Abstract: When the heading machine tunnels, a current generated by a current excitation source enters a coal seam through a movable cutting pick to form a stray current. The stray current collected by a backflow net returns to a negative electrode of a power supply through a transition resistor. When information such as the water content of the coal seam changes, the stray current and a potential difference across the transition resistor also accordingly change, and the coal seam water content information is converted into an electric signal. When the potential difference across the transition resistor is applied to two ends of a piezoelectric ceramic, the piezoelectric ceramic extends or compresses, and the electric signal is converted into a strain signal. A sensing optical fiber converts the strain signal into an optical signal detectable by a photoelectric detector. The optical signal is analyzed to obtain the coal seam water content information.

Abstract: A device for cage jamming buffer of large-tonnage hoisting system of ultra-deep shaft is provided. End cage jamming buffer mechanisms are added at both ends of an automatic wire rope tension balancing mechanism, wherein the end cage jamming buffer mechanisms include an end buffer module and an end fixing module, and the end buffer module and the end fixing module are respectively mounted on shafts of the automatic wire rope tension balancing mechanisms at two ends. The end buffer module mainly consists of a buffer bearing pedestal, a limit block, a buffer block, and a stop block sequentially mounted on the shaft of the automatic wire rope tension balancing mechanism at one end. The end fixing module mainly consists of a fixing bearing pedestal and a fixing block mounted on the shaft, wherein the fixing bearing pedestal is connected to a transmission gear by an adjusting bolt.

Abstract: Provided is a method for radially mining open-pit end slope pressed coal, including: L-shaped or U-shaped main tunnel arrangements, and radially mining; branch tunnels are formed by excavating tunnels in directions perpendicular to or obliquely crossing the main tunnel from the L-shaped or U-shaped main tunnel; In the mining method, a coal mining system and a transportation system both adopt a remote control mode, a tunneling machine excavates a tunnel to product coal; a rubber belt conveyor conveys coal; the main tunnel adopts an exhaust ventilation mode, the branch tunnels adopt a blowing ventilation mode; the lengths of the branch tunnels do not exceed a farthest control distance of a remote control system; the length of each main tunnel needs to ensure that all the end slope pressed coal is mined under the premise that the branch tunnels do not exceed the farthest control distance of the remote control system.

Abstract: A method for controlling a subsidence area caused by underground mining in an adjoining open-pit mine, applied in an open-pit and underground coordinated mining process. In the method, a ground subsidence area caused by underground mining and production is directly filled and covered with overburden materials such as soil and rock discharged from an adjoining open-pit mine; small and medium fracture zones and large fracture zones caused by mining are timely backfilled, tamped, and levelled according to areas before the ground subsidence area appears, the thickness of the levelled soil layer is kept above 1 m, and the area slope is controlled within 7°.

Abstract: A sealing pressing head for a conventional triaxial test of cuboid rocks with pre-existing fissures, and a test method, the sealing pressing head comprising an upper pressing head (14) and a lower pressing head (15); the upper pressing head (14) and the lower pressing head (15) are respectively used for being provided at upper and lower ends of a test sample (10); the upper pressing head (14) comprises a circular portion (2) and a square portion (1) which are provided in sequence from top to bottom; and the lower pressing head (15) comprises a square portion (1), a circular portion (2) and a threaded portion (3) which are provided in sequence from top to bottom.

Abstract: A stress-transfer method in tunnel with high ground pressure based on fracturing ring. According to the stress source of the tunnel, fracturing by drilling holes to form artificial weaken zones in surrounding rocks, that's named fracturing ring. The fracturing ring is the weaken zone with some width, whose inner boundary is the protective circle. The fracturing ring with small width is called the cutting and interruption circle and the cutting or interruption arc. The radius of the protective circle is determined by setting a certain width of safety coal pillar barriers at the edge of a support body. The radius of the fracturing ring is determined by the surrounding rock structure and the stress conditions as well as the construction technology. Usually, the higher the stress, the wider the radius of the fracturing ring. The cutting and interruption circle or arc could cut off all of the targeted rock which transmits the stress.

Abstract: A steel belt conveying apparatus includes upper and lower horizontal conveying portions, left and right inclined conveying chains, a connecting rod frame, an inclined frame, a drive portion, and a height adjustment cylinder. The left inclined conveying chain is separately connected to the upper and lower horizontal conveying portions. The right inclined conveying chain is separately connected to the upper and lower horizontal conveying portions. A top portion of the connecting rod frame is hingedly connected to an upper horizontal frame of the upper horizontal conveying portion. A bottom portion is hingedly connected to a lower frame of the lower horizontal conveying portion. A top portion of the inclined frame is hingedly connected to an upper horizontal drive shaft of the upper horizontal conveying portion, and a bottom portion is hingedly connected to a lower horizontal drive shaft of the lower horizontal conveying portion.

