Simulation of the Response of Equipment Located in Underground Installations to Blast Induced Ground Motions

摘要

The characteristics of the response of isolated equipment installed in underground structures to the ground motions induced by nuclear blast are defined in terms of weapon yield, distance from blast, ground conditions and natural frequency of equipment suspension. A design approach is proposed for a variable stiffness, multi-degree-of-freedom device capable of generating the isolated equipment response motions. Pneumatic double-acting cylinders and elastomer springs are selected as the variable stiffness mechanism. Pneumatic rams are selected as the displacement mechanism. The performance characteristics of a model built using the proposed design approach are defined by means of acceleration-time traces of the motions generated for different values of oscillating frequency, load and initial displacement. Conclusions and recommendations are made based on comparison of the motions generated by the model to the expected response motion of isolated equipment in underground installations. (Author)