应力路径旋转对原状软黏土小应变特性影响的研究  

INFLUENCE OF STRESS PATH ROTATION ON THE SMALL STRAIN BEHAVIOR OF INTACT SOFT CLAY

作　　者：林清辉[1] 严佳佳[2] 

机构地区：[1]台州职业技术学院建筑工程学院,浙江台州318000 [2]浙江大学建筑工程学院,杭州310058

出　　处：《工业建筑》2017年第1期96-101,共6页Industrial Construction

基　　金：台州市科技计划项目(162gy55);浙江省高等教育教学改革项目(JG2015348);国家自然科学基金项目(51608477);广东省产学研合作院士工作站(2013B090400024);浙江省大学生科技创新活动计划项目(2016R462006)

摘　　要：采用GDS应力路径三轴仪对杭州原状软黏土开展了一系列不同应力比条件下的排水试验,包括三轴压缩和三轴伸长试验,主要研究p-q平面内应力路径旋转对K0固结原状软黏土小应变刚度和变形特性的影响。试验结果表明:三轴剪切条件下原状软黏土存在显著的小应变刚度特性,在广义剪应变小于0.01%时,小应变刚度变化较小,广义剪应变在0.01%~0.1%阶段,试样小应变刚度衰减最快,剪应变在0.1%时的刚度仅为剪切初始阶段的10%左右。归一化后的原状软黏土小应变刚度随剪应变变化规律可以近似采用指数函数拟合。应力路径旋转对原状软黏土小应变阶段的应力-应变关系及刚度特性都有显著的影响。三轴伸长和压缩排水剪切时,K0固结原状软黏土都发生显著的体缩变形,剪应力对原状软黏土体应变的累积影响更为显著。A series of drained triaxial tests were carried out with different stress ratio by a GDS triaxial apparatus, including compression and extension tests. The emphasis was focused on influence of stress path rotation in the p-q plane on the stiffness and deformation behavior of intact soft clay at small strain level. The test results indicated that significant small strain stiffness of intact soft clay behavior was observed during triaxail shearing tests, the shear modulus was almost constant when shear strain was less than 0.01% , it decreased quickly when shear strain was 0.01% to 0. 1% , the shear modulus at shear strain of 0. 1% was only 10% of that at the beginning of shearing. The variation of small strain stiffness of normalized intact soft clay with shear strain could be fitted with an exponential function. The stress path rotation had obvious impact on the stress-strain and stiffness＂ behavior at small strain level. Significant volumetric strain occurred in both triaxial extension and compression drained tests, the influence of shear stress on the volumetric strain was more pronounced.

关 键 词：原状软黏土 应力路径旋转 小应变 剪切模量 

分 类 号：TU442[建筑科学—岩土工程]