EARTHQUAKE RESISTANT

CONSTRUCTION
BY
Name Enrollment No.
Shreyash Arsul 2001250001
Pruthvi Kondhare 2001250023
Chaitanay Vishwe 2001250029
Omkar Mokashi 2001250020
Sahil Shinde 2001250026
Amruta Fadtare 2001250008
Under Guidance : NISHANT UPADHYE
 INTRODUCTION

• WHAT IS EARTHQUAKE ?

• Earthquake is a natural phenomenon occurring with all uncertainties.

• During the earthquake, ground motions occur in a random fashion,
both horizontally and vertically, in all directions radiating from
epicenter.
• These cause structures to vibrate and induce inertia forces on them.

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PRINCIPLE OF EARTHQUAKE-
RESISTANT DESIGN

• The building shall withstand with almost no damage to moderate

earthquake which have probability of occurring several times during life of
a building.
• The building shall not collapse or harm human lives during severe
earthquake motions, which have a probability of occurring less than once
during the life of the building.

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RULES FOR BUILDING DESIGN

• The configuration of the building (Plan and elevation)

should be as simple as possible.
• The formation should generally be based on hard and
uniform ground.
• The members resisting horizontal forces should be
arranged so that torsional deformation is not produced.
•  The structure of the building should be dynamically
simple and definite.
• The frame of the building structure should have adequate 

ductility in addition to required strength.

CLASSIFICATION OF EARTHQUAKE

• Slight: Magnitude up to 4.9 on the Richter Scale

 
• Moderate: Magnitude 5.0 to 6.9

• Great: Magnitude 7.0 to 7.9

• Very Great: Magnitude 8.0 and above

SEISMIC DESIGN PHILOSOPHY
FOR BUILDINGS

• Severity of ground shaking at a given location during an earthquake can be minor, moderate
and strong
• Relatively speaking, minor shaking occurs frequently, moderate shaking occurs occasionally
and strong shaking rarely
• As we know that the life of the building itself may be only 50 or 100 years, a conflict arises:
whether to design the building to be “earthquake proof” where in there is no damage during the
strong but rare earthquake shaking or should we do away with the design to building
• Hence, the design philosophy should lie somewhere in between these two extremes
SEISMIC RISK TO BUILDING IN INDIA

• The construction may generally be classified into two types:

1. Non-Engineered Construction: Ex un reinforced brick masonry, stone masonry.

2. Semi -Engineered Construction: Ex Reinforced brick masonry

3. Engineered Construction: Ex Reinforced Concrete framed structures or steel structures.

CLASSIFICATION OF SEISMIC ZONES IN INDIA
• Non-Engineered buildings are those which are spontaneously and informally constructed in
various countries in the traditional manner without any or little intervention by qualified architects
and engineers in their design.

• Such buildings involve field stone, fired brick, concrete blocks, adobe or rammed earth, a
combination of wood with these traditional locally available materials in their construction

• The design frequently adopted in a non-engineered manner is , without taking into consideration
the stability of the system under horizontal seismic forces.

• Masonry buildings of all types, except those constructed with earthquake resisting elements, are
at the greatest risk of heavy damage in seismic zone III and of destruction to collapse in zones IV
and V.
INDIAN SEISMIC CODES

• IS 1893-2002, Indian Standard Criteria for Earthquake Resistant Design of Structures

(5thRevision)
• IS 4326-1993, Indian Standard Code of Practice for Earthquake Resistant Design and
Construction of Buildings (2ndRevision)
• IS 13827-1993, Indian Standard Guidelines for Improving Earthquake Resistance of Low
Strength Masonry Buildings
• IS 13920-1993, Indian Standard Code of Practice for Ductile Detailing of Reinforced Concrete
Structures Subjected to Seismic Forces
SEISMIC EFFECTS ON STRUCTURE

Inertia Forces in structure

Horizontal and Vertical Shaking
CAUSES OF EARTHQUAKE DAMAGE

• Heavy dead weight and very stiff buildings, attracting large seismic
• inertia forces.
• Very low tensile and shear strength, particularly with poor mortars.
• Brittle behavior in tension as well as compression.
• Weak connection between wall and wall & roof and wall.
• Stress concentration at corners of doors and windows.
• Overall un symmetry in plan and elevation of the building
• Un symmetry due to imbalance in the sizes and positions of openings in the wall.
• Defects in construction, such as use of sub standard material unfilled joined between bricks.
REINFORCEMENTS IN MASONRY BUILDING

• The walls, if constructed with plain masonry would be incapable of resisting the magnitude of
horizontal shear and bending forces imposed on them during earthquakes.
• For this reason, in the modern reinforced masonry systems, reinforcing steel is incorporated to
resist the shear and tensile stresses, so developed.
• When these walls are subjected to lateral forces acting on them,they behave as flexural
members spanning vertically between floors and horizontally between pilasters/ lateral walls.
• Therefore reinforcement in both vertical and horizontal directions is required to be provided to
develop resistance against tension.
ROLE OF HORIZONTAL BANDS

