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 device and method for testing bearing capacity of single-row grouped pillars in a horizontal goaf under biaxial loading is disclosed. Four fixed rings are arranged on testing machine base, and have stands installed therein respectively, bottom ends of the stands are connected with the base, top ends are connected with transverse frame, sliding rails are arranged on two sides of the base; the vertical force loading devices are arranged at a lower part of transverse frame and the horizontal force loading devices are arranged at inner sides of side frame. Simultaneous loading on multiple coal samples, rock samples, filling body samples, concrete samples, coal-filling samples and/or rock-filling samples can be achieved, the overall bearing capacity of a single-row group pillar system in the horizontal goaf under the biaxial compression condition can be obtained, and the mutual influence relation between grouped pillar individuals in the horizontal goaf can be attained.

Abstract: A device and a method for testing tensile resistance of multiple-row grouped pillars in an inclined goaf are provided. The bottoms of stands of the device are connected with a testing machine base, and the tops of the stands of the device are connected with a transverse frame; an upper slideable clamping seat and a lower slideable clamping seat are semi-cylindrical blocks, multiple lower loading jaws that are positioned to have a same central line are arranged on the lower slideable clamping seat, each of the lower loading jaws is opposite to a corresponding one of the upper loading jaws, the lower loading jaws are welded to the lower slideable clamping sea to test the tensile resistance of samples together; the upper part of the upper slideable clamping seat is connected with an upper pressure disk, and the lower slideable clamping seat is connected with a lower pressure disk.

Abstract: A loading system for a Hopkinson pressure bar test under water-gas-temperature multi-field coupling action includes: a sample sealed cabin which includes sealing flanges, Y-shaped and high-temperature resistant sealing rings, and a sealed cabin body; a gas pressure loading device which includes a high-pressure gas tank, a pressure regulating valve, a second barometer, a second high-pressure valve and a first three-way valve connected in sequence; a water pressure loading device which includes an electric pressure test water pump, a water pressure gauge, an accumulator and a one-way valve connected in sequence; a temperature loading device which includes thermocouple heating rods, a temperature display and a thermocouple temperature control circuit board connected in sequence; and a dynamic and static combined loading device which includes an axial pressure loading device, an impact loading device and a Hopkinson pressure bar member.

Abstract: A physical simulation test method for detecting a position of a ponding goaf in the excavation, which relates to physical detection of mines. This method includes: fabricating an experimental model of a composition similar to that of an excavating tunnel; fabricating a transient transmitting coil and receiving coil; connecting the coil to a wire and placing them in model A; connecting the coil to a transient electromagnetometer; injecting water into a trapezoidal goaf through a pre-buried plastic pipe; after the goaf is filled with water, immediately switching the transient electromagnetometer on to collect data; respectively transferring the coil to models B, C and D, injecting water and switching on the transient electromagnetometer to collect data; statistically analyzing detection and imaging results of the four models; and comparing the detection results with the actual data to determine detection accuracy and correction coefficient.

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 a method for testing tensile resistance of multiple-row grouped pillars in an inclined goaf are provided. The bottoms of stands of the device are connected with a testing machine base, and the tops of the stands of the device are connected with a transverse frame; an upper slideable clamping seat and a lower slideable clamping seat are semi-cylindrical blocks, multiple lower loading jaws that are positioned to have a same central line are arranged on the lower slideable clamping seat, each of the lower loading jaws is opposite to a corresponding one of the upper loading jaws, the lower loading jaws are welded to the lower slideable clamping sea to test the tensile resistance of samples together; the upper part of the upper slideable clamping seat is connected with an upper pressure disk, and the lower slideable clamping seat is connected with a lower pressure disk.

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 device and method for testing bearing capacity of single-row grouped pillars in a horizontal goaf under biaxial loading is disclosed. Four fixed rings are arranged on testing machine base, and have stands installed therein respectively, bottom ends of the stands are connected with the base, top ends are connected with transverse frame, sliding rails are arranged on two sides of the base; the vertical force loading devices are arranged at a lower part of transverse frame and the horizontal force loading devices are arranged at inner sides of side frame. Simultaneous loading on multiple coal samples, rock samples, filling body samples, concrete samples, coal-filling samples and/or rock-filling samples can be achieved, the overall bearing capacity of a single-row group pillar system in the horizontal goaf under the biaxial compression condition can be obtained, and the mutual influence relation between grouped pillar individuals in the horizontal goaf can be attained.

