鄱阳湖区域粉质黏土三轴试验研究  

Triaxial Shear Strength Analysis of Silty Clay in Poyang Lake Area

作　　者：何振华 吴浩宇 薛威 雷祖祥 HE Zhenhua;WU Haoyu;XUE Wei;LEI Zuxiang(Shangrao Transportation Construction Investment Group Co.Ltd.,Shangrao 334500;School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013)

机构地区：[1]上饶市交通建设投资集团有限公司,江西上饶334500 [2]华东交通大学土木建筑学院,南昌330013

出　　处：《土工基础》2023年第3期492-496,共5页Soil Engineering and Foundation

摘　　要：采用GDS三轴仪对鄱余特大桥工程某段的原状粉质黏土进行了固结不排水三轴剪切试验,得到了试样在不同净围压下孔隙水压的变化曲线、偏应力~应变曲线、有效应力路径。对试样孔隙水压的变化曲线进行了分析;采用邓肯~张双曲线模型对试样的偏应力~应变关系进行了拟合,得到了邓肯~张双曲线模型的5个参数;对试样的有效应力路径和破坏性状进行了总结和分析。试验表明:鄱阳湖粉质黏土具有明显的剪胀性,围压对土体剪胀影响显著;土体的偏应力~应变曲线为应变硬化型;试样的极限状态应力比为1.32,且有效应力路径呈S型;破坏形态一般为上部或下部呈鼓状变形。Consolidated and undrained triaxial shear tests of silty clay in a section of the Poyu Bridge Project were performed by using the GDS triaxial instrument.The pore water pressure change curve and the deviator stress of the sample under different confining pressures were obtained.The deviator stress-strain curve,effective stress path and the variation curve of the pore water pressure of the sample are analyzed.The Duncan-Chang hyperbolic model is used to fit the deviatoric stress-strain relationship of the sample,and the five parameters of the Duncan-Chang hyperbolic model are obtained.The effective stress path and failure behavior of the system are summarized and analyzed.The test shows that the Poyang Lake silty clay has obvious shear expansion,and the confining pressure has a significant influence on the shear expansion of the soil;the deviator stress-strain curve of the soil is strain hardening,and the parameters of the Duncan-Chang model:k=34.74,n=0.94,Rf=0.61,φ′=30.8°,c′=13.5kPa;the limit state stress ratio of the sample is Mc=1.32,and the effective stress path is S-shaped;the failure mode is generally drum-shaped deformation at the upper or lower part.

关 键 词：粉质黏土 三轴试验 偏应力~应变曲线 邓肯~张双曲线模型 有效应力路径 

分 类 号：TU411[建筑科学—岩土工程]