不同土性地基上高层隔震结构振动台试验对比研究

通过土-结构动力相互作用（SSI）体系的模型振动台对比试验，研究不同土性地基上高层隔震结构的地震反应特性和隔震效果。采用叠层剪切型土箱以减小边界效应影响，模型地基分别为刚性地基、均匀软土层地基、分层可液化地基，采用高宽比为4的五层钢框架作为上部隔震结构模型。试验发现，考虑SSI的隔震结构体系频率均小于不考虑SSI的体系频率，均匀软土层地基上隔震结构体系的阻尼比刚性地基增加，而分层可液化地基上体系的阻尼则降低；软弱地基上隔震层位移可明显大于刚性地基上的情况，而当地基发生液化时隔震层的位移则明显减小。研究结果表明，建造于软弱地基、存在液化可能地基上的高层隔震结构仍然能够发挥隔震效果。

Comparative study on high-rise isolated structure founded on various soil foundations by using shaking table tests

Shaking table tests about the comparison of dynamic Soil-Structure Interaction (SSI) systems were conducted, to investigate the seismic behavior and the isolation effectiveness of a high-rise isolated structure founded on various soil. A laminar shear soil container was designed to minimize the boundary effects. The high-rise isolated structure was modeled by a five-story steel frame with aspect ratio of 4, founded on rigid foundation, homogeneous soft soil foundation and layered liquefiable foundation, respectively. Test results indicate that the natural frequency of the SSI isolated structure system is less than that of the system when SSI is not taken into account. The damping ratio of the isolated structure on homogeneous soft soil foundation is larger than that of the structure on rigid foundation, while it is smaller when founded on liquefiable foundation. It is also shown that the isolation displacement may increase obviously when founded on soft soil, while decrease when founded on liquefiable foundation. This study concluded that, even founded on soft soil or liquefiable foundation, the isolation effectiveness of the high-rise isolated structure can be warranted.