building located

within the School of Engineering and Architecture at Saint Louis University -

Main Campus in Baguio City. The Otto Hahn building comprises four stories

along with three basements. Additionally, it features a retaining wall on the

fourth floor, positioned below ground level. This particular building served as

the primary subject for analysis in the study.

2.3 Data Gathering Tools

The primary objective of employing data-gathering tools in research

was to methodically acquire data from diverse sources or subjects to support

the research's primary goals, hypotheses, or research inquiries.

This study utilized ETABS, specialized software for building structural

analysis and design. ETABS features structural analysis, design, modeling,

dynamic analysis, integration, and visualization. It conducts complex 3D

analyses, simulating structures' responses to dead loads, live loads, wind, and

seismic forces. The software generates design specifications based on

international codes for elements like beams, columns, slabs, and foundations.

Moreover, ETABS facilitates response spectrum and time history analysis for

earthquake assessment. It includes specific types of base isolators and

dampers, such as LRB and FVD, crucial for seismic strengthening. The

software's visualization tools aid in understanding and decision-making by

displaying the structure's response to loads.

ETABS software assisted the researchers in systematically gathering,

structuring, and analyzing data, encompassing quantitative data (numerical)

per the research's particular aims. It included the data that showed the

relationship between the control, independent, and dependent variables, such

as fixed support, seismic strengthening devices on the structural model, and

the seismic response of the building, respectively.

Furthermore, the research utilized three main statistical tests:

descriptive statistics, ANOVA (one-way test), and t-test. The data gathered

from ETABS and analyzed from the statistical tests allowed derivation of

conclusions on how the seismic strengthening devices on the medium-rise

irregular building affect the structural behavior under seismic loading

conditions. The computed values derived were the storey drift, storey

displacement, base shear, floor acceleration, and torsion. Moreover, the

interpretations were based on the value of the parameters extracted from the

data-gathering tool, ETABS.

2.4 Data Gathering Procedure

 Fig. 9. Flowchart of Data Gathering Procedure

The researchers utilized the ETABS and STAAD software to model and

test the Otto Hahn Building, such as the building without lead rubber bearing
(LRB) base isolators and fluid viscous dampers (FVD), with LRB base

isolators only and with fluid viscous dampers only. The researchers

consistently inputted the building loads following the NSCP (2015) to ensure

accurate data values during seismic activity.

Utilizing the ETABS software, the researchers conducted a response

spectrum analysis to assess the seismic response of the irregular structure,

both with and without seismic mitigating devices. The Otto Hahn Building

without the base isolators and dampers was the control factor in the study.

Analyzing the structure with LRB base isolators and FVDs, we extracted the

parameters: base shear, story drift, displacement, acceleration, and torsion.

After which, optimization was conducted using robust parameter design

optimization. The researchers compared the parameter’s results to determine

which was the most cost-effective among the LRB base isolator and FVD in

mitigating the effect of seismic activity.

2.5 Treatment of the Data

In this research, data was subjected to thorough analysis, focusing on

evaluating the functioning, effectiveness, and safety of structures. The

analysis heavily relied on statistical tests and data processing. In line with the

study's goals, statistical tests were employed to scrutinize the data collected

from experiments conducted on an irregular medium-rise building's response

to seismic forces under different scenarios. Statistical analysis is a critical tool

for evaluating the influence of base isolators and dampers on the building's

seismic performance and is instrumental in reaching meaningful and

substantiated conclusions.
 The study had multiple objectives, primarily focusing on understanding

how an irregular building responds to earthquakes with the utilization of base

isolators and dampers. For this purpose, the analysis involved:

1. Descriptive Statistics: Calculating mean values, standard deviations,

and other summary statistics for different scenarios, including

conditions without a base isolator and damper, with a base isolator,

and with a damper. This is essential for characterizing the data.

2. ANOVA (one-way test): Utilizing Analysis of Variance to examine if

there are statistically significant differences in seismic responses

among the scenarios by comparing the means. This assesses the

overall impact of different conditions on the building's performance.

Additionally, the study assessed the effects of a base isolator and a damper

on the building's earthquake resistance:

3. Base Isolator Impact: The analysis aimed to evaluate the influence of

the base isolator on the building's seismic performance compared to

scenarios without a base isolator and damper. This was assessed

through ANOVA (one-way test) , determining if there is a statistically

significant difference in performance.

4. Damper Impact: The study investigated how dampers affected the

building's earthquake performance in comparison to scenarios without

both a base isolator and a damper. This was assessed through

ANOVA (one-way test) , determining if there is a statistically significant

difference in performance.

FORMULA:
● Total Sum Of Squares

Where:

is the number of group

is the number of observations in the ith group

is the jth observation in the ith group

X̅ is the overall mean of all observations

● Between-Groups Sum of Square

Where:

is the overall mean of all observations

● Within-Groups Sum of Squares

● Mean Square Between

Where:
 ● Mean Square Within

Where:

● F-statistic

● P-value

If the p-value is less than the chosen significance level (α), 0.10, the

null hypothesis is rejected, concluding that there are significant differences

between the structure without seismic mitigating devices and those with

seismic mitigating devices. If the p-value is greater than the significance level,

there is a failure to reject the null hypothesis, indicating that there is not

enough evidence to conclude that there are significant differences between

the group means.

Moreover, optimization of the Lead Rubber Bearing and Fluid Viscous

Damper was conducted to magnify the number of LRB and FVD that can

produce the optimal values and efficiency in terms of the parameters used.

For this purpose, the analysis involves a Z-score or also known as a standard
score. It is a statistical measure that quantifies how many standard deviations

a data point is from the mean of a dataset. It indicates how far and in what

direction a particular data point deviates from the mean of the dataset. Z-

score was used to standardized the values of displacement, base shear,

acceleration, story drift, and torsion to get the optimal value.

FORMULA:

Where:

is the individual data point

is the mean of the dataset

is the standard deviation of the dataset

is the z-score

A z-score of 0 indicates that the data point is exactly at the mean of the

dataset, while positive z-scores indicate that the data point is above the mean,

and negative z-scores indicate that the data point is below the mean. The

magnitude of the z-score indicates how many standard deviations away from

the mean the data point is.

In summary, the research utilized three main statistical tests,

specifically Descriptive Statistics, Z-score, and ANOVA (one-way test) to

comprehensively analyze and conclude the findings. These tests were crucial
in assessing the building's seismic performance and the impact of base

isolators and dampers.

2.6 Management of Multidisciplinary Environments

Structural Engineering: Structural engineers play a pivotal role in the

intricate interplay between the structural components and seismic mitigation

systems. They will be responsible for analyzing and designing structures on

how base isolators and dampers behave in irregular structures. They will

interpret the comparative data, allowing them to decide when or what seismic

technology will be used.

Earthquake Engineering: The role of earthquake engineers begins

with a thorough seismic hazard assessment and dynamic analysis to

understand ground motions and simulate the building's response. Utilizing

advanced modeling techniques, earthquake engineers evaluate seismic

mitigating strategies, validate analytical models, and conduct sensitivity

analyses. Their work extends to risk assessment, providing recommendations

for implementation and contributing insights to building codes. Through

effective communication of findings, earthquake engineering significantly

influences the study, offering valuable insights into the comparative

effectiveness of these seismic mitigation strategies for medium-rise irregular

structures.

Geotechnical Engineering: The geotechnical engineer plays an

essential part in the site by evaluating the seismic hazard and risk, providing

valuable information on the seismic design parameters necessary to

implement the base isolators and dampers successfully. They will provide
parameters for designing effective seismic technology suitable for irregular

structures. They will provide insights into how the foundation of the structure

may be affected by the base isolators and dampers.

Architecture: Architects will use their knowledge in understanding the

building design and aesthetics of the structure. They will consistently

incorporate the two seismic technologies in an irregular structure. Moreover,

they will provide additional considerations and ensure the implementation of

the technologies appropriate to the building, especially for historically or

culturally significant buildings.

Disaster Risk Reduction and Management: The disaster risk

reduction and management professionals will conduct detailed assessments

and analyses to evaluate the possible risks in building the structures. They will

help enhance the capability and stability of the structure to resist future

seismic activities. They will contribute to the applicable significance of base

isolators and dampers in implementing irregular structures.

2.7 Project Management

2.7.1 Team Management

Every individual member in the group had essential contributions and

outputs for the execution of this study. Each task was either assigned by the

leader or voluntarily chosen independently by the member. A description of

specific tasks done by each member is presented below:

Table 3: Team Management and Role Distribution

NAME ROLE DESCRIPTION/REMARKS

WAKIT, Faye Leader ● Facilitates group

Winslette K. meetings and
interactions
● Leads and monitors the
team performance
● Co-writer of Conceptual
& Theoretical
Framework, Research
Design & Methodology,
Critical Review of
Literature (Irregular
Structures & Base
Isolator)

NIÑALGA, Ma. Assistant Leader ● Supports the leader and

Katleen F. the group by taking the
secretarial duties
● Writer of Treatment of
the Data
● Co-writer of Critical
Review of Literature
under Dampers &
Statement of the
Problem

BAROÑA, Desiree P. Member ● Writer of Significance of

the Study
● Writer of Management of
Multidisciplinary
Environments
● Co-writer of Critical
Review of Literature
(Softwares Used for
Seismic Analysis)

CATANES, Harold E. Member ● Co-writer of softwares

used in seismic analysis
● Co-writer of scope and
delimitations
● Co-writer of project
management

FERNANDEZ, Member ● Co-writer of Constraints

Jefferson R. Used in the Study
● Co-writer of Project
management
● Co-writer of software
used in seismic analysis.
● Structural modeler

MECOS, Emmyrald G. Member ● Co-writer of the

Statement of the
 Problem
● Co-writer of Critical
Review of Literature
under dampers
● Co-writer of Research
Design and Methodology

NOVIDA, Joshua Member ● Writer of Data Gathering

Robert V. Procedure
● Co-writer of Conceptual
and Theoretical
Framework
● Co-writer of Critical
Review of Literature

RACRAQUIN, Patricia Member ● Writer of Research

Denisse N. Gathering Tools
● Co-writer of Background
of the Study
● Co-writer of Critical
Review of Literature
under Introduction,
Irregular Buildings, &
Base Isolator

TIMBOL, Ericka F. Member ● Co-writer of Background

of the Study
● Writer of Research
locale and population
● Co-writer of Critical
Review of Literature

2.7.2 Financial Management

Table 4: Finance Management for Project Duration

BUDGET ITEM PARTICULARS ESTIMATED COST

Materials/Supplies

Printed Documents/ A4 Bond papers ₱ 400.00

Manuscript (₱ 200/ rim x 2 rims)

Black Ink ₱ 240.00

(₱ 240/ bottle x 1)

Colored Ink ₱ 750.00

 (₱ 250/ bottle x 3)

TOTAL EXPENSES ₱1,390.00

2.7.3 Time Management

2.7.3.1 Activity Plan Gantt Chart

Table 5: Activity Plan Gantt Chart

Activity

1 2 3 4 5 6 7 8 9 10

A. Proposal Presentation

1. Project Brainstorming

2. Review of Literature
(Chapter 3)

3. Identifying the research

problem and objectives

4 Finalization of topic/title

4. Writing Introduction
(Chapter 1)

5. Research design and

methodology (Chapter 2)

6. Finalizing research
proposal

7. Video making and

preparation for defense
proposal

8. Proposal

9. Revision of Manuscript

B. Data Gathering

1. Tabulate Data

2. Perform software analysis

C. Processing of Data

1. Statistical analyses of data

2. Interpretation of results

D. Final report/output
preparation

1. Writing

2. Editing

E. Paper presentation/
Publication

1. Defense

2.7.3.2. Schedule of Outputs

Table 6: Schedule of Outputs

Activity Timeline Expected Output Deadline

A. Proposal
preparation

1. Project
August 24-
brainstorming Research Problem August 31
August 31

2. Review of Review of Related

September 7– September
Literature (Chapter Literature and start of
September 14 14
3) Chapter 3

3. Identifying the September 14

Research problem September
research problem – September
and objectives 21
and objectives 21

4. September 14
Finalization of the September
– September Final Topic/Title
topic/ Title 21
21

5. Writing of Chapter September 21 Chapter 1 and

October 20
1 – October 20 Chapter 3

6. Research design October 20 – Chapter 2 October 26

 and methodology October 26

7. Finalizing research October 27 –

Revised Proposal October 31
proposal October 31

8. Video making and 20-minute

November
preparation for November 3 presentation and
3
defense proposal printed manuscripts

9. November
Proposal Defense November 21
21

10.
Revised Manuscript
(incorporated
feedback, enhanced
clarity/accuracy,
Revision of adhere to guidelines,
Manuscript addressed
weaknesses, refine
visuals, and
proofread
meticulously)

B. Data Gathering

1. ETABS output,
3rd Week of
Tabulation of data summary statistics,
January
graphs

2. Code quality and

4th Week of analysis results,
Perform analysis January – 1st Response Spectrum
software Week of Analysis,
February performance
metrics,test results

C. Processing of
Data

1. Statistical 2nd Week of Data from the

analyses of data February software analysis are
analyzed using
Descriptive Statistic,
ANOVA, and t-Test.
2. The data will prove
the null hypothesis
2nd – 3rd
Interpretation of otherwise and will
Week of
results determine the more
February
superior seismic
mitigating device.

