The overburden failure causes the changes of the constant electric field, and the resistivity is the main parameter in these changes. The experimental simulation about tbe response relation between the overburden fail...The overburden failure causes the changes of the constant electric field, and the resistivity is the main parameter in these changes. The experimental simulation about tbe response relation between the overburden failure and its electrical parameter changes is made by building the similar material physics model of mining. The experiment results are used to analyze and test the in-situ detection. The research indicates that the resistivity changes with the electric characteristic of the rock in cracked zone and caving zone caused by overburden failure, the response characteristics of resistivity vary with the failure degrees at different overburden failure zone and that they are corresponding. The resistivity method used in monitoring the overburden failure can determine the height and the affecting scopes of the cracked zone and caving zone. This can provide reliable techaological guarantee for mining design and safe production.展开更多
The results of experimentaI studies about the characteristics of broken rock expansion and reconsolidation were briefly introduced in this paper, and the surface subsidence coefficient under critical mining conditions...The results of experimentaI studies about the characteristics of broken rock expansion and reconsolidation were briefly introduced in this paper, and the surface subsidence coefficient under critical mining conditions was also analysed based on the principle of expansion and reconsolidation of the broken rock strata, a equation to calculate the corresponding surface subsidence was finally produced. This calculation method can be used to calculate more accurately the convergence quantity of consolidated rocks in the broken zone of the working face. In addition, case analyses by using the introduced calculation method were conducted and satisfactory results were obtained.展开更多
In this paper, the effect of the remaining coal pillars in a room and pillar section on the long wall face in the lower coal bed are tested by using equivalent material models. The failure laws of the overburden under...In this paper, the effect of the remaining coal pillars in a room and pillar section on the long wall face in the lower coal bed are tested by using equivalent material models. The failure laws of the overburden under coal pillars are discussed. A phenomenon of sub weighting has been observed when long wall face is in process under the remaining pillars in room and pillar mining section. It is concluded that, because coal pillars underwent a course of the stress increasing before they were fully destroyed, the existence of the coal pillars would shorten the distance of periodical weighting of the main roof in the long wall face. Based on this, the characteristic equations of the overburden movement under coal pillars are presented.展开更多
文摘The overburden failure causes the changes of the constant electric field, and the resistivity is the main parameter in these changes. The experimental simulation about tbe response relation between the overburden failure and its electrical parameter changes is made by building the similar material physics model of mining. The experiment results are used to analyze and test the in-situ detection. The research indicates that the resistivity changes with the electric characteristic of the rock in cracked zone and caving zone caused by overburden failure, the response characteristics of resistivity vary with the failure degrees at different overburden failure zone and that they are corresponding. The resistivity method used in monitoring the overburden failure can determine the height and the affecting scopes of the cracked zone and caving zone. This can provide reliable techaological guarantee for mining design and safe production.
文摘The results of experimentaI studies about the characteristics of broken rock expansion and reconsolidation were briefly introduced in this paper, and the surface subsidence coefficient under critical mining conditions was also analysed based on the principle of expansion and reconsolidation of the broken rock strata, a equation to calculate the corresponding surface subsidence was finally produced. This calculation method can be used to calculate more accurately the convergence quantity of consolidated rocks in the broken zone of the working face. In addition, case analyses by using the introduced calculation method were conducted and satisfactory results were obtained.
文摘In this paper, the effect of the remaining coal pillars in a room and pillar section on the long wall face in the lower coal bed are tested by using equivalent material models. The failure laws of the overburden under coal pillars are discussed. A phenomenon of sub weighting has been observed when long wall face is in process under the remaining pillars in room and pillar mining section. It is concluded that, because coal pillars underwent a course of the stress increasing before they were fully destroyed, the existence of the coal pillars would shorten the distance of periodical weighting of the main roof in the long wall face. Based on this, the characteristic equations of the overburden movement under coal pillars are presented.
