排水条件下卸荷土体变形特性的真三轴试验研究.kdh.pdfVIP

第28 卷第7 期 岩 土 力 学 Vol.28 No.7 2007 年7 月 Rock and Soil Mechanics Jul. 2007 文章编号：1000－7598 －(2007) 07 －1387－04 排水条件下卸荷土体变形特性的真三轴试验研究 庄心善1 3 1 2 ，赵 鑫 ，何世秀 ，朱瑞赓 （1.湖北工业大学 土木工程与建筑学院，武汉 430068 ；2.武汉理工大学 土木工程与建筑学院，武汉 430070 ； 3.中国兵器工业北方勘察设计研究院，石家庄 050011 ） 摘 要：在真三轴仪上模拟基坑开挖周边土体的应力路径，进行了排水与不排水两种卸荷试验，通过对试验结果的对比分析 可知，土体在不同排水条件下应力-应变关系有着显著的差异，说明排水条件对土体的变形性状有一定的影响。进一步研究 了排水条件下卸荷土体广义剪应力与广义剪应变的关系，证明土体广义剪应力与广义剪应变关系曲线呈明显的非线性，并根 据土体实际应力路径定义了中主应力系数，推导出了土体卸荷剪切模量计算公式。 关 键 词：平面应变；排水条件；卸荷土体；变形特性；真三轴试验 中图分类号：TU 41 文献标识码：A An experimental study of soilmass deformability subject to true triaxial loads during unloading under drainage 1 3 1 2 ZHUANG Xin-shan , ZHAO Xin , HE Shi-xiu , ZHU Rui-geng (1. Hubei University of Technology, Wuhan 430068, China; 2. Wuhan University of Technology, Wuhan 430070, China; 3. Beifang Institute of China Ordnance Industrial Geotechnical Investigation and Surveying, Shijiazhuang 050011, China) Abstract: The stress-path of the soilmass surrounding the periphery of a foundation pit project during excavation is simulated using a true triaxial unit; and two kinds of unloading tests are conducted under drainage and undrainage conditions respectively. It can be known from the comparison between the testing results that there is a remarkable difference in the stress-strain relationship of the soilmass provided the drainage conditions are different, which shows that the drainage, condition has an effect to a certain degree on the soilmass’s deformability. Further studies are conducted on the relationship b