Disaster Resistant Building Introduction

Foundation and various structural designing information for Disaster Resistant Building for various places of India

1. Disaster Resistant Building
Foundation & Structural system

2. From GATE syllabus 2023
Part- A – Section-2 – Construction & Management
Principles and design of disaster resistant structures, Temporary structures for rehabilitation;
Part- A – Section 7: Services and Infrastructure
Firefighting Systems; Building Safety and Security systems; Building Management Systems;

3. Types of Foundation and
their Uses
1.Shallow foundation
1.Individual footing or isolated footing
2.Combined footing
3.Strip foundation
4.Raft or mat foundation
2.Deep Foundation
1.Pile foundation
2.Drilled Shafts or caissons

4. Details for foundation
•Procedure for construction of foundation starts with decision on its depth,
width and marking layout for excavation and centerline of foundation.
•Foundation is the part of structure below plinth level in direct contact of soil
and transmits load of super structure to soil.
• Generally it is below the ground level.
•If some part of foundation is above ground level, it is also covered with earth
filling.
•This portion of structure is not in contact of air, light etc., or to say that it is
the hidden part of the structure.
•Footing is a structure constructed in brickwork, masonry or concrete under
the base of a wall or column for distributing the load over a large area.

5. •Depth of Foundation
•Depth of foundation depends on
following factors:
•Availability of adequate bearing capacity
•Depth of shrinkage and swelling in case
of clayey soils, due to seasonal changes
which may cause appreciable
movements.
•Depth of frost penetration in case of fine
sand and silt.
•Possibility of excavation nearby
•Depth of ground water table
•Practical minimum depth of foundation
should not be less than 50 cm. to allow
removal of top soil and variations in
ground level.
•Hence the best recommended depth of
foundation is from 1.00 meter to 1.5
meter from original ground level.
•The width of footings should be laid
according to structural design. For light
loaded buildings such as houses, flats,
school buildings etc. having not more
than two storeys, the width of foundation
is given below:
•The width of footing should not be less
than 75 cm for one brick thick wall.
•The width of footing should not be less
than 1 meter for one and half brick wall.
•Width of Foundation /
Footings

6. EARTHQUAKE RESISTANT DESIGN OF
FOUNDATIONS:
•Foundation is a substructure built below the super structure. Purpose of the
foundation is to transfer the structural loads safely to the underlying soil. Safe
and economical design of a foundation under different loading conditions is the
role of geotechnical engineer.
•Proper design of a foundation against earthquake loading requires through
understanding over the behavior of soil, response of structure and interaction of
soil-structure under earthquake loading.

7. •These are as important as disaster resistant structural designs. Infect the
methodology for construction also should be designed for disaster resistance.
•We should have proper implementation of the structural details so as to let the
structure behave as envisaged.
•The quality and methodology of construction is equally important. For example
we use cover blocks. If the cover blocks are not cast properly in good quality
concrete then they facilitate concrete deterioration. Ultimately this affects
durability and serviceability of the structure.
•The Durability and serviceability are the key elements of any structure.
Ensuring Quality in construction will enable achieving durability and
serviceability as a desired end result.
Disaster Resistant Construction Techniques

9. 1. Settlement pattern and Design Considerations
PROVIDE - Clustered (zigzag) planning
avoids tunnelling effect and reduces
susceptibility to disaster
AVOID - Row house settlement with
roads leading to Sea
PROVIDE - Simple Square/Rectangular
and Symmetrical plan is Suitable -
Length of Building ≤ 2xWidth.
PROVIDE - Separation of wings into
different rectangles in plan is preferable
PROVIDE - Shorter wall facing wind
direction
AVOID - Longer wall facing the direction of
wind

10. 2. Foundation
PROVIDE - Slightly Slanting
cut - Sand Compaction
thickness more than 150mm -
PCC thickness more than
75mm

AVOID - Straight Cut - Sand
compaction less than 150mm -
PCC less than 75mm
PROVIDE –
A.Foundation width should
be 2½ times thickness of
the wall or 0.8m,
whichever is more
B. B. Use baked bricks and
stones
C. Minimum depth should be
1000mm
AVOID
A.Foundation width should
not be less than 2½ times
thickness of the wall
B. Never make a wall without
foundation C. Don't use
unbaked bricks in the
foundation
PROVIDE - Foundation on
Hard Soil AVOID - Foundation
on Loose or Soft Soil

