SOIL STRUCTURE INTERACTION WITH FOUNDATION TIPPING

Abstract

Earthquake forces are transmitted to the structure through its foundation. The method most commonly used by structural engineers for the analysis of buildings, designed. to resist earthquake forces, assumed the structures to be firmly bonded to a rigid fo undat ion. By contrast, real foundat ions provide at best a limited resistance to tension and hence the apparent tension side of a raft or footing foundation could actually lift off the ground in response to large overturning moments. Thus, in the dynamic analysis of buildings of large mass (e.g. buildings used in nuclear power plants) the response acoeleration of. the building is largely amplified during an earthquake and its base mat may tip (lift off the ground) by response overturning moment caused by a strong earthquake.. And it makes geometrical non—linear interaction between the base mat and rock foundation beneath it which produces very complex phenomena by earthquake motions.. In this study a box type cylindrical structure, subjected to horizontal ground acceleration has been analyzed. The soil—structure interaction has been described by a foundation spring system.