【摘要】 通过岩石试样高围压下的卸荷试验,研究卸荷条件下岩石的扩容性质。研究结果表明:初始扩容点即最大压缩体应变对应的变形模量可作为弹性阶段的弹性模量。根据试验研究,将岩石卸荷试验应力–应变全过程曲线分为弹性、应力屈服、峰后脆性及残余理想塑性4个阶段,并根据各阶段特征得到相应段的本构方程,最后得到卸荷岩体全过程的本构模型。用数据拟合的方法,得到不同卸荷试验下模型曲线,并验证模型曲线可以较好地模拟卸荷的应力–应变曲线。更多还原

【Abstract】 Based on the unloading test of rock specimen under high confining pressure,the dilatancy property of rock mass is studied. The study results show that the deformation modulus at initial dilatancy point where the largest compression volumetric strain can be used as elastic modulus at elastic stage. Based on the unloading test, the complete stress-strain curve for rock is composed of four phase:elasticity,unloading yield,post-peak brittleness and residual ideal plastic phases. According to the characteristics of each stage,the constitutive model for that corresponding stage can be obtained. Finally,complete constitutive model for rock mass under unloading can be established. Through data fitting method,the model curves of different unloading tests are obtained,which has been verified to well fit the experimental curves.更多还原