According to the specific geological condition, analyzed the stress distribution of the overlying strata, the displacement of pressure released seam, thickness variation and the distribution of plastic zones by FLAG3D...According to the specific geological condition, analyzed the stress distribution of the overlying strata, the displacement of pressure released seam, thickness variation and the distribution of plastic zones by FLAG3D software to simulate mining of the long-distance lower protective seam. The research results show that the distribution of vertical stress appears as a ＂Double-hump＂ within the pressure-relief range of the protected coal seam and the swelling deformation curve of coal bodies takes an ＂M＂ shape. The swelling is divided into initial swelling, swelling increase and swelling compression stability. The maximum swelling ratio of the pressure released seam is 1.84%, protection angle of the lower protective coal seam along the strike direction is about 55°, protection angle below the dip direction is about 50°, protection angle above the dip direction is about 55°, and the coal seam compression zone resembles a ＂U＂ shape.展开更多
To obtain the deep displacement of the coal seam in the working face,multi-point displacements were installed in the coal seam, but the installation of multi-point displacement is differen tunder different geological ...To obtain the deep displacement of the coal seam in the working face,multi-point displacements were installed in the coal seam, but the installation of multi-point displacement is differen tunder different geological conditions. This paper is based on the splitting and merging of 7_1 coal and 7_2 coal in Huaibei Mining(Group) Co., Ltd., and analyzes properties of the roof andcoal in the 7_2 coal of the lower coal seam of bifurcation area, and calculates the damage depth of the floor in the process of 7_1 coal mining. The multi-point displacement meter installation is often challenged by hole collapse, stuck pole and broken installation rod in 7_2 coal of the soft coal seam of bifurcation area, as a result, the base points can't be installed in the specified location. In view of this, this paper adopts a new anchor cable mounting rod which can install the whole base points to the specified location without stuck pole or broken mounting stem. All the basic displacement data can be obtained, and the law of mine pressure appearance in stope and tunnel can be accurately controlled, which can be used to maintain the stability of roadway and the safety of stope.展开更多
The influence of an upper,mined coal seam on the stability of rock surrounding a roadway in a lower coal seam is examined.The technical problems of roadway control are discussed based on the geological conditions exis...The influence of an upper,mined coal seam on the stability of rock surrounding a roadway in a lower coal seam is examined.The technical problems of roadway control are discussed based on the geological conditions existing in the Liyazhuang Mine No.2 coal seam.The stress distribution and floor failure in the lower works after mining the upper coal is studied through numerical simulations.The failure mechanism of the roof and walls of a roadway located in the lower coal seam is described.The predicted deformation and failure of the roadway for different distances between the two coal seams are used to design two ways of supporting the lower structure.One is a combined support consisting of anchors with a joist steel tent and a combined anchor truss.A field test of the design was performed to good effect.The results have significance for the design of supports for roadways located in similar conditions.展开更多
基金Supported by the Basic Research Program of National Natural Science Foundation of China(50834005)
文摘According to the specific geological condition, analyzed the stress distribution of the overlying strata, the displacement of pressure released seam, thickness variation and the distribution of plastic zones by FLAG3D software to simulate mining of the long-distance lower protective seam. The research results show that the distribution of vertical stress appears as a ＂Double-hump＂ within the pressure-relief range of the protected coal seam and the swelling deformation curve of coal bodies takes an ＂M＂ shape. The swelling is divided into initial swelling, swelling increase and swelling compression stability. The maximum swelling ratio of the pressure released seam is 1.84%, protection angle of the lower protective coal seam along the strike direction is about 55°, protection angle below the dip direction is about 50°, protection angle above the dip direction is about 55°, and the coal seam compression zone resembles a ＂U＂ shape.
基金Sponsored by National Natural Science Fund of China(51474005)
文摘To obtain the deep displacement of the coal seam in the working face,multi-point displacements were installed in the coal seam, but the installation of multi-point displacement is differen tunder different geological conditions. This paper is based on the splitting and merging of 7_1 coal and 7_2 coal in Huaibei Mining(Group) Co., Ltd., and analyzes properties of the roof andcoal in the 7_2 coal of the lower coal seam of bifurcation area, and calculates the damage depth of the floor in the process of 7_1 coal mining. The multi-point displacement meter installation is often challenged by hole collapse, stuck pole and broken installation rod in 7_2 coal of the soft coal seam of bifurcation area, as a result, the base points can't be installed in the specified location. In view of this, this paper adopts a new anchor cable mounting rod which can install the whole base points to the specified location without stuck pole or broken mounting stem. All the basic displacement data can be obtained, and the law of mine pressure appearance in stope and tunnel can be accurately controlled, which can be used to maintain the stability of roadway and the safety of stope.
基金supported by the National Natural Science Foundation of China (No.50874103)the National Basic Research Program of China (No.2010CB226805)+1 种基金the Natural Science Foundation of Jiangsu Province (No.BK2008135)by the Open Foundation of State Key Laboratory of Geomechanics and Deep Underground Engineering (No.SKLGDUEK0905)
文摘The influence of an upper,mined coal seam on the stability of rock surrounding a roadway in a lower coal seam is examined.The technical problems of roadway control are discussed based on the geological conditions existing in the Liyazhuang Mine No.2 coal seam.The stress distribution and floor failure in the lower works after mining the upper coal is studied through numerical simulations.The failure mechanism of the roof and walls of a roadway located in the lower coal seam is described.The predicted deformation and failure of the roadway for different distances between the two coal seams are used to design two ways of supporting the lower structure.One is a combined support consisting of anchors with a joist steel tent and a combined anchor truss.A field test of the design was performed to good effect.The results have significance for the design of supports for roadways located in similar conditions.
