真空-堆载预压作用下软土蠕变特性试验研究  

Test study on creep characteristics of soft clayey soils under consolidation by vacuum-surcharge combined preloading method

作　　者：刘汉龙[1] 扈胜霞[1] Ali Hassan 

机构地区：[1]河海大学岩土工程水利部重点实验室

出　　处：《岩土力学》2008年第1期6-12,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.50379010)

摘　　要：采用改进的、可施加负压的三轴仪开展了真空预压、堆载预压以及真空-堆载联合预压作用下软土的固结蠕变试验,描述了加载率、应力比和时间等对软土蠕变特性的影响,分析了轴向应变(率)、体积应变(率)及偏应变(率)与应力比和时间之间的关系。结果表明:轴向应变率和体积应变率与时间的对数关系并非线性,但经过若干天以后可近似认为是线性关系;在不同应力比n下,体应变与时间的关系可用双曲线方程来表示;偏应变、偏应变率与时间的关系符合双曲线方程,通过温州软黏土样的蠕变试验结果验证了其有效性。Creep behavior of soft clayey soils under consolidation by vacuum, surcharge, combined vacuum-surcharge preloading is investigated by using a new improved triaxial apparatus. Influence of the duration of loading and the rate of loading, as well as loading magnitude etc on compressibility of soft clay are demonstrated; meanwhile, relationship between axial strain （rate）, volumetric strain （rate）, deviatoric strain （rate）, stress ratio amd time are analyzed; Results show： The relationships of lgε, and lg lgε versus lgt are nonlinear, but part of the relationships may be approximately considered linear; A hyperbolic equation can be used to express the changes of the deviatoric strain with time for different stress ratios; The two hyperbolic equations for deviatoric strain and deviatoric strain rate with time have interesting features. The validation of it has been examined using results of creep tests of soft clayey soil samples of Wenzhou.

关 键 词：真空-堆载联合预压 软土 蠕变 

分 类 号：TU411[建筑科学—岩土工程]