花岗岩破坏过程能量演化机制与能量屈服准则

为了明确岩石破坏的能量演化特性，结合单轴实验和颗粒流程序获得花岗岩的细观力学参数，进行不同应力状态的花岗岩实验，研究不同围压下花岗岩破坏过程的能量演化机理并推导能量屈服准则。获得以下主要结论:花岗岩破坏过程中低围压下内部损伤出现较早而高围压较晚，表明低围压花岗岩内部损伤是渐进发展过程，而高围压下内部损伤一旦出现便快速发展破坏；高围压花岗岩峰值前一定应变范围弹性应变能基本保持不变，吸收的能量全部转化为耗散能，表明高围压破坏时花岗岩内部损伤程度严重；弹性应变能经历不断积累并达到弹性储能极限而后减小的变化过程，而弹性储能极限与围压之间存在线性变化规律，因此高围压下岩体开挖卸荷时极易诱发大量弹性应变能的急剧释放，引起围岩失稳甚至发生岩爆；花岗岩峰值破坏时的能量比与围压无关，为一定值；基于能量原理导出了能量屈服准则，该准则包含岩性参数和所有主应力，能够综合反映岩石破坏影响因素。

Energy evolution mechanism and energy yield criterion in granite's failure process

To understand the energy evolution mechanism in the rock failure process, this paper firstly obtained the meso-mechanical parameters of granite using uniaxial compression experiments and particle flow codes, then tested the granite under different confining pressures and finally analyzed its energy evolution mechanism in the failure process and deduced its energy yield criterion. The main results are as follows: The internal damage of granite in the failure process occurs earlier under lower confining pressures while later under higher confining pressures, which shows that the internal damage under lower confining pressures is a progressive development process but under higher confining pressures the internal damage rapidly develops into failure once it occurs. The granite's elastic strain energy remains constant in a certain strain range before the peak under higher confining pressures, and the overall energy absorbed transforms into dissipation energy, which shows that the granite internal damage under higher confining pressures is more severe. The elastic strain energy increases and reaches the elastic strain energy limit and then decreases. There exists a linear relationship between the elastic strain energy limit and the confining pressure, therefore rock excavation under high confining pressures is likely to induce a rapid release of a large amount of elastic strain energy which causes the surrounding rock to become unstable and even to burst. The energy ratio at the granite's peak failure is a definite value and independent of the confining pressure. The energy yield criterion is derived based on the principle of energy. It includes lithology parameters and all principal stresses and can reflect the comprehensive factors influencing the rock failure.