In Gengcun Colliery, Yima Coal Group Co. Ltd.the characteristics of the gateways of thick coal seam and the coal seam is with fully mechanized sublevel caving mining are that the thickness of roof coal seam of gateway...In Gengcun Colliery, Yima Coal Group Co. Ltd.the characteristics of the gateways of thick coal seam and the coal seam is with fully mechanized sublevel caving mining are that the thickness of roof coal seam of gateways is larger, their surrounding rocks are the whole-coal mass and the coal seam is prone to Spontaneous Combustion. With the natural equilibrium arch theory, the reasonable adjacent distance of No.11 mine-type metal supports was calculated in trapezoidal gateways based on these characteristics. Then, in-situ supporting experiments were carried out. The results indicate that under the action of virgin rock stress, the width of broken rocks zone of surrounding rocks is 1.7–2.0 m in return heading and 1.1–1.3 m in going headway. And their surrounding rocks belong to the Ⅳ-type soften rock and the Ⅲ-type common surrounding rock respectively. Therefore, under the movable abutment pressure, the gateways deformation is serious. It is suggested that the designed gateways have to use pre-broadened cross section to suit their deformation. At the same time, the accumulated water on gateway floor must be drained in time. These measures were taken in the 1302 and 1304 coal faces in Gengcun Colliery, and the satisfactory results have been obtained.展开更多
The roof separation was investigated in a coal mine as part of the site charac- terization of roof strata deterioration in a longwall roadway. The separation of laminated, weak roof strata was initially characterized ...The roof separation was investigated in a coal mine as part of the site charac- terization of roof strata deterioration in a longwall roadway. The separation of laminated, weak roof strata was initially characterized as the maximum separation, effect of geologi- cal setting on separation and the effect of mining activities (heading development, time-dependent and longwall extraction) on separation. Then the separation process was studied, so as to answer the questions of: when the separation occurs;where the separa- tion is located and what geological setting it relates to;how large of the separation is;and how the separation propagates.展开更多
基金Project 0511051900 supported by Natural Science Foundation of Henan Province
文摘In Gengcun Colliery, Yima Coal Group Co. Ltd.the characteristics of the gateways of thick coal seam and the coal seam is with fully mechanized sublevel caving mining are that the thickness of roof coal seam of gateways is larger, their surrounding rocks are the whole-coal mass and the coal seam is prone to Spontaneous Combustion. With the natural equilibrium arch theory, the reasonable adjacent distance of No.11 mine-type metal supports was calculated in trapezoidal gateways based on these characteristics. Then, in-situ supporting experiments were carried out. The results indicate that under the action of virgin rock stress, the width of broken rocks zone of surrounding rocks is 1.7–2.0 m in return heading and 1.1–1.3 m in going headway. And their surrounding rocks belong to the Ⅳ-type soften rock and the Ⅲ-type common surrounding rock respectively. Therefore, under the movable abutment pressure, the gateways deformation is serious. It is suggested that the designed gateways have to use pre-broadened cross section to suit their deformation. At the same time, the accumulated water on gateway floor must be drained in time. These measures were taken in the 1302 and 1304 coal faces in Gengcun Colliery, and the satisfactory results have been obtained.
文摘The roof separation was investigated in a coal mine as part of the site charac- terization of roof strata deterioration in a longwall roadway. The separation of laminated, weak roof strata was initially characterized as the maximum separation, effect of geologi- cal setting on separation and the effect of mining activities (heading development, time-dependent and longwall extraction) on separation. Then the separation process was studied, so as to answer the questions of: when the separation occurs;where the separa- tion is located and what geological setting it relates to;how large of the separation is;and how the separation propagates.
