BACHELOR OF ARCHITECTURE

DESIGN THESIS 2020 – 21

ECO – RESORT

SHEELA AJAY KUMAR

16091AA025

Under the Guidance of

SINDHUJA GARIMELLA
Assistant Professor

STRUCTURAL FEASIBILITY REPORT

Vaishnavi School of Architecture and Planning

HYDERABAD
SURVEY NO 48/A,GUTTALABEGUMPETH ,KAVURI HILLS HYDERABAD
TELANGANA 500081
 Vaishnavi School of Architecture and Planning
Survey No. 48/A, Kavuri Hills, Madhapur, Hyderabad – 500081
Affiliated to
JAWAHARLAL NEHRU ARCHITECTURE
AND FINE ARTS UNIVERSITY

This is to certify that the Design Thesis entitled ECO – RESORT carried out by
Mr. SHEELA AJAY KUMAR, bearing Hall Ticket No: 16091AA025, currently in fourth
year B.Arch., during the academic year 2020-21, in partial fulfillment for the award of the
Degree of BACHELOR OF ARCHITECTURE from Jawaharlal Nehru Architecture and Fine
Arts University is a record of bonafide work to be the best of our knowledge and may be
placed before the examination board for their consideration.

____________ ______________
Thesis Guide Thesis Co-ordinator

_____________ ______________
External examiner PRINCIPAL

ECO – RESORT i
 ACKNOWLEDGEMENTS

I would never have been able to finish my thesis without the

guidance of my faculty members, help from friends, and support from my family.

I would like to express my deepest gratitude to my advisor,

Ms. Ar. Sindhuja Garimella, for her excellent guidance, caring, patience, and providing me
with an excellent atmosphere for doing research.
I would like to thank Ast. Prof. Er. G. Vinay Kumar for guiding my
structural part of my project.

I would also like to thank my parents and friends. They have always
supported me and encouraged me with their best wishes.

However, it would not have been possible without the kind support
and help of many individuals. I am highly indebted to all of them.

ECO – RESORT ii
 ABSTRACT

The report discussed the various design issues and research

throughout the year. The proposed project is located in lambasinghi. The project has been
selected keeping in the view the need for an resort to attract more tourist and visitors.

Before proceeding with actual design and plan, an insight is given to the climatic
conditions and tourism in lambasinghi to give easier and connecting information to the
project.

It nearly covers all the major issues and requirements of eco resort. And also the project
covers all the requirements of many other activity and entertainment spaces to reduce stress
and promote health and ecological quality.

The proposed eco resort will be a pleasant addition to develop the tourism and beauty of
lambasinghi, and also fulfils the recreational and entertainment needs of people of
sorroundings.

ECO – RESORT iii

Table of Contents
NOTATIONS ......................................................................................................................... 1
1.CHAPTER .............................................................................................................................. 2
INTRODUCTION ..................................................................................................................... 2
1.1 Objectives: ................................................................................................................... 2
1.2 Project description: ...................................................................................................... 3
2 CHAPTER .......................................................................................................................... 4
DESIGN OF STRUCTURES .................................................................................................... 4
2.1 Functional design: ....................................................................................................... 4
2.2 Structural design:......................................................................................................... 4
2.2.1 Objective: ............................................................................................................. 4
2.2.2 Scope: ................................................................................................................... 5
3 .CHAPTER.3 ...................................................................................................................... 6
TYPES OF STRUCTURES ....................................................................................................... 6
3.1 Selection criteria .......................................................................................................... 6
3.2 Module For Structural Design Purpose ..................... Error! Bookmark not defined.
4.CHAPTER .............................................................................................................................. 8
LITERATURE STUDY: ........................................................................................................... 8
4.1 R.C.C. Buildings .............................................................................................................. 8
4.1.1 Advantages of reinforced concrete ...................................................................... 9
4.1.2 Disadvantages of reinforced concrete .................................................................. 9
4.1.3 Components of rcc structure: ............................................................................. 10
4.2 Philosophies for design of r.c.c ................................. Error! Bookmark not defined.
4.2.1 Working stress method: ..................................................................................... 11
4.2.2 Limit state method: ............................................................................................ 12
4.2.3 Limit state of collapse: ................................. Error! Bookmark not defined.
4.2.4 Limit State of serviceability:.............................................................................. 13
4.3 Limit state method and working stress method:........................................................ 13
4.4 Rules for calculating rotation contributions : ............................................................ 14
4.5 Types of loads: .......................................................................................................... 15
4.5.1 Dead load: .......................................................................................................... 15

ECO – RESORT iv
 4.5.2 Imposed loads or live loads: .............................................................................. 15
4.5.3 Impact loads: ...................................................................................................... 15
4.5.4 Wind loads: ........................................................................................................ 16
4.5.5 Earthquake load: ................................................................................................ 16
4.6 Analysis: .................................................................................................................... 17
5 CHAPTER ........................................................................................................................ 18
STAGES IN STRUCTURAL DESIGN: ................................................................................. 18
5.1 Instructural planning: ................................................................................................ 18
5.1.1 Positioning and orientation of columns: ............................................................ 18
5.1.2 positioning of beams: ......................................................................................... 19
5.1.3 spanning of slabs: ............................................................................................... 19
5.2 Footing: ..................................................................................................................... 20
5.3 Assumptions .............................................................................................................. 20
6 .CHAPTER ....................................................................................................................... 21
DESIGN METHODOLOGY ................................................... Error! Bookmark not defined.
6.1 Slabs .......................................................................... Error! Bookmark not defined.
6.1.1 Design of slabs ................................................... Error! Bookmark not defined.
6.2 Beam.......................................................................... Error! Bookmark not defined.
6.2.1 Doubly reinforced sections: ............................... Error! Bookmark not defined.
6.3 Shear force................................................................. Error! Bookmark not defined.
6.4 Columns .................................................................... Error! Bookmark not defined.
6.5 Types of Foundations ................................................ Error! Bookmark not defined.
6.6 Design Rules: ............................................................ Error! Bookmark not defined.
6.7 Preliminary design rules: ........................................... Error! Bookmark not defined.
6.8 General data............................................................... Error! Bookmark not defined.
6.9 Codebooks used......................................................... Error! Bookmark not defined.
7 .CHAPTER ....................................................................... Error! Bookmark not defined.
STRUCTURAL DESIGN - Maintenance Block: .................... Error! Bookmark not defined.
7.1 DATA ........................................................................ Error! Bookmark not defined.
7.2 Design Of Slabs:........................................................ Error! Bookmark not defined.
7.3 Design of beams: ....................................................... Error! Bookmark not defined.
7.4 Desgin Of Column .................................................... Error! Bookmark not defined.

ECO – RESORT v
 7.5 Footings ..................................................................... Error! Bookmark not defined.
7.6 Desgin of stair case ................................................... Error! Bookmark not defined.
8 SUMMARY...................................................................................................................... 53
9 CONCLUSION ................................................................ Error! Bookmark not defined.
Bibliography ............................................................................ Error! Bookmark not defined.

ECO – RESORT vi
List of Figures
Figure 4.1: Typical R.C.C wall. __________________________________________________________________ 9
Figure 4.2: Components of R.C.C_______________________________________________________________ 10
Figure 4.3: Stress – strain curve in working stress design ___________________________________________ 11
Figure 4.5 Sesmic load acti ___________________________________________________________________ 16
Figure 4.6: Slab Analysis _____________________________________________________________________ 17
Figure 7.1: Pile Foundation ____________________________________________ Error! Bookmark not defined.
Figure 7.2: Types of pile foundation _____________________________________ Error! Bookmark not defined.
List of Drawings:
No table of figures entries found.

ECO – RESORT vii

NOTATIONS
Asv – Cross sectional area of the stirrups

Ast – Area of steel in tension

Pt – Percentage of steel in tension

B – Breadth of the beam

D – Overall depth

d – Effective depth of the beam

d′ - Effective cover

Fck – Characteristics strength of concrete

Fy - Characteristic strength of steel

X - Moment coefficient in shorter span direction

Y - Moment coefficient in longer span direction

Ɩ - Effective length

Ɩx – Effective shorter span

Ɩy - Effective long span

K – Stiffness factor

Mυ – Factored moment

Wυ – Factored load

Q – Net upward pressure intensity

VUS – Difference of shear force in allowable & permissible stress

T ͂c – allowable shear stress

ECO – RESORT 1
 1.CHAPTER

INTRODUCTION

Resort is a place to spend holiday for relaxation and recreation. One can go and swim in
resort, can have lunch, can go just to pass time, plan an overnight stay and lit campfire, artist
can complete their portrait, novelist can finish novel, a poet can create his poem and tourist
can have charming stay there.

