Key points for underground water exploration in small coal mines
2. Before the working face is recovered, it is necessary to use geophysical exploration, drilling or road exploration to find out the faults and subsided columns in the working face. Write a report on special hydrogeological conditions, which can be recovered after being reviewed by the coal mine technical person in charge and reported to the county coal management department for approval. When water is found to be filled, reliable safety measures must be taken immediately or waterproof coal pillars must be left. Otherwise, it must not be mined.
3. Arrange the working face along the edge of the fault waterproof coal pillar. When cutting the cutting eye near the coal pillar, it is necessary to explore the waterproof coal pillar at any time to investigate whether the size of the waterproof coal pillar meets the design regulations. If it does not meet the requirements, Re-open the cutting eye according to the size of the coal pillar. After the probe, all holes must be sealed.
4. For areas where small kiln old water filling areas, water filling roads, water guiding faults, strong aquifers, subsided columns, old boreholes, etc., where water needs to be explored and released, the water warning line must be determined and accurately drawn in the mining. On the floor plan. When the pioneering tunneling project arrives at the warning, it must first explore and dig, and strictly control the advance distance of the borehole. When drilling, it is found that when the coal rock is soft, the piece is pressed, the pressure in the hole or the water pressure in the hole is suddenly increased, the amount of water is suddenly increased, and the top drill is abnormal, the drilling must be stopped immediately, but the drill pipe must not be pulled out. Immediately report to the Ministry of Mines and send people to monitor the water situation. If an emergency is found, all personnel in the water-threatening area must be evacuated immediately and then action taken.
5. Before installing the rig , the following rules must be observed:
1. Strengthen the roadway support near the drill hole, back the top, and lay a solid column and block on the work surface.
2. Clean up the coal mine in the roadway and dig the drainage ditch.
3. Install a dedicated telephone at or near the drilling location.
4. When determining the location of the main water inlet, it should be calibrated by the surveyor. The person responsible for the water work must visit the site to determine the drilling orientation, inclination and number of drilling arrangements and the depth of the drilling.
5. When detecting water at a location where the water pressure is greater than 1kg/cm2, the casing should be pre-consolidated. A gate valve shall be installed at the casing opening, and the casing depth must be specified in the design of the water to be discharged. In particularly dangerous areas, it is also necessary to pre-examine safety evasion holes, stipulate safety measures such as evacuation routes, and make construction personnel known to everyone.
6. In principle, high-pressure water-filled faults, aquifers and subsided column waters shall not be explored in coal seams. If it is really necessary, the waterproof gate wall can be built first and the water can be probed inward from the outside of the gate wall, or according to the water pressure and other conditions, as required by the provisions of the preceding paragraph.
Sixth, the layout of the exploration and drainage holes must follow the following principles:
1. Exploring the old empty water, the water drilling holes should be arranged in groups and fanned on the plan. The position of the final hole of the hole is to meet the horizontal distance of 3 meters, and the vertical hole of each hole in the thick coal seam shall not exceed 1.5 meters.
2, and the bottom fault exploration drilling discharge water soluble slate, must forward direction and downward along the excavation arranged. There must be no less than two holes in the direction of the bottom plate.
7. The advanced distance of the water drilling hole and the length of the water stop casing meet the following requirements:
The advanced drilling of the small kiln old air and the old water of the mine shall be explored. The general distance shall not be less than 10-20 meters. The coal mines may specify the lead distance according to the water pressure.
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