D. Final
report/output
preparation

1. 4th Week of
Writing February – 4th Chapter 4
Week of March

2. Revision of
interpretation and
Editing March
discussion of data
and results.

E. Paper
presentation/
Publication

1. Acknowledgement
receipt from
Defense May conference
organizer/Journal
Editor
 CHAPTER 3: REVIEW OF RELATED LITERATURE

Due to its tectonic location and position in the Pacific Ring of Fire, the

Philippines faces high risks of natural disasters, including floods, typhoons,

landslides, earthquakes, volcanoes, and droughts (Bollettino, 2018). Although

the Philippine government effectively responds to natural disasters like

typhoons, earthquakes remain among the deadliest and unpredictable. With

around 35 active fault systems, notable ones include West Panay, West

Valley, East Valley, Surigao, Bangui, and the Philippine Fault Zone (Alba et

al., 2022). Historic earthquakes, like the 1976 Moro Gulf and 1990 Luzon

earthquakes, were devastating, with the former causing 8,000 deaths.

Notably, the 1990 earthquake affected Baguio City's Hyatt Terraces Hotel, an

irregular building, causing significant damage and casualties, including 28

buildings and 130 houses toppled in Baguio City, 90 buildings collapsed in

Dagupan City, and a six-story educational institution shattered in Cabanatuan,

trapping hundreds of students. Recent earthquakes, such as the 2022 Abra

Earthquake, resulted in 11 deaths, 574 injuries, and approximately P1.6 billion

worth of damages to infrastructure and agriculture (Philippine Institute of

Volcanology and Seismology, 2022), highlighting the ongoing seismic threat in

Luzon and Mindanao regions, with several locations experiencing strong

earthquakes ranging from magnitude 5 to 7.

 Probabilistic risk analysis tools assess the effectiveness of building

structural systems. Studies on geometric-shaped buildings, both with and

without earthquake-proofing systems, analyze their behavior under various

seismic loading conditions. Base isolators and dampers are two extensively

studied earthquake-proofing systems for regular geometric structures. Base

isolation reduces building responses to earthquakes and has proven effective

in seismic design problems over the last two decades (Patel & Jamani, 2017).

Seismic dampers, mechanical devices absorbing and dissipating earthquake

energy, are also studied for their protective capabilities (Khazaei et al., 2020).

This section focuses on recent studies examining vulnerabilities in

medium-rise and irregular structures during earthquakes. Furthermore, it

explores two types of innovations, namely, base isolators and dampers, for

seismic strengthening, along with software tools analyzing buildings' seismic

responses and generated parameters.

3.1 BUILDINGS CRITICALLY AFFECTED BY SEISMIC ACTIVITY

3.1.1. MEDIUM RISE BUILDINGS

According to the National Building Code of the Philippines (NBCP),

medium-rise buildings range from 6 to 15 storeys (19 meters to 46 meters)

inclusive of an average 1.0 m provision for parapet wall or roof apex,

excluding maximum allowance for a 6.0 m tall antenna/ steel tower on top of

the structure. In regions prone to seismic activities, understanding the

behavior of these buildings during earthquakes is paramount. Seismic forces

generated during an earthquake can significantly stress on medium-rise

structures, potentially leading to structural damage or collapse if not

appropriately designed and reinforced.

According to Shareef (2023), designing medium-rise buildings in

seismic regions involves intricate structural engineering and architectural

planning considerations. Hence, engineers must account for soil composition,

local seismic activity, and building materials to ensure these structures can

withstand seismic forces. Moreover, advancements in seismic engineering

brought forth new structural control systems such as damping and base

isolating systems which, according to Freddi et al. (2021), has significantly

impacted medium-rise structures, particularly in mitigating seismic effects.

Through comprehensive research, effective design practices, and the

implementation of advanced seismic mitigation strategies, engineers and

architects can contribute significantly to creating safer and more resilient

medium-rise buildings in seismic zones (Koren & Rus, 2023).

Previous studies have highlighted the importance of understanding

how medium-rise buildings respond to earthquakes. This is crucial for the

safety of people in these buildings and the overall resilience of earthquake-

prone urban areas. With respect to these claims, this study aimed to enhance

the seismic performance of medium-rise buildings through comparing the

impact of using base isolators and dampers in these buildings and identifying

the most cost-effective solution for improving the seismic resilience of

medium-rise structures.

3.1.2. IRREGULAR BUILDINGS

 Irregularities in modern urban construction, though common, lead to

structural failures during earthquakes (Haque et al., 2016). Despite their

susceptibility to seismic vibrations, buildings often integrate irregularities for

aesthetic and practical reasons (Raagavi & Sidhardhan, 2021). The National

Structural Code of the Philippines (2015) classifies building irregularities into

Vertical Structural Irregularities and Horizontal Structural Irregularities.

Vertical Structural Irregularities are further divided into five types: (1) Stiffness

Irregularity - Soft Storey, (2) Weight (Mass) Irregularity, (3) Vertical Geometric

Irregularity, (4) In-Plane Discontinuity In Vertical Lateral-Force-Resisting

Element Irregularity, and (5) Discontinuity In Capacity - Weak Storey

Irregularity.

Fig. 10. Vertical Structural Irregularity Diagrams.

Source: Vertical Structural Irregularity (NSCP Table 208-9) Type of Irregularity Graphic
Interpretation by H. Benabon, from https://www.scribd.com/document/458923810/BUILDING-
IRREGULARITIES-and-their-GRAPHIC-INTERPRETATION

Horizontal Structural Irregularities are divided into five types as well: 1)

Torsional Irregularity, 2) Re-entrant Corner Irregularity, 3) Diaphragm

(1) (2)
Discontinuity Irregularity, 4) Out-of-Plane Offsets Irregularity, 5) Non-Parallel

Systems Irregularity.

(4)
 Fig. 11. Horizontal Irregularities
Source: Horizontal Irregularities. from
https://www.scribd.com/document/458923810/BUILDING-IRREGULARITIES-and-their-
GRAPHIC-INTERPRETATION

In the context of this paper focusing on irregular building models, Costa

et al. (2016) highlighted that irregular designs can compromise seismic

resilience, inducing stress concentration and severe damage. In multi-story

concrete buildings, uneven mass and stiffness distribution can result in

torsional sensitivity during wind and seismic events (Bhandari et al., 2023).

Recent studies by Khan et al. (2017) and Siva Naveen E et al. (2019) also

emphasize that asymmetrical buildings experience more significant lateral

displacements, significantly impacting structural response. Similarly,

Zabihullah et al. (2020) investigated irregular configurations in a G+7 storey

building, noting poor performance for horizontally irregular structures and

better performance for vertically irregular buildings.

In comparison to the studies of Khan et al. (2017), Siva Naveen E. et

al. (2019) and Zabihullah et al. (2020), the researchers considered vertical

irregularities. Furthermore, the irregular structural model in this research

represented a medium-rise school building.

 The assessment of irregular buildings should include evaluating

building performance parameters and encompass both equivalent static and

dynamic analyses. This paper, inspired by Costa et al. (2016) who evaluated

complex and asymmetrical buildings using parameters such as ground

acceleration, tensile damage, torsional effect, and compression damage, also

utilized acceleration and torsion as part of the key parameters used in this

study. This paper also evaluated building displacement which aligned with the

study of Haque et al. (2016) focusing on the significant effect of displacement

on irregular buildings as well recognized W-shaped structures as particularly

earthquake-vulnerable in static analysis.

This study included vertical irregularities in the building model for

seismic analysis. In contrast to previous research focusing on base shear,

lateral displacement, acceleration, and storey drift, this study introduced an

additional consideration: torsional irregularity.

3.2 SEISMIC STRENGTHENING INNOVATIONS

3.2.1. DAMPERS

In structural engineering, dampers are designed to strengthen buildings

or structures, especially during seismic events or high winds. Their primary

goal is to reduce vibrations, thereby enhancing structural stability and safety

by absorbing kinetic energy and converting it into heat, dissipating it (Ezzaki,

Stoica, Rece & Legendi, 2019). Moreover, with the help of dampers, reducing

potential damage and ensuring safety during earthquakes was made possible

(Bajad and Watile, 2014). In relation to this study, Fluid Viscous Dampers

were used.
 3.2.1.1. Fluid Viscous Damper

Bhavya and Lakshmi's (2017) research focused on identifying the most

effective and cost-efficient type of damper, highlighting Fluid Viscous

Dampers as superior. Moreover, they demonstrated that installing dampers in

buildings enhances structural resistance, with glycerol being an effective

substitute for damper fluid. Meanwhile, Rakhimol and Cheriyath (2018) study

investigated the impact of nonlinear viscous dampers on irregularly shaped

buildings during earthquakes. They found that placing dampers along longer

sides reduced base shear value and rooftop displacement during seismic

events. This suggests that distributing viscous dampers throughout

conventional structures can achieve cost-effective damping by preventing

relative movement between components. Both studies highlight the

importance of dampers in enhancing structural resistance and reducing

displacement during seismic events.

In the study conducted by Bogdanovic & Rakicevic (2019), the

researcher found out the optimal position of space distributed dampers in 3D

frame structures using combined fitness function with two parameters. The

process of optimization starts with nine initial configurations of damper

placement, in X and Y direction on the external frames. Optimal damper

solutions show energy dissipation between 41% and 46%. Compared to a

damper-free 3D frame, they reduce plastic hinges by 80%. Maximum X-

direction acceleration reduction is 38% (fifth story), and minimum is 8% (first

story). In the Y direction, maximum reduction is 29% (third story), with a

minimum of 5% (first story). Drift reductions are more significant, with a

maximum of 75% (fifth story) and a minimum of 20% (first story) in the X

direction. In the Y direction, maximum drift reduction is 64% (fifth story), and

minimum is 28% (first story).

While the previous studies above focused on determining the

effectiveness of either dampers or base isolators, this study compared both to

determine which one contributed more to the seismic performance of a

building. Specifically, Lead Rubber Bearing (LRB) base isolator and Fluid

Viscous Damper (FVD) was used for this study. Similar to Bogdanovic &

Rakicevic’s (2019) study, this study also determined the most optimal

placement and quantity for dampers as well as base isolators.