A resort can function as a conference centre, as a meeting centre, as a banquet, as a

restaurant, as a health club and various other functions. A resort could be day serving and
night serving, and it provides the cuisine service.

The busy people in the urban metropolitan cities, people living in congested localities and
apartment desire to relax physically and mentally during weekend and holidays by being
away from city life for which a resort is always a better solution, catering to the need of the
locals as well as the floating tourist. A resort offers scope for a greater range of activities.

Resort is a place where accommodation, reorientation is involved and most important it is a

place for enjoyment which drives the mind of a visitor within a resort. The space around it
and the facilities provided for the tourist are more liable and landscaped and form an integral
part of all tourist activity area. Thus a resort consists of loosely arranged building set in a
landscaped garden and taking full advantage of its scenic size and its setting.

OBJECTIVES:
• Provide a recreational environment for varieties of facilities and functions .
• Comfortable design which portrays an environment of leisure and promotes
interaction with nature .
• Respond to climatic and energy consumption issues raised by present day architecture
through sustainable design.
• Designing with the suitable perspective to the surrounding environment and without
the environmental disadvantages.
• Locating the buildings with public spaces and common facilities for encouraging
social interaction.
• To create an environment where the user is mentally and physically at ease.

ECO – RESORT 2
 1.1 PROJECT DESCRIPTION:

• Resorts are generally interwoven with natural surroundings without disturbing the
serene environment. Unlike hotels, resorts are spread over large areas. They provide
comfortable privacy to the families very similar to their own houses in the form of
individual residencies.
• Resorts should be provided with spacious parks, swimming pools, play areas for
children and adults.
• The scope of project is to design a nature resort with recreational facilities.
• They intended to go some distance far from city so that they can enjoy the
environment.
• The project provides a lot of scope for site planning and landscaping.
• To study the various spaces of a resort and their interdependencies and interaction
with each other.
• Creating flexible spaces which can accommodate various activities in a single space.
• A resort demands the formulation of an ambience which can provide people to relax
and leisurely spend their time, at the same time satisfying all their functional needs.

ECO – RESORT 3
 1 CHAPTER

DESIGN OF STRUCTURES

1.1 FUNCTIONAL DESIGN:

• The structure to be constructed should primarily serve the basic purpose for which it
is to be used and must have a pleasing look.
• The building should provide happy environment inside as well as outside. Therefore,
the functional planning of a building must take into account the proper arrangements
of room/halls to satisfy the need of the client, good ventilation, lighting, acoustics,
unobstructed view in the case of community halls, cinema theatres, etc.

1.2 STRUCTURAL DESIGN:

1.2.1 Objective:

• The objective of structural design is to design the structure for stability, strength and
serviceability.
• The design of a structure must satisfy three basic requirements:
• Stability to prevent overturning, sliding or buckling of the structure, or parts of it,
under the action of loads, Strength to resist safely the stresses induced by the loads in
the various structural members; and
• Serviceability to ensure satisfactory performance under service load conditions –
which implies providing adequate stiffness and reinforcements to contain deflections,
crack-widths and vibrations within acceptable limits, and also providing
impermeability and durability (including corrosion-resistance), etc.
• There are two other considerations that a sensible designer ought to bear in mind, viz.
economy and aesthetics. One can always design a massive structure, which has more-
than-adequate stability, strength and serviceability, but the ensuing cost of the
structure may be exorbitant, and the end product, far from aesthetic.
• In the words of Felix Candela, the designer of a remarkably wide range of reinforced
concrete shell structures, it is indeed a challenge, and a responsibility, for the
structural designer to design a structure that is not only appropriate for the
architecture, but also strikes the right balance between safety and economy.

ECO – RESORT 4
1.2.2 Scope:

• Systematic procedure for design of a structure that shall be followed is as under:

Loading on a structure:
• Loads on a structure can be a Live Load, dead Load, Floor Finish, Wind Load,
Seismic Load, and Special Loading (e.g. equipments etc.)
• Evaluation of loads and determination of worst loading condition: - Load evaluation is
done as per requirement of a structure. All the loads are summarized and taken for all
further calculation.
• End condition determination: - Fixing of End Conditions for a structure is done as per
structural requirements. (e.g. Cantilever, simply supported, Fix end conditions)
• Assumption of material properties: - Material properties can be Grade of Steel and
Concrete, Density, Type etc. For all marine structures concrete used is M50 and for
all other works it is M 40. Residential structures have been designed in M35. The
grade of concrete is assumed as above with Durability as the main criterion.
• Assumption of sectional details and reworking of sectional details: - Evaluation of a
minimum sectional requirement (Thickness, Depth etc.) for maximum Bending
Moment and Shear force.
• Check of section for adequacy of shear, bending, and deflection: - Check the section
for permissible one way / two way shear, deflection, and bending as per IS Code
provision.
• Determination of steel requirements: - Evaluation of a minimum steel required and
main steel requirement. Coal provision of minimum steel is taken into consideration
while determination of steel to be provided for a given section. The sections are not
designed for sudden failure.
• Transmission of loads: - Evaluation of load transmission (e.g. from slab to beam,
beam to column, column to foundation). Designs are first done by evaluation of loads
on all slabs at the top section, which is then transferred to the respective column
through the beam. Subsequently loads on the slab below this level are taken and the
loads from the top column are transferred to the column below till we reach ground
floor. All loads are then transferred to the foundation system.

ECO – RESORT 5
 2 CHAPTER

TYPES OF STRUCTURES
The different types of structures that have been used in this project are listed as below:

• R.C.C Structures.
• Shear walls.
• PT slabs.
• Curtain walls.
• Acrylic glass.

2.1 SELECTION CRITERIA

• Morphology.
• Capacity Limits.
• Code Requirements.
• Cost.
• Load Conditions.
• Resources and Technology.
• Sustainability.
• Synergy.

2.2 STATEMENT OF PROJECT

3.2.1 SALIENT FEATURES:

Name of the block Cottage

Building typology Recreational

No of stories Ground

No of staircases 0

No of lifts 0

Type of construction R.C.C framed structure

Types of walls Brick wall

ECO – RESORT 6
3.2.2 GEOMETRIC DETAILS:

Floor to floor height: 4m.

Height of plinth: 0.6m

Depth of foundation: 1.5m

3.2.3 MATERIALS:

Concrete grade M25

All steel grades Fe500

Soil type Black soil

Bearing capacity of soil 300KN/M2

ECO – RESORT 7
 4.CHAPTER

LITERATURE STUDY:
4.1 R.C.C. Buildings

Reinforced concrete (RC) is a composite material in which concrete's relatively low tensile
strength and ductility are counteracted by the inclusion of reinforcement having higher tensile
strength and/or ductility.

The reinforcement is usually, though not necessarily, steel reinforcing bars (rebar) and is
usually embedded passively in the concrete before the concrete sets. Reinforcing schemes are
generally designed to resist tensile stresses in particular regions of the concrete that might
cause unacceptable cracking and/or structural failure.

Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers
or alternate composite material in conjunction with rebar or not. Reinforced concrete may
also be permanently stressed (in compression), so as to improve the behavior of the final
structure under working loads. The most common methods of doing this are known as pre-
tensioning and post-tensioning.

For a strong, ductile and durable construction the reinforcement needs to have the following
properties at least:

• High relative strength

• High toleration of tensile strain
• Good bond to the concrete, irrespective of pH, moisture, and similar factors
• Thermal compatibility, not causing unacceptable stresses in response to changing
temperatures.
• Durability in the concrete environment, irrespective of corrosion or sustained stress
for example.

ECO – RESORT 8
Figure 4.1: Typical R.C.C wall.

