基于转动-平动组合破坏机构的含软弱夹层土坡降雨入渗稳定上限分析  

Rotation-translation combined mechanism for stability analysis of slopes with weak interlayer under rainfall condition

作　　者：黄茂松[1,2] 王浩然[1,2] 刘怡林[3,4] 

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学地下建筑与工程系,上海200092 [3]交通运输部公路科学研究院,北京100088 [4]交通运输部道路结构与材料重点实验室,北京100088

出　　处：《岩土工程学报》2012年第9期1561-1567,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家杰出青年基金项目(50825803);西部交通建设科技项目(200831822357);国家自然科学基金项目(51108215)

摘　　要：软弱夹层、降雨等因素对边坡的整体稳定性有着很大的影响。软弱夹层会使得边坡的破坏形式发生改变,从而降低其稳定性;而降雨不但会使得边坡的稳定性变差,甚至有可能使边坡内形成更加软弱的夹层。但是目前尚未有一个简单合理的方法来分析这种类型边坡的稳定性。基于转动-平动组合破坏机构,提出了一种用于含软弱夹层边坡降雨入渗稳定性极限分析上限法。采用非饱和非稳定渗流分析计算得到的浸润线位置结合降雨后的土体强度及组合破坏机构分析含软弱夹层边坡降雨入渗的稳定性,通过与弹塑性有限元数值模拟结果进行对比,验证了本文方法的有效性。分析表明,组合破坏机构能够很好的用于含软弱夹层边坡的稳定性分析并为实际工程提供一个简单有效的设计方法。Weak interlayer and rainfall have great effects on slope stability. The weak interlayer may change the failure mechanism and reduce the slope stability. The rainfall will make the slope more instable and may even induce weak interlayer formed in the slope. However, simple and rational evaluation methods for such a slope stability problem have not been proposed so far. In this paper, based on the upper bound limit analysis method, a new failure mechanism consisting of rigid blocks undergoing impending rotational or translational movements is proposed to study the slope stability under rainfall condition. Rainfall-induced change of pore water pressure in slopes is analyzed by means of the transient seepage finite element analysis. The saturation line and the soil strength after rainfall are then considered and incorporated into the limit analysis. The proposed rotation-translation combined mechanism is finally verified by comparisons with the elasto-plasticity finite element method. The comparisons show that the proposed mechanism improves the efficiency of the previously-developed rigid block mechanism to account for the presence of weak interlayer in the slopes and can be used as a simple evaluation method for the engineering design.

关 键 词：软弱夹层 降雨 边坡稳定 组合破坏机构 安全系数 

分 类 号：TU47[建筑科学—结构工程]