基于状态相关本构模型的砂土非共轴特性模拟  

Simulation of non-coaxial characteristics of sandy soil based on state-dependent constitutive model

作　　者：陈洲泉 黄茂松[1,2] CHEN Zhou-quan HUANG Mao-song(Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土力学》2017年第7期1959-1966,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.11372228);国家973计划课题(No.2012CE719803)~~

摘　　要：基于屈服面角点非共轴理论中采用Gram-Schmit正交化方法,提出了一种新的非共轴本构模型。模型修正了原有的流动法则,其中非共轴流动方向被定义为将单位应力增量方向在参考主应力正交方向上的投影,同时与塑性标量因子相关联。另外,根据广义应力的状态下的剪胀方程推导了一种新的塑性函数形式。以状态相关砂土模型为基本模型,分别采用新的非共轴模型和未修正的模型模拟了Toyoura砂的空心圆柱单剪试验和空心圆柱扭剪试验,将模型模拟的结果与试验数据进行对比,结果表明,新非共轴模型能更为合理地反映试验中非共轴现象及其变化规律,特别是固定主应力轴方向的单调剪切试验。A non-coaxial constitutive model is proposed based on the Gram-Schmidt orthogonalization process employed in the yield vertex non-coaxial theory. The flow rule is revised in this model. The model corrects the original flow rule, where the non-coaxial flow direction is defined as the projection of the unit stress increment direction in the orthogonal direction of the reference principal stress, and is associated with the plastic scalar factor. In addition, a new form of plastic function is derived according to the dilatancy equation in the generalized stress state. Based on the state-related sand model, the new non-coaxial model and the uncorrected model are used to simulate the hollow cylindrical single shear test and the hollow cylindrical torsional shear test on Toyoura sand. The simulation results are compared with the experimental data, and the results show that new non-coaxial model can more reasonably reflect the non-coaxial phenomenon and its variation in the test, especially for the monotonic shear test in the direction of the fixed principal stress axis.

关 键 词：砂土 非共轴 状态相关本构模型 空心圆柱剪切试验 

分 类 号：TU43[建筑科学—岩土工程]