车辆荷载下饱和路基挡墙主动土压力计算  

Active earth pressure induced by saturated subgrade under vehicle load

作　　者：王俊杰[1] 柴贺军[2] 

机构地区：[1]重庆交通大学河海学院,重庆400074 [2]重庆交通科研设计院道路工程所,重庆400067

出　　处：《岩土工程学报》2008年第3期372-378,共7页Chinese Journal of Geotechnical Engineering

基　　金：交通部交通应用基础研究项目(2005319740090);中国博士后科学基金资助项目(20070410206);重庆市教育委员会科学技术研究项目(KJ070416);重庆市科委自然科学基金计划资助项目(CSTC2007BB7422)

摘　　要：山区公路沿河路基的地下水受河水影响处于动态变化中,路基地下水的渗流条件、车辆荷载等必然影响作用于路基挡墙的主动土压力的大小。基于Coulomb土压力理论的基本假定,在对沿河路基及挡土结构物结构进行合理简化的基础上,结合我国现行有关规范,针对沿河路基排水系统沿墙-土界面布置、沿路基填土底部布置和排水系统完全失效3种情况,分别推导了作用于路基挡墙上的主动土压力的计算公式。讨论了路基填土的有效内摩擦角和饱和重度、墙-土界面摩擦角和车辆荷载等对主动土压力系数的影响。指出在确保路基排水系统有效性的前提下,沿路基填土底部布置排水系统的方案优于沿墙-土界面布置的方案;杜绝超载车辆运行对确保沿河路基稳定具有重要意义。Ground water states in the subgrade of mountain highways in fiver environment are often affected by the hydrological conditions of the fiver, so that the magnitude of active earth pressure acting on the retaining structure of the subgrade should be affected by many factors such as the seepage condition of the ground water and vehicle loads. Based on the basic assumptions of Coulomb＇s theory, some simplifications on the structures of the subgrade and the retaining wall and related applicable codes of China, three solutions for computing the active earth pressures of three different cases, in which the retaining walls were provided with effective drainage systems along the soil-structure interface, effective drainage systems along the base of the backfill of the subgrade, and noneffective drainage systems, respectively, were suggested. Various influence factors on the coefficients of active earth pressures such as the effective internal friction angle and saturated unit weight of the backfill of the subgrade, the soil/wall friction angle and the vehicle loads were investigated. It was emphasized that in the design of the retaining structure of the subgrade, the effective drainage system placed along the base of the backfill of the subgrade was better than that placed along the soil-structure interface, and that in order to keep the stability of the retaining wall, the vehicles running on the mountain highways in fiver environment should be never allowed to be overloaded.

关 键 词：主动土压力 理论计算 沿河路基 排水系统 车辆荷载 

分 类 号：TU476.4[建筑科学—结构工程]