Some Baisc guidelines for Earthquake Resistant construction and facts & figures

2.  An earthquake is caused by the breaking and shifting of rock
beneath the Earth's surface.
 Earthquakes, also called temblors, it’s hard to imagine they occur
by the thousands every day around the world, usually in the form
of small tremors.
 Some 80 percent of all the planet's earthquakes occur along the rim
of the Pacific Ocean, called the "Ring of Fire“
 On average, a magnitude 8 quake strikes somewhere every year
and some 10,000 people die in earthquakes annually
 Ground shaking from earthquakes can collapse buildings and
bridges; disrupt gas, electric, and phone service; and sometimes
trigger landslides, avalanches, flash floods, fires, and
huge, destructive ocean waves (tsunamis).
 Collapsing buildings claim by far the majority of lives,
but the destruction is often compounded by mud slides,
fires, floods, or tsunamis

3.  Ground Shaking: Shakes structures constructed on ground
causing them to collapse.
 Liquefaction: Conversion of formally stable cohesion-less soils
to a fluid mass, causing damage to the structures.
 Landslides: Triggered by the vibrations
 Retaining structure failure: Damage of anchored wall, sheet
pile, other retaining walls and sea walls.
 Fire: Indirect result of earthquakes triggered by broken gas and
power lines.
 Tsunamis: large waves created by the
instantaneous displacement of the sea floor
during submarine faulting

4. Damages due to earthquake in 2011

7.  Conventional Approach:-
 Design depends upon providing the building with
strength, stiffness and inelastic deformation capacity
which are great enough to withstand a given level of
earthquake generated force.
 Basic Approach:-
 Design depends upon underlying more advanced
techniques for earthquake resistance is not
to strengthen the building, but to reduce
the earthquake generated forces
acting upon it.

8.  Intensity of earthquake
 Type of earthquake waves
 Type of structure
 Type of design
 Shape of structure both in plan & elevation
 Type of soil
 Type of foundation
 Type of material used for construction
 Load of structure

9.  Increase natural period of structures by Base Isolation like :
 Lead Rubber Bearing
 Laminated Rubber Bearing
 High Damping Rubber Bearing
 Spherical Sliding Bearing
 Friction Pendulum System
 Increase damping of system by Energy Dissipation Devices
like :
 Viscous dampers
 Friction dampers
 Yielding dampers
 Visco elastic dampers
 By using Active Control Devices like :
 Sensors
 H/w & S/w
 Actuators

10.  Planning stage
 Plan building in symmetrical way (both axis)
 Avoid weak storey and provide strong diaphragm
 Don’t add appendages which will create difference in Centre of mass and
centre of rigidity
 Conduct soil test to avoid soil liquefaction
 Steel to be used of having elongation of 14% and yield strength of 415
N/mm2
 Design stage
 Avoid weak column and strong beam design.
 Provide thick slab which will help as a rigid diaphragm. Avoid thin slab
and flat slab construction.
 Provide cross walls which will stiffen the structures in a symmetric
manner.
 Provide shear walls in a symmetrical fashion. It should be in outer
boundary to have large lever arm to resist the EQ forces.
 Construction stage
 Compact the concrete by means of needle vibrator.
 Cure the concrete for at least a minimum period.
 Experienced supervisor should be employed to have
good quality control at site

11.  Guideline laid down for five category of structures
 Part 1 General provisions and buildings
 Part 2 Liquid retaining tanks - Elevated and ground supported
 Part 3 Bridges and retaining walls
 Part 4 Industrial structures including stack like structures
 Part 5 Dams and embankments
 Seismic zone identified and construction
parameters amended accordingly
 Foundation laying in various soil type is
also specified.
 Specification about material to be used
including RCC, Steel, masonry work etc.

12.  IS 1893 (Part I), 2002, Indian Standard Criteria for
Earthquake Resistant Design of Structures (5th
Revision)
 IS 4326, 1993, Indian Standard Code of Practice for
Earthquake Resistant Design and Construction of
Buildings (2nd Revision)
 IS 13827, 1993, Indian Standard Guidelines for
Improving Earthquake Resistance of Earthen Buildings
 IS 13828, 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

13.  How will you stop the building from collapsing?
 If it does not fall how will you prevent accidents in the
building as it moves?
 What about falling glass and rubble on the people
outside?
 What about problems after the earthquake (fire, gas
and water leaks, no power)?
 Where will you build it? Away from built up areas or
near emergency services?
 There are plenty of other things that you need to think
about.