黄土增湿湿陷的非线性本构方程研究  

Study of non-linear constitutional equation for humidifying collapse loess

作　　者：刘金禹[1] 邢义川[2] 张爱军[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [2]中国水利水电科学研究院,北京100044

出　　处：《西北农林科技大学学报（自然科学版）》2011年第1期210-214,221,共6页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(50779058)

摘　　要：【目的】建立黄土增湿湿陷本构方程,为黄土增湿湿陷变形的数值计算提供理论基础。【方法】在三轴等应力比分级浸水试验的基础上,应用Sigmoid的3参数方程,对不同含水率条件下平均应力p与湿陷体积应变sεvh及偏应力q与湿陷偏应变sεrh之间的关系分别进行回归分析,从而得到不同含水率条件下Sigmoid函数3个参数的回归值,分析3个参数回归值与含水率之间的函数关系,建立黄土增湿湿陷的非线性本构方程,并利用该方程求导计算黄土增湿时的材料参数。【结果】应用上述函数回归方法分别得到了不同含水率条件下平均应力p与湿陷体积应变sεvh之间及偏应力q与湿陷偏应变srεh之间的本构方程表达式,反算分析表明该本构方程是有效的。【结论】Sigmoid函数的3参数方程能较好地反映黄土增湿湿陷的变形行为,其表达式简单明了,由该方程得出的材料参数易于使用。【Objective】 The study was conducted to establish a constitutional equation for loess during humidifying collapse to provide theoretical foundation for numerical calculation of loess＇s humidifying collapse deformation.【Method】 Based on grading immersion traxial test on the condition of equal stress ratio,the paper applied three-parameter Sigmoid equation to fit the relation between average stress p and collapse volumetric strain εshv and the relation between deviator stress q and deviator strain εshr on the conditions of different water contents respectively,and then the three specific parameters of Sigmoid equations were gained.Later,the functional relation between those values of three parameters and water contents was built.Finally,the non-linear constitutional equation for humidifying collapse loess was acquired.Through this equation derivation and calculation,material parameters for humidifying collapse loess could be gained.【Result】 Using above-mentioned regression method,constitutional equations for the relation between average stress p and collapse volumetric strain εshv and the relation between deviator stress q and deviator strain εshr on the condition of different water contents were obtained respectively.Validity of those constitutional equations were proved by back calculation analytical method.【Conclusion】 This three-parameter Sigmoid equation is simple and easy to use which can express transformation behavior of collapsible loess commendably.

关 键 词：黄土 增湿湿陷 本构方程 

分 类 号：TU444[建筑科学—岩土工程]