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 (2) OVER - OVERTURNING AND SLIDING ANALYSIS OF REINFORCED CONCRETE
PROTECTIVE STRUCTURES.
(a) This special purpose program is designed specifically for
performing dynamic analyses of structures subjected to close-in explosions.
To this end, the bulk of the input data required for the dynamic analysis is
computed internally by the program.
(b) The response of the structure is determined by performing
a time-history dynamic analysis which considers the effect of the supporting
soil on the response of the structure. To avoid a rigorous and
time-consuming analysis, the structure is treated as a rigid body consisting
of infinitely stiff elements. The blast loads and elemental inertial loads
are assumed to act through the center of gravity of the structure, thus
reducing its response to the motion of its center of gravity.
(c) The results of the analysis consist of the displacement,
velocity and acceleration-time histories of the structure, and also the
bearing pressures beneath the foundation. Options are included for the
computation of the shears and moments for the foundation slab design of
cantilever wall barriers and the peak response time for the back wall
element designed to the incipient failure or post-failure fragment
conditions.
(d) The program contains three optional modes of operation:
1. Normal Option - Used for analyzing the most common
types of protective structures encountered in explosive manufacturing and
storage facilities.
2. Special Loading Option - Used to accommodate
rectangular or trapezoidal load histories in the analysis.
3. General Structure Option - Used to extend the
applicability of the program to structures of arbitrary configurations.
(e) OVER is written in FORTRAN IV for the CDC 6600 computer
system. A central memory field length of 150,000 words (octal) is required
for compilation and execution of the program on the CDC system.
(3) BLAST - BLAST LOADING IN BLAST CELLS.
(a) BLAST is a computer program capable of generating
characteristic blast loading parameters associated with confined explosions,
such as determining the internal blast environment in a rectangular cell.
(b) The program, using existing state-of-the-art explosion
theory, calculates shock pressure and gas pressure. The code includes blast
parameters of approximately 20 different explosives. For the initial shock
wave, it generates the incident and normally reflected pressure-time
histories and impulse for positive phase duration at a specified distance.
The code examines shock reflections in a closed or partially closed
rectangular structure. Gas pressure generation is computed using the energy
of chemical reaction. Venting is determined, giving the gas pressure in
various chambers at different times.
2.08-331
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