4.1.1 ADVANTAGES OF REINFORCED CONCRETE:

• Reinforced concrete has a high compressive strength compared to other building

materials.
• Due to the provided reinforcement, reinforced concrete can also withstand a good
amount tensile stress.
• Fire and weather resistance of reinforced concrete is fair.
• The reinforced concrete building 1is more durable than any other building system.
• Reinforced concrete, as a fluid material in the beginning, can1 be economically
molded into a nearly limitless range of shapes.
• The maintenance cost of reinforced concrete is very low.
• In structure like footings, dams, piers etc. reinforced concrete is the most economical
construction material.
• It acts like a rigid member with minimum deflection.
• As reinforced concrete can be molded to any shape required, it is widely used in
precast structural components. It yields rigid members with minimum apparent
deflection.
• Compared to the use of steel in structure, reinforced concrete requires less skilled
labour for the erection of structure.

4.1.2 DISADVANTAGES OF REINFORCED CONCRETE:

• The tensile strength of reinforced concrete is about one-tenth of its compressive

strength.

ECO – RESORT 9
 • The main steps of using reinforced concrete are mixing, casting, and curing. All of
this affects the final strength.
• The cost of the forms used for casting RC is
relatively higher.
• For multi-storied building the RCC column
section for is larger than steel section as the
compressive strength is lower in the case
of RCC.
• Shrinkage causes crack development and
strength loss.
Figure 4.2: Components of R.C.C

4.1.3 COMPONENTS OF R.C.C. STRUCTURE:

• Slabs
• Beams
• Columns
• Footings
• Staircase

4.2 PHILOSOPHIES FOR DESIGN

OF R.C.C.

Three philosophies for design of reinforced concrete, pre stressed concrete as well as steel
structures.

• Working stress method

• Ultimate load method
• Limit state method.

General:
• working stress method was the principal method prevalent.
• Later on the ultimate load method came in use because of its more rational approach.
• There has been a transaction to limit state method because of its still more rational
approach.

ECO – RESORT 10
4.2.1 WORKING STRESS METHOD:

• Traditional method used for reinforced concrete design where it is assumed that
concrete is elastic, steel & concrete act together elastically the relationship between
loads and stresses is linear right up to collapse of structure.
• The basis of the method is that the permissible stress for concrete and steel are not
exceeded anywhere in structure subjected to working loads.
• The sections are designed in accordance with Elastic theory of
• Bending assuming that both materials obey Hooke’s Law.
• The Elastic Theory assumes a linear variation of strain and stress from zero at neutral
axis to maximum at extreme fibre

Figure 4.3: Stress – strain curve in working stress design

• Where, At = Area of tension steel

b = width of the section

C = total force of compression

D = depth of the section

d = effective depth

jd = lever arm

Nd = depth of natural axis

T = total force of Tension

Fcb = permissible compressive stress in concrete

Fst = permissible compressive stress in steel

Σc = compressive strain in concrete

Assumption:

ECO – RESORT 11
 • Bernoulli’s assumption stating, a section which is alpine before bending remains plain
after bending.
• Bond between steel and concrete is perfect within the elastic limit of steel.
• The tensile strength of concrete is ignored
• Concrete is Elastic; the stress varies linearly form zero at neutral axis to maximum at
the extreme fibre
• The modular ratio m has the value (280/3)

Draw backs:

• Concrete is not elastic. The inelastic behaviour of it starts right from very low
stresses. The actual stress distribution in a concrete section cannot be described by a
triangular stress diagram.
• since factor of safety is on stress under working loads, there is no way to account for
different degrees of different types of loads.
• With elastic theory, it is impossible to determine the actual factor of safety with
respect to loads.
• It is difficult to account for shrinkage and creep effects by using the working stress
method.

4.2.2 LIMIT STATE METHOD:

• Originated from ultimate or plastic design.

• Object of design is to achieve probability that a structure will not become
unserviceable in its lifetime for the use for which it is intended, it will not reach a
limit state.
• Structure should be able to withstand safety all loads that are liable to act on it
throughout its life and it should also satisfy the serviceability requirements, such as
limitations on deflections and cracking.
• Relevant limit states must be considered in design to ensure and adequate degree of
safety and serviceability.

4.2.3 LIMIT STATE OF COLLAPSE:

• The state corresponds to the maximum load carrying capacity.

ECO – RESORT 12
 • Violation of collapse limit state implies failure in sense that a clearly defined limit
state of structural usefulness has been exceeded.
• However, it doesn’t mean a complete collapse.
• This limit state may correspond to
Flexure
Compression
Shear
Torsion

4.2.4 LIMIT STATE OF SERVICEABILITY:

The state corresponds to development of excessive deformation and is used for checking
members in which magnitude of deformations may limit the use of structure or its
components.

This limit may correspond to

• Deflection
• Cracking
• Vibration
• Limit state design provides a unified rational basis for design of building structures of
all materials
• Expressed inequality

4.3 LIMIT STATE METHOD AND WORKING STRESS METHOD

• Design of reinforced concrete structural members involves the knowledge of loads

material properties and factor of safety.
• The parameters that involve the element of prediction are referred to as non-
deterministic and there is no guarantee that they will actually occur. This forms the
basis of limit state design.
• In limit state design, parameters are determined based on observations taken over a
period of time. These parameters will thus be influenced by change or random effect.
Such a process is referred to as a stochastic process.
• In limit state design, stress in an element are obtained from design loads (including
load factors) and compared with design strengths (including safety factors).
• In working stress design method the stresses in an element are obtained from working
loads and compared with permissible stresses.
• The main difference between two methods lies in the fat that in farmer, a member is
considered in its limit state. Where as in later in its working stage.

ECO – RESORT 13
 • Structural members designed on basis of permissible stresses using a factor of safety
regardless of different working conditions and load combinations actually had
different safety margins.
• Limit state method is based on physical parameters. The partial safety factors are based
on statistical and probabilistic grounds and can be controlled.
• Thus, it is a more scientific approach for the design of reinforced concrete structures.

Limit state of collapse(flexure):

Design for the limit state of collapse in flexure shall be based on assumptions given below:

• Plane sections normal to the axis of bending remain plane after bending.
• The maximum strain in concrete at the outermost compression edge is taken as 0.0035
in bending.
• The relationship between the compressive stress distribution and the strain in concrete
may be assumed to be rectangular, trapezoid, parabola or any other shape.

4.4 RULES FOR CALCULATING ROTATION CONTRIBUTIONS

• Case-1: Without sides way.

• Definition: “Restrained moment at a joint is the algebraic sum of FE.M’s of
different members meeting at that joint.”
.1 Sum of the restrained moment of a joint and all rotation contributions of the far
ends of members meeting at that joint is multiplied by respective rotation factors
to get the required near end rotation contribution. For the first cycle when far end
contributions are not known, they may be taken as zero (Ist approximation).
.2 By repeated application of this calculation procedure and proceeding from joint to
joint in an arbitrary sequence but in a specific direction, all rotation contributions
are known. The process is usually stopped when end moment values converge.
This normally happens after three or four cycles. But values after 2nd cycle may
also be acceptable for academic.
• Case 2: With side sway (joint translations)
• In this case in addition to rotation contribution, linear displacement contributions
(Sway contributions) of columns of a particular storey are calculated after every cycle
as follows:
• For the first cycle.
.1.1 → Linear Displacement Contribution (LDC) of a column = Linear
displacement factor (LDF) of a particular column of a story multiplied by
[storey moment + contributions at the ends of columns of that story]
• Linear displacement factor (LDF) for columns of a storey = −32
• Linear displacement factor of a column = −32k Σk Where k=stiffness of the column
being

ECO – RESORT 14
 • considered and Σk is the sum of stiffness of all
• columns of that storey.
• (B) → Storey moment = Storey shear x13of storey height.
• (C) → Storey shear: It may be considered as reaction of column at horizontal beam /
slab levels due to lateral loads by considering the columns of each sotrey as simply
supported beams in vertical direction. “If applied load gives + R value (according
to sign conversion of slope deflection method), storey shear is +ve or vice versa.”
(2000)

• Consider a general sway case.

