压实度和含水率对含砂粉土性质的影响  

Effect of compaction degree and water content on performance of sandy silt

作　　者：肖成志 李晓峰[1] 张静娟 

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]河北工业大学河北省土木工程技术研究中心,天津300401

出　　处：《深圳大学学报（理工版）》2017年第5期501-508,共8页Journal of Shenzhen University(Science and Engineering)

基　　金：国家自然科学基金资助项目(50909032);河北省自然科学基金资助项目(E2014202038)~~

摘　　要：基于静三轴试验,分析不同含砂量、压实度和含水率对粉土应力-应变曲线和抗剪强度指标的影响.试验结果表明,相同围压下增加粉土中含砂量,粉土峰值强度呈增加趋势,且围压较低时不同含砂量粉土均呈现不同程度应变软化现象,增高围压水平时应变软化现象减弱;增加含水率对粉土强度削弱明显,且最优含水率下粉土应变软化现象明显,粉土应变软化随含水率增加呈减弱趋势;减少压实度时应变软化现象减弱并最终趋于消失,相同围压下压实度越高,粉土峰值强度越大,且围压水平越低,压实度对峰值强度的影响越明显;同等条件下增加含砂量、提高压实度或减少含水率,均可显著提高粉土黏聚力,但对其内摩擦角影响较小,且压实度越高,含水率越小,含砂量越大,粉土的抗剪强度越高.Based on the static triaxial test,the effects of sand content,compactness and water content on the stress-strain curve and shear strength were analyzed comprehensively. The tests indicate that under the same confiningpressure,the sand content in silt increases with the peak strength remarkably. The silt with different sand content is characterized by strain softening while keeping low confining pressure. The strain softening phenomenon tends to be weakened when increasing confining pressure. The peak strength of silt decreases obviously with the increase of water content. Moreover,strain softening phenomenon for silt with optimum water content is obvious and the strain softening phenomenon tends to be weakened. The strain softening has been weakened and ultimately disappears with decrease of compaction degrees of silt. For the same confining pressure,the higher compaction degree is,the greater the peak strength of silt is. When lowering confining pressure,compaction degree plays a more important role in the effect of peak strength. While keeping the remained parameters identical,increasing sand content and enhancing compaction degrees or reducing water content in silt can significantly increase its cohesion,but don＇t obviously affect internal friction angle of silt. Generally,keeping higher compaction degree,less water content and more sand content can improve silt shear strength.

关 键 词：岩土工程 粉土 静三轴试验 含砂量 压实度 含水率 

分 类 号：TU441[建筑科学—岩土工程]