• Plinth band: This should be provided in those

cases where the soil is soft or uneven in their
properties, as it usually happens in hilly areas.
This band is not too critical.
• Lintel band: This is the most important band
and covers all door and window lintel.
• Roof band: In buildings with flat reinforced
concrete or reinforced brick roofs, the roof
band is not required because the roof slab
itself plays the role of a band. However, in
buildings with flat timber or CGI sheet roof, a
roof band needs to be provided. In buildings
with pitched or sloped roof, the roof band is
very important.
• Gable band: It is employed only in buildings
with pitched or sloped roofs
•
LINTEL BANDS

• Lintel bands ties the walls together and creates a support for
walls loaded along weak direction from walls loaded in strong
direction
•  This band also reduces the unsupported height of the walls
and there by improves their stability in the weak direction
Design Of Lintel Band
IS SPECIFICATION FOR LINTEL BAND

The Indian Standards

IS:4326-1993 and IS:13828-1993 provide sizes and details of the bands.
• When wooden bands are used, the cross-section of runners is to be at
least 75mmx38mm and the spacers at least 50mmx30mm.
• When RC bands are used the minimum thickness is 75mm, and at
least two bars of 8mm diameter are required, tied across with steel
links of at least 6mm diameter at spacing of 150mm centers.
•
ROLE OF VERTICAL REINFORCEMENTS IN WALLS

• Even if horizontal
bands are provided,
masonry buildings are
weakened by the
openings in their walls.
• During earthquake
shaking, the masonry
walls get grouped into
3 sub-units, namely
Spandrel masonry,
Wall Pier masonry and
Sill masonry
• When the ground shakes, the inertiaforce causes the
small-sized
• Causes the small-sized masonry wall piers to
disconnect from the masonry above and below.
• These masonry sub-units rock back and forth,
developing contact only at the opposite diagonals
The rocking of a masonry pier can crush the
masonry the corners.
• Risking is possible when masonry piers are slender,
and when weight of the structure above is small. 
• Otherwise, the piers are more likely to develop
diagonal (X-type) shear cracking this is the most
common failure type in masonry buildings.
During strong earthquake shaking, the building may slide just under the roof, below the lintel band or at
the sill level.
• Sometimes, the building may also slide at the plinth level.
HOW VERTICAL REINFORCEMENT HELPS

• Embedding vertical reinforcement bars in the edges of the wall piers

and anchoring them in the foundation at the bottom and in the roof
band at the top forces the slender Masonry piers to undergo
bending instead of rocking.
• In wider wall piers, the vertical bars enhance their capability
to resist horizontal earthquake.
• Adequate cross-sectional area of these vertical bars prevents the
bar from yielding in tension.
• Further, the vertical bars also help protect the wall from sliding as
well as from collapsing in the weak direction.
PROTECTION OF OPENINGS IN WALLS

• The most common damage, observed after an earthquake , Is

diagonal X-cracking of walll piers, and also inclined cracks at the
corners of door and window opening.
• When a wall with an opening deforms distorts and becomes
more like a rhombus.
• Steel bars provided in the wall masonry all around the openings
restrict these cracks at the corners.
• Thus, lintel and sill bands above and below openings and vertical
edges, provide protection against this type of damage
 STRUCTURAL DESIGN

• The structure should be ductile, like the use of steel in concrete buildings. For these ductile materials
to have an effect, they should be placed where they undergo tension and thus are able to yield.
• Apart from ductility, deformability of structures is also essential. Deformability of structures is also
essential. Deformability refers to the ability of a structure to dispel or deform to a significant degree
without collapsing. For this to happen, the structure should be well- proportioned, regular and tied
together in such a way that there are no area of excessive stress concentration and forces can be
transmitted from one section to another and the ability of a structure to withstand substantial
damage without
• Damageability is another aspect to be taken into consideration. This means the ability of a structure
to withstand substantial damage without collapsing. To achieve this objective “minimum area which
shall be damaged in case a member of the structure is collapsed” is to be kept in view while
planning. Columns shall be stronger than beams for that purpose and it is known as strong column
and weak beam concept.
 TIPS FOR EARTHQUAKE-RESISTANT DESIGN
• The building plan should be in a regular shape such as square or rectangular.
• No wall in a room should exceed 6.0m in length. Use pilasters or cross walls for
longer walls. In hilly terrain, it should not than ceed 3.5m in length.
• The height of each storey should be kept below 3.2m.
• Don‟t use bricks of crushing strength less than 35kg/cm2 for single stLocation of a
door or window from edge of a wall shall. Only solid and sound bricks/ concrete
blocks should be used Provide a R.C.C band of 4” thickness throughout the run
along wall at lintel level passing over doors and windows.
• The thickness of load bearing wall should be at least 200mm
• The clear width between a door and nearest window should not be less than 600m
• Location of a door or window from edge of a wall shall be 600mm minimum.
 CONCLUSIONS

• Earthquake resistant construction is important in earthquake prone area

• The building can resist earthquake forces with almost no damage.
• The building shall not collapse or harm human lives during severe earthquake
motions.
• However these structures will be uneconomical.