液化场地桩基桥梁震害响应大型振动台模型试验研究

Large-scale shaking table model test of seismic response of bridge of pile foundation in ground of liquefaction

采用大型振动台进行液化场地桩基桥梁震害响应模型试验,很好再现了自然地震触发场地液化及结构破坏的各种宏观现象。0.15gEl Centro波输入下,上部砂层局部液化,桩-柱墩加速度主要表现为低频反应,桩动应变幅值自下而上很快增大、到达地表则大幅度减小。0.5gEl Centro波输入下,整个砂层全部液化,桩被折断且加速度也主要表现为低频反应,桩动应变幅值自下而上很快增大、到达地表则大幅度减小。砂层液化与否,对桩-柱墩动力反应影响很大。

The proportional model test of seismic response of bridge of pile foundation in liquefaction ground is done by a large-scale shaking table, which can commendably recurrence the main phenomenon of ground liquefaction and structure breakage arisen from natural earthquake. In input of 0.15gEl Centro wave, the upside of the saturation sand stratum is partly liquefied; the low-frequency response of acceleration appears on pile and pillar frusta; and the peak value of pile dynamical strain fastly aggrandizes from bottom to top; and moreover, largely minishes up to tort surface, In input of 0.5gEl Centro wave, the saturation sand stratum is entirely liquefied; the low-frequency response of acceleration also appears on pile and pile is broken; and the peak value of pile dynamical strain fastly aggrandizes from bottom to top, and moreover, largely minishes up to toft surface. It has importantly influence upon dynamic response of pile and pillar frusta that the saturation sand stratum is liquefied or not.