Safety technical measures for tunneling of the hot

2022-09-19
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The safety technical measures for the excavation of the transportation coal exploration roadway

110301 return air roadway has been excavated to the stoping line on the West Wing of the first mining area. When the 110301 transportation roadway is excavated to the measuring point a10+19.6m, it encounters a fault and breaks the 3# coal seam. According to the analysis of the front coal exploration results, the geological situation in front of the roadway is complex. After research, the company decided to construct the 110301 sub cut at the measuring point a.5m (where the coal seam is stable). Now the construction of the 110301 sub cut has been completed. In order to explore the occurrence of the coal seam in front of the cutting hole, combined with the on-site excavation and exposure of faults and the results of coal exploration, it is now decided to construct the 110301 transportation coal exploration roadway. Before construction, a ventilation hole and a coal (gangue) chute shall be constructed at a distance of 5m from the current exit of 110301 yache to the position 5m in the head-on direction of 110301 transportation roadway, for ventilation, pedestrian, material transportation and coal (gangue) chute during the excavation of 110301 transportation roadway coal exploration roadway. In order to ensure the safety during the excavation of the roadway, This measure is specially prepared

II. Technical requirements

1. The ventilation hole is excavated 10m along the coal seam at the position of a9+1.5m of the 110301 transportation roadway at the position of 21829 ′ 50 "and then turned to be constructed along the coal seam at a gradient of 5 ‰. The reverse excavation of the 110301 transportation roadway is connected with the 110301 sub cutting hole, and the forward excavation section of the 110301 transportation roadway is excavated along the coal seam at a gradient of 5 ‰. When the design intersection point of the 110301 transportation roadway and the coal slide (gangue) hole is more than 5m, At the measuring point a9+6.5m of the 110301 transportation roadway, the coal slide (gangue) is excavated along the coal seam at the orientation of 21829 ′ 50 "to connect with the 110301 transportation coal exploration roadway

2. The section width (lower) of ventilation hole and coal (gangue) hole is 1500mm, and the net height is 1500mm. Excavate by hand. Support method: when the roof is good: wood shed + wood board, when the roof is broken: wood shed + wood board + iron wire support

3. The slope of 5 ‰ of 110301 transportation coal exploration roadway is excavated along the roof of 3# coal seam. After driving to the edge of the fault or the edge of the mining area, the construction of 110301 mining face cut through with 110301 air return roadway. The estimated quantities are 177.5m

4. The net width (lower) of 110301 transportation coal exploration roadway is 2200mm, and the net height is 2000mm

5. Support mode of 110301 transportation coal exploration roadway: Trapezoidal shed + wood board + iron wire support

6. Temporary support of 110301 transportation coal exploration roadway

(1) temporary support at the top: bind two 15kg/m tracks with a length of 4m on the supported shed beam closest to the head-on with a large chain as the front detection beam, drill holes at the rear end of the track, and firmly hang the front detection beam on the rear accessible permanent support with a large chain to prevent the front detection beam from sliding down and injuring people. The front detection beam is covered with a wooden board with a specification of 1500, 200, 50 (mm2)

(2) temporary support of upper part: reinforcement [specification: adopt Ф 6.0 rebar production, with the specification of (length and width) 1800mm 1000mm, hole specification of 100mm 150mm] back wall, and then use large chains to lock four 4000mm long 15kg rails (two in a row) on the shed closest to the head-on (one end extends to the head-on), and use 14# iron wire to bind the rebar firmly on the track. The end of the track must be drilled and fixed on the rear shed with a large chain to prevent sliding

(3) temporary wall support: reinforcement [specification: adopt Ф 6.0 steel bar production, the specification is (length and width) 1800mm 1000mm, the hole specification is 100mm 150mm] back wall, then use two 3-inch steel pipes to back the steel bar, and use 14# iron wire to bind the steel bar firmly to the 3-inch steel pipe; Then hit two wooden point Posts head-on, back the 3-inch steel pipe to the wall, and tie the 3-inch steel pipe firmly to the wooden point post with 8# iron wire. Wall temporary support is only supported under the cover of top temporary support when the top temporary support moves to the wall

(4) when the ventilation eye and the coal slide (gangue effectively reduces the structural acceleration response caused by the earthquake, reduces the interlayer shear force and the corresponding shear deformation) eye opening, a top column shall be drilled under the shed beam within 5m around the opening point to strengthen the support

