考虑土拱效应的黏性土主动土压力解析解  

Analytical solution of active earth pressure considering soil arching for cohesive soil

作　　者：刘杰锋 曹海莹[2] 王优群 高艳斌 LIU Jiefeng;CAO Haiying;WANG Youqun;GAO Yanbin(School of Civil Engineering,Tianjin University,Tianjin 300350,China;School of Civil Engineering and Mechanics,Yanshan University,Qinhuangdao 066004,China;Soil and Water Conservation Experimental Station of Baoding,Baoding 071000,China)

机构地区：[1]天津大学建筑工程学院,天津300350 [2]燕山大学建筑工程与力学学院,河北秦皇岛066004 [3]保定市水土保持试验站,河北保定071000

出　　处：《铁道科学与工程学报》2023年第12期4604-4612,共9页Journal of Railway Science and Engineering

基　　金：河北省自然科学基金资助项目(E2020203168);河北省高等学校科学技术研究重点项目(ZD2020330)。

摘　　要：挡土墙是一种常见的挡土结构物,在道路工程中得到了广泛的应用。作用在挡土墙上的主动土压力是工程中挡土墙设计的一个重要指标。为了进一步提高主动土压力的计算精度,以多因素影响下的刚性挡土墙为研究对象,同时考虑挡墙墙背倾角、填土黏聚力和内摩擦角、墙-土摩擦角和黏结力以及超载等因素的影响,假定墙后形成的圆弧形土拱产生土拱效应,基于薄层单元法,推导了主动土压力分布、合力大小和滑裂面倾角的计算公式。通过与模型试验和现有理论结果的对比分析,验证本文理论解对主动土压力计算的有效性。研究结果表明:考虑土拱效应后的土压力沿墙高为非线性分布,土压力随着墙高和超载的增加而增大,随着黏聚力的增大而减小;在墙上部(约0~H/3),主动土压力随墙背倾角的增大而减小;在墙下部(约H/3~2H/3),主动土压力随墙背倾角的增大而增大;当挡土墙由光滑转为粗糙时,土压力分布由线性分布转为非线性分布;此外,墙土界面越粗糙,墙背墙角越大,土压力非线性分布程度越明显。尽管考虑因素的增多使得土压力的计算过程变得复杂,但由于计算条件与实际工况更加接近,土压力计算结果误差更小。本文建立的考虑多因素影响的主动土压力通用计算公式,可为实际复杂工程条件下的挡土墙设计提供理论指导。The retaining wall is a common retaining structure that has been widely used in road engineering.Active earth pressure acting on the retaining wall is an important index for the design of retaining wall in engineering.In order to further improve the calculation accuracy of active earth pressure,rigid retaining wall under influence of multiple factors was selected as object of this study,and effects of inclination angle of retaining wall back,internal friction angle and cohesion of backfill,wall-soil friction angle and adhesion,and surcharge were considered at the same time.Effects of soil arching was considered by assuming the shape of soil arching behind the retaining wall was a circle shape,and the formula of distribution of active earth pressure,resultant force and inclination angle of slip surface were theoretically derived based on thin-layer element method.Validity of theoretical method proposed in this study of active earth pressure was verified by comparing results of this study,model test and existing theoretical solutions.Results show that distribution of active earth pressure shows non-linear characteristic attribute to consideration in effect of soil arching.Earth pressure increases with the increase in wall height and surcharge,and it decreases with increasing cohesion.Earth pressure increases with increasing inclination angle of retaining wall back at wall height from 0 to H/3,while it decreases with increasing inclination angle of retaining wall back at wall height from H/3 to 2H/3.Distribution of earth pressure transforms from linear to non-linear when wall back is transformed from smooth to rough.The rougher of retaining wall back and the higher inclination angle of wall back,the more obvious of non-linearity in distribution of active earth pressure.Calculation process of active earth pressure becomes complex as increase in factors,but the error of calculation results of earth pressure is smaller because the calculation conditions are closer to the actual working conditions.This study establishes

关 键 词：挡土墙 薄层单元法 主动土压力 黏性填土 土拱效应 

分 类 号：TU432[建筑科学—岩土工程]