3.2.2. BASE ISOLATORS

In this study, the Lead Rubber Bearing (LRB) base isolator was used

as a proactive measure to enhance seismic resilience in reinforced structures,

aiming to mitigate potential damage from seismic activities and improve

overall safety in earthquake-prone regions.

3.2.2.1. Lead Rubber Bearing

Various studies have explored the effectiveness of base isolation

systems in enhancing the seismic resilience of buildings. Reddy, Prasad, &

Malagavalli (2021) compared a rubber bearing system with a fixed base,

analyzing parameters such as storey drift, shear, bending, torsion, time

period, and model stiffness. Similarly, Jumoad et al. (2020) and Mallah, A. &

Kumar, M. (2021) demonstrated the reduction of seismic responses using

lead-rubber bearing isolation systems. El-Assaly, M., Amin, M. A., & Galalah,
S. S. studied the impact of a base isolator on regular and vertically irregular

RC structures, emphasizing increased natural time period and reduced

seismic forces with lead rubber isolators, especially in taller structures.

Sreenivas & Mathew (2016) compared Lead Rubber Bearing (LRB) and

Friction Pendulum System (FPS) on re-entrant corner buildings, with LRB

showing superior seismic performance. Gyawali, S., Thapa, D., & Bhattarai, T.

R. (2020) highlighted the superior seismic performance of vertical irregular

buildings compared to plan irregular structures.

In summary, the collective findings of these studies underscored the

importance and varied applications of base isolation systems in improving the

seismic resilience of diverse building structures. Previous studies consistently

demonstrated that the implementation of Lead Rubber Bearings (LRB) leads

to a reduction in seismic forces across various parameters, including base

shear, story drift, floor acceleration, displacement, and torsion. In relation to

the previous studies, the current study focused on the seismic device,

specifically Lead Rubber Bearings (LRB), examining its impact on the five

parameters mentioned above. The investigation specifically targeted

vertically-horizontally irregular buildings situated in earthquake-prone regions

in Zone 4.

3.3 SOFTWARES USED FOR SEISMIC ANALYSIS

Shobana et al. (2023) conducted a comprehensive analysis and also

used ETABS software to assess seismic considerations based on the Indian

standard code. Focusing on reinforced concrete structures, they utilized the

Response Spectrum Method (RSA) within ETABS to understand structural

behavior under seismic forces. Their results underscored the importance of

RSA in evaluating and predicting structural responses to earthquakes,

emphasizing the need for advanced analytical methods and software tools.

Similar to this study, the researchers employ ETABS based on the NSCP

2015, inputting building parameters and utilizing the RSA method to analyze

and test the seismic effectiveness of the structure. Alone & Awchat (2017)

also used STAAD.Pro software to conduct seismic analysis on a 50-storey

high-rise building according to Indian standards.

Given how STAAD.Pro and ETABS software were successful in the

previous studies, the researchers used these two software in modeling the

building used for this study, as well as in analyzing the effects of LRB base

isolator and Fluid Viscous Dampers on the irregular building. Moreover,

STAAD.Pro, following NSCP 2015 guidelines, was employed as a validation

tool for results obtained from ETABS.

CHAPTER 4: PROJECT DETAILS, DESIGN, ESTIMATES, AND

MANAGEMENT
4.1 Project Analysis and Design (Faye, Pat, Kat, *Jeff)

In response to the heightened vulnerability of irregular structures in the

Philippines, particularly in areas prone to seismic activity, this study seeks to

evaluate and contrast the efficacy of seismic mitigating devices in bolstering

the resilience of such structures. With the overarching goal of enhancing the

seismic performance of an irregular medium-rise building, the study aims to

assess the building's response to seismic events under three scenarios:

without any seismic control devices, with LRB base isolators, and with fluid

viscous dampers. By meticulously analyzing and comparing these scenarios,

the study endeavors to discern which device offers superior protection and

resilience as well as cost-efficiency, thereby informing future seismic

resilience strategies for buildings and infrastructure in the region.

The inspiration for the building model used in the study was the Otto

Hahn Building in Saint Louis University located in Baguio City, Philippines.

The structure was modeled and analyzed through Response Spectrum

Analysis using ETABS software. From the analysis, the parameters: base

shear, displacement, story drift, acceleration, and torsion were extracted and

compared.

4.1.1 Structural Data

This section consists of the design specifications used for the control

building, which is the Otto Hahn. The researchers acquired all the information

from Mr. Jeffrey Gamit through the architectural plans given by the Campus
Planning, Maintenance, and Security Department. For additional information,

since there are no structural plans given, the researchers conducted rough

measurements and considered the length, width, no. of storeys, height of

storeys, slab thickness, columns (interior and exterior), beams, wall thickness

(interior and exterior), retaining and shear wall thickness, and lastly, the

supports in order to integrate this on the software to come up with the control

building that will be used in testing.

4.1.1.1 Building Description (Control Building)

Building Specifications
Length 20 m
Width 72 m
No. of Storeys 7
Height of Storeys 1st Floor 2nd - 6th Floors 7th Floor
3m 2.7 m 2.85 m
Slab Thickness 290 mm
Columns Interior Exterior
0.85 m x 0.50 m 1.20 m x 0.75 m
Beams 0.60 m x 0.50 m
Wall Thickness Interior Exterior
100 mm 150 mm
Retaining Wall 300 mm
Thickness
Shear Wall 250 mm
Thickness
Support Fixed
Material Specifications
Concrete Fc’ = 20.7 kPa
Steel Fy = 275 kPa

The following material specification used compressive strength of

concrete (F’c) equal to 20.7 kPa and yield strength of steel (Fy), which is

275 kPa. Note that there are no specific structural descriptions given in the

plans; therefore, the researcher consulted one of the engineers and a

professor of Saint Louis University, Engr. Raul Apilado.

4.1.1.2 Loading

The loads we used for the building model are Dead Loads, Live Loads,

and Seismic Loads. The loads were computed using the materials and

pressures taken from the National Structural Code of the Philippines

(NSCP) 2015.

Self Weight

(a)

Interior Column Exterior Column

(b)

Dead Load

The dead load for the structure consists of the following weights:

(a) Walls

Using Density: ; Fully Grouted; Plastered both face

Floor Exterior Walls

2nd - 6th
Floors

7th Floor

Floor Interior Walls

2nd - 6th
Floors

7th Floor
 (b) Slab

(c) Tiles

Ceramic Tile (20 mm) on 13 mm mortar bed = 0.77 kPa

(d) Ceiling

Acoustic fiber board = 0.05 kPa

(e) Partitions

Wood studs 50 x 100 (plastered two sides) = 0.96 kPa

Live Load

Live loads encompass the weight of movable partitions, both

distributed and concentrated loads, impacts, vibrations, and dust loads.

They exclude loads from wind, seismic activity, snow, temperature

changes, etc. For our building model, we used a live load of 3.8 kPa per

floor.

Seismic Load

Seismic Load Parameters

Occupancy Category III. Special Occupancy Structure

Importance Factor 1.0

R 0.85

Distance from nearest 7.6 km

seismic source

Ct 0.0731
Soil Type Sd: Stiff Soil Profile

Near Source Factor, Na 1.096

Near Source Factor, Nv 1.392

Seismic Coefficient, Ca

Seismic Coefficient, Cv

Load Combination

Combinations of self-weight, dead load, live load, and seismic load

were considered in accordance with NSCP 2015. The load combination

used was the Allowable Stress or Working Stress Design.

4.1.2 Modeling of Structure

Figure 12. Front Elevation

Figure 13. Rear Elevation Elevation

Figure 14. Left Side Elevation

Figure 15. Right Side Elevation

 Figure 16. Isometric View

4.1.3 Structural Analysis

This section shows and explains the results of the ETABS Analysis for

the different numbers and placements of LRB Base Isolators and Fluid

Viscous Dampers used on the Otto Hahn Building. It also includes the

statistical analysis of the results to determine if the LRB base isolators and

FVDs have significant effects on the seismic performance of Otto Hahn

Building in terms of displacement, story drift, base shear, acceleration, and

torsion.

4.1.3.1 Control Building

In order to evaluate the effects of the LRB Base Isolator and Fluid Viscous

Dampers on Otto Hahn Building, the control values used for comparison of the

displacement, story drift, base shear, acceleration, and torsion are listed

below.

Floor Displacement Story Drift Base Shear

X Y X Y X Y
7 303.478 114.618 0.025315 0.008731 79524.65 72891.68
6 231.685 89.953 0.02767 0.011049
5 157.286 60.286 0.027371 0.011859
4 83.558 28.341 0.021538 0.008887
3 25.469 6.475 0.009433 0.002398
2 0 0 0.00125 0.000328
1 3.376 0.886 0.00125 0.000328
 0 0 0 0 0
Max. 303.478 114.618 0.02767 0.011859

Floor Acceleration Torsional Rotation

X Y (rad)
7 24865.05 16082.84 0.5432
6 17266.8 11486.56
5 13663.37 8824.19
4 10003.79 6204.18
3 7351.11 2056.32
2 2270.87 756.16
1 13321.33 2581.37
0 1199.27 333.81
Max. 24865.05 16082.84

These values serve as the controlling variable in determining

whether the different numbers and placements of LRB Base Isolators and

FVD have an effect on the seismic performance of the building, may it be

an increase or decrease in the values of said parameters.

4.1.3.2 Displacement

4.1.3.2.1. Lead Rubber Bearing Base Isolator

Analysis:

Using level of significance, α = 0.10

Number of samples per group, N = 16

Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square
SUMMARY OF THE ANALYSIS
SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL
DF 7 119 126
SS 47542681.36 4953536.468 52496217.83
MS 6791811.623 41626.3569 6833437.98
F-STAT 163.16133
P-VALUE 0

Assessing variances in structural response across configurations

with and without lead rubber bearing base isolators using One-Way

ANOVA, the resulting p-value of 0 is less than the specified significance

level of 0.10 (p-value < α). As a result, the null hypothesis (Ho) is

rejected.

The research findings demonstrate that employing lead rubber

bearing base isolators results in a notable rise in structural displacement

within buildings. In contrast to structures without isolators, which exhibit

lower story displacement, those equipped with isolators offer efficient

seismic protection by diminishing the forces transferred to buildings

during earthquakes. While the flexibility, damping characteristics, and

base isolation principle of these isolators can contribute to increased

displacements, this heightened movement generally leads to safer

outcomes. It reduces structural harm, safeguards occupants, maintains

functionality, and ensures consistent behavior. This highlights the crucial

role played by these isolators in alleviating the impacts of seismic events

on buildings.

4.1.3.2.2. Fluid Viscous Dampers

Analysis:

Using level of significance, α = 0.10

Number of samples per group, N = 16

SKEWNESS EXCESS NORMALITY OUTLIERS MEAN SD
 KURTOSIS
control 1.521762 1.718529 0.001581 303.478 69.08819 92.19401
FVD 1 0.833626 -0.424039 0.02696 - 24.44462 25.79888
FVD 2 1.41393 1.393314 0.001437 - 49.77712 67.74536
FVD 3 0.945215 -0.125469 0.01314 - 9.24644 10.50679
FVD 4 0.727619 -0.723512 0.01511 - 17.53044 19.17769
FVD 5 1.565226 0.926395 0.00006692 28.734, 34.67, 8.35975 13.32189
38.025
FVD 6 0.919087 -0.399127 0.009324 - 9.584 11.03294
FVD 7 1.998119 3.132676 0.00003069 117.673, 40.8795 73.69301
179.077,
240.94
FVD 8 1.001902 -0.066263 0.007523 - 45.61456 53.95541
FVD 9 1.990203 3.08001 0.00002727 118.145, 40.44019 73.81865
179.005,
240.274
FVD 10 1.841741 2.746576 0.000254 215.109, 56.87844 85.86332
286.277
FVD 11 1.817202 2.657442 0.0002997 218.69, 58.44969 87.07046
290.023
FVD 12 1.562978 1.882259 0.001191 290.356 64.14719 87.91479
FVD 13 1.562978 1.882259 0.001191 290.356 64.14719 87.91479

Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square
SUMMARY OF THE ANALYSIS
SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL
DF 13 210 223
SS 102150.0792 881024.4344 983174.5136
MS 7857.6984 4195.3544 4408.8543
F-STAT 1.873
P-VALUE 0.03469

Utilizing One-Way ANOVA (Analysis of Variance) to ascertain

disparities in structural response between configurations with and without

fluid viscous dampers, the obtained p-value of 0.03469 falls below the
 chosen significance level of 0.10 (p-value < α). Consequently, the null

hypothesis (Ho) is rejected.

