基于主应力旋转的黏性填土挡墙土压力  

The earth pressure of retaining wall with cohesive fill based on principal stress rotation

作　　者：王恒利 邹正盛[1,2,3] 刘京敏 王新宇 WANG Hengli;ZOU Zhengsheng;LIU Jingmin;WANG Xinyu(College of Civil Engineering,Henan Polytechnic University,Jiaozuo,Henan 454003,China;International Joint Research Laboratory of Henan Province for Underground Space Development and Disaster Prevention,Jiaozuo,Henan 454003,China;Henan Key Laboratory of Underground Engineering and Disaster Prevention,Jiaozuo,Henan 454003,China;China Geo-Engineering Corporation,Beijing 100093,China)

机构地区：[1]河南理工大学土木工程学院,河南焦作454003 [2]河南省地下空间开发及诱发灾变防治国际联合实验室,河南焦作454003 [3]河南省地下工程与灾变防控重点实验室,河南焦作454003 [4]中国地质工程集团有限公司,北京100093

出　　处：《水文地质工程地质》2021年第4期64-71,共8页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金重点项目(U1810203);河南理工大学博士基金项目(648198)。

摘　　要：填土水平墙背竖直光滑的挡墙,墙后土体处于以自重应力和水平应力为主应力的应力状态。实际工程中,挡墙背面与土体存在一定的摩擦及黏结力作用致使挡墙附近土体中的主应力发生偏转,此时,经典朗肯土压力理论不再适用。本文对挡墙附近土中的主应力状态进行旋转处理,通过分析墙后填土中应力状态摩尔圆,得到了考虑墙土摩擦和黏结力作用的黏性填土挡墙主被动土压力计算公式,分析了填土内摩擦角与墙土摩擦角对土压力的影响,使用算例将本文方法所得结果与现有黏性土土压力计算方法所得结果进行了对比分析。结果表明,朗肯土压力公式是本文所得计算公式的特例;随着墙土摩擦角和内摩擦角的增加,被动土压力逐渐加快增大;主动土压力随着内摩擦角的增加而减小;当内摩擦角较小时,主动土压力随着墙土摩擦角的增大不断减小,当内摩擦角较大时,主动土压力随着墙土摩擦角的增大先减小后增大;土内摩擦角的影响大于墙土摩擦的影响;相对于现有方法计算结果,本文方法所得主动土压力较大,被动土压力较小,墙土摩擦越大,2种方法所得结果的差值越大,土黏聚力还会加大这一差值。本文方法考虑了墙背土体主应力方向偏转的客观事实,所得计算结果将更符合实际情况。The soil behind a wall is in a stress state with self-weight stress and horizontal stress as the main stress for the Rankine retaining wall with horizontal fill.However,there is a certain wall-soil friction and bonding force in practice.The friction and bonding force may cause the principal stress deflection in the fill near the retaining wall,and the classical Rankine earth pressure theory is not applicable for this case.In the current study,the principal stress deflection of the fill near the retaining wall is processed both by the rotation and by the analysis of the stress from the Mohr circle in the fill behind the wall.The active and passive earth pressures of the retaining wall filled with the cohesive soil is derived,considering the wall-soil friction and bonding force.The influences of the fill friction angle and the wall-soil friction angle on the earth pressures are analyzed.The examples are further used to compare the results from this study with those with the improved Coulomb method.The results show that the Rankine earth pressure is a special case of the formula presented in this study.With the increase of the wallsoil friction angle and internal friction angle,the passive earth pressures gradually increase.The active earth pressures decrease with the increase of the internal friction angle,and the decreasing rate gradually decreases.When the internal friction angle is small,the active earth pressures decrease continuously with the increase of the wall-soil friction angle,and the decreasing speed gradually decreases.When the internal friction angle is large,the active earth pressures first decrease and then increase with the increase of the wall-soil friction angle.The effect of the fill friction angle is more obvious than that of the wall-soil friction angle.Compared with the results from other methods,the active earth pressures obtained with this method are larger,but the passive earth pressure is smaller,and their differences increase with the increase in the wall-soil friction,especially when th

关 键 词：主动土压力 被动土压力 墙土摩擦作用 主应力偏转 主应力旋转 黏性土 

分 类 号：TU432[建筑科学—岩土工程]