Soil Structure Interaction Problems for Nuclear Containment Structures

The problems of soil amplification and soil structure interaction have been the subject of considerable research in recent years, particularly in relation to the seismic design of nuclear power plants. A number of sophisticated mathematical techniques and simpler engineering approximations have been developed to estimate their effects on structural forces, and more importantly, on the characteristics of the motion at different floor levels (amplified response spectra for the design of equipment). There is however some confusion and controversy on the mathematical accuracy of some of these methods and the physical significance of others. Sometimes elaborate techniques are judged appropriate even when based on incorrect assumptions, and often methods which can be shown to be mathematically equivalent are classified as different because of inconsistencies in their implementation. The various methods of analysis now available and their similarities and differences when based on consistent assumptions are examined. (auth)