非液化土-群桩基础-结构体系相互作用动力响应振动台试验研究

为深入研究非液化场地中桩-结构体系地震响应和土-结构动力相互作用问题，进行了含有一定深度的松砂层非液化场地土-结构体系动力相互作用大型振动台试验，分析非液化场地和群桩基础的加速度地震响应特征，并对土体侧向变形规律以及桩基弯矩分布进行了分析。结果表明：当输入0.05g拍波时，土体与桩基对加速度反应表现出放大作用，且距离结构较远处土体对加速度放大作用更加明显；当输入0.3g汶川地震卧龙台地震记录时，加速度只在远离桩基的土体中加速度反应有一定放大；桩身最大弯矩均超过60N·m，并且桩基弯矩幅值呈现出桩顶弯矩小(靠近桩顶处)、下部弯矩大(靠近桩端处)的规律，且在土层交界面附近弯矩存在突变；上部结构加速度反应自上而下有一定程度的减小，地震动Arias强度值减小明显，刚性场地上的结构地震动Arias强度是位于土体上结构的3~4倍，说明土体的耗能作用明显。

Dynamic interaction and seismic response of non-liquefiable soil-pile group foundation-structure system from shaking table test

In order to deeply study the seismic response of pile-structure system and soil-structure dynamic interaction in non-liquefiable sites, a large-scale shaking table test of dynamic interaction of soil-structure system was carried out, and the acceleration seismic response characteristics of non-liquefiable sites and pile group foundation were expounded emphatically in this paper. Besides, the law of lateral deformation of soil and the distribution of bending moment of pile foundation were analyzed. The test results show that the acceleration response of soil and pile foundation is amplified and the amplification of acceleration is more obvious when the soil is far from the structure as the 0.05g sine beat wave is input. When 0.3g Wenchuan Earthquake seismic record is input, the acceleration response is only magnified in the soil far from the pile foundation and the maximum bending moment of the pile is more than 60N·m, the bending moment amplitude of pile foundation basically shows the rule that the upper bending moment is small (near the top of pile) and the lower bending moment is large (near the end of pile) and the bending moment near the soil interface has a sudden change. Besides, the acceleration response of superstructure decreases to a certain extent and the intensity of Arias decreases obviously when 0.3g Wenchuan Earthquake seismic record is input, and Arias of structures on rigid sites are 3 to 4 times larger than that on soil, indicating that the energy dissipation of soil is obvious.