Supplementary safety technical measures for tunnel

2022-08-07
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Supplementary safety technical measures for transport trench driving

1. Project outline

1202 transport roadway runs through the original goaf when it is driven to 414m. There is no harmful gas or ponding in the goaf. The roof around the penetration point is relatively complete and the ground pressure is stable. According to the actual environmental response of the goaf exposed after penetration, the roadway cannot pass through and continue to advance, so it is necessary to turn back to avoid the goaf. According to the change notice issued by the production department, 1202 transport lane retreats from 414 meters to 33 meters, then builds a closed wall to turn, drives 66 meters forward at an azimuth of 120 degrees, then turns again, and continues to drive forward at an azimuth of 180 degrees, avoiding the goaf, so as to ensure safe construction

2. Construction sequence

1. Make up the anchor cable at the turning opening

2. Safe inspection → extended coal slide → coal cutting (coal output) by roadheader → right and support → permanent support → passing the acceptance and falling behind into the next cycle

3. Roadway support

1. Weight and support situation:

weight and support adopts two 4m long 3-inch thickened steel pipes. Each steel pipe is suspended on the roof bolt with two public fixtures, and sealed with nuts. At the same time, the steel pipe and the roof are firmly connected with the shed plate. The front detection beam follows the task face head-on. (see the right and support drawing)

2 is actively promoting product trial production and device process

1) after cutting and forming, all relevant staff are evacuated to Enron's address. The team leader on duty stands under Enron's reliable permanent support, and stops knocking with common things (many are 1.5m long 6-point steel pipes, one end is sharp, the other end is flat). The interval between point-to-point tapping is not more than 600mm. All live coal and gangue are chiseled off. The main team and sub team do the following Enron staff should stop monitoring the top of the gang and deal with the problems immediately if they find them

2) after confirming that there is no risk, the homework staff will lift the steel pipe, quickly cross it in parallel and move it to the task surface, adjust the position of the steel pipe and protective top plate under the supervision of the main sub team, and back it tightly with a wooden wedge to prevent the front detection beam from sliding backward

3) the cantilever section of the front probe beam shall not be greater than 1.8m, and the lag of the end of the side anchor rod behind the second operation of the roadheader shall not be greater than 5m

4) in the process of homework, the supervisor and the safety officer of the main sub team must observe the situation of the top plate at any time

5) the maximum overhead distance between the software and hardware task plane and the power and support is 2.1m, and the minimum overhead control distance is 0.3m

section III permanent support

roadway section: according to the design requirements, the roadway is a rectangular section, with a clear width of 4.4m, a clear height of 2.2m and a clear section of 9.68m2. Permanent support: anchor + reinforced joist + anchor cable support

1) roof support:

anchor rod: msglw/1800 ribbed steel anchor rod is used

anchoring method: one msck2360 and one msz2360 anchoring agent are used for end anchoring, and the drilling diameter is Φ 28mm, anchor

fixing force 64kn, anchor pre tightening torque 200n m. The application can be stopped through the anchor bolt torque multiplier (hnb-q5 type)

supporting plate: 1001008 ㎜ arched metal supporting plate with arch height not less than 36mm

bolt angle: the bolt is installed perpendicular to the roadway roof

reinforced joist: adopt double reinforced joist to protect the top, specification: F14 4200 (length) 90 (full width) -800 (spacing) mm, 6 holes

sheet specification: 5mm Round steel welding longitude and latitude, hole 100*100 ㎜, use the metal with specification of 2000 1000mm to stop lapping, and the lapping length is 100 ㎜. The overlapped parts are connected with 16ne lead wires, double wires and double buckles, and connected with the spacer holes

anchor bolt installation: rectangular installation, spacing 800, row spacing 900mm

2) roadway side (stoping side):

anchor rod: F18 1800 mm resin FRP anchor rod is used

anchoring method: one msck2360 and one msz2360 anchoring agent are used for end anchoring, and the drilling diameter is Φ 28mm, and the pre tightening torque of anchor rod shall not be less than 40N m. The anchoring force is 60kn

anchor rod angle: the anchor rod is installed perpendicular to the roadway side

piece: use 2000 1000mm flame retardant plastic to stop lapping, and the lapping length is 100 mm. The overlapped parts are connected with 16ne lead wires, with double strands and double buckles, and connected with spacer holes

anchor bolt installation: the anchor bolt spacing is 800mm, and the row spacing is 900mm

