1. DISASTER RESISTANT ARCHITECTURE
SITE SELECTION, SITE PLANING & SITE
DEVELOPMENT FOR EARTHQUAKE RESISTANT
DESIGN

2. SITE SELECTION
• The selection of suitable site is a crucial step in the design of a
building or planning a settlement in an earthquake prone area.
• There are a number of earthquake related hazards which should
always be considered when choosing a site, together with the
influence of the ground conditions at the site on the ground motion
which the building may experience in a future earthquake.
• An assessment of extent of earthquake hazard should always form
a part of overall site assessment and of specification for the design
of any structures to be built there.
• No site can be expected to be ideal in all respects, so the choice of
site will often involve a judgment about relative risks and the costs
of designing to protect from them.
• But there can be some sites which could be so hazardous that they
should be avoided if at all possible, since the cost of building is likely
to be prohibitive.
• A few important considerations for selecting the an appropriate site
are given below

3. Site selection – macro level
• Before taking considerations for site at micro
level we have to look at the parameters which
influence at macro level.
• Statistical analysis for considerations at macro
level can be done in following steps:
1. By knowing the position of site on the tectonic
plate,
2. By classifying the site in respective seismic zones
which the country is divided into,
3. And even evaluating other risk factors which the
site is subjected to..for example the presence of
hills and rocky areas near the site increases the
risk of landslides during earthquake.

4. Motion of seismic plates

5. Seismic zones in India

6. Earthquake risk zones in India

7. SITE SELECTION – MICRO LEVEL
• The site conditions play a vital role in seismic safety of a building.
Hazardous sites should be avoided for building construction to
minimize risks against natural disasters. Site Investigations will
assist in identifying potential danger of sliding, erosion, land
subsidence or liquefaction during an earthquake.
• Site Investigations will assist in identifying potential danger of
sliding, erosion, land subsidence or liquefaction during an
earthquake.
• The local practice of managing any such hazard should be given
due considerations.
A safer site is the one having:
• No danger of landslides
• Sufficient plantation on slope
• Trees not too close to the house
• Mild slope
• Far from river banks

8. POTENTIAL
HAZARDOUS SITES

9. Steep and unstable slopes
Building should not be constructed near steep and unstable
slopes. Cliffs made of soft or
crumbly, clay loam; deposits materials, etc. should be
avoided.

10. Areas susceptible to landslides and rock fall
• Landslides or rock fall areas should be avoided
while selecting a site for building construction.
• Apparently some slopes may look stable, but failure
could be triggered by an earthquake.
• Landslides and rock fall can damage buildings
partially or completely. However, building in these
areas can be constructed after providing proper
retaining walls and green barriers.
• Simple indication of sustained stability of a slope is
the presence of upright standing trees on it.
• Abnormally inclined trees on a slope indicate
instability of the hill slope.

11. Rock falls

12. Instable hill slope

13. River banks
• Buildings should be far enough from the river
to avoid flash flood and earthquake damage.

14. Geological fault and Ruptured areas
• Geological fault and ruptured areas that are usually
visible, permanent, deep and active should be
avoided for construction.
• Buildings should be constructed at least 250 m
away from these lines.

15. Site planning
• Considerations to be taken while designing
the site are:
1. Steep slopes
2. Filled up soil
3. Raft and pile foundations

16. Steep slopes
• Buildings should be sufficiently
away from steep slopes. Sites
located on or very close to steep
slopes are always prone to
landslides, especially in the
earthquake prone regions.
• Even if the building has good
earthquake resistant construction,
they are prone to damages or total
destructions on such sites.
• The periodic landslides are Buildings located near
triggered by other aspects like steep slopes
excess rains, seepage etc.
• The Himalayan regions are
particularly prone to landslides.
Such landslides often prove to be
more disastrous than the actual
earthquake event.

17. Filled up soil
• Foundation should rest
only on firm soil and not
on filled up soil.
• Such constructions on
filled up soils have
witnessed extensive Buildings
located on filled – up soil
damages in the January should be avoided
2001 Gujarat earthquake.

18. Raft and pile foundations
• Many times it is
unavoidable to
construct the structure
on filled up soil, as in
most cases choice of
site is not the option we
Buildings located on
have. filled – up soil should be provided
• In such situations raft with raft on pile foundations
on pile foundations
have to be provided as
shown in figure.

19. Forest and trees
• The forests are really useful to stop landslides but buildings
should not be constructed close to any big tree, as there
might be a possibility of falling of the trees during
earthquake.
• The distance between tree and house should preferably be
at least equal to the height of tree or house, whichever is
greater.

20. Too Close building
• Building should not be constructed close to another
building: there might be a possibility of falling of
building during earthquake.
• The distance between two houses should be at least
equal to the height of house.

21. CONCLUSITION
• Finally it must be recognized that the
architectural requirements will often make
asymmetrical design difficult or sometimes
impossible.
• In these circumstances it is necessary, depending
upon the size of the building and the type of
asymmetry, to subdivide the major masses of the
building to improve the seismic performance.