4.5 TYPES OF LOADS

The loads are broadly classified as vertical loads, horizontal loads and longitudinal loads. The
vertical loads consist of dead load, live load and impact load. The horizontal loads comprises
of wind load and earthquake load. The longitudinal loads i.e. tractive and braking forces are
considered in special case of design of bridges, gantry girders etc.

4.5.1 DEAD LOAD:

Dead loads are permanent or stationary loads which are transferred to structure throughout
the life span. Dead load is primarily due to self weight of structural members, permanent
partition walls, fixed permanent equipment's and weight of different materials.

4.5.2 IMPOSED LOADS OR LIVE LOADS:

Live loads are either movable or moving loads with out any acceleration or impact. There are
assumed to be produced by the intended use or occupancy of the building including weights
of movable partitions or furniture etc. The floor slabs have to be designed to carry either
uniformly distributed loads or concentrated loads whichever produce greater stresses in the
part under consideration. Since it is unlikely that any one particular time all floors will not be
simultaneously carrying maximum loading, the code permits some reduction in imposed
loads in designing columns, load bearing walls, piers supports and foundations.

4.5.3 IMPACT LOADS:

Impact load is caused by vibration or impact or acceleration. Thus, impact load is equal to
imposed load incremented by some percentage called impact factor or impact allowance
depending upon the intensity of impact.

ECO – RESORT 15
4.5.4 WIND LOADS:
Wind load is primarily horizontal load caused by the movement of air relative to earth. Wind
load is required to be considered in design especially when the heath of the building exceeds
two times the dimensions transverse to the exposed wind surface.For low rise building say up
to four to five storeys, the wind load is not critical because the moment of resistance provided
by the continuity of floor system to column connection and walls provided between columns
are sufficient to accommodate the effect of these forces. Further in limit state method the
factor for design load is reduced to 1.2 (DL+LL+WL) when wind is considered as against the
factor of 1.5(DL+LL) when wind is not considered. IS 1893 (part 3) code book is to be used
for design purpose.

4.5.5 EARTHQUAKE LOAD:

Earthquake loads are horizontal loads caused by the earthquake and shall be computed in
accordance with IS 1893. For monolithic reinforced concrete structures located in the seismic
zone 2, and 3 without more than 5 storey high and importance factor less than 1, the seismic
forces are not critical. (875)

Figure 4.4 Sesmic load acting

ECO – RESORT 16
4.6 ANALYSIS

Slab loads will be transferred to beam’s equalant UDL’s by

• one way

𝑤𝑙𝑥
2

• two way
𝑤𝑙𝑥
3
𝑤𝑙𝑥 1
× 2
2 𝑙𝑦
1 − 3 ( ⁄𝑙 )
( 𝑥 )
Figure 4.5: Slab Analysis

• Beams are analysed as continuous beams and bending moments are arrived using
moment distribution method.
• Wherever equal spans and equal loading are there a protype beam was analysed and
adopted for remaining beams.
• Reaction’s from continuous beams were calculated and cumulated at each column
support of one floor and multiple by no. of floors to get total load of column at base.
• loads on footing are same as column’s loads at the base.
• Grouping is done for columns and footings accordingly to the loads.

ECO – RESORT 17
 5 CHAPTER

STAGES IN STRUCTURAL DESIGN:

The process of structural design involves the following stages.

• Structural planning.
• Action of forces and computation of loads.
• Methods of analysis.
• Member design.
• Detailing, Drawing and Preparation of schedules.

5.1 INSTRUCTURAL PLANNING

After getting an architectural plan of the buildings, the structural planning of the building
frame is done. This involves determination of the following. Position and orientation of
columns.

b. Positioning of beams.

c. Spanning of slabs.

d. Layouts of stairs.

e. Selecting proper type of footing.

5.1.1 POSITIONING AND ORIENTATION OF COLUMNS:

Following are some of the building principles, which help in deciding the columns positions.

1. Columns should preferably be located at (or) near the corners of a building, and at the
intersection of beams/walls.

2. Select the position of columns so as to reduce bending moments in beams.

3. Avoid larger spans of beams.

4. Avoid larger centre-to-centre distance between columns.

5. Columns on property line.

orientation of columns:

ECO – RESORT 18
1. Avoid projection of columns:

The projection of columns outside the wall in the room should be avoided as they not only
give bad appearance but also obstruct the use of floor space, creating problems in placing
furniture flush with the wall.

The width of the column is required to be kept not less than 200mm to prevent the column
from being slender. The spacing of the column should be considerably reduced so that the
load on column on each floor is less and the necessity of large sections for columns does not
arise.

5.1.2 POSITIONING OF BEAMS:

Beams shall normally be provided under the walls or below a heavy concentrated load to
avoid these loads directly coming on slabs.

Avoid larger spacing of beams from deflection and cracking criteria. (The deflection varies
directly with the cube of the span and inversely with the cube of the depth i.e. L3/D3.
Consequently, increase in span L which results in greater deflection for larger span).

5.1.3 SPANNING OF SLABS:

This is decided by supporting arrangements. When the supports are only on opposite edges or
only in one direction, then the slab acts as a one way supported slab. When the rectangular
slab is supported along its four edges it acts as a one way slab when Ly/Lx < 2.

The two way action of slab not only depends on the aspect ratio but also on the ratio of
reinforcement on the directions. In one way slab, main steel is provided along with short span
only and the load is transferred to two opposite supports. The steel along the long span just
acts as the distribution steel and is not designed for transferring the load but to distribute the
load and to resist shrinkage and temperature stresses.

A slab is made to act as a one way slab spanning across the short span by providing main
steel along the short span and only distribution steel along the long span. The provision of
more steel in one direction increases the stiffness of the slab in that direction.

According to elastic theory, the distribution of load being proportional to stiffness in two
orthogonal directions, major load is transferred along the stiffer short span and the slab
behaves as one way. Since, the slab is also supported over the short edge there is a tendency
of the load on the slab by the side of support to get transferred to the nearer support causing
tension at top across this short supporting edge.

Since, there does not exist any steel at top across this short edge in a one way slab
interconnecting the slab and the side beam, cracks develop at the top along that edge. The
cracks may run through the depth of the slab due to differential deflection between the slab

ECO – RESORT 19
and the supporting short edge beam/wall. Therefore, care should be taken to provide
minimum steel at top across the short edge support to avoid this cracking. A two way slab is
generally economical compare to one way slab because steel along both the spans acts as
main steel and transfers the load to all its four supports. The two way action is advantageous
essentially for large spans (>3m) and for live loads (>3kN/m2). For short spans and light
loads, steel required for two way slabs does not differ appreciably as compared to steel for
two way slab because of the requirements of minimum steel.

5.2 FOOTING
The type of footing depends upon the load carried by the column and the bearing capacity of
the supporting soil. The soil under the foundation is more susceptible to large variations.
Even under one small building the soil may vary from soft clay to a hard murum. The nature
and properties of soil may change with season and weather, like swelling in wet weather.
Increase in moisture content results in substantial loss of bearing capacity in case of certain
soils which may lead to differential settlements. It is necessary to conduct the survey in the
areas for soil properties. For framed structure, isolated column footings are normally
preferred except in case of exists for great depths, pile foundations can be an appropriate
choice. If columns are very closely spaced and bearing capacity of the soil is low, raft
foundation can be an alternative solution. For a column on the boundary line, a combined
footing or a raft footing may be provided.

5.3 ASSUMPTIONS
The following are the assumptions made in the earthquake resistant design of structures:
Earthquake causes impulsive ground motions, which are complex and irregular in character,
changing in period and amplitude each lasting for small duration. Therefore resonance of the
type as visualized under steady-state sinusoidal excitations, will not occur as it would need
time to build up such amplitudes.Earthquake is not likely to occur simultaneously with wind
or max. Flood or max. sea waves.

ECO – RESORT 20
 6 CHAPTER

METHODOLOGIES

This project is mostly based on software and it is essential to know the details about these

software’s. List of software’s used

1. Auto CAD

2. Microsoft Excel

3. STAAD.Pro

2.1 STAAD PRO

STAAD is powerful design software licensed by Bentley. STAAD stands for Structural
Analysis and Design. Any object which is stable under a given loading can be considered as
structure. So first find the outline of the structure, whereas analysis is the estimation of what
are the type of loads that acts on the beam and calculation of shear force and bending moment
comes under analysis stage. Design phase is designing the type of materials and its
dimensions to resist the load. This we do after the analysis.