3) roadway side (non mining side):

anchor rod: msglw/1800 ribbed steel anchor rod is used

anchoring method: one msck2360 and one msz2360 anchoring agent are used for end anchoring, and the drilling diameter is Φ 28mm, anchoring force 64kn, anchor bolt pre tightening torque 200n m. The application can be stopped through the anchor bolt torque multiplier (hnb-q5 type)

supporting plate: 1001008 ㎜ arched metal supporting plate with arch height not less than 36mm

anchor rod angle: the anchor rod is installed perpendicular to the roadway side

reinforced joist: adopt double reinforced joist to protect the top, specification: F14 2000 (length) 90 (full width) -800 (spacing between R & D resources continuously invested by the company) mm, 3 holes

sheet specification: 5mm Round steel welding longitude and latitude, hole 100*100 ㎜, use the metal with the specification of 2000 1000mm to stop lapping, and the lapping length is 100 ㎜. The overlapped parts are connected with 16ne lead wires, double wires and double buckles, and connected with the spacer holes

anchor bolt installation: the anchor bolt spacing is 800mm, and the row spacing is 900mm

4) reinforced support with anchor cable:

anchor cable: the specification of anchor cable data is f17.8 mm, the length is 6500mm, 17 strands of high-strength low damage steel strands, and the drilling diameter Φ 28mm, 2 msck2360 and 1 msz2360 resin anchoring agent are used to anchor the anchor cable, and the anchoring force is 150kn

anchor cable tray: adopt arch steel support plate made of Q235 low carbon steel, 30030016mm, and the arch height shall not be less than 60mm

5). Process flow

the tunneling machine is adopted for tunneling. The tunneling process flow is as follows:

safe inspection → extending the coal slide → cutting coal (coal out) by the tunneling machine → right and support → permanent support → passing the acceptance and falling behind into the next cycle

technological process of anchor rod device:

Enron inspection → calibration of anchor rod position → drilling and hole cleaning → installation of resin drug roll and anchor rod → mixing of resin drug roll with anchor rod machine to the specified time → stop mixing and wait for 60 s → hanging → installation of reinforcement joist → installation of iron support plate → tightening of nut

6). Anchor rod construction process

a: top anchor rod construction process

1. The top anchor rod construction shall be stopped under the right and support, and the distance between the permanent support end and the task face shall not exceed 1.8m. Before the permanent support of the top plate is stopped, the knocking on the side and the top plate must be stopped in strict accordance with the regulations

2. The anchor bolt hole shall be completed by mqt120 single pneumatic anchor bolt machine. First use 1.0m short drill pipe, then replace with 1.0m long drill pipe, and use 28mm drill bit. When drilling, the anchor bolt machine is raised to pull out the post accident calibrated eye position, and then start the anchor bolt machine to stop drilling. The hole depth is required to be 175030mm, which is 20mm longer than the anchor bolt tray to the beginning, and the drilling angle is guaranteed. After the drill bit reaches the predetermined hole depth, the anchor bolt machine shall be retracted, and the hole shall be cleaned at the same time to break the pulverized coal and mud

3. Detailed device steps:

(1) put in resin anchoring agent. The anchor rod body is sleeved with a nut, the rod tail is connected with the head of the anchor bolt machine through a process device, the rod end is pulled out of the hole filled with resin anchoring agent, the anchor bolt machine is pulled up, and the anchoring agent at the orifice is sent to the hole bottom

(2) push the resin anchoring agent and anchor rod into the specified hole position, wear nuts on the anchor rod body, operate the anchor rod and anchor rod agitator to push the resin anchoring agent into the hole through the upward thrust of the anchor rod machine until the anchor rod tray is 10mm away from the top plate. Pay attention not to twist when pushing the resin anchoring agent. It is strictly prohibited to press the tray tightly on the top plate

