高应力状态下岩石非线性统一强度理论

Hoek-Brown破坏准则和广义Hoek-Brown破坏准则广泛应用于岩石工程,其缺点是没有考虑中间主应力效应。为此,建立了一对双剪模型,它们包含两个双剪应力、对应于双剪应力作用面的两个正应力和两个或一个较小主应力。根据这一对模型,可以推出俞茂宏提出的统一强度理论和昝月稳、俞茂宏和王思敬提出的岩石非线性统一强度准则和广义非线性统一强度准则。当b = 0时,岩石非线性统一强度准则就变成了Hoek-Brown破坏准则。当岩石所受到的应力状态从低应力水平到高应力水平时,岩石的破坏从脆性破坏转化为韧性破坏。与Hoek-Brown破坏准则相同,岩石非线性统一强度准则和广义非线性统一强度准则只适应于3s

NONLINEAR UNIFIED STRENGTH THEORY OF ROCK UNDER HIGH STRESS STATE

The Hoek-Brown failure criterion and the generalized Hoek-Brown failure criterion are widely used in rock engineering. But the criteria need improvements as they do not consider the effect of the intermediate principal stress. A couple of twin shear stress models are presented to take account of the twin shear stresses by Yu Maohong,two normal stresses and two or one smaller principal stress. Based on these models,the unified strength theory by Yu Maohong,the nonlinear unified strength criteria and generalized nonlinear unified strength criteria proposed by Zan Yuewen,Yu Maohong and Wang Sijing can be established. Meanwhile the Hoek-Brown failure criterion is one special case of them. Rocks failure mode transfers from brittle failure to ductile failure when its stress state develops from low level to high level. The proposed criteria are of clear physical concept and wide prospect of application