橡胶砂芯组合砌块应用于泸定地震倒塌房屋隔震研究

Application of rubber sand mixure composite blocks in seismic isolation of collapsed houses during Luding Earthquake

该文采用有限元软件对一种适用于村镇房屋隔震的橡胶砂芯组合砌块(rubber-sand mixture cored composite block,RSMCB),在已有振动台试验的基础上进行隔震响应还原模拟。然后在MOXI波和Turkey波输入工况下,对四川省甘孜州泸定县6.8级地震中发生跪坐倒塌的某砖混结构办公楼,进行铺设橡胶砂芯组合砌块前后的地震动响应模拟,对层间位移和层间剪力进行对比分析,得出以下结论:输入加速度在经过橡胶砂芯组合砌块垫层过滤后均有一定程度的下降,其对高频振动频率的衰减过滤是其主要的隔震机理;模拟结果与试验所得误差较小,充分验证数值建模方法的正确性以及子程序本构关系的可靠性;铺设RSMCB的办公楼结构的加速度反应、层间位移和层间剪力较未铺设RSMCB结构模型明显减小,层间位移以底部隔震层最大,XYZ输入工况下,铺设RSMCB的上部结构的响应最大;RSMCB的对房屋的隔震作用十分显著且满足在村镇欠发达地区的低成本隔震需求。在实施农村发展的过程中表现出良好的应用前景。橡胶砂芯组合砌块取材便捷造价低廉,隔震效果显著,可作为一种低成本的长寿命隔震技术。

Here,finite element software was adopted to simulate seismic isolation response of rubber-sand mixture cored composite block(RSMCB)suitable for rural housing.Based on existing shake table tests,simulations were performed to restore seismic isolation response.Then,seismic response simulations both before and after laying RSMCB were performed for a certain brick-concrete structure office building in Luding County,Ganzi Prefecture,Sichuan Province which experienced a knee-sitting collapse during a magnitude 6.8 earthquake under input conditions of MOXI wave and Turkey wave.Inter-story displacements and shear forces were analyzed contrastively.The results showed that(1)input acceleration decreases to a certain extent after being filtered with RSMCB cushion,RSMCB’s attenuating and filtering high-frequency vibration frequencies is its main seismic isolation mechanism;(2)smaller errors between simulation results and test data fully verify the correctness of the numerical modeling method and the reliability of the subroutine constitutive relations;(3)acceleration responses,inter-story displacements and inter-story shear forces of office building structure with RSMCB laid obviously decrease compared to those of the structure model without RSMCB laid,inter-story displacement is the maximum at bottom isolation layer,and responses of upper structure with RSMCB laid are the maximum under XYZ input condition;(4)RSMCB’s seismic isolation effect on houses is very significant and meets the low-cost seismic isolation needs of underdeveloped rural areas,it exhibits good application prospects in rural development processes,RSMCB has advantages of convenient material selection,low cost,significant seismic isolation effect,and can be used as a low-cost long-life seismic isolation technology.