This finding suggests a notable decrease in the displacement of the

structure once the fluid viscous damper was applied. Looking at the

graph, it shows that the story displacement is relatively higher on a

structure without fluid viscous damper when compared to the

displacement of those with dampers. The decrease in the value of the

said parameters indicates that fluid viscous dampers are effective in

minimizing the displacement of a building, therefore enhancing its

capacity to withstand seismic loadings.

4.1.3.3 Maximum Storey Drift

Story drift is typically expressed as a ratio of the displacement to the

height of the story, and it's often given in terms of a percentage or in inches

per story. In ETABS software, maximum story drift is considered unitless

because it is normalized by the height of the story. By dividing the absolute

displacement by the height of the story, you obtain a ratio that is

independent of the units used to measure the displacement or the height.

This normalization allows for consistent comparison of story drift values

regardless of the units employed.

4.1.3.3.1. Lead Rubber Bearing Base Isolator

 Analysis:

Using level of significance, α = 0.10

Number of samples per group, N = 16

Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square

SUMMARY OF THE ANALYSIS

SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL
DF 7 120 127
SS 0.007 0.0248 0.0318
MS 0.001 0.0002 0.0012
F-STAT 4.84091
P-VALUE 0.00008

By employing One-Way ANOVA to analyze differences in

structural response between setups with and without lead rubber bearing
base isolator, the resulting p-value of 0.00008 falls beneath the chosen

significance threshold of 0.10 (p-value < α). As a result, the null

hypothesis (Ho) is rejected.

The study reveals that employing lead rubber bearing base

isolators may result in a notable increase in story drift within a structure

compared to those lacking such isolators, nonetheless broadly, higher

story drift with a base isolator is considered safer than lower story drift

without one. By insulating the building from ground motion during

earthquakes, base isolators effectively reduce structural damage. This

reduces the stresses acting on the building and mitigates potential

damage by allowing the structure to absorb seismic energy through

higher story drift. To put it simply, base isolators' ability to reduce

structural shift strengthens the structure's ability to endure seismic

forces, highlighting its vital role in enhancing seismic resilience and

safety.

4.1.3.3.2. Fluid Viscous Damper

Analysis:
 Using level of significance, α = 0.10

Number of samples per group, N = 16

SKEWNESS EXCESS NORMALITY OUTLIERS MEAN SD
KURTOSIS
control 0.775318 -0.853382 0.007602 - 0.0098379 0.010286
FVD 1 1.358561 1.7754 0.02652 0.010036 0.0028454 0.0027853
FVD 2 0.733634 -0.915775 0.003503 - 0.0076056 0.0087039
FVD 3 -0.0445779 -1.771501 0.00704 - 0.001252 0.0010835
FVD 4 0.689257 -0.556569 0.07469 - 0.0022608 0.0021538
FVD 5 1.615703 1.809821 0.0006623 0.004737 0.0011024 0.001469
FVD 6 0.146157 -1.591579 0.03911 - 0.0014025 0.0012118
FVD 7 1.273896 -0.21625 0.00007526 - 0.0060034 0.0089137
FVD 8 0.152714 -1.716518 0.01912 - 0.006631 0.0058971
FVD 9 1.265777 -0.252614 0.00006028 - 0.0059036 0.0089002
FVD 10 1.12566 -0.347406 0.0008503 - 0.0082673 0.010151
FVD 11 1.106861 -0.386912 0.000987 - 0.0084116 0.010195
FVD 12 0.821741 -0.776289 0.005558 - 0.009311 0.010266
FVD 13 1.12356 -0.48726 0.0005569 - 0.0080058 0.010031

Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square

SUMMARY OF THE ANALYSIS

SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL
DF 13 210 223
SS 0.002134 0.01208 0.01421
MS 0.0001641 0.00005751 0.00006373
F-STAT 2.8538
P-VALUE 0.0008345

Applying One-Way ANOVA to examine differences in structural

response between configurations with and without fluid viscous dampers,

the obtained p-value of 0.0008345 falls below the chosen significance

level of 0.10 (p-value < α), leading to the rejection of the null hypothesis

(Ho).
 This finding suggests a significant reduction in the story drift of the

structure following the application of fluid viscous dampers. The graph

illustrates that structures without fluid viscous dampers exhibit relatively

higher story drift compared to those with dampers. The decrease in this

parameter indicates the effectiveness of fluid viscous dampers in

minimizing story drift, thereby enhancing a building's ability to withstand

seismic loadings.

4.1.3.4 Base Shear

4.1.3.4.1. Lead Rubber Bearing Base Isolator

Analysis:

Using level of significance, α = 0.10

Number of samples per group, N = 2

 Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square
SUMMARY OF THE ANALYSIS

SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL

DF 7 8 15
SS 7567867595 2829828217 10397695810
MS 1081123942 353728527.2 693179720.8
F-STAT 3.0564
P-VALUE 0.07009

Investigating differences in structural response across

configurations with and without lead rubber bearing base isolators using

One-Way ANOVA, the resulting p-value of 0.07009 is less than the

specified significance level of 0.10 (p-value < α). As a result, the null

hypothesis (Ho) is rejected.

The study reveals that lead rubber bearing base isolators

significantly reduce the base shear experienced by buildings during

seismic events. Graphical data shows that structures with these isolators

show a decrease in base shear compared to those without them. This

reduction enhances the building's resilience to seismic pressures. This

highlights the importance of incorporating innovative seismic mitigation

techniques into building design and construction methodologies,

ultimately contributing to safer and more robust structures in earthquake-

prone regions. Thus, incorporating these techniques into building design

and construction methodologies is crucial.

4.1.3.4.2. Fluid Viscous Dampers

 Analysis:

Using level of significance, α = 0.10

Number of samples per group, N = 16

SKEWNESS EXCESS NORMALITY OUTLIERS MEAN SD
KURTOSIS
CONTROL -0.035968 -5.513545 0.2494 - 42453.65195 39301.433
98
FVD 1 0.0321494 -5.36945 0.3053 - 44614.50753 44576.073
64
FVD 2 0.242457 -4.533661 0.3706 - 69842.29005 72872.762
2
FVD 3 1.750843 3.234311 0.1851 - 59274.84187 40828.718
25
FVD 4 0.177969 -4.736798 0.4129 - 63145.79165 54186.375
17
FVD 5 -1.196299 0.49493 0.4201 - 30232.07513 19093.233
41
FVD 6 0.248138 1.416759 0.9887 - 106122.9879 75946.071
84
FVD 7 1.093524 0.0130612 0.4911 - 116530.6078 72728.452
1
FVD 8 0.83031 1.689483 0.9339 - 82458.3343 44750.013
14
FVD 9 1.092266 0.01333 0.4984 - 124417.5783 77213.294
04
FVD 10 0.688919 -1.639378 0.8145 - 41428.31223 40417.584
93
FVD 11 0.598107 -2.558691 0.5463 - 41462.5442 39220.951
32
FVD 12 1.244009 0.97111 0.5743 - 40312.23675 40258.031
85

Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square
SUMMARY OF THE ANALYSIS
SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL
DF 12 39 51
SS 48280938610 112872092800 161153031400
MS 4023411551 2894156225 3159863360
F-STAT 1.3902
P-VALUE 0.2118

Applying One-Way ANOVA to examine differences in structural

response between configurations with and without fluid viscous dampers,

the obtained p-value of 0.2118 falls above the chosen significance level

of 0.10 (p-value > α), leading to the acceptance of the null hypothesis

(Ho).

This finding suggests there is no significant difference between the

base shear of a building that does not have fluid viscous damper than

that with a fluid viscous damper. The acceptance of the null hypothesis

reflects that Dampers complement these design strategies by providing

additional control over the dynamic response of the structure, but their

main function is to reduce structural deformations and vibrations rather

than directly reducing the base shear.

4.1.3.5 Acceleration

4.1.3.5.1. Lead Rubber Bearing Base Isolators

Analysis:

Using level of significance, α = 0.10

Number of samples per group, N = 16

 Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square

SUMMARY OF THE ANALYSIS

SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL
DF 7 120 127
SS 92578011.58 3938392670 4030970682
MS 13225430.23 32819938.92 46045369.15
F-STAT 0.40297
P-VALUE 0.89889

Investigating differences in structural response across

configurations with and without lead rubber bearing base isolators using

One-Way ANOVA, the resulting p-value of 0.89889 is greater than the

specified significance level of 0.10 (p-value > α). As a result, the null

hypothesis (Ho) is accepted.

The results indicate that there is no significant impact on the

acceleration of the structure after implementing lead rubber bearing base

isolators. The decrease observed in this parameter suggests that the

presence of lead rubber bearing base isolators does not have a notable

effect on reducing acceleration. Therefore, whether the building is

equipped with isolators or not, it remains capable of withstanding seismic

loads.
 4.1.3.5.2. Fluid Viscous Damper

Analysis:

Using level of significance, α = 0.10

Number of samples per group, N = 16

SKEWNESS EXCESS NORMALITY OUTLIERS MEAN SD
KURTOSIS

control 0.385055 -0.114292 0.9206 - 11242.69875 7838.38665

FVD 1 -0.230509 -0.931456 0.8232 – 11126.8675 5055.46495
FVD 2 0.907299 0.237638 0.4799 - 9660.71125 8513.37676
FVD 3 -0.73388 -0.51196 0.1264 - 18804.5875 8100.62481
FVD 4 0.024675 -1.130501 0.7559 28705.33 12907.62562 5496.6728
FVD 5 0.99515 1.768517 0.2394 - 11751.94688 6578.54122
FVD 6 0.518871 -0.931469 0.09268 - 14458.37812 5597.84368
FVD 7 0.675301 -0.549997 0.211 - 1725.0125 1253.5615
FVD 8 0.556499 -1.641277 0.003373 - 22921.93437 19953.85308
FVD 9 1.274681 0.762532 0.005326 - 5277.17625 5734.95736
FVD 10 0.889355 0.562998 0.2045 - 8743.06937 6765.76273
FVD 11 0.878139 0.579622 0.2472 - 8833.30062 6736.03205
FVD 12 0.796815 0.23813 0.1701 - 8488.17813 7251.18686

Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square
SUMMARY OF THE ANALYSIS

SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL

DF 12 195 207
SS 5963269788 13132099970 19095369760
MS 496939149 67344102.42 92248163.09
F-STAT 7.3791
P-VALUE 0.00000000003994
 Utilizing One-Way ANOVA (Analysis of Variance) to ascertain

disparities in structural response between configurations with and without

fluid viscous dampers, the obtained p-value of 0.00000000003994 falls

below the chosen significance level of 0.10 (p-value < α). Consequently,

the null hypothesis (Ho) is rejected.

This finding suggests a notable contrast in structural response to

seismic loading between buildings equipped with fluid viscous dampers and

those without. The analysis reveals substantial variation in acceleration

levels contingent upon the application of fluid viscous dampers within the

structure. Based on the graph, it is evident that the implementation of 30

fluid viscous dampers results in a more pronounced reduction in

acceleration. This observation underscores the effectiveness of fluid

viscous dampers in enhancing the seismic resistance of the structure,

particularly when contrasted with a building lacking such dampers.

