极低温度下LRB力学性能及对高层结构地震响应的影响

摘 要：研究极低气温（﹣40℃）下温度变化对隔震结构中铅芯橡胶支座力学性能的影响及其力学性能变化特征，及﹣40℃至40℃区间支座的温度相关性。选用直径为600 mm的原型铅芯橡胶支座，采用电液伺服加载系统完成剪切应变为100%情况不同恒定温度下的低周反复加载试验。发现支座在极低温度下的力学性能与常温下的力学性能差异显著。提出铅芯橡胶支座屈服后刚度与屈服荷载的温度修正方程，及隔震结构设计中铅芯橡胶支座基于温度的力学参数取值建议。给出考虑温度影响的隔震结构地震反应影响算例，分析结果表明温度对强震下隔震结构的隔震层位移、上部结构层间剪力以及上部结构顶层的加速度响应影响显著。

Mechanical properties of LRB in low temperature state and its influence on earthquake response of high buildings

The variation of mechanical properties of lead rubber bearing(LRB) used as an isolation structure at low temperature of-40℃ was studied the correlation between properties of LRB and the temperature ranged from-40℃ to 40℃ was investigated.Three LRB specimens with diameter of 600mm were tested,and the low-cycle reversed loading experiments under 100% shear deformation at different temperatures were accomplished on an electro-hydraulic servo loading system.The study shows that there exist significant differences in mechanical properties of LRB at extremely low temperature compared with those at room temperature.Based on the test results,considering the temperature effect,the corrections on the equatios for the stiffness of LRB after yielding and for the yield load were proposed and the ranges of parameters suitable for isolation structure design were provided.The results of practical examples show the significant temperature effects on the displacement of isolated system,the shear force between stories and the acceleration response at the top of upper structure under strong earthquake.