11. 3. Walls
PROVIDE - Average wall height should
be 2700 to 3000mm
AVOID - Too High Walls
PROVIDE - Average wall height should
be 2700 to 3000mm
AVOID - Too High Walls
Stone Masonry
A. Through stone should be placed
horizontally at a minimum spacing of 1200mm
center-to-center
B. Through stone should be placed vertically at
a minimum-spacing of 600mm

12. - Vertical Rod should be
placed at 125mm from the
inner face of the Brickwork
Rat-trap Bond (T-Joint)
- Vertical Rod should be
placed at 245mm from the
inner face of the Brickwork
Rat-trap Bond (L-Joint)
Vertical rod must be
connected using extra
“L” bar with main steel of
Plinth band and Lintel
band. The bar will be
able to perform
efficiently if it is
anchored at Foundation
and Slab and linked with
- Locate the vertical bar at
165 mm from the outer face
of 230 mm wall English
Bond (L-Joint)
1.Joints in brickwork
should be staggered.
2. For regular bond use
only mortar of 1:6 or
richer and for Rat -
Trap bond 1:5 or
richer.
3. Vertical rods should
be protected with a
minimum cover of
40mm in M20
concrete.

13. Sectional View of Disaster Resistant Wall
Reinforcement in Siesmic Beams
and Bands
Disaster Resistant Beams and Bands in the Walls
A. Grade Beam (In case of Frame)
B. Plinth Band
C. Lintel Beam
RCC Band Details

14. Openings are the most Vulnerable part in a building. Large shear forces get accumulated around
openings and therefore, edges of the openings should be specifically strengthened. Due to lateral
thrust openings are subjected to movements attempting to make them a Rohmbus - stretching
opposite diagonals as shown. Because of this it is likely that after an Earthquake; diagnonal / shear
cracks occur around unsecured openings and brick piers.
4. Openings
No Corner Reinforcement -
Diagonal Cracking in building with
no Corner Reinforcement
No Cracks in Buildings with
Vertical Reinforcement
Protect Openings with
Reinforced Band all around as
shown. Detail of reinforcement
is shown in cross-section of the
Jamb at ‘t”
Design Considerations -
Avoid too many openings
in the wall -The minimum
distance between
unreinforced openings
should be 600mm

15. Brick Masonry
B1+B2+B3
≤ 0.5L (for One Storey)
≤ 0.42L (for Two Storey)
≤ 0.33L (for Three storey)
-[600mm ≤ B4 ≥ 0.5H2)]
Horizontal distance (pier width) between two openings
should not be less than 50% the height of the shorter
opening (and not less than 600mm)
-[600mm ≤ B5 ≥ 0.25H1]
Openings to be located away from the corners by clear
distance equal to at least one fourth of the height of
opening or 600mm whichever is more
-[H3 ≤ 600mm or 0.5(B2 or B3)]
Vertical distance from an opening to opening above
should not be less than 600mm and half the width of

16. Placing vertical bars and closed ties in Columns
PROVIDE -
Adequate Lap
Length with
slope of 1:6
AVOID -
Insufficient Lap
Length
Splice with
Offset
Cranked bar
in a Column
PROVIDE - Bend the
Stirrup through 135°
AVOID -Inadequate
Stirrup Details
Min concrete Grade for
RCC should be M20 i.e.
1: 1.5 :3 for volumetric
proportioning. Where 3
is a mix of 10mm and
20mm down aggregates
in 50/50 or 60/40 ratio.
Columns & Beams

17. Reinforcement Detail of Beam
Beam bars bent in joint region
overstress the core concrete
adjoining the bends
A.Reinforcement Detail of Beam Column Joint at
Roof Level
B. Reinforcement Detail of BeamColumn Joint at Floor
Level
Column should have
minimum four 12
diameter bars. It is
preferable to use TMT
bars near the coast line.
Column & Beam Junctions

18. CYCLONE -
Structures should be erected in areas, which provide a protective shield from high
winds with natural firm level foundation. Flat roof arrangement should be avoided.
So should be the projecting elements like antennas and chimneys, eave projections,
sunshades etc.
The construction should have adequate diagonal bracing, reinforced machinery,
thicker plate glass, and anchoring of purlins to gable ends. As far as flood resistant
housing is concerned, prohibited zones should be totally avoided.
Layout of the buildings/ houses should be such that they do not block free flow of
water. Construction should be done on raised mounds.
Waterproofing treatment, adequate bracing, afforestation in catchment areas are
required for flood- prone areas. The Expert Committee Report covered the following
issues:
Identification of various hazard-prone areas
Vulnerability and risk assessment 'of buildings
Outlining the disaster damage scenarios
Technical guidelines for hazard resistant construction of buildings
Upgradation of hazard resistance of existing housing stock by retrofitting