Abstract: The present invention discloses a hard rock roadway and tunnel boring machine with actively rotating hobs, including a rack provided with a crawler track unit. The rack is provided with a hydraulic power unit and a high-pressure abrasive jet generation system connected therewith. A transmission box is fixedly arranged at one of ends of the rack. The transmission box is provided with two input shafts and one output shaft. The input shafts are connected with planetary reduction mechanisms. Input ends of the planetary reduction mechanisms are connected with cantilever disc driving motors. A cantilever disc is fixed to the output shaft. Four cantilevers are hinged to the cantilever disc. Cantilever driving motors are further arranged on the cantilever disc. Actively rotating hob devices are arranged at ends of the cantilevers away from the cantilever disc. The transmission box is further provided with rotary sealing devices.

Abstract: An apparatus for controllably unfolding a flexible mesh for a continuous miner includes a mesh roll storage rack, a height adjustment post, a mesh rolling shaft and a flexible mesh. The flexible mesh includes a mesh roll and an unfolded mesh. The mesh roll and the unfolded mesh are an integrated structure. The mesh roll is located on the mesh roll storage rack. The unfolded mesh is clamped on the mesh rolling shaft, and is pressed on a cut un-supported tunnel roof via a roof bolt. The mesh rolling shaft is rotatably connected to a top portion of the height adjustment post. The mesh roll storage rack and the height adjustment post are both mounted on the continuous miner. The mesh rolling shaft is located at a back end of the mesh roll storage rack. A limit mechanism and a damping mechanism are disposed on the mesh rolling shaft.

Abstract: In a method, a gyroscope and an endoscopic camera are first used to investigate coal-seam strike trend, coal-seam dip trend, and coal-seam thickness data of a to-be-extracted area. According to gas extraction standard requirements of a to-be-extracted area, boreholes are then designed and constructed, and trajectories of boreholes are tracked to obtain a correspondence relationship between designed borehole parameters and actual borehole trajectory parameters. Next, drilling parameters are adjusted according to the correspondence relationship between the designed borehole parameters and the actual borehole parameters to construct boreholes at predetermined borehole locations. Subsequently, the boreholes are connected to an extraction pipeline, and gas extraction flow rates and gas extraction amounts per meter of the boreholes are observed. Eventually, other boreholes are designed and constructed according to the adjusted borehole construction parameters and extraction data.

Abstract: A large-tonnage skip anti-blocking system includes a skip, wherein two parallel rows of guide rails are fixed to upper and lower shaft walls of a shaft on two sides of the skip correspondingly, a plurality of pulleys are mounted on the guide rails in a matched mode, impact plates are mounted between the upper and lower pulleys, front plates of the impact plates are mounted between the upper and lower sets of pulleys in the front row, rear plates of the impact plates are mounted between the upper and lower sets of pulleys in the back row, a length of rib plates of the impact plates is greater than a width of the skip, hydraulic cylinder bases and vibration motors are mounted on outer sides of the rib plates at intervals.

Abstract: A method for classifying a phreatic leakage disaster level in shallow coal seam mining includes the following steps: S1. arranging a monitoring hole in a coal mine working face and burying a telemetering water level gauge to perform water level monitoring; S2. monitoring a ground elevation, calculating a ground subsidence amount, and collecting mining advance distance information; S3. plotting variation relationship curves of mining advance distance and phreatic water level as well as mining advance distance and ground subsidence according to monitored information, respectively; and S4. comparing the curves with a no-leakage graph, a slight-leakage graph, and a heavy-leakage graph, and determining a leakage level; and S5. further classifying a studied area as an environmental disaster area or an environmentally friendly area.

Abstract: An experiment system and transparent experiment method for replicating fluid displacement in a pore structure of a natural rock mass are provided. The natural pore structure is extracted and a digital porous model corresponding to the natural rock mass is reconstructed with the image processing method. Based on the digital porous model, a three-dimensional pore structure model with a transparent and visible internal structure is printed by a 3D printing device, such that the pore space inside the three-dimensional pore structure model is visible. In this way, the whole fluid flow during the displacement-seepage process within the natural rock mass can be replicated and visually observed from the outside when performing the displacement-seepage experiment. Further, temperature, flow rate, and pressure can be accurately controlled, to replicate various experiment conditions, so as to perform quantitative analysis on distribution features of a seepage field and a fluid speed field.

