【摘要】 该文在清华大学土工离心机振动台上开展了倾斜可液化地基中刚性单桩基础的试验研究,观测了地基的加速度、位移、孔压和桩基础的弯矩等响应。研究结果显示:地震中地基浅层部分较快达到液化状态,不同深度超静孔隙水压力的累积与消散并不相同;砂土的液化使得地基的加速度响应发生变化,有效地过滤了地震波的部分高频段;地震过程中桩身弯矩峰值出现在浅层地基达到初始液化后,且最大弯矩出现在桩头;倾斜地基使得桩身产生了较大的残余弯矩。由此表明在侧向流动地基中,液化前、液化后大变形和地震后永久位移三个不同阶段桩的受力并不相同。在进行可液化地基中桩基础的研究中,应考虑这三个不同阶段桩基础的受力要求。该研究加深了对倾斜液化地基中桩基础的地震响应的理解,有助于进一步的揭示地震过程中可液化地基桩基础的震损机理。更多还原

【Abstract】 Dynamic centrifuge model tests on single pile foundation in sloping liquefiable ground were conducted to investigate the behavior of pile foundations in liquefiable soil during earthquakes.Acceleration and excess pore pressure of the foundation and moment of the pile were measured and recorded during the test.Test results showed the top of the ground liquefied and excess pore pressure patterns varied with the depth.Upon liquefaction,soil filtered out high frequency contents of the earthquake,reducing the maximum acceleration of the earthquake.The maximum moment of the pile occurred after initial liquefaction at the pile head.Relatively large residual moment was observed in the pile after the excitation.These results indicate that the response of piles varies in the three different stages including pre-liquefaction,post-liquefaction and lateral ground displacement after earthquakes,and further studies should consider these differences.This research enhanced the understanding of pile responses during earthquake,and would provide basis for further investigation into the soil-pile-structure interaction mechanism in liquefiable soil.更多还原