Safety technical measures for shotcrete construction of anchor shaft in auxiliary shaft yard

The new well-turned cage at the bottom of the auxiliary shaft has been loosened and separated from the roof of the roadway. It can no longer meet the safety production needs. According to the “Five-Your” mine construction and the safety of the descendants of the mine, it is decided that the 25 teams will expand the site. To ensure construction safety, the construction measures are specially prepared.

First, the location and scope of the expansion:

The new cages are out of the roadway.

Second, the roadway section and support form:

1. The new turn cage is still semi-circular after the expansion of the roadway, and the net arch radius is 2,450mm. After the expansion, the new height of the cage will be 4.15m above the road surface, and the new width of the roadway will be 4.9m (the outer edge of the waterway side track will be 1.2m away, and the outer edge of the other side track will be 1. 1m). Straight wall 1.7 meters, the floor of the roadway does not move.

2, the expansion uses "two sprays and one anchor", that is, after the top of the brush is expanded, the first shot is temporarily sprayed for temporary support and leveling, then the anchor rod is used, the net is hung, and finally the re-spray molding. Using the top ¢ 22 * 2250mm straight head bolt, two groups using the bolt twist ¢ 20 * 2000mm, a metal mesh diamond back top back help.

Third, the construction process and technical requirements:

1. After expanding the top of the brush, first carry out a strict knocking on the top, brush to the real top, solid bottom, and immediately spray the initial support for the temporary support and top, help leveling, then hit the anchor to hang the net, and finally re-spray Forming.

2. The ratio of shotcreting materials is: ash: sand = 1:2.5, the blending amount of quick-setting admixture is 3-4% of cement, and the water-cement ratio is 0.45.

3. When spraying, the nozzle should be vertically sprayed, and the nozzle should not be larger than 1.5 meters from the spray surface. The nozzle has a circular or elliptical trajectory to make a spiral slow movement. Strictly control the water-cement ratio and the amount of wind pressure and quick-setting agent to minimize rebound. The thickness of the spray layer should not be less than 100 mm, and the appearance is beautiful, the spray layer is compact, the surface is flat, and there is no barefoot or skirt.

4. The bolt specifications are ¢20*2000mm twist bolts (two gangs) and ¢22*2250mm straight anchors. The spacing between the bolts is 600*600mm. The anchors are perpendicular to the roadway contour and the rock face, and the bottom anchors are tied down. The angle is 16 degrees. The length of the bolt exposed to the anchor plate should be less than 50, and it can meet the flatness of the nut. Use a special torque wrench to tighten the nut so that the anchor plate is pressed against the rock face. The anchor preload force is not less than 200N.m.

5, the metal mesh lap length is 100 mm, each 200 mm with a buckle, according to the "three flowers" arrangement, the tray is pressed tightly, close to the rock face.

6. The construction is strictly in accordance with the waist line construction of the local survey department.

Fourth, security measures:

a) Blasting operations:

1. Before you open your eyes, you must clean up the living and dangerous stones in the roadway and the debris in the roadway within 10 meters before and after the expansion point.

2. Before and after the blasting operation, before the workers enter the construction site, the team leader and the team leader should strictly inspect the roof, the slag and the exposed old bolts from the outside to the inside. In the case, strictly implement the knock-on top system and the special person supervision system. The team leader personally arranged two experienced old workers to carry out the package. One person uses a long-handled tool to knock the top of the top to deal with the live sputum, and the other person monitors the top plate full-time and finds hidden dangers in a timely manner. Operators must operate in a safe location under permanent support and ensure that the retreat is unobstructed and that empty top operations are strictly prohibited.

3. The blasting is mainly based on small guns. The depth of the blasthole is not less than 0.6 meters. The number of blastholes per blast can not exceed 5, and the charge of each eye should not exceed 1 knot. It emphasizes more eye-opening, less charge, and the remaining blasthole must Filled with gunnery seals, it is strictly forbidden to put a cannon.

