山地掉层框架隔震结构振动台试验研究

Shaking table test on isolated step-terrace frame structure in mountainous area

在山地掉层结构的上、下接地层设置橡胶隔震支座,形成山地掉层隔震结构。为研究山地掉层隔震结构的抗震性能,对某8度抗震设防区掉2层1跨的7层钢筋混凝土框架结构以相似关系1∶10制作了振动台试验模型,通过在试验模型底部安装和拆卸橡胶支座的方法分别进行了掉层隔震与非隔震结构模型的振动台试验,对比分析了山地掉层隔震与非隔震结构模型宏观试验现象、频率变化、楼层加速度、楼层位移以及混凝土应变的区别。结果表明:与山地掉层非隔震结构相比,山地掉层隔震结构的扭转效应减小,地震响应得到有效控制,其抗震性能明显高于非隔震结构,且安全储备高;将隔震技术应用于山地掉层结构中是可行的。

With rubber bearings installed in upper and lower ground layers,the isolated step-terrace structure in mountainous area is constituted.In order to investigate the seismic performance of isolated step-terrace structure in mountainous area,an seven-story isolated step-terrace concrete frame structure model with two dropped-layers and one span in eight degree fortification area was designed according to the 1∶10 similarity ratio.Shaking table tests of the isolated and non-isolated structure model were carried out separately through installing or removing rubber bearings at the bottom of the model.The differences of test phenomenon,frequency shift,floor acceleration,floor displacement and concrete strain between the isolated and non-isolated structure model were compared and analyzed.The results show that the seismic response is effectively controlled while the torsion effect is reduced in the isolation test.The seismic behavior and the safe capacity of the isolated step-terrace structure are more favorable than non-isolated structure.It can be proved that seismic isolation technology may provide a feasible way in improving the seismic performance of isolated step-terrace structure in mountainous area.