(3). After the second step is completed, quickly twist the anchor rod for seconds (do not apply thrust during twisting and mixing), and then push the anchor rod upward to make the tray close to the top plate

(4) when mixing is completed, stop for 60 seconds to let the anchoring agent fully coagulate

(5). Tighten the nut: tighten the nut of the mixer. When tightening the nut, the maximum torque shall be given instead of applying thrust to tighten the nut with the maximum limit

(6) use torque reducer or hand to strive for beauty and service life. At the same time, we also hope that consumers like to use the extended wrench to further tighten the nut to achieve the specified device stress

(7). The anchor bolt device can be summarized as: one push (pushing the anchor agent to the specified position of the drilling hole), two turns (twisting the mixing anchor agent), three grades (waiting for the anchor agent to condense), and four tightens (fastening the nut)

(8) strictly follow the steps of the device during the installation process. Otherwise, there will be "long tail anchor rod" or failure to open damping. This will greatly affect the results of bolt support, and even failure

b. quality inspection standard of anchor rod device:

qualified anchor rod device shall meet the following standards:

1) exposed length of anchor rod: greater than 30mm and less than 50mm outside the nut

2) check with a torque wrench, and the bolt torque shall not be less than 200n m。

5. Construction equipment

list of construction equipment

name, model and quantity unit remarks

2 sets of pneumatic roof bolter mqt-120/2.7

1 set of roadheader ebz-132

3 sets of pneumatic pump FQ, 1 for use, 1 for standby 1. Inspect 4

anchor rod agitators M18

2 handheld air drills zqs-50/1.6

2 belt walkers SPJ-800

40t coal slide SGW-40

2 local fan FBD № 5.6/2*11, 1 standby

anchor rod tension meter ldz-200, 2 standby

anchor cable tensioning machine ms/50, 2 standby

torque wrench 0 ~ 300N M2 1 spare

roof anchor rod construction tools: mqt-120/2.7 pneumatic anchor rod roof drill, B19mm drill pipe with length of 0.5m, 1.0m, 1.5m and 2.0m, Φ 28mm diamond bit, agitator and fastener

anchor rod construction tools: zqs-50/1.6 handheld air drill, 2.0m fried dough twist drill pipe Φ 28mm diamond bit, agitator and fastener

6. Lesson style

lesson style: full roadway heading machine

during excavation, some fans shall be used for ventilation, and the air duct shall closely follow the task face, and the head-on wind shall be smooth. 40t coal slides are transported together by belt. The right and support of front detection beam, and the construction method of anchor + reinforced joist + anchor cable permanent support

7. Excavation ventilation

1. Ventilation style: Press in partial ventilator for ventilation

2. Air supply: according to the air volume required for the original roadway excavation, the air volume required for the current excavation is not less than 260m3/min

3. Ventilation line:

novelty: air → main inclined shaft → transportation lane → 1202 transportation trough → task face

lack of charm: task face → 1202 transportation lane → 1202 transportation lane air bridge → return air lane → return air shaft → air

8. Water supply and drainage lines

1. Water supply lines: aerial static pressure pool - auxiliary shaft - East Rail Lane -12 transportation link Lane - East transportation lane - task plane

3. Drainage lines: task plane → transportation Danian Lane → 1201 transportation link Lane → water bunker → air

9. Communication, lighting, signal fragments

1. Communication tools and required cables are provided by the monitoring team, and the extension and hanging tasks are implemented by the construction team. Sound and light signals shall be set at the head and tail of each belt conveyor, the head and tail of the coal chute, the small winch and the track terminal to ensure that both sound and light can be used without any shortage. The system of "one stop and two start" shall be strictly implemented. No one is allowed to randomly signal signals

2. For the convenience of communication, a telephone shall be installed at the head and task face of the roadway belt escort and the mobile substation. All communication, monitoring and signal cables are laid on the cable hook on the left side of the roadway

3. The distance between the two parts of the task plane and the opening and head-on shall not exceed meters, and the distance between the German wind line and the power cable is more than 100mm

4. All lighting and signal cables are laid on the cable hook on the left side of the roadway

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