Mine coal furnace room groove 1501 of the coal mining face layer K5 seam, seam thickness between 1.37-1.73, an average thickness of about 1.5 meters, located at an upper seam K5 Xuanwei second segment, the first card from the group The bottom boundary is about 25m, the roof of the coal seam
For the initial sandstone and gray-white siltstone, the lithology is brittle. According to the mining experience of the coal mining face of the K5 coal seam in the past, the initial step of the K5 coal seam is about 20 meters, and the initial pressure step of the old roof is 15- About 25 meters, the cycle step distance is about 10-15 meters. According to the past experience, after the ceiling distance reaches 15 meters, the safety technical measures of initial pressure or cycle pressure should be adopted according to the actual situation. In order to effectively control the safety, this safety technical measure was specially prepared.
Second, the first pressure or cycle safety technical measures
When the first pressure comes, the general safety measures are:
1. Strengthen the support of coal mining face and add 1-2 rows of dense pillars and masts along the side of the largest controlled top goaf;
2. Improve the stability of the pillars, add a wooden raft every 5-8 meters along the top line, and add a three-column shed.
3. Adopt multi-cycle operation mode to speed up the advancement of the working surface to maintain the integrity of the coal wall and make it have good support operations.
4. After the coal cutter falls into the coal, it should be immediately supported 10 meters behind the shearer, and the number of support of the pillars and the quality of the support should be maintained. The initial support force of the single column should not be less than 90KN, and the crossover ratio of the top beam can be reached. More than 95%, the single column should be strong against the mountains, not to owe mountains or mountains.
5. Set a pit wood signal column with a diameter of about 15cm in the goaf of the working face to judge the pressure of the top surface of the working face.
6. When the cycle is pressed, in addition to adopting the safety technical measures with the first pressure, it is necessary to shorten the control top distance of the working face as much as possible to reduce the pressure of the old top on the working face;
7. During the initial pressure or period of pressure, each class should be arranged with experienced personnel to check the situation on the spot, observe the situation of the roof, and find that people with large abnormalities should immediately withdraw from the work surface, the support strength is insufficient, and the working face is top. After stabilization, arrange for personnel to support dense pillars and masts.
8. In the process of coal cutting, the coal cutting machine cuts the coal wall straight and cuts neatly. According to the actual situation, if the coal wall is subjected to large pressure and the coal wall is soft, it is necessary to set the slab column immediately. The pressure of the coal wall.
9. The soft floor of the bottom plate, the single pillar should wear shoes, so as to avoid the single pillars sinking into the bottom plate, the initial support force of the smaller single column.
10. The pillars in the goaf must be recycled to make the direct roof fully collapsed to cushion the impact of the old roof on the work surface bracket.
11. During the initial pressure or period of pressure, the coal mining face shall be inspected and supervised by the class leaders and team leaders. On-site support management must be strengthened when there is a cycle to pressure the omen.
12. After the initial pressure on the working face, it is necessary to strengthen the monitoring of the cycle pressure. The inspection is strengthened by the team leader. After the mine pressure appears, it is necessary to report to the person in charge of the mine in time, and prepare for the prevention of the cycle. The person in charge of the mine must on-site inspection and supervision of the implementation of preventive measures.
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