4.1.3.6 Torsion

Representing torsion in terms of rotation in ETABS reflects the physics

of structural behavior. It is represented in terms of rotation since torsional

effects are primarily concerned with the rotation of structural elements,

particularly beams and columns, about their longitudinal axis. This

rotational deformation is a critical aspect of structural behavior, especially in

buildings and other structures subjected to lateral loads, such as wind or

seismic forces.
 This approach aligns with the fundamental principles of structural

mechanics, where torsional effects are often characterized by rotational

deformations rather than linear displacements.

4.1.3.6.1. Lead Rubber Bearing Base Isolators

Analysis:

Using level of significance, α = 0.10

Number of samples per group, N = 12

Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square
SUMMARY OF THE ANALYSIS
SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL
DF 7 88 95
SS 1.6478 3.5979 5.2457
MS 0.2354 0.0409 0.2763
F-STAT 5.75757
P-VALUE 0.00002

Utilizing One-Way ANOVA (Analysis of Variance) to ascertain

disparities in structural response between configurations with and without

fluid viscous dampers, the obtained p-value of 0.00002 falls below the

chosen significance level of 0.10 (p-value < α). Consequently, the null

hypothesis (Ho) is rejected.

The study indicates a notable decrease in structural torsion after

implementing lead rubber bearing base isolators. The data graph

demonstrates that structures lacking these isolators generally experience

greater torsion compared to those equipped with them. This reduction

underscores the efficacy of lead rubber bearing base isolators in

diminishing torsion. Consequently, lowering torsional effects in a

structure holds paramount importance for bolstering its ability to

withstand seismic activity, safeguarding occupants and assets, and

mitigating the potential for structural collapse during earthquakes.

4.1.3.6.2. Fluid Viscous Dampers

 Analysis:

Using level of significance, α = 0.10

Number of samples per group, N = 12

SKEWNESS EXCESS NORMALITY OUTLIERS MEAN SD
KURTOSIS
control 1.093123 -0.546173 0.002649 - 0.15761 0.20438
FVD 1 0.712841 -1.408011 0.01432 - 0.14335 0.14085
FVD 2 1.507478 0.780655 0.0004329 0.6348 0.14158 0.22896
FVD 3 0.758346 -1.34084 0.008395 - 0.28838 0.31694
FVD 4 1.180634 -0.0951884 0.006162 - 0.18767 0.21615
FVD 5 1.821372 2.339729 0.001118 0.5114,0.6228 0.17303 0.19238
FVD 6 1.144745 -0.416714 0.002492 - 0.21637 0.26295
FVD 7 1.332239 0.95294 0.02509 0.5579 0.18777 0.17318
FVD 8 1.175538 0.216632 0.02112 - 0.21941 0.18859
FVD 9 1.399447 1.022399 0.01423 0.5578 0.18078 0.17371
FVD 10 1.10006 -0.46228 0.002832 - 0.16207 0.19176
FVD 11 1.038448 -0.668127 0.003472 - 0.16001 0.18888
FVD 12 1.051573 -0.752778 0.002116 - 0.19949 0.2525

Where:

DF = Degrees of Freedom

SS = Sum of Square

MS = Mean Square
SUMMARY OF THE ANALYSIS
SOURCE BETWEEN GROUPS WITHIN GROUPS TOTAL
DF 12 143 155
SS 0.225 6.5923 6.8173
MS 0.01875 0.0461 0.04398
F-STAT 0.4067
P-VALUE 0.9591

Using One-Way ANOVA to compare structural responses between

setups with and without fluid viscous dampers, the resulting p-value of

0.9591 exceeds the predetermined significance threshold of 0.10 (p-

value > α), thus supporting the acceptance of the null hypothesis (Ho).

This outcome implies that there isn't a noteworthy distinction in

torsional effects between the use of and their absence. The potential for

increased torsional effects may stem from various factors, including the
 dampers' resistance to torsional motion, their non-linear stiffness, low

damping ratios, resonance amplification, and the intricate dynamics of

the system.

4.1.4 Optimization

Optimizing the equivalent number of Fluid Viscous Dampers to LRB

Base Isolators is found not possible as the devices have contrasting effects

on the structure, especially for displacement, story drift, and base shear. LRB

Base Isolators amplify displacement and story drift due to decoupling the

superstructure to the substructure which increases the flexibility of the

structure. In contrast, FVD works by dissipating energy from the structure

during earthquakes, thereby reducing the magnitude of displacements and

story drift experienced by the building. On the other hand, LRB Base Isolators

exhibit great base shear reduction while FVD did not because as the FVDs

absorb energy from the building's motion, the lateral force exerted on the

foundation, or base shear, increases to counterbalance this energy loss.

Since the number of FVD equivalent to LRB Base Isolators cannot be

determined, the objective of the optimization instead is to find the optimal

number of LRB and FVD devices that provide the most economical and safe

performance in enhancing seismic resilience. This involves minimizing the

cost associated with installing the devices while ensuring that the structure

meets safety criteria based on peak values of displacement, story drift, base

shear, acceleration, and torsion. For the economical effect of the devices, we

assumed that the cost is directly proportional to the number of LRB Base

Isolators or Fluid Viscous Dampers used on the structure.

 The concept we used for the optimization was Robust Parameter

Design which also incorporates trial and error optimization. Robust parameter

design is a variation of the Taguchi method that focuses on optimizing system

performance while minimizing sensitivity to variations or uncertainties in input

factors. By conducting experimental trials and observing peak values or

extreme outcomes, parameter settings that maximize performance and

minimize variability under different operating conditions can be identified.

Robust parameter design aims to achieve reliability and robustness in system

performance, even in the presence of uncertainties or variations in input

parameters.

The design variables in this case are the number of LRB and FVD

devices installed on the structure. These variables represent the parameters

that can be adjusted to optimize the performance of the seismic devices. Then

we established the constraints to ensure the safety and reliability of the

structure. The constraints for the study are the maximum allowable peak

values for displacement, story drift, base shear, acceleration, and torsion of

the control or the structure without LRB Base Isolators and Fluid Viscous

Dampers. We conducted a series of analyses on the structure using different

numbers of LRB and FVD devices (separately) to gather data on the

performance of each configuration using Response Spectrum Analysis on

ETABS. Then we analyzed the results of the experimental trials to identify

peak values of displacement, story drift, base shear, acceleration, and torsion

for each configuration of LRB and FVD devices and compared these peak

values against the safety constraints to determine which configurations meet

the safety criteria. Applying the principles of Robust Parameter Design to

identify the optimal number of LRB and FVD devices that provide the most

economical and safe performance, we iteratively adjusted the number of

devices, re-analyzed them through ETABS, and analyzed the resulting peak

values until they converge towards an optimal solution that minimizes cost

while meeting safety criteria.

The lowest values are considered the peak values and when multiple

peaks are present, the first peak will be considered since the objective of the

optimization is safety and economy.

4.1.4.1 Lead Rubber Bearing Base Isolator

The graph above shows the maximum values for displacement,

story drift, base shear, acceleration, and torsion for the different applied

numbers of LRB Base Isolators in the Otto Hahn Building. For the values

of the parameters, they have been standardized on the same scale using

z-score or standard score which involves dividing a score's deviation by

the standard deviation in a data set.

Upon observing the graph, it is evident that the base shear,

acceleration, and torsion first peaked when the number of LRB base
isolators used on the structure was 46. The values of these peaks also

show a great reduction compared to the values from the control, with

53.46% reduction in base shear, 25.53% reduction in acceleration, and

14.95% reduction in torsional rotation. Although there is an increase in

displacement and story drift, this is inevitable when using LRB base

isolators because of the nature of their mechanical behavior and design.

With these, the optimized number of LRB Base Isolators for the Otto

Hahn Building is 46, which is LRB Placement 6.

4.1.4.2 Fluid Viscous Damper

 The graph above shows the maximum values for displacement,

story drift, base shear, acceleration, and torsion for the different applied

numbers of Fluid Viscous Dampers in the Otto Hahn Building. Similar to

the LRB base isolators, the values of the extracted parameters have been

standardized on the same scale using z-score.

The graph showed multiple peaks at different numbers of FVDs.

The first peaks (displacement and acceleration) were evident when the

number of FVD is 14. However, it showed a 70.65% increase in base

shear and 2.69% increase in torsion. Similarly, the rest of the numbers

also showcase great reduction in two or three parameters as well as

increases to the other parameters, except for when the number of FVDs

is 40. When 40 FVDs were used, there was a 74.51% reduction in

displacement, 63.73% in story drift. 26.24% in acceleration, and 31.41%

in torsion. While there was a 12.20% increase in base shear, it can be

explained through the concept that energy dissipated by the FVDs must

be compensated for by an increase in base shear to maintain equilibrium

within the structure. As a result, while FVDs reduce the forces transmitted
 to the superstructure, they may lead to a redistribution of forces and an

increase in base shear. Hence, the most optimal number for FVD is 40.

4.2 Project Plans and Details (Josh, Ecka)

The Otto Hahn Building stands as a pivotal structure that requires

extensive analysis and strategic planning to mitigate potential risks. This

comprehensive study sets out to evaluate the building’s current structural

condition, using advanced modeling and analysis techniques, ETABS, to

simulate earthquake scenarios.

4.2.1. Implementation Plan

A. Data Collection and Building ● Conduct an initial survey of

Inspection the Otto Hahn Building to
assess its current
structural condition.
● Gather architectural and
engineering drawings and
previous retrofitting efforts.
● Consult with structural
engineers and
stakeholders familiar with
the building to identify
specific areas of concern.

B. Modeling and Analysis Setup ● Using ETABS software,

in Etabs develop a detailed 3D
model of the Dr. Otto Hahn
Building incorporating
accurate geometric and
material attributes.
● Incorporating LRB and
FVD on the structure
model.
● Design boundary
conditions and load cases
using local building codes
and seismic design factors.
● Use appropriate modeling
tools to represent
 irregularities in the
building’s geometry.
● Optimization of the number
of LRB equivalent to the
number of FVD in terms of
effectiveness in seismic
mitigation and cost-
effectiveness.
● Verify the accuracy of the
model through parameter
analysis.

C. Simulation of Earthquake ● Apply seismic loads to the

Scenarios ETABS model for each
scenario, incorporating
both lateral and vertical
ground motion.
● Apply statistical tests and
data processing in ETABS
to assess the structural
reaction of the building to
each seismic event.
● Monitor and record key
performance metrics such
as displacement, story
drift, base shear,
acceleration, and torsion to
determine the current
structural system’s
effectiveness.

D. Comparative Analysis ● Evaluate the structural

response of the Dr. Otto
Hahn Building with and
without earthquake-
proofing devices (LRB and
FVD).
● Analyze and interpret
simulation data to identify
differences in structural
behavior, stiffness,
damping and energy
dissipation.
● Indicate the optimization
results whether it is
possible or not. When
optimization is not
possible, another solution
to be proposed is to study
alternative approaches or
 strategies to achieve the
desired outcome.

The process outlined for assessing and analyzing seismically the Dr.

Otto Hahn Building demonstrates an organized approach to ensuring

structural integrity and earthquake resilience. The use of advanced modeling

software, such as ETABS, allows for the 3D models with precise boundary

conditions, load cases, and seismic simulations. The created 3D models for

Lead Rubber Bearing can be found on Appendix D-1 on page/s 104 to 105

which showcase the placement of LRB on the structure. Also, the 3D models

for Fluid Viscous Damper can be found on Appendix D-2 on page/s 106 to

108 which includes the front, rear, left and right elevations for the placement

of dampers on the structure.

The optimization of earthquake-proofing devices such as LRB and FVD

demonstrates a commitment to seismic mitigation effectiveness as well as

cost-efficiency. Despite efforts to validate and verify the accuracy and

reliability of the simulation data, complete assurance was not achieved.