4. Before firing, the team leader must assign a special person to remove the cable in the range of 20 meters before and after the roadway and cover the old belt, 50 cm thick pine board, etc., and protect the pipeline with thick planks and old belts. After effective screening, the construction line will be covered with old belts after the power line is cut off, and the color strips will be wrapped.

5, the gun must adhere to the "one shot three inspection system." Before the shooting, the team leader must personally arrange a special person to act as an alert on all roads that are 150 meters away from all access points and may enter the shooting location. The security personnel must be on guard in a safe place with cover. The team leader must count the number of people and confirm the correctness before issuing the order. After the gunner receives the command from the team leader, it can only detonate after waiting for 5 seconds.

6. Install 2 spray sprinkler dust-reducing devices in the downwind side of the 20-meter roadway near the shooting point to ensure normal use.

7. After the blasting, after the guns on the working surface are blown away, the gunners, gas inspectors and team leaders must first inspect the shooting location, check the ventilation, gas, roof, cable pipeline protection, refusal, residual explosion, etc. If there is a dangerous situation, it must be disposed of immediately. Only when the guns are blown off at the working surface, and the guards are personally withdrawn by the team leader who arranged the warning, the personnel can enter the work surface.

8. The vehicle is strictly forbidden during the shooting.

9. The captain of the class must wear a portable tile detector. When the gas concentration is greater than 0.5%, it is strictly forbidden to shoot.

10. After each shot, the personnel must enter the work front, and the squad leader must first use the long handle tool of 2.5 meters or more to perform the detailed knocking on the top and the top of the guard. Must be processed. When knocking on the top, the person must stand in the upper part to help the safe position, and pre-clean up the safe retreat. No one should work or stay in the lower 10 meters.

b) Security measures:

1. During non-blasting operations, due to the construction of the parking lot in Xinfan cage, it is very important to guard the work. The team leader and the team leader personally arranged the competent responsible personnel to serve as the police officer. The warning distance was a safe place 50 meters away from the construction site. The first team of each team arranged a team leader and 25 teams to coordinate the work. The non-transportation team, the coordinator of the department, the 25 team and the team to jointly allow, the vehicle is strictly prohibited.

2. Strictly implement the system of “no driving, pedestrians do not drive” and “do not drive”, and the sound and light signals of the motor car are complete. During the operation of the 25th team, vehicles are strictly prohibited. When it is necessary to drive, the coordinator of the first team must first contact the team leader of the 25th team. After approval, all the personnel must hide in the rear of the car.

3, shotcrete and anchor net work should follow the order from top to bottom, first top and back. The length of each expansion shall not exceed 1.5 meters. The distance between the top and the top shall not exceed 0.4 m. It is strictly forbidden for personnel to directly construct under the empty roof.

4. The construction must be wrapped with colored strips of cloth and other facilities to prevent splashing of mortar.

5. Due to the large section of the roadway, when drilling, anchoring and spraying, it is necessary to build a firm working platform with a 100 mm thick pine board on a ladder welded with a half steel pipe, and securely fix it. Both the team and the team leader should carefully check to ensure safe operation. The safety distance between the platform and the motor car and the outer edge of the car and the open line is not less than 0.3m.

6. The 5m area of ​​the open line before and after the construction point shall be taken off by the first team to ensure safe construction.

7. At any time, it is strictly forbidden to face the personnel to prevent accidents.

8. All personnel must wear complete and effective labor protection products according to the regulations, tighten the cuffs, pants and pipes, and cooperate with each other to make mutual security and mutual security.

9. At the working point, 10 meters and 20 meters away from each side of the working point, there is a purified water curtain that can cover the whole section and ensure that it can be sprayed normally.

10. After the end of each shift, the environmental sanitation of the upper and lower 10 meters of the working section must be cleaned up and the materials should be neatly arranged.

11. This measure sends a copy of the team to the relevant personnel.

12. This measure must be implemented in detail to all construction personnel and perform the signing procedures.

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