岩体结构面切向循环加载本构关系研究  

STUDY OF CONSTITUTIVE MODEL FOR ROCK INTERFACES AND JOINTS UNDER CYCLIC SHEAR LOADING

作　　者：尹显俊[1] 王光纶[1] 张楚汉[1] 

机构地区：[1]清华大学水利水电工程系,北京100084

出　　处：《工程力学》2005年第6期97-103,57,共8页Engineering Mechanics

基　　金：国家自然科学基金资助项目(50209004)

摘　　要：回顾岩体结构面切向循环加载的力学试验和数值模型,并建立新的本构模型。在粘接状态下,结构面切向本构关系表示为由双曲线和直线段组成的滞回曲线。在接触状态由粘接变为滑移的过程中,峰值摩擦角以双曲线函数逐渐降低至残余摩擦角,体现出峰值剪切特性。考虑结构面切向与法向耦合的剪胀关系,建立相应的接触刚度矩阵,并引入初始剪胀角和残余剪胀角来建立分段抛物线形式的剪胀曲线。循环加载导致的磨损对结构面的摩擦和剪胀特性均产生影响,通过以切向塑性功指数函数表示摩擦角和剪胀角的磨损过程。模型在物理意义上反映了切向循环加载的特性,计算结果能较好地拟合试验曲线。The tests and numerical models of rock interfaces and joints under cyclic shear loading are reviewed, and a new constitutive model is developed. When the contact state is stick, the joint loading follows conventional hyperbolic response, and unloading follows linear response. When the contact state changes from stick to slide, the friction degree falls from pick to residual in terms of hyperbolic function. The dilation relation, which causes coupling of the normal and shear responses, is described by dilation degree, and the contact stiffness matrix is established. The dilation curve is composed of subsections of parabolic curves, which are calculated from initial and residual dilation degree. The wear of the contact surface in cyclic loading influences the friction and dilation character of the interfaces and joints, new friction degree and dilation degree after surface damage are calculated according to each exponential function of shear plastic work. This model describes the physical significance of rock interfaces and joints under cyclic shear loading. The prediction agrees with test responses.

关 键 词：水工结构 本构关系 数值模型 切向循环加载 岩体结构面 

分 类 号：TU458.3[建筑科学—岩土工程]