Despite the use of validation tools such as STAAD, there may be inherent

uncertainties or limitations in the modeling process that affect the results'

precision. These uncertainties highlight the importance of interpreting the

findings with caution and acknowledging the possibility of margin of error in

the analysis.

4.3 Construction Estimates

4.3.1 Retrofitting using Lead Rubber Bearing Base Isolators

 We based the cost estimate of the LRB Base Isolator retrofitting from the

study of Gupta, R, et.al (2021), wherein they determined the cost-benefit ratio of

the construction and material cost of retrofitting using LRB base isolators. On the

other hand, the cost of the LRB base isolator is adapted from the study of

Catlioglu, O., et.al. (2023) wherein they compared the project budget of a

conventional building and a seismically isolated building. The cost for a single

base isolator is 2500 EUR which is 20,367.56 PHP.

Items Unit Unit Price Total Amount

I. Excavation Work 1,152 sqm P 82.3 94809.6

II. Material Cost

Lead Rubber Bearing 46 P 20,367.56 P 7,056,188.4

Base Isolator

III. Equipment Cost

Hydraulic Cylinder 2 P 32,615 P 65,230

Jack

Wire Saw 1 P 45,227.6 P 45,227.6

Total Cost P 7,261,455.6

4.3.2 Retrofitting using Fluid Viscous Dampers

For the cost of FVDs and their installation, information on the cost of the

device and its installation are very limited. Hence, we adapted the cost from the

study of Kim, et.al (2014) wherein they evaluated the seismic performance and

cost effectiveness of a multiple slim-type damper system. The cost for a

damper device including its installation is 4000 USD which is worth

226,126 PHP in the Philippines.

Items Unit Unit Price Total Amount

I. Fluid Viscous Damper 40 P 226,126 P 9,045,040

(including installation)

Total Cost P 9,045,040

4.4 Project Schedule (PERT/CPM) (Emmy, Des)

4.4.1 PERT FOR BASE ISOLATOR (LRB)

Activity Duration (days)

A-B Investigation of Otto Hahn Building for 4

retrofitting

B-C Design and Analyzation of the base 7

isolator (LRB) in the structure

C-D Personnel Preparation 5

D-E Preparation of tools and equipment 5

D-F Seismic isolation (LRB) Pre installation 10

inspection

E-G 30
F-G Grind the lower support pier to level it, 35
clean the debris, and ensure the top
surface of the sleeve should not be
higher than the concrete surface of the
lower support pier.

G-H Model annotation: According to the 2

design drawings, label the
specifications and models of the
isolation bearings on the surface of the
lower support pier.

H-I Install LRB seismic isolators: Use 30

hydraulic cylinder jack to position
support specifications according to
design. Screw bolts into sleeves and
 tighten symmetrically in two stages.
Use torque wrench for high-strength
bolts in special projects.

I-J Model review: Refer to the design 3

drawings and check each seismic
isolation type and position one by one
to ensure they are correct. Focus on
reviewing the installation positions of
lead rubber bearing (LRB) and lead-
free bearing (LNR) of the same
diameter, and avoid installation errors.

J-K Installation inspection: Check seismic 3

isolation gap with lower pier surface,
ensure bolt tightness, and record
support production number. Check
height difference for double supports.

4.4.2 PERT FOR DAMPERS (FVD)

Activity Duration (days)

A-B Evaluation of the condition of Otto Hahn 4

Building for retrofitting

B-C Import of existing structural model in 5

ETABS and analyzation of structural
behavior without dampers

C-D Identification of critical areas for 4

damper placements

D-E Design retrofit strategy: Enhancement 7

 of structural resilience, safety, and
performance of the structure and
dampers

D-F Placement determination using FVD 4

E-G Validation of model with damper 8

integration

F-G Definition of damper properties and 3

characteristics

G-H Analysis and Simulation with FVD in 12

ETABS: Run dynamic analysis,
optimization and evaluation of damper
settings and structural response under
seismic loads

H-I STAAD Validation: Verification of 4

accuracy of data generated from
ETABS

I-J Update and documentation of damper 5

locations and settings in ETABS model

J-K Procurement of Fluid Viscous Dampers 14

K-L Preparation for the Installation of 7

Retrofitting Columns: Review and
evaluate the proposals received from
the suppliers

L-M Installation of Fluid Viscous Dampers: 17

Installing mounting brackets, attaching
the dampers securely, and connecting
hydraulic hoses

M-N Test and Commission Dampers: 10

Ensuring FVD effectively reduce
structural vibrations

N-O Monitoring, inspection and Maintenance 3

of the Installed FVD

4.5 Resource Requirements (Harold)

Project resources are components that are necessary for successful

project implementation. These are the crucial assets needed to accomplish

the project: work, cost, time, and material cost.

 In this study, the work resources, which were the essential resources,

the researchers were modeled and analyzed through Response Analysis

using ETABS software. From the analysis, the parameters: base shear,

displacement, story drift, acceleration, and torsion. Through proper time

management and teamwork, the researchers successfully finished the work in

time. Lastly, material resources were the National Structural Code of the

Philippines (NSCP) raw materials, were computed using the material

specification and pressures taken from the (NSCP) 2015.

These resources must be prepared and assigned to the project to

ensure timely completion. Thus, this project section provided the seismic

performance of an irregular medium-rise building for model Otto Hahn

Building in Saint Louis University located in Baguio City, Philippines.

CHAPTER V: SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS

5.1 Summary - Josh, Emmy, Des

This study, which made use of a comparative approach assessed the

response and compared the cost-effectiveness of base isolators and dampers

in withstanding seismic activities, where their effects were compared to

buildings’ performance without the two seismic mitigating devices. This

approach helped in identifying both differences and similarities of the seismic

mitigating devices to which among them can provide the greatest resilience

and protection with the optimal number of these devices for the Otto Hahn

Building, while balancing safety and economic considerations.

The building was modeled through ETABS and STAAD software

incorporating the seismic mitigating devices—LRB Base Isolator and Fluid

Viscous Dampers. ETABS extracted the parameters such as the base shear,

story drift, displacement, floor acceleration, and torsion. It was validated

through the STAAD software, resulting in results’ discrepancies

Through optimization, it showed that 46 base isolators and 40 dampers

demonstrated significant reductions in some of the parameters despite the

increase of displacement and story drift on the isolator and base shear on the

dampers. Furthermore, the descriptive statistics and ANOVA (one-way test)

were used to treat the data of the parameters gathered.

KEY FINDINGS

MAJOR FINDINGS —- COST EFFECTIVE DEVICE

Based on the discussions presented in the previous chapter, the

following summary of findings meets the objective outlined in the study.

1. The researchers determined the response of an irregular building (the

inspiration for the building model used in the study was the Otto Hahn

Building in Saint Louis University located in Baguio City, Philippines) against

earthquake:
 a) without base isolator and damper;

b) with base isolator

Displacement: Increase displacement but provide seismic protection

by reducing forces, ensuring safer outcomes. Story Drift: Lead to higher story

drift with isolators, considered safer. Base Shear: Isolators notably reduce

base shear, improving seismic resilience. Acceleration: Isolators don't

significantly impact acceleration, buildings can withstand seismic loads.

Torsion: Significant decrease in torsion with isolators, highlighting their

efficacy.

In this section, an increased displacement provides seismic protection

through reduction of forces to ensure safer outcomes. Story Drift: Lead to

higher story drift with isolators, considered safer. Base Shear: Isolators

notably reduce base shear, improving seismic resilience. Acceleration:

Isolators don't significantly impact acceleration, buildings can withstand

seismic loads. Torsion: Significant decrease in torsion with isolators,

highlighting their efficacy.

c) with damper

Displacement: Dampers decrease displacement, enhancing seismic

resistance. Story Drift: Dampers reduce story drift, improving seismic

resilience. Base Shear: No significant difference in base shear with or without

dampers. Acceleration: Dampers decrease acceleration, enhancing seismic

resistance. Torsion: No significant difference in torsional effects with

dampers.
5.2 Conclusion - Faye, Kat, Pat

The analysis draws conclusion that lead rubber bearing base isolators

effectively reduce seismic forces, while fluid viscous dampers minimize

structural displacement. Lead rubber bearing base isolators notably reduce

base shear, and despite an increase in displacement and story drift, they

enhance seismic resilience by allowing the building to absorb seismic energy.

Similarly, fluid viscous dampers significantly reduce displacement and story

drift and improve the building's ability to withstand seismic loads. However,

while lead rubber bearing base isolators do not impact structural acceleration,

buildings equipped with fluid viscous dampers show a notable reduction in

acceleration. Lastly, lead rubber bearing base isolators reduce structural

torsion, though the presence of fluid viscous dampers does not significantly

affect torsional behavior. Overall, integrating both techniques into seismic

design strategies is essential for enhancing structural safety and resilience

against earthquakes.

In terms of optimization, the analysis of maximum values for

displacement, story drift, base shear, acceleration, and torsion across

different configurations of LRB Base Isolators and Fluid Viscous Dampers in

the Otto Hahn Building reveals key insights. LRB Base Isolators, particularly

when 46 isolators are utilized, demonstrate significant reductions in base

shear, acceleration, and torsion, enhancing seismic resilience despite

increases in displacement and story drift. Alternatively, the effectiveness of

Fluid Viscous Dampers varies with configuration, with the most optimal setup

of 40 dampers showing reductions in displacement, story drift, acceleration,

and torsion but an increase in base shear. These findings emphasize the

importance of selecting appropriate seismic mitigation techniques and

configurations to manage structural response parameters effectively and

enhance seismic resilience in buildings.

Overall, Lead Rubber Bearings and Fluid Viscous Dampers

demonstrate equal effectiveness in withstanding the parameters applied

during optimization. However, they differ in the quantity of devices required

for optimal results; 40 dampers and 46 isolators are deemed necessary.

Despite their similar safety performance, dampers prove to be costlier than

isolators when factoring in the expense associated with the required quantity

of units. Therefore, while both devices offer adequate seismic resistance,

opting for isolators could provide cost savings without compromising safety.

5.3 Recommendations - Ericka & Harold

According to the analysis, due to the possibility of optimizing the

equivalent number of LRB (Lead Rubber Bearing) and FVD (Fluid Viscous

Damper) devices was not validated, and given their contrasting effects on the

structure, it is recommended to optimize the number of LRB and FVD devices

separately. This allows one to determine which combination provides the most

cost-effective and safe performance in terms of seismic resilience. This

method ensures a thorough evaluation of each device's contribution to

structural safety and earthquake resistance.

It is also recommended to employ other optimization methods when

determining the equivalent number of LRB (Lead Rubber Bearing) devices to

FVD (Fluid Viscous Damper) devices. One approach is to use mathematical

modeling and simulation techniques to analyze the structure's dynamic

response under various LRB and FVD configurations.

Advanced optimization algorithms, such as evolutionary algorithms,

simulated annealing, and gradient-based methods, can be used to find the

best LRB-to-FVD ratio. These algorithms iteratively adjust the number of LRB

and FVD devices in order to achieve the most efficient and effective structural

response to seismic forces, taking into account predefined objectives and

constraints.

Furthermore, probabilistic methods, such as reliability-based

optimization, can be used to account for uncertainty in material properties,

ground motion characteristics, and structural behavior. Engineers can create

designs that are resistant to seismic variations and uncertainties by

incorporating probabilistic analysis into the optimization process.

In addition, economic optimization techniques like life-cycle cost

analysis can be used to calculate the long-term costs of different LRB and

FVD configurations. This analysis considers not only the initial investment, as

well as the maintenance, repair, and replacement costs over the structure's

lifetime.

