地下连续墙成槽整体稳定性的工程评价方法  

Engineering evaluation method for overall stability of slurry trenches

作　　者：黄茂松[1,2] 王鸿宇 谭廷震 李耀良 HUANG Mao-song;WANG Hong-yu;TAN Ting-zhen;LI Yao-liang(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Geotechnical andUnderground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;Shanghai Foundation Engineering Group Co.,Ltd.,Shanghai 200002,China)

机构地区：[1]同济大学土木工程学院地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]上海市基础工程集团有限公司,上海200002

出　　处：《岩土工程学报》2021年第5期795-803,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金重点项目(51738010);国家重点研发计划课题(2016YFC0800202)。

摘　　要：当前分层地基中地下连续墙成槽整体稳定性验算多采用水平条分法。当槽段宽度与成槽深度比相对较小时,三维水平条分法所给出的计算结果可能偏于不安全。此外,验算时一般采用有效抗剪强度指标并按水土分算原则验算成槽稳定性。然而在当前我国大量的工程实践中,地质勘察报告往往仅提供直剪固结快剪强度指标,如何结合工程实践现状验算槽壁稳定性值得进一步的研究。首先介绍了水平条分法的理论框架,并详细讨论了水平条分法与楔形体滑体模式的内在联系。随后结合某一现场试验展开案例分析,指出了饱和黏土中三维楔形体模式存在的不足,并提出一种基于三维等效楔形体的改进方法。最后结合10个工程案例的验算结果,分析了二维与三维水平条分法在计算结果上的差异,以及强度指标选取和水土压力计算原则对分析结果的影响,为今后的工程实践提供参考。The horizontal slice method is commonly used for examining the trench stability in layered soils. Unsafe results may be given by the 3D horizontal slice method when the ratio of trench length to depth is relatively small. In addition, the effective soil strength parameters are recommended for trench stability analysis. However, the soil strength parameters in engineering reports are often obtained from the direct shear tests. Further investigation is needed to incorporate the trench stability analysis with the current practice. In this study, the theoretical framework of the horizontal slice method is introduced, and its connection with the sliding wedge method is discussed. The deficiency of the 3D sliding wedge method in undrained clay is shown by a field test, and the improvement by an equivalent 3D wedge method is proposed. A discussion on influences of the differences between 2D and 3D methods, selection of soil strength parameters and water pressure calculation on the calculated results is carried out through 10 collected case studies.

关 键 词：地下连续墙 成槽稳定性 水平条分法 强度指标 安全系数 

分 类 号：TU43[建筑科学—岩土工程]