Performance of Seismic Isolation Hardware Under Service and Seismic Loading

Keywords: Seismic isolation systems.  Hardware.  Seismic damping systems.  Seismic loads.  Service-type loads.  Aging.  Ambient temperatures.  Elastomeric bearings.  Sliding bearings.  Frictional heating.  Hysteresis.  Lead rubber bearings (LRB).  Seismic performance.

Abstract: This report presents a comprehensive description of the current stage of knowledge on the behavior of hardware used in seismic isolation and seismic damping systems.  Particular emphasis is placed on the description of fundamental behavior under both non-seismic, service-type of loading conditions and under high-speed seismic conditions.  Specific problems described and addressed include: aging of and effect of ambient temperature on the behavior of elastomeric and sliding bearings; prediction and experimental verification of effects of frictional heating on the sliding and effects of hysteretic heating on the lead-rubber bearings (LRB); analysis of elastomeric and sliding bearings; design of elastomeric and sliding bearings based on load and resistance factor design (LRFD) and ASD principles; establishment of upper and lower bound values of properties of seismic isolation bearings for use in the analysis and design; and detailed new testing protocols for seismic isolators and dampers.  This information may represent the basis for the development of contemporary Guide Specifications for Seismic Isolation Design.