地震作用下双排抗滑桩支护边坡振动台试验研究

利用大型振动台试验研究双排抗滑桩支护在地震荷载作用下的抗震性能。通过对比上部锚杆+下部双排桩共同支护与单一桩支护的破坏过程,分析两种情况下坡体的动力响应与破坏机制。试验表明在桩+锚杆共同支护下,桩后边坡坡脚首先发生剪切破坏,当地震动作用增大到一定范围,坡顶出现张拉裂缝,两者贯通时边坡发生越顶破坏；单一桩支护条件下,首先在坡顶出现张拉裂缝,裂缝随着地震动作用增大向下扩展,当同下部剪切滑移带贯通时,边坡失稳破坏。通过坡体裂缝发展过程、位移及加速度监测数据表明,前者的抗震性能显著优于后者；在地震动作用下,边坡破坏是张拉–剪切复合作用的结果。试验研究为双排抗滑桩抗震设计奠定了坚实的基础。

Shaking table tests on double-row anti-slide piles of slopes under earthquakes

A large shaking table test is performed to study the seismic performance of a slope with double-row anti-slide piles triggered by seismic load. Different dynamic response characteristics and failure mechanisms are studied by comparing the failure processes of a pile-anchor mixed support system and a single pile support system. The tests show that shear failure first occurs at the slope toe under a pile-anchor mixed support. As the horizontal acceleration increases, tension crack starts to develop at the top of the slope. The overall failure of the slope occurs when a global failure surface is formed, connecting the shear failure at the toe and tension crack at the top. However, tension cracks first appear at the slope top under the single pile support conditions. These cracks extend towards the slope toe as the acceleration increases and eventually lead to the overall slope failure. The experimental observations and data demonstrate that the seismic performance of the former is better than that of the latter. The slope failure is the result of the combined effect of tension and shear. This experimental study has laid a solid foundation for the seismic design of anti-slide piles.