In order to ensure the safe production of the driving face and prevent the occurrence of roadway roof accidents, it is necessary to take targeted measures according to the cause of the accident.
First, the cause of the topping accident in the face
(1) It belongs to the geological aspect: the surrounding rock of the roadway is soft or highly weatherable, such as coal and shale ; the joint cracks of the surrounding rock are developed; the roadway is broken by strata, folds and other structural changes, the rock formation is broken; the roadway passes through the rock formation. The lithology suddenly changes, and it is easy to produce collapse at the junction, such as Shimenjing coal; harmful gases, such as gas, coal dust.
(2) Due to unreasonable design: improper selection of roadway location makes the roadway in soft rock formation; lack of detailed geological and hydrogeological data, lack of guidance for construction, lack of contingency measures; unreasonable form and structure of support, insufficient To withstand the ground pressure and so on.
(3) Misunderstandings caused by construction work: lack of preparation for passing through soft rock formations; improper construction measures or mistakes; not one lane, the surrounding rock exposure time is too long, causing weathering, loosening, causing collapse; support Does not meet the design requirements, does not erect according to the operating procedures, neglects the quality, so that the bracket can not function, the bracket is unstable and causes collapse; the distance between the empty top of the working surface is too long, the temporary support is invalid; the construction in the soft layer, the amount of explosives used Too much, destroying the stability of the surrounding rock; not working on the working face, asking for the top work, not paying enough attention to the inspection and treatment of the pumice , not causing the pumice to fall in time.
Second, the treatment method of roadway roofing accident
(1) Treatment method for local roof failure occurred in roadway
(1) Firstly reinforce the intact brackets before and after the landing zone. If the shed is used for support, the support of the fifth section of the roadway shall be based on the pressure of the surrounding rock to encrypt the shed, and the shed shall be stabilized. A tie rod should be placed between the sheds to form a joint body, and the shed top should be tightly braked.
(2) Closing in time to control the expansion of the roof. It is generally handled by the method of erecting rafts. The person stood in a safe place and used a long pole to smash the top of the falling rock. In the absence of risk of falling, hold the brackets in time and arrange the top rafts until the top of the roof is topped.
(3) The rock roadway is treated with anchor spray support to treat the roof area. When anchoring and spraying support conditions are met, priority should be given to the use of anchor spray support to treat the roof area.
1 Firstly, the top of the landing area will be smashed away. The sprayer will stand on the safe side and spray a layer of concrete 30mm~50mm thick into the roof area, first seal the top, and then seal the two gangs;
2 After the initial sprayed concrete is solidified, the anchor rod is hit again, and the net is sprayed once again. The thickness of the double spray is generally not more than 20 mm;
3 After the top treatment is completed, the brickwork is carried out as required. In order to protect the dome, the dome is filled with a vermiculite of about 0.5 m thick as a buffer layer. Erection may also be a metal stent, Yan HangingWall back surrounded by a layer of waste rock can be filled, install rod between the supports, so that integrally linked between the shed and improve stability.
(2) Treatment method when the roof range is large
1. Small section rapid repair method
This method can be used if the roof area is large and affects ventilation or some people are stuck inside. That is to say, the temporary bracket is set up much smaller than the original roadway specification, so that the roadway can be temporarily restored, and the permanent bracket is installed after the coal shovel is cleaned.
The treatment of the top part is: using the wedge method to control the falling meteorite, and when the top plate is no longer falling, remove the meteorite from both sides of the roadway, and manage the two gangs while clearing, to prevent the coal gang from flowing into the roadway. After the top guard is maintained, a permanent bracket can be set up.
2. Once completed road repair method
This method is applicable when the secondary roadway with a large roof area and the length of repair time have little effect on production. When repairing, according to the original roadway specifications, use the wedge method to form the lane once, as shown in Figure 5-5. The wedges are inserted with wooden boards, and the two gangs should be tightly guarded. There must be a thick layer of vermiculite above the wedge. If it is too thin, it should also be stacked with a thickness of not less than 0.5 m of wood or vermiculite in the roof. The question of the beam and the wedge is to be true. In the whole process of handling the roof and erecting the bracket, a special person should be observed to observe the roof.
Wood raft
The raft method is a commonly used method. For example, the height of the roadway roof is less than 5m, and the length of the landslide is more than 10m. The rock above the landslide is basically stable, and the falling rock can be partially removed to form a natural accumulation slope. When the staff is allowed to space up and down and transport materials, and they can be ventilated, they can directly support the roof from the shovel on the falling coal shovel on both sides.
First, two rows of lifting sheds are placed on the bracket near the roof area to improve the support capacity of the bracket. Bounce under the cover of the bracket. The pre-treatment personnel are stationed in a safe place to handle the top stone with a long handle tool. Erect the raft to ensure a smooth and safe exit. Before the raft is placed, two brackets are arranged side by side at the exit of the landing area, and the struts are tightened by the pull rods to make them stable. A wear rod is placed on it. Side-by-side brackets are used in the case of loose meteorites; topping columns should be added under the wearing rods, but it should be carried out under the conditions of laying pits or stalks on the rods to prevent them from being injured. When the raft is placed, the top layer of the first raft is applied with a topping rod to ensure the safety of the second raft. The raft should be supported on the top, leaning on the upper gang, leaning against the slab at the back of the board, and tightening it with a wedge. Then the second raft is placed, and so on until the processing is completed.
4. Bypass method
If the length of the roof is large, it is difficult to handle and the roof is blocked, you can bypass the road, bypass the landing area to rescue the blocked person, or bypass the landing area and then transfer the normal excavation.
Third, the roadway film help processing method
Wood raft
When the roadway piece is not too serious, the side of the piece is slightly topped, the leg is bent, and the coal smash is pushed into the roadway. First, a top column is placed under the top beam, and then the new column is replaced with a wooden frame. The raft, the back plate of the bracket and the back of the jingle are removed, and the top column is removed.
2. Wedge method
The side of the roadway is very serious. When the crushed column legs are removed, the coal rock will flow out, and the piece will continue to expand, which can be treated by the wedge method. Select the intact column legs at the location of the film and apply a wedge wedge of about 1.4m. Then, under the top beam, put the top column, replace the new column legs, the top of the bracket should be tight, and then the brackets should be repaired.
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