含砂量对砂-粉土混合物强度特性的影响试验研究  

Influence of Sand Content on Strength Characteristics of Sand-Silt Mixture

作　　者：常留成 王红雨[1,2] 曹静[1,2] 王亚 CHANG Liu-cheng;WANG Hong-yu;CAO Jing;WANG Ya(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;Engineering Research Center of Ministry of Education on Efficient Use of Modern Agriculture Water Resources in Arid Area,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学土木与水利工程学院,银川750021 [2]宁夏大学旱区现代农业水资源高效利用教育部工程研究中心,银川750021

出　　处：《长江科学院院报》2023年第10期96-102,共7页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(41962016);教育部博士点基金项目(20136401110003);宁夏高等学校一流学科建设项目(NXYLXK2017A03)。

摘　　要：为研究砂粒对砂-粉土混合物强度特性的影响规律及作用机制,对不同含砂量的砂-粉土混合物进行三轴固结排水剪切试验和压汞试验。研究结果表明:随含砂量的增加,砂-粉土混合物的内摩擦角和峰值偏应力增大,黏聚力降低,含砂量≤30%时变化幅度最明显,其后较弱并趋于稳定;同时,峰值偏应力增幅随着围压的增加而增大。含砂量<15%时,砂-粉土混合物的强度由黏聚强度控制,随着含砂量增大,摩擦强度逐步超过黏聚强度对强度起主要作用。砂-粉土混合物的体积收缩致使土体更加密实,从而导致砂-粉土混合物内摩擦角和峰值偏应力的增加。The aim of this study is to explore the influence of sand content on strength characteristics of sand-silt mixtures.To this end,triaxial consolidated drained shear tests and MIP tests were conducted on sand-silt mixtures with varied sand content.Test results indicate that as sand content increases,both the internal friction angle and peak deviatoric stress of sand-silt mixture increase while cohesion decreases.Such changes were more pronounced when sand content is below 30%,and then weakens and tends to stabilize.The increment of peak deviatoric stress raises as the confining pressure increases.When sand content is less than 15%,the strength of sand-silt mixture is controlled by cohesive strength.As sand content increases,the role of frictional strength gradually surpasses that of cohesive strength in influencing the overall strength.The volume shrinkage of the sand-silt mixture leads to a denser soil structure,resulting in an increase in the internal friction angle and peak deviatoric stress.

关 键 词：砂-粉土混合物 含砂量 峰值偏应力 压汞试验 微观机制 强度特性 

分 类 号：TU41[建筑科学—岩土工程]