To calculate S.F.D and B.M.D of a complex loading beam it takes about an hour. So, when it
comes into the building with several members it will take a week. STAAD pro is a very
powerful tool which does this job in just an hour’s STAAD is a best alternative for high rise
buildings.

Now a days most of the high-rise buildings are designed by STAAD which makes a
compulsion for a civil engineer to know about this software.

This software can be used to carry R.C.C, Steel, Bridge, Truss etc. according to various
country codes.

2.1.1 ALTERNATIVES FOR STAAD:

Struts, Robot, Sap, adds pro which gives details very clearly regarding reinforcement and
manual calculations. But these software’s are restricted to some designs only where as
STAAD can deal with several types of structure.

ECO – RESORT 21
2.1.2 STAAD EDITOR:

STAAD has very great advantage to other software’s i.e., STAAD editor. STAAD editor is
the programming for the structure we created and loads we taken all details are presented in
programming format in STAAD editor. This program can be used to analyze other structures
also by just making some modifications, but this require some programming skills. So, load
cases created for a structure can be used for another structure using STAAD editor.

2.1.3 LIMITATIONS OF STAAD PRO:

i. Huge output data

ii. Even analysis of a small beam creates large output.

iii. Unable to show plinth beams.

2.2 AUTOCAD
AutoCAD is powerful software licensed by auto desk. The word auto came from auto desk

company and CAD stand for Computer Aided Design. AutoCAD is used for drawing
different layouts, details, plans, elevations, sections and different sections can be shown in
AutoCAD. It is very useful software for civil, mechanical and electrical engineer. The
importance of this software makes every engineer a compulsion to learn this software’s. We
used AutoCAD for drawing the plan, elevation of a residential building. We also used
AutoCAD to show the reinforcement details and design details of a stair case. AutoCAD is a
very easy software to learn and much user friendly for anyone to handle and can be learn
quickly Learning of certain commands is required to draw in AutoCAD.

2.4. DESIGN PHILOSOPHIES

RC structures can be designed by using the following design philosophies

• Working stress method for serviceability

• Ultimate load method for safety

• Limit state method

ECO – RESORT 22
2.4.1 WORKING STRESS METHOD:

Working stress method was traditional method of design basically assumes that the structural
material behaves in a linear elastic manner, and that adequate safety can be ensured by
restricting the stresses induced in the material by the expected working loads (service loads)
on the structure. Permissible stresses are kept well below the material strength. The ratio of
strength of the material to the permissible stresses is referred to as the “Factor of safety “. The
design usually results in relatively large section of structural members (comparative U.L.M)
there by resulting in better serviceability, performance under the usual working loads. This
method is notable for its essential simplicity in concept as well as in application.

2.4.2 ULTIMATE LOAD METHOD (ULM):

The ultimate load method design, the stress condition at the stage of impending collapse of
structure is analysed and the non - linear stress strain curves of concrete and steel are made
use of, the safety measures in design is introduced “Load factor “which is the ratio of
ultimate load (design load) to working load. This method generally results in more slender
sections and often more economical designs when compared to WSM, particularly when high
strength steel and concrete are used.

2.4.3 LIMIT STATE METHOD (LSM):

Limit state method is judicious amalgamation of WSM and ULM removing all drawbacks of
both methods but maintaining their good points. LSM aims for a comprehensive and rational
solution to design problems by considering safety at ultimate loads and serviceability at
working loads. The structures shall be designed to carry design loads safety throughout its
life and satisfy the serviceability requirements such as limitations on deflection and cracking.
The acceptable limit for safety and serviceability requirements before failure occurs is called
a “Limit state “. The aim of design is to achieve acceptable probabilities so that the structures
will not become unfit for the use for which it is intended.

There are two types of limit states:

Limit state of collapse: Deals with strength, overturning, sliding, buckling, fatigue, fracture
etc.,

Limit state of serviceability: Deals with comfort to accompany and malfunction, caused by
excessive deflection, crack width, vibration etc., and loss of durability etc.,

ECO – RESORT 23
2.5 METHOD OF ANALYSIS:

Structural analysis involves the determination of internal forces like axial forces, bending
moments, shear forces etc., in the component members for which these members are to be
designed under the action of given external loads.

The different approaches to structural analysis are as given below:

• Elastic analysis based on elastic theory.

• Limit analysis based on plastic theory or ultimate load theory.

In this project, an elastic analysis has been adopted.

Elastic analysis deals with the study of strength and behaviour of members and structures at
working loads. The elastic analysis is based on the following assumptions:

• Relation between force and displacement is linear.

Displacements are extremely small when compared to the geometry of the structure.

ECO – RESORT 24
 7 CHAPTER

PLAN AND ELEVATION

7.1 PLAN
The auto cad plotting no.1 represents the plan of the Cottage. The block is located at
Lambasingi. In block the entire floor consists of a various room which occupies most of the
floor area.

The plan shows the details of dimensions of each and every room and the type of room and
orientation of the different rooms like bed room, bathroom, living area, etc. The entire plan
area is about 304 sqm. The block only has ground floor.

FLOOR PLAN

ECO – RESORT 25
7.2 ELEVATION DIAGRAM ON STAAD Pro
The figure below represents the Elevation line diagram of the building in STAAD Pro. Each
support represents the location of different columns and beams in the structure. The lines
parallel to X- axis and Z- axis represent beams and the lines parallel to Y-axis represent
columns. The software is used in generating the entire structure using a tool called
transitional repeat and link steps. After using the tool, the structure created can be analysed in
STAAD Pro under various loading cases.

Below figure represents the skeletal structure of the building which is used to carry out the
analysis of our building.

All the loadings are acted on this skeletal structure to carry out the analysis of the building.
This is not the actual structure but just represents the outline of the building in STAAD Pro.
A mesh is automatically created for the analysis of these building.

3D RENDERED VIEW

ECO – RESORT 26
 8 CHAPTER

COLUMNS

8.1 COLUMNS POSITIONING

• Columns should preferably be located at (or) near the corners of a building, and at the
intersection of beams/walls.

• Select the position of columns to reduce bending moments in beams.

• Avoid larger spans of beams.

• Avoid larger centre-to-centre distance between columns.

8.2 ORIENTATION

• Avoid projection of columns

• Orient the column so that the depth of the column is contained in the major plane of
bending or is perpendicular to the major axis of bending.

COLUMN CENTRELINE

ECO – RESORT 27
8.3 INTRODUCTION
A column or strut is a compression member, which is used primary to support axial
compressive loads and with a height of at least three it is least lateral dimension. A reinforced
concrete column is said to be subjected to axially load when line of the resultant thrust of
loads supported by column is coincident with the line of C.G of the column in the
longitudinal direction.

8.4 DESIGN OF COLUMN

The design of column involves the following steps.

1. Categorization of columns
• Internal columns or axially loaded columns
• Side columns or Columns subjected to axial load and uniaxial bending
• Corner columns or columns subjected to axial load and biaxial bending

2. Computation of floor loads

• Exact method
• Approximate method
• Assessment of unit loads of Slab, Wall, Column
• Assessment of total load on column in each storey
• Marking of column load transfer areas
• Calculation of loads are each floor level

3. Calculation of moment in columns

• Exact method
• Approximate method

4. Determination of effective length and type of column – short or long

5. Grouping of columns

6. Design of column section

Appropriate equivalent axial load method

• Preliminary design
Allowance for moment in column

Allowance for slenderness of column

Calculation of total equivalent axial design load

Section design

Check for moment in column

ECO – RESORT 28
 • Exact theoretical method
Axially loaded short columns

Short columns under combined axial load and uniaxial bending

Short columns under combined axial load and biaxial bending

Slender columns

8.5 DESIGN OF A COLUMN

ECO – RESORT 29
 DEFLECTION SHEAR BENDING

DESIGN OF A COLUMN

STEP 1

Pu = 41.93 KN

Mux = 5.22 KN-m

Muy = 58.39 KN-m

fck = 25 N/mm

fy = 500 N/mm²

d’ = 25

STEP 2

As per IS:456, the area of longitudinal steel in a column shall not be less than 0.8% nor
exceed more than 6% of gross areas.

