Investigation of the seismic response of high rise buildings supported on tension resistant elastomeric isolation bearings
Summary In many applications of seismic isolation, such as in high rise construction, lightweight construction, and structures with large height to width aspect ratios, significant tension forces can develop in bearings, raising concerns about the possible rupture of elastomeric bearings and the uplift of sliding bearings. In this paper, a novel tension resistant lead plug rubber bearing (TLRB) with improved tension resisting capabilities is developed and experimentally and numerically assessed. This TLRB consists of a common lead plug rubber bearing (LRB) and several helical springs. After describing the theory underlying the behavior of the TLRB, the mechanical properties of reduced scale prototype bearings are investigated through extensive horizontal and vertical loading tests. The test results indicate that TLRBs can improve the shear stiffness and tension resistance capacity even under significant tensile loads. A series of shaking table tests on scaled models of high rise buildings with different aspect ratios were conducted to investigate the dynamic performance of the TLRB and the seismic responses of base isolated high rise buildings. Three different cases were considered in the shaking table tests: a fixed base condition and the use of TLRB and LRB isolation systems. The results of the shaking table test show that (a) base isolated systems are effective in reducing the structural responses of high rise buildings; (b) an isolated structure's aspect ratio is an important factor influencing its dynamic response; (c) TLRBs can endure large tensile stresses and avoid rupture on rubber bearings under strong earthquakes; and (d) the experimental and numerical results of the responses of the models show good agreement. Copyright (c) 2016 John Wiley Sons, Ltd.