降雨条件下基坑坡度和平台宽度对稳定性的影响  

Effect of Pit Slope and Platform Width on Stability under Rainfall Conditions

作　　者：周斌 张弘 林春秀 付冬平 ZHOU Bin;ZHANG Hong;LIN Chunxiu;FU Dongping(Beijing Municipal Engineering Design and Research Institute Co.,Ltd.Beijing 100082,China)

机构地区：[1]北京市市政工程设计研究总院有限公司,北京100082

出　　处：《广东土木与建筑》2025年第2期28-31,共4页Guangdong Architecture Civil Engineering

基　　金：国家自然科学基金资助项目(52078285)。

摘　　要：降雨是引起基坑放坡失稳的主要诱发因素之一。以广州市番禺区某边坡为案例,采用有限元软件建立了三维应力—渗流耦合的边坡计算模型,并结合强度折减法进行瞬态渗流作用下边坡稳定性计算,分析了中雨条件(6 mm/h、6 h)下不同平台宽度以及坡度比对边坡位移以及塑性区的影响。研究结果表明:边坡平台宽度增加会使斜坡中部位移增速减慢,坡度比减小会使位移主要向边坡顶部发展;边坡的塑性区主要在滑移面和边坡底部,平台宽度增加和坡度比减小会使塑性区不明显,当平台宽度达3.0 m和坡度比达1∶2.0时,边坡不会出现贯通的塑性区。文章研究成果可为基坑开挖时放坡提供参考。Rainfall is one of the main triggering factors that cause slope instability of foundation pit release.Taking a slope in Panyu District,Guangzhou City as a case study,a three-dimensional stress-seepage coupling slope calculation model was established using finite element software,and combined with the intensity discount method to calculate the stability of the slope under transient seepage,and analysed the effects of different platform widths and slope ratios on the displacement and the plastic zone of the slope under the conditions of moderate rainfall(6 mm/h and 6 h).The results show that:increasing the platform width will slow down the displacement growth in the middle of the slope,and decreasing the slope ratio will make the displacement mainly to the top of the slope;the plastic zone of the slope is mainly in the sliding surface and the bottom of the slope,increasing the platform width and decreasing the slope ratio will make the plastic zone not obvious,and the plastic zone will not appear when the platform width is up to 3.0 m and the slope ratio is up to 1∶2.0.The research results can provide reference for slope release during foundation pit excavation.

关 键 词：降雨 坡度比 稳定性 基坑 放坡 

分 类 号：TU443[建筑科学—岩土工程]