地震作用下土钉支护边坡动力分析

应用动力弹塑性有限元方法，研究了双向地震激励下土钉支护边坡动力响应。考虑土体与支护结构相互作用及其协同工作建立三维有限元模型。给出了地震波和阻尼的选取方法。应用了非线性静动力性能的弹塑性模型模拟土体；采用了可以描述土钉在进入塑性阶段强化性质的双线形弹塑性模型模拟土钉；土与结构的相互作用由接触单元模拟。研究内容包括边坡竖向地震响应、水平地震响应，土钉的地震响应，土压力地震响应。结果表明土钉支护边坡延性大，有很好的抗震性能；地震作用后各层土钉轴力都增大；边坡在地震作用下产生永久位移；地震作用下土压力峰值形状与地震作用前的土压力形状相似。这些结论对土钉支护边坡的抗震设计与动力分析有较高的参考价值。

Seismic Behavior of a Slope Protected by a Soil Nailing Retaining Wall during an Earthquake

The dynamic elastic plastic finite element method was used to study the seismic performance of a slope protected by a soil nailing retaining wall. On the basis of working in parallel and interaction between loess and a flexible retaining wall, a 3 D nonlinear finite element method (ADINA) also was established. Rational earthquake excitation and damping were discussed for geological engineering. Horizontal and vertical excitations were considered simultaneously in the analyses. A model capable of simulating the nonlinear static and dynamic elastic plastic behavior of soil was used to model the soil, and a bilinear elastic plastic model having hardening behavior was used to model the soil nailing. A friction element was employed to describe the soil structure interaction behavior. Our research focused on the seismic performance of the horizontal and vertical slope deformation, soil nailing axial force, and earth pressure subjected to horizontal and vertical excitations. The results show that the seismic performance of slope protected by soil nailing is good; soil nailing axial force increases after an earthquake; permanent slope displacement occurs during an earthquake; and the peak earth pressure distribution during an earthquake is similar to the earth pressure before the earthquake. These conclusions can provide references for seismic analyses and design in soil nailing engineering.