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为了研究坚硬顶板岩梁的破裂及演化规律,基于能量法分析坚硬顶板岩梁初次垮落时的能量种类及其转化。应用弹-脆性双支梁模型分析基本顶岩梁破裂过程中能量的种类,并计算储存积聚的能量和释放的能量。储存积聚的弹性势能一部分转化为辐射能和热能,这部分能量等价于岩石破裂克服抗拉强度所耗散的能量,另一部分弹性势能将转化为破裂岩块所释放的动能。根据能量守恒定律,给出基本顶单一裂纹破裂的能量判据,并计算能量释放率。通过分析可知,基本顶岩梁储存积聚的弹性势能随上覆岩层重量及开采距离的增大而增大,随基本顶高度的增加而减小;能量释放率与岩梁的抗拉强度、岩梁的厚度成正比,与裂纹扩展速度的平方成正比。
In order to study the rupture and evolution of hard roof rock beam, the energy method and its transformation of hard roof rock beam during its first collapse were analyzed based on energy method. The elastic-brittle double-beam model is used to analyze the energy types during the rupture of the basic roof rock beam and to calculate the accumulated energy and the released energy. Some of the accumulated elastic energy is converted into radiant and thermal energy. This part of energy is equivalent to the energy dissipated by the rock to overcome the tensile strength, and the other part of the elastic potential energy is converted into the kinetic energy released by the rock mass. According to the law of conservation of energy, the energy criterion for the rupture of the basic top single crack is given and the energy release rate is calculated. The analysis shows that the elastic potential energy of the accumulation and accumulation of the basic roof rock beam increases with the increase of the overburden weight and the mining distance and decreases with the increase of the basic roof height. The energy release rate is related to the tensile strength of the rock beam, The thickness of the beam is proportional to the square of the crack growth rate.