Assuming that, asc=3% of ag

ac= ag-0.03ag = 0.97ag

Calculating the gross area of the column:

Puz = 0.45*fck*ac+0.75*fy*asc

41.93 x 103 = 0.45 x 25 x (0.97ag) + 0.75 x 500 x 0.03ag

ag = 1892.14 mm2

Length of the column = 4 m

ECO – RESORT 30
leff = 0.65 x L

= 0.65 x 4

= 2.6 m = 2600 mm

For column to be designed as short column, leff/b < 12

b ≥ leff/12

b ≥ 2600/12

b ≥ 216.6 mm

Consider the section b = 300mm d = 300mm

asc = 0.03 ag = 0.03 x 300 x 300

asc = 2700 mm2

Assuming 16 mm dia. bars,

No of bars = asc/(area of single bar)

n = 2700/(π/4 12^2 )

n=8

Design of lateral Reinforcement:

Diameter of lateral tie = ¼ (longitudinal bar dia.)

= 2 mm

(As Per design guidelines, in no case shall the lateral reinforcement bar dia. can be less than 6
mm)

Therefore, Consider diameter of Ties = 6mm

Maximum spacing

1) b = 300mm

2) 16*longitudinal bar dia. = 256mm

3) 300mm

Considering one of the above three values

Provide 6mm dia. bars as lateral ties @ 300mm c/c.

ECO – RESORT 31
 9 CHAPTER

BEAMS

9.1 POSITIONING OF BEAMS

PRIMARY BEAMS:

• The beams that are connecting columns for transferring loads of a structure directly to
the columns are known as primary beams.

SECONDARY BEAMS:

• The beams that are connecting primary beams for transferring loads of a structure to
the primary beams are known as primary beams.

• These beams are provided for supporting and reducing the deflection of beams and
slabs.

BEAM CENTRELINE

ECO – RESORT 32
9.2 INTRODUCTION
A reinforced concrete beam should be able to resist tensile, compressive and shear stress in it
by loads on beam. Concrete is strong in compression but very weak in tension. Plane concrete
beams are thus limited in carrying capacity by load tensile strength. Steel is very strong in
tension. Thus, tensile weakness of concrete is to overcome by provision of reinforcing steel in
the tension zone around the concrete to make reinforced concrete beam.

9.3 TYPES OF BEAMS

There are 3 types of beams.

• Singly reinforced beams.

• Doubly reinforced beams.

• Flanged beams.

8.3.1 SINGLY REINFORCED BEAMS:

In these beams reinforcing steel bars are placed near bottom of the beam where they are more
effective in resisting tensile bending stresses. In singly reinforced cantilever beams
reinforcing bars are placed near the top of the beam.

8.3.2 DOUBLE REINFORCED BEAMS:

These beams are reinforced both in compression and tension r4egions. The section of beam
may be rectangular, T or L section. The necessity of using steel in compr4ession zone due to

1. When depth of the beam is restricted the strength available from a singly reinforced
beam is inadequate.

2. At support of continuous beam where bending moment changes sign.

8.3.3 FLANGED BEAMS:

In most reinforced concrete structures, concrete slabs and beams are cast monolithic. Thus,
beam from part of floor system together with slab. In bending the slab forming the top part of
the beam at mid-span would be in compression for a definable width greater than width of the
rib. Thus, increasing the moment of resistance for given rib width. At continuous supports the
position is reversed. The slab in tension and part of it have cracked in tension, this beam is
equivalent to rectangular section at support.

ECO – RESORT 33
9.4 DESIGN OF BEAMS
Reinforced concrete beams are structural elements that designed to carry transverse external
loads. The loads cause bending moment, shear forces and in some cases torsion across their
length.

Moreover, concrete is strong in compression and very weak in tension. Thus, Steel
reinforcement used to take up tensile stresses in reinforced concrete beams.

Furthermore, beams support the loads from slabs, other beams, walls, and columns. They
transfer the loads to the columns supporting them.

Additionally, beams can be simply supported, continuous, or cantilevered. they can be

designed as rectangular, square, T-shaped, and L-shaped sections.

Beams can be singly reinforced or doubly reinforced. The latter are used if the depth of the
beam is restricted.

Finally, in this article, the design of rectangular reinforced concrete beam will be presented.

9.5 DESIGN GUIDELINES

Prior to the design of reinforced concrete beam begin, there are certain assumption that need
to be made.

IS CODE PROVISIONS

1. The loading on beam is as taken as per clause 24.5 of IS:456-2000.

2. For continuous beam with equal/unequal spans and equal/unequal loads, the bending
moment is obtained by using Kani’s method.

3. Effective span and effective depth of beam is same as explained in slab provisions.

4. The beams at mid span are designed as T-beams and the same steel reinforcement is
provided for all beams and it is minimum.

At supports when the moment of resistance exceeds balancing moment, the section is
designed as a double reinforced section.

Minimum r4einforcement I tension shall not be less than Ast/bd=0.85/Fy.

(clause 26.5.1.1(a)).Minimum reinforcement in tension shall not exceed 0.04bxD. (clause
26.5.1.1(b)).

Maximum area of compression n reinforcement shall not exceed 0.04bxD and

reinforcement is enclosed by strength side. (clause 26.5.1.2).

ECO – RESORT 34
 Nominal shear stress for uniform depth shall be τv=vu/bd. ( clause 40.1)
Minimum shear reinforcement will be provided when τv<τc given in table-19.
Maximum spacing of shear reinforcement shall not exceed the least of 0.75d or 300
mm for vertical stirrups (clause 26.5.1.5).

Shear reinforcement will be provided to carry a shear equal to Vu- τc bd . The strength
of shear reinforcement Vs shall be calculated for vertical stirrups.

Vs = (0.87 Fy Asv d)/Sv

At least 1/3rd positive moment reinforcement in simple beam and 1/4th positive
moment reinforcement in continuous beam shall extend along the same phase of the member
to the support to a length equal to Vu/3 (clause 26.2.2.3).

Specifications regarding spacing of stirrups placed in doubly reinforced beams:

Compression steel placed in doubly reinforced beams also had to be restrained against local
buckling during its action like the compression steel. Accordingly, the diameter of the
stirrups should be 6 mm.

DESIGN OF BEAM

ECO – RESORT 35
 DEFLECTION SHEAR BENDING

STEP 1

Self-weight of the beam = width of the beam X overall depth of the beam X density of R.C

= 0.3 x 0.3 x 25 = 2.25 kN/m

Dead+ load considered for the beam = 10.625 KN/m

Live load = 2 kN/m

Total load (w) = 15.068 kN/m

Bending moment (M) =(wl^2)/8

= (15.068 x 〖5.281〗^2)/8 = 52.52 kN-m

Factored Moment (M.R) = 52.52 x 1.5 = 78.79 kN-m

ECO – RESORT 36
STEP 2

ASSUMING UNDER REINFORCED SECTION:

f y Astx
M. R = 0.87 fy Astx (d- )
f ckb

At = 613.465 mm2

Actual depth:
0.87 𝑥 613.465 𝑥 415
X= = 107mm
0.36 𝑥 25 𝑥 230

0.0035𝑑
Xm = 0.87 𝑓𝑦 = 205.73mm.
0.0055+
𝐸𝑠

X<Xm, The X value is less than Xm, hence the assumption is correct.

We now have to find At (min) and At (max)

0.85𝑏 𝑑 0.85 𝑥 230 𝑥 400
At(min) = =
𝑓𝑦 415

= 188.435 mm2

At (max) = 0.04bd = 3200 mm2

At (min) < At (provided) < At (max), Hence safe.

STEP 3

Let the diameter of the steel bars be 12mm

𝐴𝑡 613.465
Number of bars = = 𝜋 = 4.05, hence 4 bars
𝑎𝑠𝑡 x 162
4

Hence 4 bars of 12mm diameter are used in the beam design.

