Abstract: The present disclosure provides a stress gradient loading test apparatus and a method of accurately determining loading energy, relating to the technical field of a rock mechanical test. The apparatus includes an upper pressure-bearing plate, a specimen fixing device, a stress transfer device, and a simulation specimen. A computer processes stress and strain monitoring data. The stress transfer device includes a plurality of plate-like high strength materials in combination. A simulation roadway is opened in the simulation specimen, and a strain gauge and a stress sensor are disposed on the simulation specimen. In a test using the apparatus, stress gradient loading is realized and elastic strain energy is calculated by the plate-like high strength materials with different stiffnesses of the stress transfer device, and loading energy acting on the simulation specimen is calculated in combination with energy applied by a tester.

Abstract: The present disclosure provides a stress gradient loading test apparatus and a method of accurately determining loading energy, relating to the technical field of a rock mechanical test. The apparatus includes an upper pressure-bearing plate, a specimen fixing device, a stress transfer device, and a simulation specimen. A computer processes stress and strain monitoring data. The stress transfer device includes a plurality of plate-like high strength materials in combination. A simulation roadway is opened in the simulation specimen, and a strain gauge and a stress sensor are disposed on the simulation specimen. In a test using the apparatus, stress gradient loading is realized and elastic strain energy is calculated by the plate-like high strength materials with different stiffnesses of the stress transfer device, and loading energy acting on the simulation specimen is calculated in combination with energy applied by a tester.

Abstract: The present disclosure provides a device and a method for an anchor bolt (cable) supporting structure test and an anchoring system performance comprehensive experiment, and relates to the technical field of anchoring tests.

Abstract: It discloses a grouting bolt-cable composite beam and supporting method for advanced support of fractured surrounding rock in deep coal mines. The quadrate plates are fixed at both ends of the steel beam, the anchor cable holes are arranged in the center of the steel beam and the quadrate plates, and the diameter of anchor bolt holes should be larger than that of the grouting cables. There are four anchor bolt holes on each quadrate plate, and each anchor bolt hole corresponds to a anchor plate, the horizontal surface of the anchor plate is close to the quadrate plate, and the arc parts of the four anchor plates are all facing the center of the quadrate plate.

Abstract: An anchor bolt length determination method based on monitoring of a roof rock stratum horizontal extrusion force includes drilling a borehole in the middle of a roadway roof to determine a surrounding rock fracturing scope by a borehole television. The method includes selecting the number and locations of horizontal extrusion force measuring points according to the surrounding rock fracturing scope. The method includes monitoring and recording a change of the horizontal extrusion force over time in the borehole by a device for monitoring a roof rock stratum horizontal extrusion force. The method includes selecting a location with the largest horizontal extrusion force as a center of a anchoring segment of an anchor bolt to determine a distance between the anchoring center and the roof. The method includes calculating a total length of the anchor bolt.

Abstract: The present disclosure provides a device and a method for an anchor bolt (cable) supporting structure test and an anchoring system performance comprehensive experiment, and relates to the technical field of anchoring tests.

Abstract: A rock mechanics test system with impact loading-confining pressure unloading and its usage method. The test system includes bearing frame unit, axial compression loading unit, impact loading unit and confining pressure loading unit. The bearing frame unit includes pedestal, column and cross beam. The column is vertically installed on both sides of the upper surface of the pedestal, and the cross beam is horizontally fixed on the upper part of the column. The axial compression loading unit is fixed at the middle position of the upper surface of the pedestal and is used to exert the axial bottom-up pressure to the sample. The impact loading unit is fixed on the cross beam and is used to exert the axial top-down impact load on the sample.

Abstract: A reverse rotary sprinkler drilling pipe system with anti-sticking function and its application method. This system comprises the front and rear drilling pipes which are arranged in sequence, a water spraying device, a rotary device. The rear drilling pipe is connected with an external drilling rig. The front and rear drilling pipes are respectively arranged with through holes in an inner axial direction. The water spraying device comprises a first cylinder and a connecting body, and symmetrical multiple groups of water spraying holes are arranged on the inner sidewall of the first cylinder. A limit block is arranged in the upper part of the inner sidewall. The connecting body is disposed with water conveyance hole which is connected with the through hole and the inner part of the first cylinder.

Abstract: A reverse rotary sprinkler drilling pipe system with anti-sticking function and its application method. This system comprises the front and rear drilling pipes which are arranged in sequence, a water spraying device, a rotary device. The rear drilling pipe is connected with an external drilling rig. The front and rear drilling pipes are respectively arranged with through holes in an inner axial direction. The water spraying device comprises a first cylinder and a connecting body, and symmetrical multiple groups of water spraying holes are arranged on the inner sidewall of the first cylinder. A limit block is arranged in the upper part of the inner sidewall. The connecting body is disposed with water conveyance hole which is connected with the through hole and the inner part of the first cylinder.