地震荷载作用下土钉支护边坡稳定性拟静力分析  

Stability analysis of slope protected by soil nailing under earthquake loads based on pseudo static method

作　　者：邓东平[1] 李亮[1] 罗伟[1] 

机构地区：[1]中南大学土木工程学院,长沙410075

出　　处：《岩土力学》2012年第6期1787-1794,共8页Rock and Soil Mechanics

基　　金：西部交通建设科技项目(No.2006318802111);贵州省交通运输厅科技项目(No.2010-122-020);铁道部科技研究开发计划重点资助项目(No.2008G032–3);湖南省交通厅科技项目(No.2007–29)

摘　　要：在极限平衡分析框架内,使用滑动面搜索新方法和圆弧滑动面方法对地震作用下的土钉支护边坡进行稳定性分析。考虑地震作用时,采用拟静力分析方法,并根据不同的条分模式,推导出水平地震动态分布系数的计算公式。针对地震效应下圆弧滑动面竖直条分法的不足,采用水平和竖直条分法相结合的改进方式。通过算例对比分析,并研究土钉支护间距与不同地震烈度条件下土钉长度的变化对边坡静力和动力稳定性的影响,结果表明,滑动面搜索新方法计算得的最小安全系数与圆弧滑动面方法的计算结果颇为接近,且比以往研究成果要小,可说明滑动面搜索新方法的可行性;在土钉支护边坡的静力和动力稳定性分析中,滑动面搜索新方法计算得的临界滑动面与临界圆弧滑动面接近,但表现出非圆弧特性;在一定程度上可减小土钉支护间距和增大土钉长度,可有效地改善土钉支护边坡在地震作用下的稳定性。In the framework of limit equilibrium analysis,stability of slope protected by soil nailing is analyzed by using a new method of searching for sliding surface and circular sliding surface method.When considering earthquake,pseudo static method is adopted.Then,according to different modes of slice,a formula of calculating dynamic distribution coefficient of horizontal seism is derived.Aiming at the shortage of vertical slice method of circular sliding surface under earthquake,the mode of combining horizontal slice method with vertical slice method is used.Through analyzing examples and studying the effect of space change of soil nailing and length of soil nailing under different earthquake intensities on the static and dynamic stabilities of slope protected by soil nailing,some conclusions are obtained.The minimum factor of safety（FOS） calculated by new method is quite close to that calculated by circular sliding surface method,and is also smaller than previous results,so it shows that the new method of searching for sliding surface is feasible.In analyzing the static and dynamic stabilities of slope protected by soil nailing,the critical sliding surfaces got by the new method is close to the those got by critical circular sliding surfaces,but they perform the characteristics of non-circular feature.Reducing space of soil nailing and increasing length of soil nailing to a certain degree can effectively improve stability of slope protected by soil nailing under earthquake.

关 键 词：边坡稳定性分析 土钉 地震作用 拟静力法 曲线滑动面 圆弧滑动面 安全系数 

分 类 号：TU435[建筑科学—岩土工程]