基于能量理论的岩石动态破坏准则

A dynamic strength criterion of rock materials based on energy theory

现有的岩石破坏理论并未充分考虑工程扰动影响,往往会导致岩体工程灾害的发生,因此,亟需发展考虑应变率效应的岩石动态破坏准则。从能量转化的角度分析岩石材料整体破坏规律是破解岩石材料强度的有效途径,采用能量理论对岩石动态破坏准则进行研究。以岩石动态强度和整体破坏规律为基础,探索围压对能量释放方向的影响,创新构建岩石材料应变能释放分散连续性函数;引入考虑应变率效应的归一化单轴动态强度模型,建立岩石材料考虑应变率效应的最大能量释放率的临界值Gcd表达式;基于岩石材料动态最大能量释放率,提出考虑应变率效应的岩石动态破坏准则。结果表明,基于弹性应变能的岩石动态强度准则的理论预测结果与3种岩石(类岩石)材料的试验结果吻合较好,可以较好地描述岩石(类岩石)材料的非线性动态强度特性。新构建的岩石动态破坏准则可以充分考虑岩石应变率效应,物理力学意义明确,对于研究动力扰动下岩石材料的屈服与破坏特性具有重要意义。

The current rock failure criteria fail to fully consider the influence of engineering disturbances,leading to potential disasters.Therefore,there is an urgent need to develop a dynamic rock failure criterion considering the effect of the strain rate.Exploring the strength law of rock materials from the perspective of energy transformation in the overall failure process proves to be an effective approach.Thus,this study investigates the dynamic failure criterion based on energy theory.Drawing inspiration from the dynamic strength and overall failure laws of rock materials,a novel continuity function for the strain energy release dispersion coefficient considering the external stress environment was constructed.This function can accurately reflect the influence of the confining pressure on the energy release direction of rock materials.Additionally,the critical value Gcd,which represents the dynamic maximum energy release rate of rock material considering the strain rate effect,was established by introducing a unified dynamic uniaxial compressive strength model.Finally,the dynamic failure criterion considering the strain rate effect was proposed based on the maximum dynamic energy release rate of rock materials.The results demonstrate a good agreement between the theoretical predictions of the proposed rock dynamic strength criterion and the experimental results obtained from three different types of rock or rock-like materials.This criterion provides a better description of the nonlinear dynamic strength characteristics of rock or rock-like materials.Furthermore,the results indicate that the newly constructed energy dynamic failure criterion has a clear physical and mechanical meaning.The findings of this study have important engineering significance for studying the yield and failure characteristics of rock materials under dynamic disturbances.