CN108661643A - It a kind of coal working face end adopts return channel and cuts top release shield lane method - Google Patents

Abstract

A method of roof cutting, pressure relief and roadway protection for the withdrawal channel at the end of mining working face belongs to the technical field of mine pressure control and roadway maintenance in mining engineering, and can solve the problem of protecting coal pillars between the stop production line of the existing working face and the main roadway in the mining area The large size leads to the problem of low recovery rate in the mining area. The present invention cuts off the propagating path of the mining advance support pressure of the working face through the deep hole pre-splitting coal seam roof, and provides a method of excavating ahead of time along the stop line position. Face support equipment retraction channel and deep hole pre-splitting coal seam roof cut off the propagation path of mining advance support pressure, protect the main road in the mining area from the impact of mining on both sides of the mining face and reduce the stop line and mining area of the working face A method to protect the width of coal pillars between roadways to increase the recovery rate of the mining area. The invention improves the mining area recovery rate of non-renewable coal resources on the premise of ensuring the safety and stability of the main road in the mining area.

Description

A method for roof cutting, pressure relief and roadway protection of the withdrawal passageway at the end of coal mining face

technical field

The invention belongs to the technical field of mine pressure control and roadway maintenance in mining engineering, and in particular relates to a propagating path for advance supporting pressure in advance excavation of support equipment along the position of a stop-mining line and a deep hole pre-splitting coal seam roof to cut off the working face mining advance support pressure. The method of protecting the main roadway in the mining area from the influence of mining on both sides of the mining face and reducing the protection of the coal pillar between the stop line and the main roadway in the mining area to improve the recovery rate of the mining area.

Background technique

Coal is the basic energy that guarantees the rapid development of my country's national economy. In order to meet market demand, the production scale of my country's coal production enterprises is getting larger and larger. Under the current production technology conditions, most underground mines in my country adopt the mining area production system. The mining area is a mining block with an independent transportation and ventilation system in the mine field. In the middle of the mining area, the mining area transportation up (down) hill and the mining area track up (down) hill are arranged, respectively responsible for the operation of the entire mining area. Transportation and ventilation tasks, referred to as mining area alleys. The main road in the mining area runs through the entire mining area, and is generally arranged in the central position of the mining area. Longwall working faces are arranged on both sides of the main road in the mining area to form a double-wing mining area. The service life of the roadway in the mining area is long. Once the instability, deformation and damage are serious, it will affect the production of the entire mining area. Therefore, it is required that the roadway support in the mining area is in good condition and the surrounding rock remains stable. The main roadway in the mining area is located in the middle of the mining area and is affected by the mining of the working faces on both sides. In addition to the natural factors of the location of the roadway, its maintenance status mainly depends on the mining of the working faces on both sides.

In order to ensure the safety of the main road in the mining area, the mining face on both sides of the main road in the mining area generally has a large width of protective coal pillars to determine the position of the stop line, and some protective coal pillars are even more than 100m wide. Leaving large-width protective coal pillars not only wastes a large amount of valuable non-renewable coal resources, reduces the recovery rate of the mining area, and does not meet the current requirements for high-yield and efficient mine construction in my country; moreover, there are many coal bodies left in the goaf, and spontaneous combustion of the left coal in the goaf Fire hazards threaten the long-term development of the entire mine. A protective coal pillar with a relatively large width is reserved between the stop production line of the working face and the main roadway in the mining area to reduce the impact of mining on the working face on both sides of the mining area roadway and the construction of a high-yield and efficient modern mine and increase the recovery rate of the mining area. The contradiction between them is one of the main contradictions that my country's underground mines are currently facing.

In the open literature, the patent of "Method and Device for Optimizing the Stop Production Line Position by Using Hydraulic Fracturing Pressure Relief" with the publication number CN106321049 A can be obtained. The method for optimizing the stop production line position is to preset multiple The hydraulic fracturing pressure relief holes arranged in sequence are used for hydraulic fracturing pressure relief, forming cutting cracks and reducing the impact of the advanced support pressure of the working face on the roadway in the mining area. There are at least two shortcomings or deficiencies in this method. One is that there is no clear timing for hydraulic fracturing pressure relief, which may affect the normal mining of the working face and other production work; the other is that the rock mass contains many natural defects. For example, pores, micro-cracks, etc., due to the strong permeability of water, under the action of high-pressure hydraulic force, these natural pores and cracks will become water-conducting channels, allowing high-pressure water to seep and reduce the pressure, which cannot meet the requirements of fracturing rock mass. strength requirements. Hydraulic fracturing transports high-pressure water with a pressure of 50-60 MPa through the pipeline. Therefore, there may be a danger of breaking through the connection of the pipeline. Once the connection of the pipeline is broken, the high-pressure water with a pressure of 50-60 MPa is very destructive. If it is large, it will cause certain damage to the surrounding equipment and construction personnel, and there is a great potential safety hazard.

