Seismic Performance of Low-ductility Precast Wall Structure with Base Isolation

It is both impractical and uneconomic to design a structure that remains elastic throughout severe ground motions. The main seismic design philosophy of a fixed-base structure is that minor structuraldamages are acceptable as long as the structure does not collapse. Hence, seismic base isolationprovides a better alternative in earthquake structural design. This paper presents finite element analysis carried out to investigate the feasibility of applying locally produced elastomeric rubber bearing base isolators in seismically isolating non-ductile precast concrete wall structures from earthquakeexcitations. The precast wall structures were analyzed in terms of in-plane and out-of-plane isolation effects due to dynamic lateral loads. Ground excitations from three classifications of acceleration history based on different a /v ratios were used in dynamic analyses of the structures. The resultsshowed that although the base isolator had successfully reduced most of the critical structural responses such as floor acceleration and base shear demand, relative inter-story drift reduction as compared to fixed-base structure was not significant. Current design philosophy for seismic baseisolation should be urgently revisited. Imperative discussion and review of the feasibility in utilizing base isolators as seismic mitigation plan for seismic prone areas are presented

کلیدواژه ها:

Seismic Isolation ، Precast Wall ، Low-ductility ، Elastomeric Rubber Bearing ، Time History Analysis