Abstract: A method for determining a segmentation threshold of a digital image of a rock-soil material is disclosed. The method comprises the following steps: S1: acquiring a gray-level histogram curve of an SEM image of the rock-soil material; S2: determining a value range of a segmentation threshold T according to the gray-level histogram curve; S3: acquiring second derivatives of the gray-level histogram curve; and S4: determining the segmentation threshold T according to the second derivatives of the gray-level histogram curve and the value range of the segmentation threshold T. The present invention can rapidly and accurately determine the segmentation threshold of the digital image of the rock-soil material, and accurately distinguish a pore or fissure structure from a surface soil skeleton structure of the rock-soil material in the digital image.

Abstract: A steel belt conveying apparatus includes upper and lower horizontal conveying portions, left and right inclined conveying chains, a connecting rod frame, an inclined frame, a drive portion, and a height adjustment cylinder. The left inclined conveying chain is separately connected to the upper and lower horizontal conveying portions. The right inclined conveying chain is separately connected to the upper and lower horizontal conveying portions. A top portion of the connecting rod frame is hingedly connected to an upper horizontal frame of the upper horizontal conveying portion. A bottom portion is hingedly connected to a lower frame of the lower horizontal conveying portion. A top portion of the inclined frame is hingedly connected to an upper horizontal drive shaft of the upper horizontal conveying portion, and a bottom portion is hingedly connected to a lower horizontal drive shaft of the lower horizontal conveying portion.

Abstract: A tension balance system for steel wire ropes on a friction hoisting driving end of an ultra-deep well includes a friction wheel, left and right guiding wheels, left and right steel wire ropes, left and right adjustment wheels, left and right rewinding wheels, left and right adjustment oil cylinders, a hydraulic pipeline, a pump station, a pipeline switch group, left and right hoisting containers, balance ropes, and reels. The friction wheel is disposed in the middle, the left and right adjustment wheels and the left and right rewinding wheels are circularly distributed around the friction wheel, the left and right guiding wheels, the left and right adjustment wheels, and left and right rewinding wheels are all symmetrically disposed on two sides of the friction wheel; both a quantity of left steel wire ropes and a quantity of right steel wire ropes are even numbers more than 2.

Abstract: A prefabricated stair modular assembly mold comprises a base, a step standard module, an upside module of a lower platform, an underside rotating module of a lower platform, an upside module of an upper platform, an underside rotating module of an upper platform, an underside common module, and an underside adjustment modules. Prefabricated stair molds of different dimensions are formed by means of locating holes provided in the assembling modules, and are then fixed by means of sliding holes at two ends. Further disclosed is a mounting method for said assembly mold. Said assembly mold has high positioning accuracy, and small accumulated error, improving the mounting efficiency of the prefabricated staircase mold.

Abstract: A simulation test system for gas extraction from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity. A coal series stratum structure reconstruction and similar material simulation subsystem simulates a tectonically-deformed coal reservoir. A horizontal well drilling and reaming simulation subsystem constructs a U-shaped well in which a horizontal well adjoins a vertical well, and performs a reaming process on a horizontal section thereof. A horizontal well hole-collapse cavity-construction depressurization excitation simulation subsystem performs pressure-pulse excitation and stress release on the horizontal well, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section. A product lifting simulation subsystem further pulverizes the coal and lifts the mixture. A gas-liquid-solid separation simulation subsystem separates the coal, liquid and gas.

Abstract: A multilevel deep well cooling and geothermal utilization system and process. The system has a deep well heat harnessing system, a shallow part heat-exchanging system, and a high-temperature water lifting system. The deep well heat harnessing system has a heat absorbing pipe, a thermally-conductive fluid lifting pipe, a thermally-conductive fluid lowering pipe, temperature sensors, and a water pump. The shallow part heat-exchanging system has a heat-dissipating pipe, a heat-storing water pool, a water intake pump, a water intake valve, a temperature sensor and a liquid level meter. The high-temperature water lifting system has a water discharging pump, a flowmeter, a water discharging valve, and a high-temperature water lifting pipe.

Abstract: Disclosed is an underground coal preparation process adopting a water medium, comprising: feeding exploited raw coal into a ?25 mm raw coal classifying screen for screening; performing dry coal preparation on a classifying screen oversize product with a particle size greater than 25 mm and feeding a classifying screen undersize product with a particle size less than 25 mm into a special underground compact jigging machine for sorting to obtain jigging machine overflow clean coal, jigging middling coal and jigging gangue; screening and dewatering the jigging machine overflow clean coal to obtain a clean coal product, and screening and dewatering the jigging middling coal to obtain a middling coal product, sorting slime water to be sorted and generated during sorting to obtain coarse clean coal slime and coarse middling coal slime, and performing circulating water treatment on a final liquid.