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| A new criterion of rock burst proneness based on the linear energy storage law and the residual elastic energy index |
| GONG Fengqiang1，2，YAN Jingyi1，LI Xibing1，2 |
| (1. School of Resources and Safety Engineering，Central South University，Changsha，Hunan 410083，China；2. Hunan Key Laboratory of Resources Exploitation and Hazard Control for Deep Metal Mines，Central South University，Changsha，Hunan 410083，China) |
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Abstract Considering the energy consumption characteristic during the whole loading process of rock materials， a new rock burst proneness criterion was introduced based on the linear energy storage law and the residual elastic energy index. A series of uniaxial compression tests having one loading and unloading cycle were conducted on 14 kinds of rock materials(including six types of granite，two types of marble，four types of sandstone，a type of slate and a type of limestone) at different unloading levels. The values of total input energy density，elastic energy density and dissipation energy density of the rock specimens at different unloading levels were obtained with the graph integral method. The quantitative relationship between elastic energy density，dissipation energy density and total input energy density were investigated. A linear relationship between elastic energy density and total input energy density was found. The energy storage coefficient(the ratio of elastic energy density to total input energy density at different stress levels) is approximately a constant. Based on this linear energy storage law，a new method for calculating elastic energy density stored in rock before peak strength was thus proposed，and then the calculation method of energy impact index was modified firstly and a new rock burst proneness criterion based on the residual elastic energy index(the residual elastic energy index is defined as the difference between peak elastic energy density and failure energy density of post peak) was introduced. According to the failure characteristics of 14 kinds of rock materials，a classification standard of rock burst proneness in laboratory tests in terms of qualitative index and quantitative index was also put forward. The calculated results with the new rock burst criterion agreed with the actual rock burst proneness grade of rock materials.
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2018, Vol. 37 
