<<
[an error occurred while processing this directive] | [an error occurred while processing this directive] >>
Mechanical Evolution Law of Macroscopic Deformation and Failure of Surrounding Rocks in Deep Mining
(1 Hunan Key Laboratory for Geomechanics and Engineering Safety, College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan 411105；2 Key Laboratory of Safety and High-efficiency Coal Mining, Ministry of Education, Anhui University of Science and Technology,Huainan 232001; 3 School of Environment and Resources, Xiangtan University, Xiangtan 411105)
Abstract In order to study the macroscopic deformation-failure characteristics and time-space evolution rules of stress distribution of surrounding rocks in deep mining, mechanical evolution laws of roof crack field, overlying rock displacement field and surrounding rock stress field in deep mining were studied by using the methods of computer numerical simulation and laboratory similar model test. The results show that the surrounding rock has experienced gradual failure process of transient mutation, jump development, sequential unloading and continuous transmission,overlying rock fissure field has the time and space evolution characteristics of pressure relief induced instability,crack opening, crack development, through- penetration, shrinking fitting and closed stability. The migration of strata has a strong influence on“adjacent space effect”: the roof surrounding rock is closer to the coal seam, the influence of displacement measurement line is stronger, and the range of spatial effect is more concentrated, the stage controllability of the strata movement becomes weaker, otherwise when the distance between the roof layer and the coal seam is larger, the impact mechanism of adjacent space decreases, overburden subsidence is smaller, the stress transfer and load transfer mobility is inert. The stress distribution of surrounding rock in deep mining has interval evolutionary characteristics of the significant influence on the near field mechanical effect and the weakening of the far field force chain bearing system. The sudden increase in stress of surrounding rock in short time and superposition effect of high stress concentration caused by irregular mining are the mechanical causes of impact dynamic instability of mining field.
Abstract：
In order to study the macroscopic deformation-failure characteristics and time-space evolution rules of stress distribution of surrounding rocks in deep mining, mechanical evolution laws of roof crack field, overlying rock displacement field and surrounding rock stress field in deep mining were studied by using the methods of computer numerical simulation and laboratory similar model test. The results show that the surrounding rock has experienced gradual failure process of transient mutation, jump development, sequential unloading and continuous transmission,overlying rock fissure field has the time and space evolution characteristics of pressure relief induced instability,crack opening, crack development, through- penetration, shrinking fitting and closed stability. The migration of strata has a strong influence on“adjacent space effect”: the roof surrounding rock is closer to the coal seam, the influence of displacement measurement line is stronger, and the range of spatial effect is more concentrated, the stage controllability of the strata movement becomes weaker, otherwise when the distance between the roof layer and the coal seam is larger, the impact mechanism of adjacent space decreases, overburden subsidence is smaller, the stress transfer and load transfer mobility is inert. The stress distribution of surrounding rock in deep mining has interval evolutionary characteristics of the significant influence on the near field mechanical effect and the weakening of the far field force chain bearing system. The sudden increase in stress of surrounding rock in short time and superposition effect of high stress concentration caused by irregular mining are the mechanical causes of impact dynamic instability of mining field.
.Mechanical Evolution Law of Macroscopic Deformation and Failure of Surrounding Rocks in Deep Mining[J] MODERN TUNNELLING TECHNOLOGY, 2019,V56(1): 99-106
2019, Vol. 56 