This study was conducted in support of the Defense Civil Preparedness Agency's (DCPA) Crisis Relocation Planning (CRP) program in which existing structures will be upgraded to provide fallout shelters for a relocated population. A demonstration test was conducted in which a residential dwelling was upgraded by placing soil against the walls and on the roof of the structure. The shelter was large enough to house 80 people. Upgrading was accomplished partially by hand labor and machinery. The test showed that a conventional structure could be upgraded and that the shelter occupants using tools and materials found in most homes could if necessary upgrade their shelter during the expected 2- or 3-day period of crisis relocation preceding a nuclear attack.
The objectives of the investigation were to design and model test a blast-resistant reinforced concrete slab system serving as the roof of a basement shelter area. The slab system was designed to offer sufficient radiation and blast protection to insure a survival probability for its occupants of 85 to 95 percent for a fa 15-psi airblast overpressure loading. Static and dynamic tests were conducted on two 1/4-scale models of a prototype shelter. The prototype shelter, as designed, has a reinforced concrete flat slab roof consisting of three 18-foot spans in each direction supported by four interior columns and by a continuous wall around the perimeter. The model included the perimeter walls and different panel configurations which would influence the load-carrying capacity of the prototype structure. The slab system was designed using the empirical method of the 1963 American Concrete Institute Code with modifications to account for the dynamic loading effects. (Author).