This paper is a theoretical and numerical study of the stability of light-weight
low-cost elastomeric isolators for application to housing, schools and other public
buildings in highly seismic areas of the developing world. The theoretical analysis
covers the buckling of multilayer elastomeric isolation bearings where the reinforcing
elements, normally thick and inflexible steel plates, are replaced by thin flexible
reinforcement. The reinforcement in these bearings, in contrast to the steel in the
conventional isolator (which is assumed to be rigid both in extension and flexure), is
assumed to be completely without flexural rigidity. This is of course not completely
accurate but allows the determination of a lower bound to the ultimate buckling load
of the isolator. In addition, there are fewer reinforcing layers than in conventional
isolators which makes them lighter but the most important aspect of these bearings is
that they do not have end plates again reducing the weight but also they
are not bonded to the upper and lower support surfaces. The intention of
the research program of which this study is a part is to provide a low-cost
light-weight isolation system for housing and public buildings in developing
countries.
Pacific Earthquake Engineering
Research Center
University of California, Berkeley
1301 South 46th Street Building 452
Richmond, CA 94804-4698
United States