季节冻土区土钉支护边坡地震反应动力特性分析

为了更科学地评价地震荷载作用下土钉支护季节冻土边坡的抗震性能,基于热-动力理论控制方程,应用大型非线性有限元软件ABAQUS,建立带有黏弹性人工边界的地震荷载作用下土钉支护季节冻土边坡的数值模型,对比分析夏季和冬季这两个典型季节时的加速度响应、位移响应以及土钉轴力响应。结果表明：无论是夏季还是冬季,加速度峰值随着季节冻土边坡高程以及激振加速度峰值增加而增加,在夏季时刻的季节冻土边坡坡顶位置处达到最大。此外,在不同地震波峰值加速度作用下,相同位置处的位移响应峰值却有明显的不同,同一地震烈度地震波激震时,夏季的季节冻土边坡坡顶位移最大,表明地震荷载对夏季的季节冻土边坡坡顶破坏效应最为明显,土钉轴力具有高程放大效应和坡面放大效应,季节冻土边坡坡底至坡顶的土钉端部轴力峰值逐渐增大。文中数值模拟模型及结论可为制定地震荷载作用下土钉支护季节冻土边坡抗震设计提供一定的参考。

Dynamic characteristics of seismic response of soilnailed slopes in seasonal frozen areas

To scientifically evaluate the seismic performance of soil nailed slopes in seasonal frozen areas, based on the theory equation of thermal-dynamics, a numerical model of soil nailed slope with viscoelastic artificial boundary in seasonal frozen area was established under earthquake load by using large-scale nonlinear finite element software ABAQUS. The acceleration response, displacement response, and axial force response of soil nails in summer and winter were compared and analyzed. The results showed that whether in summer or winter, the peak acceleration increases with the increase of the slope elevation and the peak value of excitation acceleration, and reaches the maximum at the top of slope in summer. In addition, under the action of seismic waves with different peak acceleration, the peak displacement responses at the same position are obviously different. When seismic wave with the same intensity is excited, the largest displacement shows at the top of slope in summer, indicating that the seismic load has the most obvious damage effect on the top of slope in summer. The axial force of soil nails has elevation amplification effect and slope amplification effect. The peak value of axial force at the end of soil nails gradually increases from the bottom of slope to the top. The numerical simulation model and conclusions in this paper can provide some reference for the seismic design of seasonally frozen soil slope supported by soil nails under seismic load.