岩石的卸荷劣化及其本构模型研究

卸荷条件下,岩石的变形参数产生劣化效应,弹性模量E在卸荷较小时变化较小,随着卸荷量的增加其快速减小;而泊松比μ则随着卸荷量的增加而变大.岩石的破坏阶段,变形参数与其应力跌落量有关:E随着应力跌落量的增加而减小;并呈线性关系.根据岩石变形参数的变化规律,将卸荷条件下岩石的损伤本构模型分为三段:一般加载段、卸荷段、应力跌落段.结合试验证明修正的统计损伤本构模型较为符合实际.

Study On The Unloading Degradation And Constitutive Model of The Rock

In the conditions of unloading, deformation parameters of rock produce the degradation effect. Elastic modulus is small change when unloading is smaller, but with the increment of unloading it decrease rapidly; poisson's ratio is added with the increase of unloading. In the failure stage of Rock, there are a relationship between deformation parameters and stress drop: E decreases with the increment of stress drop in a linear relationship. According to the law of rock deformation parameters, under the condition of the unloading, rock damage constitutive model is divided into three sections: general loading, unloading, stress drop. Combined with experiment shows the statistical damage constitutive model is more conform to the actual.