三维应力状态下岩石损伤破坏的卸荷效应

Damage study on brittle rock failure under complicated stress

利用连续介质损伤力学方法,通过岩石微元体强度的Weibull统计分布和库仑准则假定,建立了一个简明的岩石三维各向同性损伤模型及弹脆性本构方程.探讨了岩石试样试验的应力-应变全过程特征、损伤演化规律、岩石试样加载的围压效应以及卸荷破坏下强度及脆化特征,理论与试验结果表明,卸载破坏比加载破坏表现得更为脆性、更突然.

A single, effective damage model and constitutive equation, which based on the assumption of rock microelement strength Weibull distribution and Coulomb criterion, were presented through Continuum Damage Mechanics method. Good correspondence between the theoretic and actual testing results, including the stress-strain process of rock under multi-axial compress, linear increment of bearing capacity in axial direction, small change of strength, peak strain degradation, and rock becoming more brittle under confining unloading condition, is (achieved.)