Overburden fracture zone development characteristics of composite coal seam mining
The repetitive disturbance effect during the mining process of composite coal seam is likely to induce problems such as violent deformation of the roof and abnormal mineral pressure manifestation.In order to investigate the development characteristics of overburden fracture zone under the mining state of composite coal seam in Huangling No.2 Coal Mine,a full-scale numerical model is established using 3DEC numerical simulation software.The overburden transport map and frac-ture field development map under the mining state of composite coal seam are analyzed,and the overburden fracture charac-teristics before mining of lower group coal are analyzed by drilling.The results show that:the mining disturbance of upper group coal seam causes a large number of split fractures and vertical fractures in the stratum,leading to the increase of wa-ter-contributing space,and some fractures are filled by mudstone in the stratum.The lower group coal mining increases the collapse zone by 37％～56％and the water-conducting fracture zone by about 42％～46％.At the same time,the height of the water-conducting fracture zone formed by composite mining is significantly higher than that of single-seam mining,with an overall increase of 9％～15％.
composite coal seamnumerical simulationborehole measurementoverburden fracture zone
万方数据
维普
