斜入射地震作用下坡面形态对碎石土边坡稳定性影响研究

Effect of Slope Shape on Gravel-Soil Slope Stability in Obliquely Incident Seismic Wave

本文研究了在震源近场时,地震波斜入射条件下,不同坡面形态对碎石土边坡稳定性的影响。利用FLAC3D有限差分软件,建立了多种坡面形态的边坡模型。采用对比方法,分析了边坡在地震波作用下的稳定性。结果表明:临空坡面对输入地震波有放大效应;坡面的水平位移与加速度峰值随高度增加而增大,随坡度增加而增大;随着坡面凹度的增大,剪应力增量向坡肩处集中,坡肩愈加不稳定;随着坡面凸度的增大,剪应力增量向坡腰处集中,坡腰愈加不稳定;台阶对坡面的加速度放大效应有削弱作用,台阶数越多越稳定。同时给出了边坡防治的几点建议:减小坡面的坡度;对凹型坡加强坡肩位置处的防治,对凸型坡加强坡腰位置处的防治;对高边坡可设置多级台阶增加稳定性。

In this paper we study the different effect of slope shape on gravel-soil slope stability under condition of obliquely incident seismic wave at the source near field. We use the FLAC3D to set up slope model with a variety of slope shape. We also use the comparison method to analyze the stability of slope under seismic action. Our results showed that faced slope has amplification effect on entered earthquake waves; the level displacement and acceleration peak of slope surface increase with the slope height and gradient increase. With increase of slope surface concave degree, shear stress increment concentrates on slope shoulder, slope shoulder become not stable; with increase of slope surface convex degree, shear stress increment concentrates on slope waist, slope waist become not stable. Slope steps can weaken the acceleration amplification effect of slope surface, the more the step number the slope has, the more stable it is. Finally, we suggest the following countermeasures to increase the stability of slope in the future, i.e. reducing the slope gradient; strengthening the concave slope; and setting more steps.