液化场地-群桩基础-结构体系动力响应分析—大型振动台模型试验研究

进行了液化场地-结构体系动力相互作用大型振动台试验,对土体和桩基的加速度反应、饱和砂土层的孔压反应等进行了测试。重点阐述了土体和群桩基础的加速度地震响应特征和饱和土体的孔压发展规律,并对土体侧向变形规律进行了分析。试验研究结果表明：0.05g拍波输入时,土体和桩基对加速度反应有着明显放大作用,土体各处孔压比增长幅度不大,土体侧向位移较小;0.3g汶川地震卧龙台地震记录输入时,桩基加速度反应规律与土体反应基本一致,土体孔压比增长明显,上部土体完全液化;土体水平侧向变形较大。本文成果可为液化场地-群桩基础动力相互作用研究做对比分析和验证数值模拟工作提供参考。

Dynamic response analysis of liquefied site-pile group foundation-structure system —large-scale shaking table model test

In this large-scale shaking table model test, the acceleration responses of soil and structures and pore water pressures and other signals are measured. The seismic responses of soil and pile group foundations, the development of pore water pressure of liquefiable soil are introduced, and the lateral deformation of soil is analyzed. The results show that when 0.05g beat wave is input, the acceleration responses of soil and pile foundation are enlarged obviously, and the pore pressure ratio increases stightly throughout the soil. Besides, the lateral displacements of soil are small. When 0.3g Wenchuan Earthquake seismic record is input, the law of acceleration response of pile foundation is basically the same as that of soil. The pore pressures rise rapidly and the soil has been liquefied, and lateral displacements of soil are large. The results of this paper are dynamic response of liquefied non-free site test in a series of large-scale shaking table tests on soil-pile group-superstructure system. The results can be used for comparative analysis and verification of numerical simulation in the future.