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 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 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.