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可液化场地微型桩的地震响应分析是确保工程安全和优化抗震设计的前提。应用动态离心机试验和三维有效应力数值分析方法,研究了微型单桩桩台的侧向变形和加速度、不同埋深桩身弯矩、可液化场地的加速度及超孔隙水压力等响应特征。首先开展了相对密实度为57%饱和土层、输入波是频率为1 Hz和峰值加速度为1.516 m/s2正弦波的微型桩40 g动态地震响应离心机试验,进而应用基于多重剪切机构塑性模型和液化前缘状态面概念的三维有效应力分析方法,反演了试验结果,并进行了对比分析,结果表明,数值模拟与离心机试验结果吻合,液化场地特性控制着建于其中微型桩的地震响应特征,微型桩桩台的水平变形和残余变形可达78、30 mm,桩身最大弯矩和最大残余弯矩呈现向桩身底部迁移特点,同时表明,基于动态土工离心机试验和数值分析相结合的研究方法,分析可液化场地微型桩地震响应特性是有效可行的,研究结论为可液化场地微型桩的抗震设计提供了可靠的依据和参考。
Seismic response analysis of micro pile in liquefiable site is the premise of ensuring engineering safety and optimizing seismic design. The dynamic response of the micro-single-pile platform to lateral deformation and acceleration, pile bending moment at different depth, acceleration of liquefiable ground and excess pore water pressure were studied by dynamic centrifuge test and three-dimensional numerical analysis of effective stress. Firstly, 40 g saturated soil with relative density of 57% was used. The input wave was a 40 g micro-pile dynamic seismic response centrifuge with a frequency of 1 Hz and a peak acceleration of 1.516 m / s2. The plasticity Model and liquefied front edge state plane concept of three-dimensional effective stress analysis method, the experimental results were inverted, and compared and analyzed, the results show that the numerical simulation and centrifuge test results agree, liquefied field characteristics control the micro-pile built therein Seismic response characteristics, the horizontal deformation and residual deformation of micro-pile can reach 78,30 mm, the maximum bending moment and the maximum residual bending moment of pile show the characteristics of migration to the bottom of the pile, meanwhile, based on dynamic geocentrifuge test and numerical It is effective and feasible to analyze the seismic response characteristics of the micro pile in the liquefiable site. The research conclusion provides a reliable basis and reference for the seismic design of the micro pile in the liquefiable site.