This document provides information on blast resistant building design. It discusses the objectives of blast design which are to reduce injury, facilitate rescue, expedite repair and return to full operations. It describes major causes of life loss after a blast like flying debris, smoke, and progressive structural collapse. Principles of blast resistant design are outlined such as maintaining standoff zones and limiting localized damage. Various structural elements are described for improving blast resistance, including connections, column wrapping, shear walls, glazing, and miscellaneous measures. Case studies on the WTC collapse and Israeli buildings adapted for military blast design are presented. The conclusion states that while withstanding any attack isn't practical, performance can be improved through an appropriate threat-based design process.

1. WELCOME
1

2. Blast Resistant
Buildings
• Guide :
Mr. Arun.K.A
Asst. Professor
Civil Engg
SIMAT
• Presented By :
Paul Jomy
SYAKECE033
Civil Engg
SIMAT
2

3. Introduction
• One of the most popular design
issue.
• Increase in number of Terror
attacks and accidents.
• Subject is popularly applied in
modern and important buildings.
• Emerging branch in the field of
structural engineering
3

4. Objective Of The Blast Design
The primary objectives for providing blast
resistant design for buildings are:
•
•
•
•
Reduce the severity of injury
Facilitate rescue
Expedite repair
Accelerate the speed of return to full
operations.
4

5. 5

6. Major Causes Of Life Loss After
The Blast
•
•
•
•
•
•
•
Flying Debris
Broken glass
Smoke and fire
Blocked glass
Power loss
Communications breakdown
Progressive Collapse of structure
6

7. Principles of Blast Resistant
Design
 Maintain safe separation of attackers
and targets, i.e. STAND-OFF zones.
 Design to sustain and contain certain
amount of bomb damage. Avoid
progressive collapse of the building.
 Allow for limited localized damage of
members
7

8.  Minimize the quantity and hazard of
broken glass and blast induced debris.
 Facilitate rescue and recovery
operation with adequate time of
evacuation of occupants.
8

9. Blast Load Definition
• An explosion is a rapid release of
potential energy characterized by
eruption enormous energy to the
atmosphere.
• A part of energy is converted to
thermal energy radiation (flash) and a
part is coupled as air blast and shock
waves which expand radially.
9

10. Effects of Blast On The
Structure
10

11. 11

12. Basic Requirements To Resist
Blast Loads
• The first requirement is to determine
the threat. The major threat is caused
by terrorist bombings.
• The threat for a conventional bomb is
defined by two equally important
elements,
12

13. The bomb size (or) charge weight,
The standoff distance – the minimum
guaranteed distance between the blast source
and the target
• Another requirement is to keep the bomb as
far away as possible, by maximizing the
keep out distance.
• No matter what size the bomb, the damage
will be less severe the further the target is
from the source.
13

14. Treatments Provided To
Various Parts Of A
Structure To Improve
Blast Resisting
Mechanism
14

15. Planning And Layout
• Sufficient stand-off distance must be
provided.
• In case of congested areas where
there is no provision for stand off
distance, bollards, trees or street
furniture are to be provided as
obstacles.
15

16. 16

17. Stand Off Distance
• Blockades, planters, fountains, fences
as obstacles to ramming vehicles or
truck bomb.
• Allow only emergency vehicle
access.
• Raise the building 2m above ground
level
17

18. 18

19. Roofs
• Arches and domes
are the types of
structural forms
that reduce the
blast effects on the
building compared
with a cubicle
form.
19

20. Floorings
• They must be
prevented from
‘falling off' their
supports. Pre-cast
flooring is to be
avoided in case of
blast resistant
structures.
20

21. Beam-to-column
Frame structures
Connectionsare deficient in 2
aspects:
failure of beam to column connections
Inability of the structure to tolerate
load reversal
providing additional robustness to
these connections can be significant
enhancement.
21

22. Side plate connection for a
steel structure
Beam to column connection in
Reinforced concrete structure
22

23. Wrapping of columns:
• Wrapping is done to done for external
protection of columns and also to protect
the column from shock waves.
• Two types of wrapping can be applied.
Wrapping with steel belts or wrapping
with carbon fiber-reinforced polymers
(CFRP).
23

24. Wrapped Columns
24

25. Shear Walls
• Use a well distributed
lateral load resisting
mechanism in the
horizontal floor plan.
• Shear plan around the
plan will improve the
overall seismic as well
as blast behaviour of
the building.
25

26. Installations:
•Gas, water, steam installations, electrical
connections, elevators and water storage systems
should be planned to resist any explosion affects.
Bomb shelter areas:
•The bomb shelter areas are specially designated
within the building where vulnerability from the
effects of the explosion is at a minimum and
where personnel can retire in the event of a
bomb threat warning.
26

27. Glazing and Cladding:
• Glass from broken
and shattered
windows could be
responsible for a large
number of injuries
caused by an
explosion in a city
centre.
27

28. Miscellaneous Measures
Partially or fully embed buildings are
quite blast resistant.
Projected roofs and floors are
undesirable
Single story buildings are more blast
resistant than multi story buildings
Double- Dooring should be used.
28

29. 1. Case Study – WTC
Collapse two passenger
• On 11 September 2001,
planes were hijacked by terrorists and
crashed into the WTC Towers in New York.
• The impact of the plane crashes directly
caused significant structural damages to
both World Trade Center towers.
• The multiple floors fires ignited by the jet
fuel finally weakened the remaining
structures and the towers collapsed.
29

30. 2. Israel as a Case Study
• Israel has adapted military blast design to blast
design to be used as a part of civilian
structures.
• In the 1970s civilians in Israel were being
threatened along its border with Lebanon.
• Throughout northern Israel rooms designed to
protect a buildings inhabitants from an
explosion were included in most homes as
well as schools and public buildings
30

31. Conclusion
It is not practical to design buildings to
withstand any conceivable terrorist
attack.
It is possible to improve the
performance of structures should one
occur in the form of an external
explosion.
Design process to ensure that appropriate
threat conditions and levels of protection
31

32. Thank You
32

33. 33