Experimental study of key seismic performance parameters of lead rubber bearing isolator under extreme low-temperature effect
Considering that some regions in northern China are affected by extremely cold climates in winter,the study of performance changes and regulatory applicability of lead rubber bearing isolators in this environment is of great significance for the seismic safety of structures.The shear performance tests on three different shapes of lead rubber bearing isolators at different temperatures(-60-40℃),and different low temperature exposure time(1,2 and 7 d)were conducted.The change rule between key seismic performance parameters of bearings(characteristic strength,horizontal equivalent stiffness,post-yield stiffness and equivalent damping ratio)under different temperatures and different low temperature exposure time were obtained.Research has shown that the shape of the bearing has little effect on the low-temperature isolation performance of lead rubber bearing isolator.The influence of rubber ratio is crucial at extremely low temperatures.On the premise of meeting various performance requirements,low-temperature seismic isolation bearings should preferentially select bearings with smaller seismic modulus.The key seismic performance parameters of the bearing reach a relatively stable state after being exposed to low temperature for about 2 d.
lead rubber bearing isolatormechanical propertytemperature correlationlow temperature exposure timeshear performance test