Abstract: A method for carrying out grouting between adjacent gateroads in internal-staggered split-level coal mining. A return air gateroad of a stoping face and an inlet air gateroad of a heading face are not on the same level. The return air gateroad of the stoping face is arranged along a roof of a coal seam. The inlet air gateroad of the heading face is arranged along a floor of the coal seam. There is a height difference between the return air gateroad and the inlet air gateroad in a vertical direction. During the construction process, the inlet air gateroad is excavated at a delay distance of 180-200 meters from the return air gateroad. The drilling and grouting are performed while excavating the roadway, where grouting holes are arranged in a single row. A device for implementing the method is also provided.

Abstract: A device and method for testing the bearing capacity of grouped pillars in the inclined goaf under coupled biaxial static and disturbance stresses are provided. Four protection rings are arranged on a base, each protection ring is installed with one machine frame therein, a bottom end of the machine frame is connected with the base and a top end thereof is connected with a transverse frame. Sliding rails are arranged on two sides of the base, side frames are installed on the sliding rails. A vertical force loading device is arranged at a bottom of a workbench, transverse force loading devices are arranged on inner sides of the side frames respectively. A force disturbance device is arranged at the bottom of the transverse frame. An upper slidable clamping seat and an upper pressure disk are arranged above the samples, and a lower slidable clamping seat is arranged below the samples.

Abstract: A method for carrying out grouting between adjacent gateroads in internal-staggered split-level coal mining. A return air gateroad of a stoping face and an inlet air gateroad of a heading face are not on the same level. The return air gateroad of the stoping face is arranged along a roof of a coal seam. The inlet air gateroad of the heading face is arranged along a floor of the coal seam. There is a height difference between the return air gateroad and the inlet air gateroad in a vertical direction. During the construction process, the inlet air gateroad is excavated at a delay distance of 180-200 meters from the return air gateroad. The drilling and grouting are performed while excavating the roadway, where grouting holes are arranged in a single row. A device for implementing the method is also provided.

Abstract: A device and method for testing the bearing capacity of grouped pillars in the inclined goaf under coupled biaxial static and disturbance stresses are provided. Four protection rings are arranged on a base, each protection ring is installed with one machine frame therein, a bottom end of the machine frame is connected with the base and a top end thereof is connected with a transverse frame. Sliding rails are arranged on two sides of the base, side frames are installed on the sliding rails. A vertical force loading device is arranged at a bottom of a workbench, transverse force loading devices are arranged on inner sides of the side frames respectively. A force disturbance device is arranged at the bottom of the transverse frame. An upper slidable clamping seat and an upper pressure disk are arranged above the samples, and a lower slidable clamping seat is arranged below the samples.

Abstract: A rock sanding device includes a base, a bottom sanding plate, an adjustable connecting rod, an elastic loader, a connector, a side sanding brush, a top sanding plate, an inner rod, a prong and a drill rod. The top of the drill rod is fixedly connected with the rotating shaft of the external water drilling rig and the external water drilling rig has a water inlet joint to introduce water into the drill rod. The inner rod and drill rod are connected and fixed coaxially, and the bottom of the drill rod is symmetrically welded with four prongs. The rock specimen is placed in the center of the side sanding brush. The top sanding plate and the bottom sanding plate are provided in the top side and bottom side of the rock specimen, respectively.

Abstract: A rock sanding device includes a base, a bottom sanding plate, an adjustable connecting rod, an elastic loader, a connector, a side sanding brush, a top sanding plate, an inner rod, a prong and a drill rod. The top of the drill rod is fixedly connected with the rotating shaft of the external water drilling rig and the external water drilling rig has a water inlet joint to introduce water into the drill rod. The inner rod and drill rod are connected and fixed coaxially, and the bottom of the drill rod is symmetrically welded with four prongs. The rock specimen is placed in the center of the side sanding brush. The top sanding plate and the bottom sanding plate are provided in the top side and bottom side of the rock specimen, respectively.