|
Welcome
to the HOT
TOPIC in
Architectural Surety # 3A !
|
|
FLYING
DEBRIS / TERRORIST
BLAST PROTECTIVE
DISPENSABLE STRUCTURAL SHIELD
|
| It was widely
believed until recently that a building subject to an explosive attack
had a chance to remain standing only if it possessed some extraordinary
resistive capacity. This belief rested on the assumption that the
specific impulse or the time integral of pressure, which is a dominant
characteristic of the external blast load, is fully beyond our control.
Fortunately, the last statement is just half-true. |
|
We, actually, cannot control a magnitude of a load itself but we can influence
a timing of its application to structural elements as well as a pattern
of interaction of those elements, which was engaged in Blast
Protective Structural System described in Topic
3 . However, there is a more effective way to shield internal
premises of the building against air blast effects. The method is based
on the concept of energy consumption, which means a temporary storage plus
dissipation and dispersion, of window glass debris' kinematical energy
with the help of a protective dispensable system called Sails-Rigging
Blast Protective Shield or, in short, BPS.
BPS
includes sails, pilasters and riggings. Each sail consists of a
vertical protective layer of a flexible and,
at least partially, transparent fabric stretched internally
parallel to windows between the external wall pilasters and running from
the top of protected floors level of the building to its foundation. The
pilasters divide external walls into the separate window protective sections. |
|
The riggings are vertical and horizontal. The vertical riggings consist
of array of parallel ropes, cables or rods supporting the sail membrane
against the impact of glass debris. They represent tension
components of the rigging system. Floor diaphragms or horizontal
riggings are compression components
of the system. |
|
The primary objective of BPS is
to dissipate the kinetic energy of the flying glass debris through the
mechanism of plastic deformation in the tension components while transferring
the rest of the blast energy to the whole building structure through the
compression components of high resistive capacity in the range of elastic
deformations. The dispensable elements of BPS
were recently tested at CSUN*,**. |
* Shustov, V.
, 2001, “Testing Components for Blast Debris Protection”, Research report
for Karagozian & Case Structural Engineers, Volumes 1 - 2, CSUN,
Northridge, CA.
** Shustov, V.
, 2001, http://www.seaint.org/seaocconvention/convention1999/Proceedings/BP_Shield.pdf
, “Sail-Rigging Blast Protective Structural Shield”,
CSUN, Northridge, CA. |
This page was last
updated on 06/01/01
|