By incorporating these advanced optimization methods into the

process of determining the equivalent number of LRB to FVD devices,

engineers can identify the optimal configuration that maximizes seismic

resilience while minimizing costs and effectively addressing safety

requirements.
*** 20s Video - Jeff
***PPT - Josh (tapusin by Saturday para mapacheck kay ma’am)

*** Video Presentation (Sunday)

- Script - Tapusin ng Saturday

*** RUBRIC
*** MANUSCRIPT
*** VIDEO PRESENTATION
(SUBMISSION: MONDAY, APRIL 15)

OVERVIEW OF THE PROPOSED PROJECT

In a region prone to seismic activity, such as the Pacific Ring of Fire,

the Philippines faces substantial earthquake risks, as evidenced by the 1990

Luzon earthquake. This study addressed the imperative for seismic

strengthening measures, focusing on irregular structures that, despite their

vulnerability, play a crucial role in architectural diversity and cost-

effectiveness.
 The study's primary objectives were to compare the seismic

performance of a medium-rise irregular building with and without base

isolators and dampers. Specifically, it seeked to assess earthquake response

under various conditions and compare the effectiveness of the Lead Rubber

Bearing (LRB) Isolator and Fluid Viscous Damper.

A comparative methodology was employed, utilizing Linear Dynamic

Analysis, specifically Response Spectrum Analysis, implemented through the

Extended Three-Dimensional Analysis of Building System (ETABS) software.

The focus of the analysis was the Otto Hahn Building, situated within the

School of Engineering and Architecture at Saint Louis University-Main

Campus in Baguio City.

The significance of this study extended to various stakeholders. Future

researchers can leverage detailed information on dampers and base isolators,

guiding the selection of optimal seismic strategies for irregular structures.

Structural engineers gain valuable insights for informed decision-making in

implementing seismic protection measures. Construction industry

professionals benefit from understanding the economic and practical impacts

of using base isolators and dampers in designing irregular structures. The

study also contributes to public safety and welfare by minimizing the risk of

fatalities and injuries and reducing the long-term financial burden associated

with earthquake damages and reconstruction. Aligned with Sustainable

Development Goals 9 and 11, the research aimed to make cities more

inclusive, safe, resilient, and sustainable (SDG 11), and promote resilient

infrastructure and sustainable industrialization (SDG 9).

 The expected outcome of the study was to determine the most

effective and economically viable seismic strengthening device between the

Lead Rubber Bearing Isolator and Fluid Viscous Damper in terms of

improving the seismic performance of the medium-rise vertically irregular

building. By advancing knowledge in seismic engineering, this study aims to

influence future projects, contribute to the development of resilient

infrastructure, and align with global sustainability goals.

APPENDICES

APPENDIX A
 Fig. 12. Philippines hazard map.
Source: Combined Risk to Geophysical Disasters, Adapted from MDPI Open
Access Journals, by M. Gumasing & M. Sobrevilla, 22023, from https://www.mdpi.com/2071-
1050/15/8/6427

APPENDIX B
 Fig. 13. Hazard Assessment Map and Result of the location of the Dr.
Otto Hahn Building.
Source: HazardHunterPH, from https://hazardhunter.georisk.gov.ph/map

APPENDIX C

Table 7. Most Devastating Earthquakes that Struck the Philippines from the
1960's to Present

Source: Most Severe Earthquakes in the Philippines, by PhilAtlas, from

https://www.philatlas.com/articles/most-severe-earthquakes.html

APPENDIX D-1
 Intersections marked with dashed lines ( - ) indicate LRB Base isolators
while intersections marked with plus signs (+) indicate fixed supports.

Figure 17. LRB 1 (N = 70), wherein LRB Figure 18. LRB 2 (N = 36), wherein LRB
are placed on all footings. are placed alternately.

Figure 18. LRB 3 (N = 55), wherein LRB Figure 19. LRB 4 (N = 4), wherein LRB
are placed on the building’s perimeter. are placed on the building’s corner
footings.
Figure 20. LRB 5 (N = 53), wherein LRB Figure 21. LRB Placement 6 (N = 46)
are not placed on the building’s retaining
wall.

Figure 22. LRB 7 (N = 57)

APPENDIX D-2
FVD 1 (N = 40) FVD 2 (N = 30)

Front Front

Rear Rear

Sides Sides

FVD 3 (N = 66) FVD 4 (36)

Front Front

Rear Rear

Sides Sides

FVD 5 (N = 46) FVD 6 (N = 50)

Front Front
 Rear Rear

Sides Sides

FVD 7 (N = 22) FVD 8 (N = 14)

Front Front

Rear Rear

Sides Sides

FVD 9 (N = 32) FVD 10 (N = 24)

Front Front
 Rear Rear

Sides Sides

FVD 11 (N = 20) FVD 12 (N = 28)

Front Front

Rear Rear

Sides Sides

APPENDIX E

Table 8. Summary of Data for Displacement (Without Fluid Viscous Damper

and Lead Rubber Bearing Base Isolator)
Table 9. Summary of Data for Story Drift (Without Fluid Viscous Damper and
Lead Rubber Bearing Base Isolator)

Table 10. Summary of Data for Acceleration (Without Fluid Viscous Damper
and Lead Rubber Bearing Base Isolator)

Table 11. Summary of Data for Base Shear (Without Fluid Viscous Damper
and Lead Rubber Bearing Base Isolator)
Table 12. Summary of Data for Torsion (Without Fluid Viscous Damper and
Lead Rubber Bearing Base Isolator)

Table 13. Summary of Data for Displacement (Fluid Viscous Damper)

Table 14. Summary of Data for Story Drift (Fluid Viscous Damper)
Table 15. Summary of Data for Acceleration (Fluid Viscous Damper)
Table 16. Summary of Data for Base Shear (Fluid Viscous Damper)

Table 17. Summary of Data for Torsion (Fluid Viscous Damper)

Table 18. Summary of Data for Displacement (Lead Rubber Bearing Base
Isolator)
 Table 19. Summary of Data for Story Drift (Lead Rubber Bearing Base
Isolator)

Table 20. Summary of Data for Acceleration (Lead Rubber Bearing Base
Isolator)
 Table 21. Summary of Data for Base Shear (Lead Rubber Bearing Base
Isolator)

Table 22. Summary of Data for Torsion (Lead Rubber Bearing Base Isolator)

BIBLIOGRAPHY

Afzali A., Mortezaei A., & Kheyroddin A. (2017). Seismic Performance of

High-Rise RC Shear Wall Buildings Subjected to Ground Motions with

Various Frequency Contents. Retrieved October 14, 2023 from

https://pdfs.semanticscholar.org/f490/fb4b272ebf1da083761478d587cd

1217ffdf.pdf
Aijaj, S., & Deshmukh, G. S. (2016). Seismic Analysis of Vertically Irregular

Building. SRTMU’s Research Journal of Science, 2(1), 101–111.

Retrieved October 11, 2013 from

https://www.researchgate.net/publication/305471676_Seismic_Analysis

_of_Vertically_Irregular_Building

Aleksandra B., & Zoran R. (2019). Optimal Damper Placement Using

Combined Fitness Function. Retrieved December 8, 2023 from

https://www.frontiersin.org/articles/10.3389/fbuil.2019.00004/full?fbclid=

IwAR3654Z9yJGu8fSnHztFoY-

9tdlRppbWzZcTLGkAyXnSVj9bukExJSC8af0#B28

Alone B. P., & Awchat, G. (2017). Study on Seismic Analysis of High-rise

Building by Using Software. International Journal of Current Research.

Retrieved October 11, 2013 from

https://www.journalcra.com/sites/default/files/issue-pdf/25245.pdf

Behsazan Larzeh Davam Co. (n.d.). Technical Posts. Retrieved March 26,

2024 from https://irandamp.com/technical-posts/

Bhandari, A., Suwal, R., & Khawas, A. (2023). Seismic Fragility Assessment

of Irregular High Rise Buildings using Incremental Dynamic Analysis.

Advances in Engineering and Technology, 2(1), 69–76. Retrieved

October 11, 2013 from

https://www.researchgate.net/publication/366861954_Seismic_Fragility

_Assessment_of_Irregular_High_Rise_Buildings_using_Incremental_D

ynamic_Analysis

Bhavya, k., & Lakshmi, B. (2017, March - April). Modified Dampers for

Earthquake Resistant Building. International Journal of Technical

 Research and Applications e-ISSN: 2320-8163, 5(2), 49-55. Retrieved

from https://www.ijtra.com/view/modified-dampers-for-earthquake-

resistant-building.pdf

Chirde, A., Malvatkar, Y., Madhwai, S., Gavale, G., &; Surve, M. (2022,

September). STUDY OF BASE ISOLATION. ResearchGate. Retrieved

September 2, 2013 from

https://www.researchgate.net/publication/363740572_STUDY_OF_BA

SE_ISOLATION?fbclid=IwAR2tub_5hmrurKVeLCdZd2hobowT8E0IuX

MO4HpnOkNSJ3Z1tth-3q_wORI

Chitte, C. (2020). Study of Seismic Retrofitting Techniques. ResearchGate.

Retrieved October 13, 2023 from

https://www.researchgate.net/publication/348592766_Study_of_Seismi

c_Retrofitting_Techniques

Costa, P. d., Bosse, R. M., Miranda, G. d., & Gidrão, S. (2016). American

Journal of Civil Engineering. Science Publishing Group. Retrieved

October 11, 2013 from https://doi.org/10.11648/j.ajce.20160403.11

Dash S., & Biswal K. (2015). Seismic Analysis of High-Rise Building by

Response Spectrum Method. Retrieved October 14, 2023 from

http://ethesis.nitrkl.ac.in/7023/2/Seismic_Dash_2015.pdf

Deshmukh, K., & Hamane, A. (2022). Effect of Earthquake Resistant System

on Vertically Geometric Irregular RC Tall Building. International Journal

of Research in Engineering and Science (IJRES), 10(8), 38–46.

Retrieved October 11, 2013 from https://www.ijres.org/papers/Volume-

10/Issue-8/10083846.pdf
El-Assaly, M., Amin, M. A., & Galalah, S. S. (2021). Regular Versus Vertical

Irregular R.C Buildings Using Base Isolation . IOSR Journal. Retrieved

September 13, 2013 from https://www.iosrjournals.org/iosr-

jmce/papers/vol18-issue4/Ser-2/D1804022633.pdf

Elnashi, A. & Di Sarno, L. (2015). Fundamentals of Earthquake Engineering

from Source to Fragility (2nd ed.). John Wiler & Sons, Ltd. Retrieved

November 3, 2023, from

https://books.google.com.ph/books?hl=en&lr=&id=o2g7CgAAQBAJ&oi

=fnd&pg=PA377&dq=Introduction+To+Earthquake+Engineering&ots=1

7KvFSvYfX&sig=hRnoxGKsPlfiVE_3FrDbfF8QLko&redir_esc=y#v=one

page&q=Introduction%20To%20Earthquake%20Engineering&f=false

Ezzaki, N., Stoica, D., Rece, L. & Legendi, A. (2019). The Use of Damper

Systems in Buildings with Reinforced Concrete Structures. Retrieved

from

https://ojs.journals.cz/index.php/CBUIC/article/view/1474/2001?fbclid=I

wAR3n3z-2VjR18jTLO9OYhiQ8YTQ0ZSfARMB6V-

GoXnGUriCGlAGpclj0vY

Fragiadakis, M. (2021). Response Spectrum Analysis of Structures Subjected

to Seismic Actions. Retrieved from https://www.researchgate.net/public

ation/278661406_Response_Spectrum_Analysis_of_Structures_Subje

cted_to_Seismic_Actions

Gluck, N., Reinhorn, A. M., Gluck, J., and Levy, R. (1996). Design of

supplemental dampers for control of structures. J. Struc. Eng. 122,

1394–1399M. C. doi: 10.1061/(ASCE)0733-9445(1996)122:12(1394)

Gyawali, S., Thapa, D., & Bhattarai, T. R. (2020). Effect of Base Isolation in

Multistoried RC Regular and Irregular Building by Using Response

Spectrum Analysis. Saudi Journal of Civil Engineering. Retrieved

September 13, 2013 from

https://saudijournals.com/media/articles/SJCE_45_77-84.pdf

Gumasing, M. J. J., & Sobrevilla, M. D. M. (2023). Determining Factors

Affecting the Protective Behavior of Filipinos in Urban Areas for Natural

Calamities Using an Integration of Protection Motivation Theory,

Theory of Planned Behavior, and Ergonomic Appraisal: A Sustainable

Disaster Preparedness Approach. Sustainability, 15(8), 6427.

