考虑渗流效应的盾构始发井土压力研究  

Study of earth pressure of shield-construction origination shaft considering seepage effect

作　　者：冯梅梅[1] 吴疆宇 王忠昶[2] FENG Meimei WU Jiangyu WANG Zhongchang(State Key Laboratory for Geomechanics and Deep Underground Engineering,School of Mechanics and Civil Engineering, China University of Mining ＆ Technology, Xuzhou, Jiangsu 221116, China School of Civil Engineering and Safety Engineering, Dalian Jiaotong University, Dalian, Liaoning 116021,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室力学与建筑工程学院,江苏徐州221116 [2]大连交通大学土木与安全工程学院,辽宁大连116021

出　　处：《中国矿业大学学报》2016年第5期930-936,共7页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(51404266);国家重点基础研究发展计划(973)项目(2013CB227900)

摘　　要：采用统一强度理论推导出极限状态条件下考虑渗流效应的土压力计算公式,引入了中主应力对土压力的影响参数b,提出了与各土层物理力学参数相关的系数ξ,研究了某盾构始发井围护工程土压力的分布特征.结果表明:影响参数b不同,中主应力对土压力的计算结果影响程度不同,b值愈大,主动土压力pa愈小,引起土压力值的最大差异可达18%;渗流效应对地下连续墙侧的水土压力影响较大,与未考虑渗流的计算结果相比,最大差异可达20%;系数ξ与土层的水力梯度相关,其计算多层土时的水压力分布呈非线性,得到的总压力值更接近实际情况.The unified strength theory was used to derive the earth pressure formula considering seepage under limit state conditions. The coefficient b considering the effect of intermediate principal stress was introduced into the formula, and the coefficient ξ related to physico-mechanieal parameters of soils was presented. This calculation method was applied to study the earth pressure of shield-construction origination shaft. The results show that the impact parameter b contributes to the effect of the intermediate principal stress on the calculated results of the earth pressure. The higher b, the lower active earth pressure Pa, and the biggest difference in earth pressure up to 18% was found. The seepage has a significant impact on the waterearth pressure of the underground diaphragm wall. Compared to the case without seepage effect, the biggest difference quantity can be up to 20%. The coefficient ξ is related to soil hydraulic gradient and the total pressure value obtained is closer to the practical situation, in which the water pressure distribution of multi-layer soil is nonlinear.

关 键 词：基坑工程 水土压力 统一强度理论 中间主应力 渗流 

分 类 号：TU432[建筑科学—岩土工程]