Safety technical measures for construction of refu

Technical safety measures for the construction of refuge chambers in mining areas

I. overview

because the safety technical measures in the North Fourth mining area of longhuayuan in Shaqu mine do not comply with Article 102 of the provisions on the prevention and control of coal and gas outburst: mining areas with outburst coal seams must be provided with mining area shelters. Now, according to the "provisions on the prevention and control of coal and gas outburst", the relevant departments of the mine have decided to transform the 6# refuge cave in the North rail main roadway into the refuge cave in the North Fourth mining area, so as to ensure the safety and smoothness of the green life passage

since the current refuge chamber section of 2m 2m cannot meet the disaster avoidance requirements of the refuge chamber, it is necessary to brush the side, lift the roof, and deepen the roadway section of 5m 2.5m 4m. The support method is the combined support of anchor cable shotcreting and w-steel belt. This measure is specially prepared for guidance to ensure safe construction

II. Construction preparation

1 Organize the construction personnel to carefully study this measure, so that the division of labor is clear and distinct to ensure construction safety

2. Transport the required materials to the construction site, stack them neatly, install temporary Feng Shui

pipelines, and prepare various tools required for construction

3. The cables in the 1# bottom extraction roadway opposite the refuge chamber shall be protected by blasting to ensure that the cables within 40m around the alley entrance will not be damaged during blasting

III. basic requirements

1 The rated number of people in the refuge chamber shall meet the refuge requirements of the most people working at the same time in the service area, and consider a margin of not less than 5%. According to the regulations on prevention and control of coal and gas outburst, the refuge chamber shall meet the requirements of at least 15 people for refuge

2. The setting of the refuge chamber should avoid the geological structure zone, the stress abnormal area and the water seepage threat area, and should be arranged in the rock stratum as far as possible, with the roof intact and the support intact

3. The refuge chamber shall be equipped with a compressed air self rescue system, and the compressed air pipe supplying compressed air, which is directly connected with the mine dispatching, shall be equipped with sufficient drinking water and isolated self rescuers

4. The refuge chamber shall be provided with concise and easy to understand instructions on the use and operation steps to guide the personnel in distress to correctly use the disaster avoidance facilities and safely avoid danger

IV. construction scheme

1. Considering the small amount of construction work in this section (see the plan and section drawings), the construction methods of blasting, topping, deepening and manual gangue removal are adopted

2. According to the actual situation of the whole staff and the whole process of the roadway participating in the quality management, the support mode of the refuge chamber can be adjusted appropriately

3. Every time before striking and charging, the top plate must be carefully checked, the top of the wall must be knocked, and the dangerous rocks and live stones must be carefully handled

4. The roof and roof brushing are constructed by front drilling and blasting. When blasting, shallow drilling, small blasting, less charge and secondary blasting must be used. The hole position calibration and drilling work must be carried out according to the section size of the roof brushing and roof lifting of the refuge chamber. The originally constructed chamber is used as a free surface, the depth of the auxiliary hole and the surrounding hole is not more than 1000mm and not less than 600mm, and the spacing between the surrounding holes is not more than 400mm. The sealing mud length of each blast hole shall not be less than 0.5m. After blasting, use a large shear to cut the fragments, and use a saw bow to saw off the bolts and anchor cables that burst out of the blasting. And re drill the bolt, hang the shotcrete and form the roadway

5. When brushing the upper and lifting the top, only the most is allowed each time. This is an incorrect operation method. Large brushing the upper and lifting the top 1.2 meters. Support as you dig and maintain the original support. That is, the row spacing of anchor rods is 0.8m and the spacing is 0.8m. The bolt is a threaded bolt, with a side bolt of 18mm and a length of 2.0m, and a top bolt of 20mm and a length of 2.4m. During the construction process, if the roof rock is broken, reduce the cycle progress to 0.8m per cycle, and add anchor cables. The anchor cables are 17.8mm long and 6.3m long. There are 3 anchor cables in each row, with a spacing of 1.6m and a row spacing of 800mm

6. When the chamber is deepened, shallow hole drilling, small blasting, less charge, secondary blasting and smooth blasting are adopted. The depth of the cutting hole is 1.2m, the depth of the auxiliary hole and the surrounding hole is 1.0m, and the length of the blast hole sealing mud is not less than 0.5m. Support is carried out with excavation, and the support is the same as brushing and jacking. During the construction process, if the roof rock is broken, the anchor cable shall be added

v. safety technical measures

1. Before charging and blasting, put all tools in a safe place 40 meters away from the blasting site, and reliably cover the cables, pipelines and equipment within 40 meters away from the blasting site with old belts to prevent blasting collapse. Before each blasting, the team leader shall personally check whether the protection is in place. Blasting can be carried out only after confirming that the protection is in place

2. Before charging, the roof and support of the blasting site should be checked, and the gas concentration near the bottom drainage roadway can be used. Charging and blasting can be carried out only after it is confirmed to be safe

3. During charging, wiring and blasting, all work shall strictly comply with the relevant provisions of article 315 and 342 of the safety regulations for mine blasting

4. The blasting must strictly implement the three inspection system of one shot and the three person chain firing system. Before blasting, the team leader must personally assign special personnel to guard the warning line and all roads that may enter the blasting site. The vigilant must guard at a safe place. Warning signs, railings or ropes shall be set at the warning line. When connecting, the connection of the foot line can be carried out by the specially trained team leader with the assistance of the blaster. Only one blaster is allowed to operate the blasting bus connection pin line, inspection line and power on work

5. Warning safety distance: not less than 300 meters

attachment: schematic diagram of blasting warning position

6. When the gas concentration in the air flow within 20 meters near the blasting site reaches 0.8%, charging and blasting are strictly prohibited. Blasting is strictly prohibited for blast holes without sealing mud, with insufficient sealing mud or with untrue sealing, and blasting in the open air is strictly prohibited. Water blasting mud must be used for blasting

7. After blasting, after the blasting smoke is sucked away from the blasting site, the blaster, security inspector and team leader must first patrol the blasting site and check the ventilation, gas, coal dust, roof, support, refusal of blasting, residual blasting and other conditions. If there is a dangerous situation, it must be handled immediately. Article 342 of the coal mine safety regulations must be strictly implemented when dealing with the non explosion and residual explosion. Only after the team leader comprehensively inspects the blasting site and confirms the safety, can the warning personnel be removed, and the construction personnel can enter the blasting site to work

8. Other matters not covered shall strictly comply with the relevant provisions of the coal mine safety regulations