LRB支座疲劳温度力学试验及隔震结构地震响应影响分析

摘要

对直径为600mm和1100mm的LRB进行循环加载试验, 试验结果表明支座在往复运动中产生疲劳温度效应, 屈服力下降29％-34％.并进行LRB支座疲劳温度效应理论与试验结果对比, 数据表明支座疲劳温度效应引起的支座温度变化量与初始屈服应力成正比, 与支座高度成反比.进一步对12层LRB隔震结构在常温和极寒两种环境温度下选用远、近场和双峰值地震波对结构进行动力响应分析, 结果表明在超设计0.8g地震作用下, 考虑支座疲劳温度效应时, 常温工况支座屈服力下降23.5％, 极寒工况为19.4％;支座位移增大常温工况为5.8％, 极寒工况为26.4％.两种工况下上部结构动力响应最大影响率为9.8％.实际地震的疲劳温度效应对支座力学性能的影响与静力试验80圈结果一致, 在设计时应考虑极寒环境在超设计地震作用时支座位移增大带来隔震沟碰撞风险.%In this paper, the horizontal shear experiment on LRB 600 and LRB 1100 is conducted.The experiment shows yield force drops with the increasing of the temperature, and the droop rate is 29％-34％.The contrast analysis of theory and experiment is given, and the results show temperature variation is proportional to initial yield stress, and inversely proportional to height of lead core.A numerical model of the isolated structure under far-field, near-field and serial earthquakes excitation considering fatigue effect in room temperature and cryogenic conditions is presented.The yield force declines by 23.5％in room temperature and falls by 19.4％in cryogenic conditions under 0.8 gseismic input when the fatigue effect is considered.With homologous conditions, the displacement of LRB increases by 5.8％in normal temperature and 26.4％in cold.Therefore, the impact of the quake insulation groove caused by increased LRB displacement under cryogenic conditions should be taken into account in design.