Study on Damage Energy Evolution of Coal Rock Under Different Stress Paths and Circumferential Pressures
In order to study the transformation mechanism of energy in the process of damage evolution of coal and rock body,triaxial loading tests are carried out for the raw coal of 9105 working face in Wangzhuang coal mine under different stress paths and peripheral pressures,using HC-SPT-100 high-pressure triaxial tester,HC-U7 non-metallic ultrasonic detector,4K scientific research camera and other instruments,and adopting the non-contact digital image processing technology.The results show that:(1)the energy evolution of coal rock damage during the triaxial loading under different stress paths and circumferential pressures can be divided into three stages:compression,elasticity and brittle fall;(2)the energies of the specimens vary significantly in different loading paths and under different initial circumferential pressures,which means that the elastic,dissipative and total energies of the specimens under the conventional triaxial loading paths are greater than the corresponding energies of the specimens under the triaxial cyclic loading paths for the same initial circumferential pressures;(3)during the triaxial loading process,the axial strain of the specimen under different loading paths exhibits evolution of overall fluctuation and localization→localization→localization→overall fluctuation and localization in the densification-to-destruction stage;(4)the stress concentration in the destructive stage of the specimen is different in different loading paths and peripheral pressures.Under the conventional triaxial loading path,the stress concentration mainly takes on the newborn type under the low peripheral pressure,and inherited type under the high peripheral pressure,while under the triaxial cyclic loading paths the stress concentration is mainly the inherited type for both low and high peripheral pressures.
energy evolutiontriaxial loadingnon-contact digital image processingstress concentration
万方数据
维普
