Experiment investigation and seismic performance evaluation of hybrid isolation bearing with uncoupled compression and shear mechanism

Summary Lead rubber bearings (LRBs) are widely used in the seismic isolated structures. However, the lateral and vertical stiffness of rubber bearing would degrade under high pressure and larger shear strain, which has influence on the structural safety under great earthquakes. This paper proposes a novel hybrid isolation bearing (HIB) with uncoupled compression and shear mechanism. The HIB consists of sliding bearing and rubber springs, carrying superstructural weight and providing lateral stiffness, respectively. The configuration and mechanical model of the HIB are introduced, and an experiment investigation on two sizes of HIB was completed. Through the model test, the deformation mechanism and the mechanical model were verified. A numerical simulation of a frame–shear wall structure was performed, and the variation of structural responses is illustrated. Compared with conventional LRB isolated structure, the HIB isolated structural has similar response variations under earthquakes from frequent to rare levels. Under extremely rare earthquakes, the HIB has more stable mechanical behavior.