Safety measures for the withdrawal of the hottest

Safety measures for the withdrawal of the trough pillar

1. Overview

1022 there are multiple single hydraulic pillars at the return air passage of the trough and part of the trough. After discussion and decision at the mine Enron adjustment meeting, the single hydraulic pillar will stop withdrawing after the anchor bolts and cables are set in part of the roadway

2. Construction style

1. At first, there is a mine manager on duty, who confirms the pillars that need to be withdrawn, and makes signs. Then, according to the use of the site and the roadway, determine whether the bolt and anchor cable support is set

2. Strictly implement the system of knocking on the side and asking for the top rail, stop checking the task address to be entered from the outside to the inside and from the bottom up, remove live rocks and dangerous gangues, clear the way out, and then stop supporting and setting anchor bolts and cables

3. The withdrawal task must first make up the anchor bolt and anchor cable or set the weight and point the column, strengthen the roof management, and then stop the column withdrawal task from inside to outside and from top to bottom

4. In the support section where there is no need to set anchor bolts and anchor cables, the support must be stopped by using rope hooks (the rope hooks are composed of hemp ropes and iron hooks, the length of hemp ropes is not less than 6m, and the diameter of the steel bars making the rope hooks is 18mm). It is strictly forbidden to manually retract the column without using the long handle

5. First pull out the pressure relief wrench from the three-way valve port of the pillar that needs to be withdrawn, and then tie a 5mm diameter steel wire rope or No. 8 iron wire at the beginning of the pressure relief wrench with a length of no less than 6m. The staff shall withdraw to the safe interval (usually twice the length of the retreated support), and then stop the pressure relief task

6. The staff who withdraw the pillars must stop at the place where the roof is complete, the support is reliable, there is no obvious slip pattern, and there is no roof pressure flash; In the process of withdrawal, one person is used to relieve pressure, one person uses an iron hook (the handle length is not less than 2m) to hook out the support data that fell to the ground, one person is used as lighting and observe the surrounding environment to stop safe supervision, and two people are used to transport and withdraw the data to the task area

the support must be strengthened at the three forks, four-way junctions, roof cracks, and the geological organs of the roadway. The retreat task can be stopped in the front after confirming that it is safe and reliable

7. The team leader is responsible for preparing the things needed for the withdrawal, such as rope hook (length not less than 6m), long handle things (not less than 2m), big hammer, chain block (model not less than 3 tons), and preparing 4 ~ 6 suitable wooden columns (small head diameter not less than 150mm) as the right and pillar

when it is not necessary to drill the anchor rod and anchor cable section to withdraw the support, first drill the weight and stop the support of the wooden column, and then fall behind to withdraw. It is strictly prohibited to stop the withdrawal without the reliable weight and support. When retreating, the retreat route must be cleared, and the Enron officer or the mine manager on duty shall stop monitoring on the site

8. Only one shed is allowed to be withdrawn at a time. When the interlocking rope is removed, only the shed interlocking anti fall rope that is about to be withdrawn is allowed to be removed to prevent the retreated shed from knocking down the adjacent shed

9. The retreated scaffolding shall be transported away in time (one shall be transported away after retreating), and cannot be stored on site to keep the construction site clean

10. Data with a length of more than 2m, such as pillars, must be carried by two people. When carrying and lowering, they must have the same signal before and after, and cannot show disharmonious scenes such as shoulder biting and staggered steps

3. Specification of anchor rod and anchor cable support

1. Anchor beam support assisted by anchor cable hanging beam is used as permanent support, and end anchored anchor rod is selected as anchor rod. The data of the rod body is equal strength ribbed steel made of 5 # (A5) steel. The diameter and length of the anchor rod are ∮ 18mm and 2300mm. The end of the anchor rod adopts fried dough twist rod body. The anchor hole ∮ is 28mm, and the anchoring length of the rib anchor head is not less than 500mm. The anchoring agent is msck 2550, not to mention other properties. The row spacing between anchor bolts is 800mm 800mm, and the arrangement style of anchor bolts is 3 and 3, that is, each row also provides various equipment information and 3 anchor bolts

2. Anchor cable Φ It is made of 15.24mm low relaxation prestressed steel hinged wire. The design length of the anchor cable is not less than 5.0m. It is guaranteed that the anchor cable is anchored into hard rock for more than 1.0m. 2 ~ 3 resin rolls are used for anchoring. The cable hole depth is 5.2m, and the exposed length of the anchor cable is ≯ 300mm, ≮ 150mm. The anchor cable beam is made of 7 π steel or mining 9# I-steel. Two anchor cables and one long steel beam form a group

3. The anchor cable is arranged every three groups of anchor rods, i.e. a group of 2.4m. The anchor cable beam adopts two specifications with a total length of 2.1 ~ 2.8m, and the cable hole spacing is medium to medium 1.4m. (under special circumstances, the anchor cable beam is made of mining 9# I-steel, and the beam length is less than 0.1M of the roadway length. Each anchor cable beam is equipped with two anchor cables, and each cable hole is installed on the middle line of the I-steel. The spacing between the cable holes is 1.4m from the middle to the middle, and the spacing between the middle of the cable holes is 500mm from the end on the opposite side)

4. In the process of roadway construction, in case of fault, fracture zone, roof bedding crack development, and large fracture pressure of roof, including hydraulic universal testing machine and electronic universal testing machine, support must be strengthened in time according to the on-site environment to reduce the row spacing of anchor cables or change to two-way anchor cables; Lengthen the length of steel hinge line, ensure that the depth of anchor cable anchored into hard rock is not less than 1.0m, and make up in time

4. Enron technical measures

1. Engineering staff must learn this method and be familiar with Enron measures before they can intervene in this task

2. In the process of construction, it is necessary to first lay anchor bolts and cables or support the right and support, clear the way out, and now the Enron officer gives instructions on the site to stop retreating with long handles. The withdrawal method in the construction method must be performed, and it is strictly forbidden to stop the withdrawal task without supervision

3. When the roof is broken, the chain block must be used to stop retreating. It is strictly forbidden to pull out manually. At any time, it is not allowed to probe into the empty area of falling support

4. When retreating, the retreated data shall be transported to the designated address in time and placed neatly by classification

5. The retreat task should be careful and detailed. You cannot take risks and act recklessly. You should first ensure that the position of the staff is safe, and then stop the retreat task