岩石加荷破坏弹性能和耗散能演化特性

Rock elastic strain energy and dissipation strain energy evolution characteristics under conventional triaxial compression

开展大理岩、灰岩和砂岩的常规三轴试验,研究岩石变形过程的能量非线性演化特征。结果表明:岩样屈服前外力功大部分转化为弹性应变能存储于岩样内部,耗散能增加的很少,屈服点后耗散能快速增加,弹性能增速变缓。岩石的极限存储能具有围压效应,随着围压增加,岩石破坏时的极限存储能逐渐增加。极限存储能还与岩石本身的性质有关,岩石的强度越高,脆性越强,极限存储能愈大。灰岩极限存储能最大,大理岩极限存储能次之,砂岩极限存储能最小。根据弹性能和耗散能的演化规律,构建了岩石变形破坏过程中弹性应变能的非线性演化模型,理论模型与3种岩石的试验结果吻合较好。

In order to get features of energy nonlinear evolution during rock failure process, conventional triaxial com- pression tests of marble, limestone and sandstone were carried out. Results show that most of external work is converted into rock elastic strain energy before rock yielding. Dissipation strain energy increase rapidly after rock yielding. How- ever, elastic strain energy increases slowly. Rock limit storage energy increases with the confining pressure increasing. Rock limit storage energy is also related to the rock nature. The higher strength and stronger brittleness of rock, its lim- it storage energy is larger. The maximum limit storage energy of limestone is biggest in three kinds of rock. The maxi- mum limit energy storage of marble is bigger than that of sandstone. According to the interaction mechanism between energy accumulation and energy dissipation, rock energy nonlinear evolution model was established. The model agrees well with three kinds of rock experimental results.