Approximate seismic analysis of piping or equipment mounted on elastoplastic structures

In recognition of the importance and complexity of the seismic design of the electrical and mechanical equipment in nuclear power plants and other critical facilities, several approximate methods have been proposed to facilitate such a design. For the most part, however, these approximate methods have been restricted to linear systems, without due consideration to the fact that most of the structures to which equipment is attached are designed to yield under the effect of a strong earthquake. As a result, such methods may overestimate the design seismic forces, and thus they may lead to uneconomical and unrealistic designs.