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.

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.

The present disclosure relates to a technical field of coal mining, in particular to a surrounding rock stability control method adapted for a coal mining area main roadway. The method comprises the following steps: reinforcing support on a roof and two sides of the mining area main roadway on a basis of an original support form; digging a safety roadway along a stop line of a present working face required by coal mine design, and supporting the safety roadway, wherein a protective coal pillar is formed between the safety roadway and the mining area main roadway; performing slitting blasting on the roof in the safety roadway, wherein blast holes are arranged on a roadway corner line on one side of the present working face to form a pre-splitting slit; and performing stoping at a next working face after completing coal mining at the present working face when stoping at the present working face advances to the safety roadway. By cutting the roof and relieving pressure at the stop mining line of the working face, an influence of mining disturbance on stability of the mining area main roadway in the stoping process of the working face is reduced, and by reinforcing support, a yielding deformation capacity of the mining area main roadway is improved, and the stability of the surrounding rock of the mining area main roadway is further improved.

The present disclosure relates to a technical field of coal mining, in particular to a surrounding rock stability control method adapted for a coal mining area main roadway. The method comprises the following steps: reinforcing support on a roof and two sides of the mining area main roadway on a basis of an original support form; digging a safety roadway along a stop line of a present working face required by coal mine design, and supporting the safety roadway, wherein a protective coal pillar is formed between the safety roadway and the mining area main roadway; performing slitting blasting on the roof in the safety roadway, wherein blast holes are arranged on a roadway corner line on one side of the present working face to form a pre-splitting slit; and performing stoping at a next working face after completing coal mining at the present working face when stoping at the present working face advances to the safety roadway. By cutting the roof and relieving pressure at the stop mining line of the working face, an influence of mining disturbance on stability of the mining area main roadway in the stoping process of the working face is reduced, and by reinforcing support, a yielding deformation capacity of the mining area main roadway is improved, and the stability of the surrounding rock of the mining area main roadway is further improved.

Disclosed is a wireless monitoring system for a coal-gangue mixing ratio based on a non-Hermite technology, including a signal generation monitoring device, an excitation coil, a receiving coil and a parallel plate capacitor. The signal generation monitoring device is connected with the excitation coil; the receiving coil is connected with the parallel plate capacitor to form an LC resonance system; the receiving coil is placed in parallel with the excitation coil, and the axis of the receiving coil and the axis of the excitation coil are on a same horizontal line; the signal generation monitoring device is used to generate a pulse current and collect reflected signals; the excitation coil excites an initial magnetic field based on the generated pulse current, and the LC resonance circuit performs an electromagnetic field induction to generate an induced magnetic field, and feeds back the reflected signals to the signal generation monitoring device.

Disclosed is a wireless monitoring system for a coal-gangue mixing ratio based on a non-Hermite technology, including a signal generation monitoring device, an excitation coil, a receiving coil and a parallel plate capacitor. The signal generation monitoring device is connected with the excitation coil; the receiving coil is connected with the parallel plate capacitor to form an LC resonance system; the receiving coil is placed in parallel with the excitation coil, and the axis of the receiving coil and the axis of the excitation coil are on a same horizontal line; the signal generation monitoring device is used to generate a pulse current and collect reflected signals; the excitation coil excites an initial magnetic field based on the generated pulse current, and the LC resonance circuit performs an electromagnetic field induction to generate an induced magnetic field, and feeds back the reflected signals to the signal generation monitoring device.

The present disclosure provides a coal bump control method for sectional hydraulic fracturing regions of a near vertical ultra thick coal seam. The method includes: deepening a main shaft from a mining level to a fracturing level; excavating a cross-hole from a roof rock layer of a coal seam at the fracturing level to enter a coal seam being mined, and excavating a roadway along the strike of the coal seam; and drilling hydraulic fracturing boreholes in a dedicated fracturing roadway along an inclination angle of the coal seam to the coal seam above the roadway, wherein the length of the borehole makes the borehole in communication with a goaf, and the spacing of the boreholes along the strike and the sectional spacing of the boreholes in an inclination direction are designed according to the parameters of fracturing equipments and the fracturing length.

A method is to excavate main roadways in the upper and lower parts separately and an inclined intake roadway in the central part of the mine and pre-excavate an inclined seam roadway as the first mining face at the boundary on one side of the mine. Staring from the mine boundary, the retreating mining shall be carried out on the first mining face strip by strip with belt conveyors arranged in the upper main roadway and assistant conveying devices in the lower main roadway and inclined intake roadway; the open-off cut of the first mining face shall be built on the underside of the upper main roadway at the boundary of the mine to carry out the downward inclined mining on the strike and along the inclination.

A method is to excavate main roadways in the upper and lower parts separately and an inclined intake roadway in the central part of the mine and pre-excavate an inclined seam roadway as the first mining face at the boundary on one side of the mine. Staring from the mine boundary, the retreating mining shall be carried out on the first mining face strip by strip with belt conveyors arranged in the upper main roadway and assistant conveying devices in the lower main roadway and inclined intake roadway; the open-off cut of the first mining face shall be built on the underside of the upper main roadway at the boundary of the mine to carry out the downward inclined mining on the strike and along the inclination.

A prediction method for coal and gas outburst based on comparing borehole gas flow curves includes the following steps: constructing a seam-crossing borehole in the coal seam, measuring or calculating gas flow corresponding to critical gas pressure P, which is a reference gas flow Q(t).sub.reference; performing linear regression on the reference gas flow Q(t).sub.reference to form a reference flow curve; constructing a predicted seam-crossing borehole in a predicted area, and directly testing a gas flow at each time t in a delayed manner, which is a predicted gas flow Q(t).sub.prediction; prediction; performing linear regression on the predicted gas flow Q(t).sub.prediction to form a predicted flow curve; and judging whether the predicted flow curve is above the reference flow curve or whether the predicted flow curve intersects with the reference flow curve, and judging whether the coal seam in the predicted area has a risk of coal and gas outburst.