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 three-dimensional analog simulation test system for gas-liquid countercurrent in an abandoned mine goaf includes a three-dimensional analog simulation device configured to simulate an analog environment of gas-liquid countercurrent in an abandoned mine goaf, a gas supply system, an automatic water pressure control system and a hydraulic loading system. The three-dimensional analog simulation device includes a reaction frame and a three-dimensional analog simulation chamber. The reaction frame includes a beam, a base and a column for connecting the beam and the base. The three-dimensional analog simulation chamber is arranged inside the reaction frame. The test system can be used to simulate the gas-liquid countercurrent in an abandoned mine goaf so as to study the evolution of water accumulation and gas enrichment in long-term abandonment of closed mines and the migration evolution rules of gas-liquid two-phase in abandoned mines with high gas density.

Abstract: A supercritical CO2 reactor and a test system of creepage, diffusion and erosion of rock mass. The supercritical CO2 reactor includes a reactor body having a test chamber, a heating layer arranged in a side wall of the reactor body, a temperature sensor and a pressure sensor arranged in the test chamber, a sealing cover configured to seal an opening of the reactor body, a fixing component arranged on the sealing cover, a hydraulic loading component configured to apply an axial load on the specimen. The reactor body is provided with an air inlet/outlet pipe configured to communicate the test chamber with external environment. The air inlet/outlet pipe is provided with a air valve, and the fixing component includes vertical guide bars, an upper pad and a lower pad slideably arranged on the vertical guide bars. The hydraulic loading component includes a oil-loading tank and an axial loading rod.

Abstract: A physical simulation test method for detecting a position of a ponding goaf in the excavation, which relates to physical detection of mines. This method includes: fabricating an experimental model of a composition similar to that of an excavating tunnel; fabricating a transient transmitting coil and receiving coil; connecting the coil to a wire and placing them in model A; connecting the coil to a transient electromagnetometer; injecting water into a trapezoidal goaf through a pre-buried plastic pipe; after the goaf is filled with water, immediately switching the transient electromagnetometer on to collect data; respectively transferring the coil to models B, C and D, injecting water and switching on the transient electromagnetometer to collect data; statistically analyzing detection and imaging results of the four models; and comparing the detection results with the actual data to determine detection accuracy and correction coefficient.

Abstract: A three-dimensional analog simulation test system for gas-liquid countercurrent in an abandoned mine goaf includes a three-dimensional analog simulation device configured to simulate an analog environment of gas-liquid countercurrent in an abandoned mine goaf, a gas supply system, an automatic water pressure control system and a hydraulic loading system. The three-dimensional analog simulation device includes a reaction frame and a three-dimensional analog simulation chamber. The reaction frame includes a beam, a base and a column for connecting the beam and the base. The three-dimensional analog simulation chamber is arranged inside the reaction frame. The test system can be used to simulate the gas-liquid countercurrent in an abandoned mine goaf so as to study the evolution of water accumulation and gas enrichment in long-term abandonment of closed mines and the migration evolution rules of gas-liquid two-phase in abandoned mines with high gas density.

Abstract: A supercritical CO2 reactor and a test system of creepage, diffusion and erosion of rock mass. The supercritical CO2 reactor includes a reactor body having a test chamber, a heating layer arranged in a side wall of the reactor body, a temperature sensor and a pressure sensor arranged in the test chamber, a sealing cover configured to seal an opening of the reactor body, a fixing component arranged on the sealing cover, a hydraulic loading component configured to apply an axial load on the specimen. The reactor body is provided with an air inlet/outlet pipe configured to communicate the test chamber with external environment. The air inlet/outlet pipe is provided with a air valve, and the fixing component includes vertical guide bars, an upper pad and a lower pad slideably arranged on the vertical guide bars. The hydraulic loading component includes a oil-loading tank and an axial loading rod.

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.