Challenge:
A BBRE booth which is 10′ x 12′ x 10′ tall is to be installed 12 feet above ground level for observation purposes. The structure will be subject to a high blast load of 25 psi incident pressure.
Resolution:
In order to reduce the load effects on the support structure and the foundation, a three- dimensional steel space frame with four columns is chosen to elevate the BBRE booth 12 feet above grade. The effective blast load acting on the support structure is highly reduced due to the open nature of the support frame.
Since the blast dynamic load on a flexible structure is lower than a rigid one, a tapered member concept is used to reduce the overall structural stiffness. The large sectional areas at column and beam ends are located only at the higher load locations.
In order to reduce the overall plan dimensions of the foundation, the anchor rods at the column base are installed close to the edges of the reinforced concrete foundation. Mechanical anchors are used and designed against failure due to concrete breakout at the foundation edges. A 16′ x 14′ x 6′ reinforced concrete foundation is used to stabilize the structure from overturning and sliding.
