非饱和土刚性挡墙抗滑移稳定性上限分析  

Upper Limit Analysis of Anti-sliding Stability of a Rigid Retaining Wall in Unsaturated Soils

作　　者：邓波 杨明辉[2] 赵明华[2] DENG Bo;YANG Minghui;ZHAO Minghua(College of Civil Engineering,University of South China,Hengyang 421001,China;College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]南华大学土木工程学院,湖南衡阳421001 [2]湖南大学土木工程学院,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2023年第1期171-180,共10页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51678230);湖南省自然科学青年基金资助项目(2021JJ40460);湖南省教育厅科学研究项目(21C0269)。

摘　　要：在以往挡墙稳定性分析中多假定墙后回填土为饱和土,忽略了吸应力效应对挡墙滑动稳定性的影响,从而导致计算结果失真.鉴于此,在广义有效应力原理基础上,推导了适用于非饱和土的功能平衡方程,并在此基础上采用能量法提出了一种挡墙-非饱和土系统抗滑移上限稳定性系数计算方法.通过对比OptumG2数值软件和已有理论方法的结果验证了该方法的合理性,并探讨了土体剪切强度、进气值和渗流量等主要参数对挡墙稳定性的影响.结果表明:1)相比砂土,吸应力对黏土挡墙稳定性影响更大,而相比黏土,砂土中黏聚力变化对墙土系统稳定性更为敏感;2)随着进气值增加,吸应力对墙土系统稳定性的贡献减少,最终趋于恒定,且吸应力对于高度较低的挡墙影响更明显;3)相比无吸力情况,考虑吸力作用的稳定性系数更大,不同渗流量对墙土系统稳定性的影响大小为:蒸发>静水>入渗,且渗流量对黏土和粉土挡墙稳定性影响最大,黄土次之,砂土最小.In the previous analyses of retaining wall stability,it was assumed that the backfill soil behind the wall was saturated soil,and the influence of the suction stress effect on the sliding stability of the retaining wall was ignored,which led to the distortion of the calculation results.In view of this,based on the generalized effective stress principle,the work-energy balance equation applicable to unsaturated soils was derived,and on this basis,a method for calculating the upper limit stability coefficient for anti-sliding of the retaining wall-unsaturated soil system was proposed by using the energy method.The rationality of the method in this paper was verified by comparing the results of OptumG2 numerical software and the existing theoretical methods.And the influence of parameters such as soil shear strength,air-entry value,and seepage flow on the stability of the retaining wall was discussed.The research results show that:1)Compared with sand,suction stress has a greater impact on the stability of retaining wall in clay,while the change of cohesion in the sand is more sensitive to the stability of the wall-soil system;2)With the increase of air-entry value,the contribution of the suction stress to the stability of the wall-soil system decreases and eventually tends to be constant,and the influence of the suction stress on the low retaining wall is more obvious;3)Compared with the case without suction,the stability coefficient considering suction is larger,the influence of different seepage flow on the stability of the wall-soil system is as follows:evaporation>no flow>infiltration,and the seepage flow has the greatest influence on the stability of retaining wall in clay and silt,followed by loess and sand.

关 键 词：挡墙 抗滑移稳定性 吸应力 能量法 功能平衡方程 

分 类 号：TU411[建筑科学—岩土工程]