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为了探究岩性对受载岩石能量演化特征的影响规律,对煤岩、红砂岩和花岗岩等3种典型岩石试件进行了轴向加卸载试验.结果表明:与煤岩相比,红砂岩和花岗岩峰前不可逆变形较小,峰后应力跌落幅度较大,抗压强度分别是煤岩的4.37倍和5.02倍,弹性模量是煤岩的4.54倍和5.29倍,脆性指数是煤岩的2.32倍和2.81倍.煤岩在接近破坏时弹性能密度显著弱化,而红砂岩和花岗岩此特征不明显;岩石的强度和刚度越大,其储能极限和弹性能增长速率越大;脆性越强,其峰后弹性能释放越快速和彻底.3种岩石的能量分配模式在峰前阶段相似,而峰后阶段岩石脆性越大弹性能比例下降越大,且下降至最小值时所需时间较短,反映了其破坏过程的剧烈性.
In order to explore the influence of lithology on the energy evolution characteristics of rock under load, axial loading and unloading tests were carried out on three typical rock samples, including coal rock, red sandstone and granite.The results show that compared with coal rock, red sandstone and The irreversible deformation before granite peak is smaller and the post-peak stress drop amplitude is larger. The compressive strength is 4.37 times and 5.02 times that of coal rock, the elastic modulus is 4.54 times and 5.29 times that of coal rock, and the brittleness index is 2.32 times of coal rock Times and 2.81 times, respectively.The elastic energy density of coal and rock is significantly weakened when approaching failure, while the characteristics of red sandstone and granite are not obvious.The larger the strength and stiffness of rock, the larger the growth rate of energy storage and elastic energy, the stronger the brittleness , The post-peak elastic properties can be released more quickly and thoroughly.The energy allocation patterns of the three kinds of rock are similar at the pre-peak stage, while the larger the rock fragility at the post-peak stage, the larger the decline of the elastic energy ratio, and the time required to reduce to the minimum Short, reflecting the violent destruction of the process.