(5) when the surrounding rock is stable and the roof is in good condition, the maximum roof control distance before the blast must be less than 0.8m, and the maximum roof control distance after the blast must be less than 2.0m. That is, permanent support must be carried out once per cycle. In the process of permanent support, personnel are strictly prohibited to enter the empty roof area and empty roof operation is strictly prohibited

(6) when the surrounding rock is broken and passes through the geological structural zone, the maximum roof control distance before the blast must be less than 0.7m, and the maximum roof control distance after the blast must be less than 1.6m. That is, permanent support must be carried out once per cycle. In the process of permanent support, personnel are strictly prohibited to enter the empty roof area and empty roof operation is strictly prohibited

7. The tunneling method of 110301 transportation coal exploration roadway

⑴ the method of drilling and blasting is used to break (coal) rock, and the roadway is formed at one time in the whole section

⑵ Coal Roadway Drilling Tools: the working face is equipped with 2 typhoon coal drills, and Rock Roadway Drilling Tools: 2 air leg rock drills, 1 for use and 1 for standby

⑶ blasting dust removal: wet drilling, water blasting mud charging, and water curtain dust reduction during blasting. Wash the roadway side after blasting

8. Blasting operation

⑴ the cutting type used in roadway excavation is wedge cutting, and the number of holes is 4

⑵ blasting equipment: Grade III Coal Mine Permissible Emulsion Explosive and No. 8 millisecond delay electric detonator shall be selected, and the electric detonator must be numbered

⑶ charging structure: positive continuous charging is adopted, that is, the primary explosive package is located outside the blast hole. During charging, the explosive roll should be carefully sent to the eye bottom with a gun stick. It is not allowed to install the wrong detonator segment number, and it is not allowed to break the detonator foot line. Then install water cannon mud, and install 40mm ~ 60mm cannon mud between water cannon mud and explosives. Finally, fill the blast hole with cannon mud. Reverse charging is strictly prohibited

⑷ initiation mode: use mfd-500 detonator to detonate in full section at one time, and connect the full section in series

9. Blasting layout and blasting instructions

⑴ blast hole depth and diameter. According to the operation mode of roadway excavation, drilling equipment, surrounding rock conditions and roadway section, the blast hole depth is 1.4m when the surrounding rock and coal seam are stable, 1m when the surrounding rock and coal seam are soft, and the blast hole diameter is Φ 42mm。

⑵ number of blast holes

① auxiliary holes: the minimum resistance line w1=550 ~ 6. The domestic production capacity of polyurethane raw material MDI (2 phenylmethane 2 isocyanate) has soared to 3.02 million tons/year 00mm, and the eye distance e1=550 ~ 600mm. According to W1, E1 and roadway section s, the number of blast holes is: 7

② peripheral holes: minimum resistance line w2=450 ~ 500mm, eye distance e2=450 ~ 500mm, according to W2, E2 and roadway section s, the number of blast holes is 13

③ bottom hole: the eye distance e1=500 ~ 700mm, the eye opening should be 150 ~ 200mm higher than the roadway floor, the eye bottom should be 100 ~ 200mm lower than the roadway floor, and the number of blast holes: 5

④ ditch hole: the number of blast holes is 1

10. Ventilation mode and air supply distance

(1) two fbdn0 6.3/230 local fans, one working and one standby, are installed in the fresh air flow 30m from the intersection of 11 transportation crosscut and 110301 transportation roadway to the wellhead

(2) the local ventilator must be installed in strict accordance with the requirements of "three special and two locking". Local fans must strictly implement the "double fans, double power supply", and ensure that the two fans can be switched automatically

(3) the continuous operation of the fan must be ensured, and it is not allowed to cut off the power and air without reason

(4) the ventilation and prevention department must detect the suction air volume of the local ventilator at any time to ensure that the inlet air volume is greater than the suction air volume of the local ventilator

(5) adopt Ф 600m resin flame-retardant air duct supplies air to the working face

11. Air volume calculation

(1) according to the maximum number of people working at the same time: q=6n=6 10=60 (m3/min)

n - the maximum number of people working at the same time on the working surface

(2) according to the calculation of gas emission: q=100 Q k=100 1.6 1.6=256 (m3/min)

it is estimated that the maximum gas emission during the excavation of the working face q is 1.6, and Q is the unbalanced coefficient of gas emission, taking 1.6

