地震和地下水耦合作用下砂土边坡稳定性研究

Stability of sandy soil slope under the coupling of earthquake and groundwater

基于砂土边坡的有限元模型研究了地震和下水耦合作用下砂土边坡的稳定性。研究表明,规范中考虑地震和地下水影响的叠加法计算边坡的安全系数适用范围是非常有限的;采用边坡永久位移指标进行边坡的稳定性评价比安全系数更精确;随着地下水的升高边坡坡面的最大剪应变出现减小的趋势,且在边坡底部出现了最大值,为边坡容易剪出破坏位置,且边坡底部减的有效应力明显减小,对边坡的稳定极为不利;随着地下水升高,土钉的轴力和弯矩出现减小趋势,在靠近边坡底部位置的土钉轴力产生了最大值。最后,基于室内振动台试验结果与数值模拟的结果的对比分析,验证了本文数值模拟结果的准确性。

Based on the finite element model of sandy soil slope, the stability of sandy soil slope is studied. The results show that superposition method of coupling of earthquake and groundwater in codes is very limited. The evaluation index of permanent displacement is more accurate than safety factor. With the increase of groundwater, shear strain decreases, and the maximum value appears at the bottom of the slope which is destroyed easily, and the effective stress at the bottom of the slope decreases obviously, which is disadvantage for the stabilization of the slope. With the increase of groundwater level, the maximum axial force and the maximum bending moment show a decreasing trend, and the soil nailing axial force of the slope has the maximum value near the bottom of the slope. Based on the comparison between shaking table test and the numerical simulation, the accuracy of the numerical simulation results are verified.