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 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 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 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.