ECO – RESORT 37
 10 CHAPTER

SLAB

Slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs,
bridges, and other types of structures. The slab may be supported by walls, by reinforced
concrete beams usually cast monolithically with the slab, by structural steel beams, by
columns, or by the ground. The depth of a slab is usually very small compared to its span.

10.1 CLASSIFICATION OF CONCRETE SLABS

In general, slabs are classified as being one-way or two-way. Slabs that primarily deflect in
one direction are referred to as one-way slabs. When slabs are supported by columns
arranged generally in rows so that the slabs can deflect in two directions they are usually
referred to as two-way slabs.

10.1.1 ONE-WAY AND TWO-WAY SLABS:

One more definition regarding one-way and two –way slab is that if one direction span to
other direction span ratio (or more precisely if longer dimension to shorter dimension ratio) is
greater than 2 it is termed as two-way slab, otherwise if less than two it is termed as two-way
slab.

ECO – RESORT 38
10.2 CLASSIFICATION OF TWO-WAY SLABS

10.2.1 FLAT SLABS:

Flat slabs include two-way reinforced concrete slabs with capitals, drop panels, or both.
These slabs are very satisfactory for heavy loads and long spans. Although the formwork is
more expensive than for flat plates, flat slabs will require less concrete and reinforcing than
would be required for flat plates with the same loads and spans. They are particularly
economical for warehouses, parking and industrial buildings, and similar structures, where
exposed drop panels or capitals are acceptable.

10.2.2 FLAT PLATES SLAB:

These are solid concrete slabs of uniform depths that transfer loads directly to the supporting
columns without the aid of beams or capitals or drop panels.

Slabs are also designed as per IS456-2000

ECO – RESORT 39
 SLAB DESIGN OF ENTIRE FLOOR

10.3 DESIGN OF TWO WAY SLAB

Slab: S1 = 4200 x 3400 mm

Edge Condition = “Two adjacent edges are discontinuous”
Clear span in shorter direction (Lx) = 3.40 + 0.125 = 3.525m
Lear span in longer direction (Ly) = 4.20 + 0.125 = 4.325m
Width of support = 230 mm
Grade of materials:
Concrete = M25 ; Steel = fe415
Side ratio:
ly 4325
= = 1.230 <2.0
l x 3525
Hence designed as a Two way Slab

The code considers a slab is divided in each direction into middle strips and edge strips.
The width of the middle strip = 3/4th of the span and
the width of edge strip = 1/8th of span

From Indian Standards code book:

Using interpolation we get the values of x and y

ECO – RESORT 40
x = 0.0867 and y = 0.0578

LOADS:

Live load = 2 KN/m2

Floor finish = 1.5 KN/m2

Dead load = 0.125 x 25 = 3.125 KN/m2

Total load = 6.625 KN/m2 x 1 m = 6.625 KN/m

Factored load =1.5 x 6.625= 9.9375 KN/m

BENDING MOMENT:
Shorter span
Mx = xwlx2 = 0.0867 x 9.9375 x 3.5252

= 10.7 kN-m.

My = ywlx2 = 0.0578 x 9.9375 x 3.5252

= 7.37 kN-m

As Mx is maximum, Using the higher value of bending moment, the effective depth of slab is
calculated.

BM = 0.36 fck b xm (d-0.42xm)

10.7 x 106= 0.36 x 1000 x 0.48d x 25 (d-0.42 x 0.48d)

3102.269 = d2

d = 55.69 = 60mm ≈ 80mm

Taking Clear cover as 20mm

The depth calculated above is too small to be safe in deflection; hence we are increasing the
value of depth.

Hence d = 130 mm and D = 150 mm

CALCULATION OF REINFORCEMENT

Equating,

Total compressive force = Total Tensile force

Reinforcement in middle strip:

Steel along shorter span,

ECO – RESORT 41
X- Direction:

0.36 fck b xm = 0.87 fy Astx

0.36 x 25 x 1000x 0.48 x 130 = 0.87 x 415 x Astx

Astx = 1555.46 mm2

Adopt 10mm diameter bars:

𝜋
a st 𝑥 102
Spacing =  1000 = 1555.46
4
× 1000
Ast

= 50.4 = 50 mm

1555.46
Number of bars = = 19.8 = 20 bars

x10 2
4

Provide 20 - 10mm diameter bars with 50 mm c/c spacing.

Y-direction:

The area of steel Asty is calculated by

BMy = Force of tension x Lever arm

f y Astx
BMy =0.87 fy Astx (d’- )
f ckb

Providing 8mm diameter bars,

10 8
d’ = d – - 2 (10mm and 8mm diameter respectively)
2

d’ = 130 – 5 – 4 = 121 mm
415 𝑥 𝐴𝑠𝑡𝑦
7.137 x 106 = 0.87 x 415 x Asty (121 – 25 𝑥 1000
)

Hence, Asty = 167.1 mm2

𝜋
𝑥 82
Spacing = 4167.1 × 1000 = 300mm

167.1
Number of bars = = 3.32 = 4 bars

x8 2
4

Provide 4 - 8mm diameter bars at 300 mm c/c spacing.

Reinforcement in edge strip:

ECO – RESORT 42
As per IS code, a minimum reinforcement of 0.12% of the total cross-section of area should
be provided along the edge strips

= 0.12% x bD

= 0.0012 x 1000 x 150 = 180 mm2.

𝜋
a l 𝑥 82 𝑥 3525
Spacing along shorter span = st x x = 4

Ast 8 180 𝑥 8

= 122.98 = 120mm
𝜋
a st l y 4
𝑥 82 𝑥 4325
Spacing along longer span = x = = 150.89 = 150 mm
Ast 8 180 𝑥 8

As per IS code the spacing should be < 3d = 390

Hence safe.

Corner Reinforcement (or) Tension Reinforcement:

The Area of torsion reinforcement = 75% of the area required for maximum mid span
moment and this should be provided for a length of 1/5th of effective span.
3
Torsional reinforcement area = 75% of Atx = x 1555.46 = 1166.59 mm2
4

𝑙𝑥 3525
Shorter span: = = 725mm
5 5

𝑙𝑦 4325
Longer span: 5 = = 865mm
5

𝜋
𝑥 82 𝑥 725
4
Spacing Lx: = 31.22 mm = 30mm with diameter of 8mm
1166.59

𝜋
𝑥 82 𝑥 865
4
Spacing Ly: = 37.2 = 35 mm with diameter of 8mm.
1166.59

Check for development length:

Shorter span:
𝑀1
Ld ≤ + Lo
𝑉

∅ 𝜎
Ld = 4τb 𝑠
d

τ𝑏𝑑 =1.6 x 1.2 (60% increase for HYSD)

10 x 0.87 x 415
= 4 x 1.2 x 1.6
= 470.11mm = 0.47m

Let Lo = 0

ECO – RESORT 43
 f y Astx
M1 = 0.87 fy Astx (d- )
f ckb

1 415 𝑥 1555.46
=0.87x 415 x 1555.46 x 2 (130 – )
2 𝑥 25 𝑥 1000

= 32.87 kN-m
𝑤𝑙𝑥 9.9375 𝑥 3.525
Shear Force (V) = = = 17.51KN
2 2

𝑀1 32.87
= 1.3 x = 2.43m
𝑉 17.51

𝑀1
Ld ≤ , hence it is safe.
𝑉

Longer span:
∅ 𝜎
Ld = = 4τb 𝑠
d

τ𝑏𝑑 =1.6 x 1.2 (60% increase for HYSD)

8 x 0.87 x 415
= =376.08 mm = 0.38 m
4 x 1.2 x 1.6

M1= 0.87 x 415 x 167.1 x 1/2 (100 – (415 x 167.1)/(2 x 25 x 100) )

= 3.87 kN-m

V = (9.9375 x 4.325)/2 = 21.48

M_1/V =1.3 x 3.87/21.48 = 0.23 m, Hence it is not safe.

L-Bend = 0.23 + 0.8 = 0.31 m

U-Bend = 0.31 + 0.8 + 0.3= 0.42 mm

Ld ≤ M_1/V , Hence U-bend is safe.

Check for deflection:

X-Direction:

l_x/d < 20 = (3525 )/130 = 27.11 > 20

Hence tension reinforcement is necessary.

