粘性土的卸荷应力路径试验研究  

Experimental study on unloading stress path test of cohesive soil

作　　者：张淑朝[1] 张建新[1] 伊尧国[2] 

机构地区：[1]天津市软土特性与工程环境重点实验室,天津城建大学,天津300384 [2]地质与测绘学院,天津城建大学,天津300384

出　　处：《工程勘察》2016年第5期21-25,共5页Geotechnical Investigation & Surveying

基　　金：天津市高等学校科技发展基金计划项目(20130908);天津市科技特派员项目(14JCTPJC00514)

摘　　要：通过室内模型加荷试验,对微型土压力盒在粉质粘土中的应力微应变关系参数进行校正。然后进行加卸荷试验,确定测试土样的静止土压力系数和卸荷土压力系数分别为0.38和0.33。取模型内试验土样进行三轴应力路径试验,按模型试验测定的加荷侧压力系数进行K0固结,然后按轴向和侧向卸荷比3∶1进行卸荷试验得到测试土样的卸荷应力应变曲线,对其进行双曲线拟合后,得到卸荷变形模量,从而为基坑、隧道等开挖卸荷工程计算回弹变形提供依据。The stress-strain relation parameters of micro earth pressure cells in silty clay were calibrated through model test. The lateral earth pressure coefficient of the silty clay is 0. 38 and 0. 33 respectively in the loading and unloading model test. Then triaxial stress path test is conducted on the soil of the model test specimen. The soil is consolidated according to the lateral earth pressure coefficient of loading model test firstly. The stress-strain curves of unloading test are obtained by the unloading test under the axial to lateral stress ratio of 3 ∶ 1 after consolidation. After hyperbolic fitting of the stress-strain curves,the unloading deformation modulus is obtained,which could be used for the resilience deformation calculation of deep excavation and tunnel excavation.

关 键 词：卸荷应力路径试验 微型土压力盒 模型试验 三轴试验 

分 类 号：TU411[建筑科学—岩土工程]