Retrieved September 2, 2023, from https://doi.org/10.3390/su15086427

Gurgoze, M., and Muller, P. C. (1992). Optimal positioning of dampers in

multi-body systems. J. Sound Vibr. 158, 517–530. doi: 10.1016/0022-

460X(92)9042

Hahn, G. D., and Sathiavageeswaran, K. R. (1992). Effects of added-damper

distribution on the seismic response of buildings. Comp. Struc. 43,

941–950. doi: 10.1016/0045-7949(92)90308-M2-T

Haque, M., Ray, S., Chakraborty, A., Elias, M., & Alam, I. (2016). Seismic

Performance Analysis of RCC Multi-Storied Buildings with Plan

Irregularity . American Journal of Civil Engineering , 4(2), 52–57.

Retrieved September 3, 2023 from

https://doi.org/10.11648/j.ajce.20160403.11

HazardHunterPH. (n.d). Seismic Hazard Assessment. Retrieved December

12, 2023 from https://hazardhunter.georisk.gov.ph/map.

Hui Siang A.F. (2019). Seismic Fragility Assessment of Tall Concrete Wall

Structures In Malaysia Under Far-Field Earthquakes Considering Mass

Irregularity. Retrieved October 14, 2023 from

http://eprints.utm.my/id/eprint/92749/1/AlexFungHuiSiangMSKA2019.p

df

Hymavathi R., & Reddy J. (2017). Building Design With Linear Static &

Dynamic Seismic Analysis. Retrieved October 14, 2023 from

https://core.ac.uk/download/pdf/228553036.pdf

Khannavar, S., & Kolhar, M. H. (2016). SEISMIC ANALYSIS OF RC

STRUCTURES USING BASE ISOLATION TECHNIQUE. International

Research Journal of Engineering and Technology (IRJET), 03(07).

Kelly, P. (2001). The Installation of Seismic Isolation System for Building

Retrofit. Retrieved March 26, 2024 from

https://core.ac.uk/download/pdf/19878924.pdf

Khan, J. J., Sekhar, S., & Prasad, B. S. (2017). Seismic Performance of

Symmetrical and Asymmetrical Buildings with Heavy Loads. Research

India Publications. Retrieved October 2013 from

https://www.ripublication.com/ijaer17/ijaerv12n22_33.pdf

Khattar S., & Muthumani K. (2018). Seismic Performance of High-Rise

Building. Retrieved October 14, 2023 from

https://iaeme.com/MasterAdmin/Journal_uploads/IJCIET/VOLUME_9_I

SSUE_3/IJCIET_09_03_087.pdf

Lo-oy, L. (2022). AR DRRMC warns 6.7 and 7.2 earthquake possible if

Kalinga and Bangui Faults move. Guru Press Cordillera. Retrieved

December 12, 2023, from https://www.gurupress-

 cordillera.com/post/car-drrmc-warns-6-7-and-7-2-earthquake-possible-

if-kalinga-and-bangui-faults-

move#:~:text=Other%20earthquakes&text=Meantime%2C%20if%20th

e%20Tubao%20Fault,Union%2C%20Benguet%2C%20and%20Pangas

inan.

Majdi, A., Sadeghi-Movahhed, A., Mashayekhi, M., Zardari, S., Benjeddou,

O., & Domenico, D. D. (2023, May 14). On the Influence of Unexpected

Earthquake Severity and Dampers Placement on Isolated Structures

Subjected to Pounding Using the Modified Endurance Time Method.

MDPI. Retrieved October 13, 2023 from https://www.mdpi.com/2075-

5309/13/5/1278

Mallah, A. A., & Kumar, M. (2021). MITIGATING SEISMIC HAZARD BY

BASE ISOLATION. Elementary Education Online, 20(2), 1056-1056.

Retrieved October 2013 from https://www.ilkogretim-

online.org/fulltext/218-1618686146.pdf

Maulana, T. I., Faturrochman, J. N., & Saito, T. (2019). Preliminary Seismic

Performance-based Evaluation of Academic Reinforced Concrete

Building in Yogyakarta based on Displacement Parameter. Retrieved

from: file:///C:/Users/USER/Downloads/125919767.pdf

Miri, S., & Shahrokh, Z. (2019). A Short Introduction to Comparative

Research. Retrieved from https://www.researchgate.net/publication/

336278925_A_Short_Introduction_to_Comparative_Research

Mishra, P., & Awchat, G. (2017, June). Base isolation technique for design of

earthquake resistant structures. Researchgate. Retrieved October

2013 from
 https://www.researchgate.net/publication/355926925_BASE_ISOLATI

ON_TECHNIQUE_FOR_DESIGN_OF_EARTHQUAKE_RESISTANT_

STRUCTURES

Naveen, S., Abrahamb, N. M., & Kumari, A. (2019, August). Analysis of

Irregular Structures under Earthquake Loads. ResearchGate. Retrieved

October 2013 from

https://www.researchgate.net/publication/334978115_Analysis_of_Irreg

ular_Structures_under_Earthquake_Loads

Optimality criteria based seismic design of multiple tuned-mass dampers for

the control of 3D irregular buildings. Researchgate.net. Retrieved

October 13, 2023 from

https://www.researchgate.net/publication/276584512_Optimality_criteri

a_based_seismic_design_of_multiple_tuned-mass-

dampers_for_the_control_of_3D_irregular_buildings

Ozkul T., & Ergunes O. (2022). Seismic Assessment of Tall Buildings

Designed According to the Turkish Building Earthquake Code.

Retrieved October 14, 2023 from

https://avesis.itu.edu.tr/yayin/0120079f-b392-430b-b98c-

3686b16a3f54/seismic-assessment-of-tall-buildings-designed-

according-to-the-turkish-building-earthquake-code

Pankar, A., & Awari, U.R. (2020). Suitability of different base isolation systems

according to length to width ratio of high-rise buildings. Retrieved

October 14, 2023 from

http://ijasret.com/VolumeArticles/FullTextPDF/642_31.SUITABILITY_O

F_DIFFERENT_BASE_ISOLATION_SYSTEMS_ACCORDING_TO_LE
 NGTH_TO_WIDTH_RATIO_OF_HIGH-RISE_BUILDINGS.pdf

PhilAtlas. (n.d.). Most Severe Earthquakes in the Philippines – PhilAtlas.

Www.philatlas.com. Retrieved September 2, 2023, from

https://www.philatlas.com/articles/most-severe-earthquakes.html

Powale, S., & Pathak, N. (2019). A Comparative Study Of Torsional Effect Of

Earthquake On “L” And “S” Shaped High Rise Buildings.

INTERNATIONAL JOURNAL of SCIENTIFIC & TECHNOLOGY

RESEARCH , 8(8), 1355–1359. Retrieved October 11, 2013 from

https://www.ijstr.org/final-print/aug2019/A-Comparative-Study-Of-

Torsional-Effect-Of-Earthquake-On-l-And-s-Shaped-High-Rise-

Buildings.pdf

Raagavi, M. T., & Sidhardhan, D. S. (2021, April 27). A Study on Seismic

Performance of Various Irregular Structures. Academia.edu. Retrieved

October 11, 2013 from

https://d1wqtxts1xzle7.cloudfront.net/79879658/B09051219-

libre.pdf?1643512415=&response-content-

disposition=inline%3B+filename%3DA_Study_on_Seismic_Performanc

e_of_Variou.pdf&Expires=1693642109&Signature=dlFZ2sUeUNq9mtkf

ERfZaWKmXu7TqXjgqWyrcGzQQcjoYuQuGC4y

Ramdas L., Santhi H., & Malathi G. (2022). A Study on High-rise RC Structure

with Fluid Viscous. Retried March 26, 2024 from

https://jresm.org/archive/resm2022.362ea1101.pdf

damper using python

Reddy, K. A., Prasad, R., &; Malagavalli, V. (2021). COMPARATIVE STUDY

OF MULTI-STOREY RC BUILDING WITH AND WITHOUT BASE-

 ISOLATION. Ilkogretim Online - Elementary Education Online.

Retrieved September 14, 2013 from https://www.ilkogretim-

online.org/fulltext/218-1622139937.pdf

Sadeq S.F., Muhammad B.R. , & Zuheriy A.J. (2021). Seismic Behaviour of

Rc Building Located in Erbil, Iraq and Strengthening by Using Steel

Frame Sections Precast BoltConnected Steel-Plate Reinforced

Concrete. Retrieved October 14, 2023 from

https://iopscience.iop.org/article/10.1088/1755-1315/961/1/012012/pdf

Shashidhar K. & Balaji K.V.G.D. (2015). Comparison of Influence of Wind and

Earthquake Forces on Low-Rise and High-Rise Multi Story Structures.

Retrieved October 14, 2023 from

https://www.researchgate.net/profile/Balaji-Kvgd-

2/publication/284716304_COMPARISON_OF_INFLUENCE_OF_WIND

_AND_EARTHQUAKE_FORCES_ON_LOW-RISE_AND_HIGH-

RISE_MULTI_STORY_STRUCTURES/links/5656da2708ae1ef9297b7

ab9/COMPARISON-OF-INFLUENCE-OF-WIND-AND-EARTHQUAKE-

FORCES-ON-LOW-RISE-AND-HIGH-RISE-MULTI-STORY-

STRUCTURES.pdf

Shobana R., Aarthy E., Thenmozhi S., Gowri V., & Kumar B. S. C. (2023).

Seismic analysis of RC building (G+9) by response spectrum method.

Retrieved October 11, 2013 from

https://www.sciencedirect.com/science/article/abs/pii/S2214785323017

261

Sreenivas, D., & Mathew, A. (2016). Evaluation of Seismic Performance of

Re-Entrant Cornered Buildings with Base Isolators. International

 Journal of Science Technology & Engineering , Vol. 3(3).

Takewaki, I. (1997). Optimal damper placement for minimum transfer

functions. Earthq. Eng. Struc. Dyn. 26, 1113–1124. doi:

10.1002/(SICI)1096-9845(199711)26:11<1113::AID-

EQE696>3.0.CO;2-X

Tremblay, R., Polytechnique, E., DeVall, R., & Anderson, D. (n.d.). University

of Calgary. University of Calgary. Retrieved October 11, 2013 from

https://www.ucalgary.ca/en/civil/csce_calgary/2004/andersonirregulariti

es.pdf

Wu, B., Ou, J. P., and Soong, T. T. (1997). Optimal placement of energy

dissipation devices for three dimensional structures. Eng. Struc. 19,

113–125. doi: 10.1016/S0141-0296(96)00034-X

Yamini Nagwanshi Y., & Kodwani H. (2018). A Review: Seismic Responses of

Multistoried Structures. Retrieved October 14, 2023 from

https://www.ijresm.com/Vol_1_2018/Vol1_Iss10_October18/IJRESM_V

1_I10_82.pdf

Yang Z.D. and Lam E.E.S. (2012). Dynamic Response of Fixed-Based Core-

Tube and Base-Isolated Frame Structure Subjected to Strong

Earthquake Motions. Retrieved March 26, 2024 from

https://publications.waset.org/5800/pdf