8/3/2019 AKSHAY BISHNOI
1/18
8/3/2019 AKSHAY BISHNOI
2/18
The design of civilian or commercialbuildings to withstand the effects of
a terrorist blast is unlike the design
of military installations or the designof embassy buildings.
The objectives of the Structural
Engineering Guidelines for the
Design of New Embassy Buildings
are to prevent heavy damage to
components and structural collapse.
8/3/2019 AKSHAY BISHNOI
3/18
Architectural and structural features
play a significant role in determining
how the building will respond to the
blast loading. These features can
include adjacent or underground
parking, transfer girders, slab
configurations, and structural-frame
systems
8/3/2019 AKSHAY BISHNOI
4/18
External car bomb
Internal car bomb
Internal package
Suicidal car bombs
8/3/2019 AKSHAY BISHNOI
5/18
Flying debris
Broken glass
Smoke and fireBlocked glass
Power loss
Communications breakdown
Progressive collapse of structure
8/3/2019 AKSHAY BISHNOI
6/18
Reduce the severity of injury
Facilitate rescue
Expedite repairAccelerate the speed of return to full
operations.
8/3/2019 AKSHAY BISHNOI
7/18
8/3/2019 AKSHAY BISHNOI
8/18
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 importantelements,
The bomb size (or) charge weight,
The standoff distance - the minimumguaranteed distance between the
blast source and the target
8/3/2019 AKSHAY BISHNOI
9/18
Another requirement is to keepthe bomb as far away as possible, by
maximizing the keepout distance. No
matter what size the bomb, the
damage will be less severe the
further the target is from the source.
8/3/2019 AKSHAY BISHNOI
10/18
8/3/2019 AKSHAY BISHNOI
11/18
1. More attention must be paid to thedesign and detailing of exterior bays and
lower floors, which are the most
susceptible to blast loads .2. If vertical clearance is a problem, shear
heads embedded in the slab will improve
the shear resistance and improve the
ability of the slab to transfer moments tothe columns
8/3/2019 AKSHAY BISHNOI
12/18
3. In exterior bays/lower floors, drop
panels and column capitols are requiredto shorten the effective slab length and
improve the punching shear resistance
8/3/2019 AKSHAY BISHNOI
13/18
1. The potential for direct lateral loadingon the face of the columns, resulting from
the blast pressure and impact of
explosive debris, requires that the lowerfloor columns be designed with
adequate ductility and strength
2. The perimeter columns supporting the
lower floors must also be designed to
resist this extreme blast effect
8/3/2019 AKSHAY BISHNOI
14/18
3. Encasing these lower-floor columns in
a steel jacket will provide confinement,increase shear capacity, and improve the
columns' ductility and strength. An
alternative, which provides similar
benefits, is to embed a steel column
within the perimeter concrete columns or
wall section
8/3/2019 AKSHAY BISHNOI
15/18
8/3/2019 AKSHAY BISHNOI
16/18
4. For smaller charge weights, spiral
reinforcement provides a measure of
core confinement that greatly improvesthe capacity and the behavior of the
reinforced concrete columns under
extreme load.
8/3/2019 AKSHAY BISHNOI
17/18
There are structural techniques that can
increase the capacity of building
structures to resist certain kinds ofterrorist attacks. However, there is
absolutely no reliable way to design for
the impact of a large scale commercial
airliner.
8/3/2019 AKSHAY BISHNOI
18/18
THANK YOU
!!