(3) calculated according to the explosive consumption: q=25a=25 10.95=273.75 (m3/min)

a - the maximum explosive used for one-time blasting in tunneling work

(4) calculated according to the actual suction air volume of local fans (fbdno 6.3/2 30 counter rotating fan is preliminarily selected, the suction air volume is 415 ~ 660m3/min, and 440 m3/min is taken during two-stage normal operation):

q =q suction i=440 1=440 (m3/min)

i - number of local fans

(5) calculated by 100 meter air leakage rate:

q =q suction - (Q suction al 100) i=440-440 1%650 100 1=411.4 (m3/min)

a - 100 meter air leakage rate, calculated by 1%

l - maximum ventilation distance, taken as 650m

12. Local fan selection

(1) according to the air volume calculation, the air volume required for the working face is 273.75m3/min, the air leakage rate of 100 meters is calculated as 1%, and the design ventilation distance is 650m

(2) wind speed check calculation

select the maximum air volume q=411.4m3/min as the check calculation basis

check calculation according to the minimum wind speed (maximum section): Q excavation =15s=15 4.71=70.65m3/min 411.4 m3/min

check calculation according to the maximum wind speed (minimum section): Q excavation =240s=240 3.7=888m3/min > 411.4m3/min

meet the provisions of coal mine safety regulations

(3) considering comprehensively, two fbdn0 6.3/2 30 local fans are selected, with two-stage operation, one for operation and one for standby

13. Ventilation system during reverse excavation of construction ventilation tunnel and 110301 transportation coal exploration roadway

fresh air: 11 transportation crosscut → 110301 transportation roadway → ventilation tunnel → (110301 transportation coal exploration roadway) → working face

exhaust air: working face → (110301 transportation coal exploration roadway) → ventilation hole → 110301 transportation roadway → 110301 sub cutting hole → 110301 return air roadway → 110301 return air roadway ventilation hole → 1782 return air connecting roadway → 11 return air crosscut → return air adit → ground

14. Ventilation system during construction of coal (gangue) chute

fresh air: 11 transportation crosscut → 110301 transportation roadway → coal (gangue) chute → working face

exhaust air: working face → coal slide (gangue) hole → 110301 transportation roadway → 110301 sub cut hole → 110301 return air roadway → 110301 return air roadway ventilation hole → 1782 return air connecting roadway → 11 return air crosscut → return air adit → ground

15. Ventilation system during the construction of 110301 transportation coal exploration roadway

fresh air: 11 transportation crosscut → 110301 transportation roadway → ventilation hole → 110301 transportation coal exploration roadway → working face

exhaust air: working face → 110301 transportation coal exploration roadway → 110301 sub cutting hole → 110301 return air roadway → 110301 return air roadway ventilation hole → 1782 return air connecting roadway → 11 return air crosscut → return air adit → ground

16. Loading and transportation

⑴ coal loading and rock loading method: manual coal loading, rock loading, tramcar, chute and belt transportation are used in the tunneling construction. In the process of loading coal and rock, pay attention to whether there is misfire. If it is found, deal with it in time. Before the misfire is handled, do not carry out other work unrelated to the handling of misfire

⑵ coal transportation route: working face → 110301 transportation coal exploration roadway → coal slide (gangue) hole → 110301 transportation roadway → 11 transportation crosscut → coal bunker → main inclined shaft → ground (chute belt transportation)

⑶ gangue discharge line: working face → 110301 transportation coal exploration roadway → coal slide (gangue) hole → 110301 transportation roadway → 11 transportation crosscut → the first central parking lot of the auxiliary inclined shaft → auxiliary inclined shaft → ground (Tramcar Transportation)

⑷ material transportation system: ground → auxiliary inclined shaft → the first middle parking lot of auxiliary inclined shaft → 11 transportation crosscut → 110301 transportation roadway → ventilation hole → 110301 transportation coal exploration roadway → working face

17. Pipeline laying

⑴ during excavation, cables and air and water pipes are laid on the side of the sidewalk. The cable shall be hung 1.8m away from the bottom plate, and the cable sag shall not exceed 50mm. The temporary air and water pipes shall be hung at 1m and 0.8m away from the bottom plate respectively. The air and water pipelines shall not be less than 2 inches, and the interfaces shall be tight without air and water leakage

⑵ a tee is set every 50m for the air and water pipe

18. Construction process: shift handover, quality acceptance, maintenance → drilling → charging → blasting →

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