压实黏性土固结排水多级直剪试验  

Consolidation drainage of compacted clay based on multistage direct-shear test

作　　者：高宇 张一鸣 董毅 GAO Yu;ZHANG Yiming;DONG Yi(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China;Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Wuhan 430071,China)

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]中国科学院武汉岩土力学研究所,武汉430071 [3]岩土力学与工程国家重点实验室,武汉430071

出　　处：《上海大学学报（自然科学版）》2024年第4期635-643,共9页Journal of Shanghai University:Natural Science Edition

基　　金：国家自然科学基金资助项目(51779254,41572293)。

摘　　要：抗剪强度是决定岩土工程中地基、边坡等土体和结构稳定性的重要力学参数,一般通过直剪或三轴试验获取.这类试验常采用3~4个试样测定土的黏聚力和内摩擦角,但多个试样的差异性会影响结果准确性.基于此,在常规直剪仪器的基础上进行改进,使其可针对一个试样反复剪切,获取样品的抗剪强度参数,由Mohr-Coulomb包络线得到土的黏聚力和内摩擦角,并将压实土的固结排水多级直剪试验与常规直剪试验结果进行对比.结果表明,多级直剪试验抗剪强度略小于常规直剪,内摩擦角误差在±2.5°.该固结排水多级直剪方案可以用来评估压实黏性土抗剪强度.Shear strength is an important mechanical parameter that determines the stability of soil and structures,such as foundations and slopes.Its value is generally obtained via direct-shear or triaxial tests.In these tests,three or four samples are typically used to measure the cohesion and internal friction angle of soil;the differences among samples will inevitably affect the accuracy of the results.Hence,this study improves the conventional direct-shear instrument so that it can be used to obtain the shear strength of a sample via repeated shears as well as the cohesion and internal friction angle of soil using the Mohr–Coulomb envelope.The results of multistage direct-shear tests for the consolidation drainage of compacted soil are compared with those of conventional direct-shear tests.The results show that the shear strength obtained from the multistage direct-shear test is slightly lower than that obtained from the conventional direct-shear test.Additionally,the error for the internal friction angle is±2.5◦,which verifies that the multistage direct-shear scheme of consolidation drainage can be used to evaluate the shear strength of compacted soil.

关 键 词：多级直剪试验 常规直剪试验 抗剪强度 MOHR-COULOMB 包络线 黏聚力 内摩擦角 

分 类 号：TU41[建筑科学—岩土工程]