% of tension reinforcement = A_(tx )/bd x 100= 1555.46/(1000 x 100) x 100 = 1.55%

fs = 0.58 x 415 = 240 N/mm2

Modification factor = 0.9

l/d = 20 x 0.9 = 36

ECO – RESORT 44
27.11 < 36, hence safe

Y-Direction:

l_y/d = 4325/130 = 33.27 > 20

Hence % tension reinforcement required = ( A_ty)/bd x 100 = 1166.59/(1000 x 100) x 100

= 0.16%

Modification factor = 1.8

l_y/d= 20 x 1.8 = 36

33.27 < 36, Hence it is safe in deflection.

SLAB PANEL

SLAB DESIGN

ECO – RESORT 45
 CORNER STRESSES IN SLAB

ECO – RESORT 46
 11 CHAPTER

FOOTINGS

11.1 INTRODUCTION
Foundations are structural elements that transfer loads from the building or individual column
to the earth. If these loads are to be properly transmitted, foundations must be designed to
prevent excessive settlement or rotation, to minimize differential settlement and to provide
adequate safety against sliding and overturning.

Isolated Rectangular Footing

Column size = 300 mm x 300mm
Grade of Materials:
fck =25N/mm2; fy = 500N/mm2.
Available Data:
Load from the column (Pu ) = 850kN
Bearing capacity of soil (fb) = 300kN/mm2
DESIGN:
Load from column (Pu) = 850kN
Self wt. of footing 10% of Pu = 85 kN
Total load on footing = 935kN
Pu
Area of footing Af =
fb

935
= = 3.74m2
250
300
Length to breadth ratio of = = 1; i.e.; D = 1 b
300
column

The same ratio is followed for footing also i.e.; L = 1B

From the ratio,
Lf = 1.696m  1.80m
Bf = 2.20m  2.20m
Area of footing provided = 3.96m2> 3.74m2
Hence safe.

ECO – RESORT 47
 1.5 x935
Net upward soil pressure for factored load (wu) = =354.16kN/m
3.96

DEPTH OF FOOTING FROM BENDING CONSIDERATION:

The Critical section for Bending Moment occurs at the face of the column.

Maximum Bending Moment along longitudinal direction,

wu x 2
BM x=
2

Lf − b
Here x=
2

354.16 x 2.2 x 0.7852

= 2

= 240.07 kN-m

Maximum Bending Moment along transverse direction

wu y 2
BMy =
2

Bf − D
Here y=
2

354.16 x 1.8 x 0.952

= 2

= 287. 62 kN-m.

Consider higher moment value of above two

So maximum Bending Moment=287.62kN-m.

Effective depth is calculated for this moment value

BM = 0.36 x fck x b x o.48d (d-0.42xm)

For Fe 500 xm =0.48 d

ECO – RESORT 48
287.62 x 106 = 0.36 x 25 x 1800 x0.798d2

D=215mm

The above value of depth obtained is very low from shear consideration.

Hence increase the value by 335mm.

D=215+335=550mm

Provide effective cover = 50 mm

Overall depth D = 600mm.

Area of steel required:

f y Astx
BMx =0.87 x fy x (Ast) x (d- )
f ckb

415xAstx
287.62 x 106 =0.87 x 500 x (550- )
25 x1800

Astx = 1485.4 mm2

Adopt 10mm diameter bars,
π
x 102
4
Spacing = 1446.118 × 1800

= 95 mm c/c
Provide 10mm bars @ 95mm centre-to-centre.
Area of steel alloy in transverse direction,
240.47 x 106 = 0.87 x 415 x Asty [540 – 7.54 x 10-3 Asty]
Asty = 1206.15 mm2
Adopt 10mm diameter bars,
π
x 102
4
Spacing = 1026

= 160.65 mm = 160 mm c/c

Provide 10mm bars @ 160mm centre-to-centre.
Check for 1-way shear:

ECO – RESORT 49
The critical section for one way shear occurs at a distance‘d’ from the face of the column.
The maximum shear force, Vu = w. x1.
Where, x1 = 0.95 – d = 0.95 – 0.55 = 0.40 m
Vu = 354.16 x 1.8 x 0.40
= 254.99 KN
Nominal shear stress,
V
Ʈv = bu
d

254.99 x 102
= 1800 x 550

= 0.26 N/mm2
A
Actual shear force p = b xstd x 100
1485.4
p = 1800 x 550 x 100

p = 0.15 %
From IS 456, for M25 grade Concrete at p = 0.15%, c = 0.29 N/mm2
Ʈv< Ʈ c
Hence, footing is safe in one way shear.
Check for 2-way shear:
The critical section for 2-way shear occurs at a distance of‘d/2’ along the periphery of the
column.
Vu = [(1.8 x 2.2) – (0.78 x 0.85)] x 354.16
= 1167.67 KN
Nominal shear stress,
Vu
Ʈv = b
o d

1167.66 x 103
= 3260 x 550

= 0.651 N/mm2

Actual shear stress,

Ʈ c´= k s x Ʈ c

Where, k s = 0.5 + Ʈ c, < 1

ECO – RESORT 50
 shorter side of column
Ʈc= longer side of column

Ʈ c = 230/300 = 0.77
K s = 0.50 + 0.77, < 1
So, ks =1.
Ʈ c´= 1 x Ʈ c

Where, Ʈ c = 0.25√fck

= 0.25√25
= 1.25 N/mm2
Ʈ v < Ʈ c’
Hence, footing is safe in one way shear.
Check for development length:
∅ x σs
ld = 4τbd

10 x 361
= 4τbd

For M15 grade concrete, τbd = 1.4 N/mm2.

Therefore, τbd =1.6 x 1.4 (60% increase for HYBP)

10 x 361
ld = 4x1.6x1.4

= 402.90 mm
Where, ld = Development length.
Available length along x-direction = 785 – 50 = 735
Available length along y-direction = 950 – 50 = 900
ld < available
Hence, the footing is safe in bond.
Check for load transfer:
Factored Load
Nominal Bearing stress in column, σbr = Area of column

1.5 x 850 x 103

= 230 x 300

= 17.06 N/mm2.

Allowable Bearing stress = 0.45 σu

ECO – RESORT 51
 = 0.45 x 25 = 11.25 N/mm2.
Since, Nominal Bearing stress > Allowable Bearing stress, it is unsafe. Hence, extra steel has
to be provided.
Excess Load, P = (18.47- 11.25) x 230 x 300
= 400.89 kN.
Excess load
Excess steel = 0.67σy

400.89 x 103
= 0.67 x 415

= 1441.79 mm2.
Using 16mm diameter bar,
1441.79
No. of bars = π =6
x 162
4

ECO – RESORT 52
12 SUMMARY
S.no Structural Element Specification
1 Foundation Pile Foundation
2 columns Square column
Size:300mmx300mm
Reinforcement Details:
• 16mm∅ bars#8no
• 6mm lateral ties at pitch of 300mmc/c

3 Beams Singly Reinforced Beam

Size:300x300mm
Reinforcement Details: 12mm Ø bars#4no.
4 Slabs Two- Way slabs
Depth 150mm
Reinforcement Details: 20-10mm Ø bars@50c/c in
X- direction.
4-8mm Ø bars@300c/c in Y- direction.

5 Footing Depth of the footing 550 mm

Area of footing – 3.74 meter square
Reinforcement Details:
10mm bars @ 95mm centre-to-centre.
steel alloy in transverse direction
10mm bars @ 160mm centre-to-centre.

CONCLUSION

Structurally a building may consist of load bearing walls and floors. The floor
slabs may be supported on beams which in turn may be supported on walls or
columns. But for a multi-storied structure, a building frame either of steel or
reinforced concrete is made. This frame is designed for all the vertical and
horizontal loads transmitted to it. The openings between the columns that are
provided for certain equipment needs, where necessary, will be filled with thin

ECO – RESORT 53
brick walls. A frame of this type will consist of columns and beams built
monolithically forming a network. This provides rigidity to the connections of
members. By this arrangement the bending moments for the members of the
structures are reduced. Earthquake loads and other horizontal loads due to wind
etc. are evenly distributed to the whole structure. This makes the structure not
only safe but economical.

ECO – RESORT 54