广义破裂活动准则

Generalized fracturing activation criteria

岩石破裂及其后续活动是最基本的构造变形方式,然而,经典的破裂准则(Coulomb-Mohr准则、Griffith准则和以Byerlee律为代表的滑动摩擦律)在实际应用中存在不同方面的局限。文章在经典破裂准则的基础上,从产生破裂(扩张破裂和剪切破裂)的物理本质出发,结合广义剪切活动准则和长期的研究实践,通过理论分析,提出了“广义破裂活动准则”。该准则用统一的无量纲因子(破裂活动趋势因子)来表达扩张破裂活动和剪切破裂活动,可以用来定量判断任意介质、在任意三轴应力状态下、任意方位界面(包括先存薄弱面和非薄弱面)发生破裂活动的可能性以及破裂的类型,把Coulomb-Mohr准则、Byerlee律和Griffith准则统一起来,将破裂(fracturing)扩展到破裂活动(fracturing activity)。该准则在与破裂活动相关的资源勘探开发(如页岩气、干热岩等)、灾害(如地震与滑坡等)预测和防治中具有广阔的应用前景。

[Objective]Rock fracturing and its subsequent activations are the most basic tectonic deformation modes.However,the classical fracturing criteria(Coulomb-Mohr criterion,Griffith criterion,and Byerlee sliding-friction law)have different limitations in practical applications.[Methods]Based on the classical fracturing criteria and the analysis of the physical nature of fracturing generation(extensional fracturing and shear fracturing),combined with the generalized shear activation criterion and long-term research practice,a"generalized fracturing activation criterion"is proposed through theoretical analysis in this paper.[Conclusion]This criterion can be used to quantitatively determine the possibility and types of fracturing of any medium,under any triaxial stress state,and at any orientation interface(including pre-existing weak surface and non-weakness surface).It unifies the Coulomb-Mohr criterion,Byerlee's law,and Griffith's criterion,and extends fracturing to fracturing activation.[Significance]The proposed criterion has broad application prospects in the fracturing activation-related resource(such as shale gas and hot,dry rock)exploration and development and prediction and prevention of natural disasters(such as earthquakes and landslides).