绍兴重塑非饱和黏土三轴剪切特性试验研究  

Experimental Study of Triaxial Shear Properties of Shaoxing Remolded Unsaturated Clay

作　　者：吴瑞潜 杨光 林群仙 项祺辰 WU Ruiqian;YANG Guang;LIN Qunxian;XIANG Qichen(School of Civil Engineering,Shaoxing University,Shaoxing,Zhejiang 31200;School of Architectural Engineering,Zhejiang Industry Polytechnic College,Shaoxing,Zhejiang 31200)

机构地区：[1]绍兴文理学院土木工程学院,浙江绍兴312000 [2]浙江工业职业技术学院建筑工程学院,浙江绍兴312000

出　　处：《绍兴文理学院学报》2022年第2期8-15,共8页Journal of Shaoxing University

基　　金：浙江省教育厅项目“非饱和土抗剪强度的预测与实验研究”(Y201839206);浙江省教育厅项目“非饱和土土水特征及其强度指标实验研究”(FG2018148).

摘　　要：绍兴地区存在大量湖沼与海相沉积软黏土层,上部土层多为非饱和土,其土性较饱和土复杂多变.采用全自动非饱和土三轴仪,对绍兴地区非饱和黏土重塑样进行一系列控制基质吸力的三轴固结排水剪切试验.研究结果表明,控制基质吸力与净围压条件下应力-应变关系曲线呈应变硬化型,没有明显的破坏点,在轴向应变达3%之前,曲线斜率较大,之后逐渐减小.在试验条件范围内,非饱和黏性土强度参数黏聚力相较于有效内摩擦角对基质吸力的增大更为敏感,黏聚力值增幅大于有效内摩擦角值.在三轴剪切过程中,体积应变呈现剪胀现象,基质吸力越大,净围压越大,体积应变就越大.基质吸力引起的体积应变小于由净围压引起的体积应变.There are large quantities of lacustrine and marine sedimentary soft clay layers in Shaoxing.The upper layer is mostly unsaturated soil,whose soil properties are more complex and changeable than those of saturated soil.In the paper,a series of triaxial consolidation drained shear tests were carried out on remolded unsaturated clay samples in Shaoxing by means of automatic triaxial apparatus.The results show that the stress-strain curve under the condition of controlling matric suction and net confining pressure is of the strain hardening type,without an obvious failure point.The slope of the curve is large before the axial strain reaches 3%,and then decreases gradually.In the range of test conditions,the cohesion of unsaturated cohesive soil strength parameter is more sensitive to the increase of matrix suction than the effective internal friction angle,and the increase of cohesion value is greater than that of effective internal friction angle.In the process of triaxial shear,the volumetric strain presents a dilatancy phenomenon.The larger the matric suction,the greater the net confining pressure,and the larger the volumetric strain.The volume strain caused by matric suction is smaller than that caused by net confining pressure.

关 键 词：非饱和土 基质吸力 剪切特性 三轴试验 

分 类 号：TU411.7[建筑科学—岩土工程]