基于能量理论的冲击地压细观过程研究

为了解冲击地压细观发生过程,从而分析冲击地压不同阶段特点,从能量消耗角度对该过程进行了研究。认为冲击地压是岩体系统由于外界扰动引起的能量释放过程,总释放能量理论上等于岩体形成期间残余弹性势能。由于该弹性势能和岩体形成后裂隙发育的不同,导致岩体受开采扰动后经历的能量释放形式有所不同。大体上能量释放形式可分弹性变形、可产生裂隙的大变形、岩体破碎飞石、广义变形集中区岩体失稳和伴随裂隙产生的机械振动5种。过程可分三部分:初期变形和裂隙、中期飞石-变形-破碎-飞石的循环破坏过程(岩爆)、末期广义应变失稳破坏。使用颗粒流理论的PFC3D对上述过程进行了模拟,结果表明:-120 m、-220 m、-320 m时开采面岩体只发生变形和裂隙;-420 m、-520 m、-620 m岩体先经历变形和裂隙,然后发生岩爆;-720 m和-820 m岩体经历变形和裂隙、岩爆和广义应变区失稳坍塌。

On the mesoscopic process rock burst based on the dynamic theory

In order to understand the mesoscopic process of the rock burst more comprehensively,the paper has done an investigation and exploration of the said process from the point of view of energy consumption through an analysis of the characteristic features of the rock burst dynamics in different stages. As is traditionally believed,the rock burst is a kind of energy releasing process from the rock mass system due to the external force disturbance or interference,whereas the total amount of energy release should be theoretically equal to the residual elastic energy accumulated in the process of the rock formulation. The process can be actually divided into three steps: the initial deformation and fracture; the failure cycle of the flying rock-deformation and the rockburst due to the fracturing rock flying as the result of the said instability caused by the deformation here generalized. In the present paper,we have simulated the above process in accordance with the theory of particle flow of the PFC3D,proving that such deformation and fracture of the surface rock mass tends to take place only in the condition when the mining surface rock mass turns to get fractured in a depth of-120 m,-220 m,-320 m; and,then,fracture would happen,which is followed by the deformation; and then the rock burst is supposed to be caused by the instability of the deformation generalized,which may take place at the depths of 420 m,-520 m,-620 m below and beneath the mining surface. And,furthermore,the deformation and fracture of such surface rock mass may tend to occur at a depth of -720 m,-820 m beneath the surface during the period of 0-0. 01 s,when the rock mass remains in the process of deformation and failure. And,during the period of 0. 01-0. 1 s,the rock mass may also stay in the stataus-in-situ of going to get burst. As a step further,during the period of 0. 1-5. 18 s,the rock mass may tend to go into a strain area instability collapse. From what is said above, the process of the rock bursts tend to take place in almost the same way in accordance with the difference of the mining depth (the said accumulated elastic potential energy) and the degree of rock fracture,though the final stable phase may turn out to be different whereas the fracturing time of the early and the middle phase can basically be the same.