In order to reduce the influence of mining work on both sides of the main road in the mining area, reduce the size of the protective coal pillar between the stop line and the main road in the mining area, and ensure the safety and stability of the main road in the mining area. The recovery rate of coal resources in the mining area urgently needs to find a way to excavate the retraction channel of the support equipment in advance along the position of the stop production line and cut off the propagation path of the advanced support pressure of the working face with the deep hole pre-splitting coal seam roof to protect the large area of the mining area. The roadway is not affected by the mining of the working face on both sides and the method of reducing the width of the protective coal pillar between the stop line of the working face and the main roadway of the mining area to improve the recovery rate of the mining area.

Contents of the invention

Aiming at the problem that the size of the protective coal pillar between the stop line of the existing working face and the main roadway of the mining area is large and the recovery rate of the mining area is low, the present invention provides a top-cutting and pressure-relief protection for the withdrawal channel at the end of the mining working face. Roadway method, the invention is a method of cutting the propagating path of the advanced support pressure of the working face through the deep hole pre-split coal seam roof, and provides a method of excavating the retraction channel of the support equipment of the working face in advance along the stop line position and deep hole pre-splitting The roof of the cracked coal seam cuts off the propagating path of the advanced support pressure of the working face, protects the main road in the mining area from the influence of mining on both sides of the mining face, and reduces the width of the protective coal pillar between the stop line of the working face and the main road in the mining area. A method to increase the recovery rate of the mining area.

The present invention adopts following technical scheme:

A roadway protection method for roof cutting, pressure relief and roadway protection of an end-mining withdrawal passage in a coal mining face, comprising the following steps:

The first step is to calculate and determine the cycle of the old top of the mining face to press the step distance L, , where, L is the periodic pressure step distance of the old roof of the mining face on both sides of the main roadway in the mining area; h2 is the thickness of the old roof of the coal seam _; The uniformly distributed load; R _T is the ultimate tensile strength of the old top rock formation;

In the second step, at the position S=2L away from the main road in the mining area, determine the position of the retraction channel of the mining equipment at the end of the working face mining, that is, the width of the protective coal pillar between the stop line position of the working face and the main road in the mining area S=2L;

The third step is to dig a working face support along the coal seam floor in the direction parallel to the main roadway in the mining area at the determined stop line position of the working face after the installation of mining equipment such as mining roadway excavation and open cut hole support is completed. The withdrawal channel of the mining equipment, the width of the withdrawal channel is 2m, and the height of the withdrawal channel is the minimum support height of the hydraulic support of the working face. Net joint support, the side of the withdrawal channel close to the mining face is supported by cutting glass fiber reinforced plastic bolts and flame-retardant plastic net joint support;

The fourth step is to start from the position 10m away from the end of the withdrawal channel, and drill a deep hole pre-splitting drill hole in the middle of the top plate in the withdrawal channel. The angle between the hole and the vertical direction is 45°; the diameter of the borehole Φ=75mm; the depth of the borehole H=( h ₁ + h ₂ )÷sin45°, h ₁ is the thickness of the immediate top of the mining coal seam, h ₂ is the mining The thickness of the old top of the coal seam; the interval between adjacent drill holes l = 5m, when the distance between the last drill hole and the other end of the withdrawal channel is less than 10m, stop drilling, and all drill holes Form a straight line along the retracement channel, and number the drilled holes sequentially from 1 according to the drilling sequence;

The fifth step, when all the drill holes have been drilled, sprinkle water in the retraction channel to reduce dust, and prepare to start loading explosives into the drill holes, and fill explosives in the odd-numbered drill holes as blast holes; The boreholes are not filled with explosives, and are used as pilot holes to provide free surfaces to guide the roof strata to crack along the withdrawal channel, that is, the pre-cracks formed in the roof strata by deep hole blasting are parallel to the roadway in the mining area;

The sixth step is to use the uncoupled charge method to load explosives into the blasting hole, adopt double detonators and double detonation index blasting, and connect the two detonators in parallel outside the blasting hole, and use 3 blasting holes as a group and use series connection Connection, if there are less than 3 blasting holes, it is a group separately, and the blasting busbar is well insulated and suspended in the air;

The seventh step is to use gun sticks to load the explosives required for each blast hole into the hole one by one and push them to the bottom of the hole. If the charge is small, it can be loaded at one time. The charge length is the drilling length of the old top of the coal seam. , that is, the charge length is ( h ₂ ÷ sin45°);

Before loading the first roll of priming charge, put two detonating cords into the charge roll in advance. The rolls are sent to the bottom of the blast hole; then the remaining charge rolls are loaded one by one. When the charge length reaches the design requirements, the prepared hole-sealing mud is loaded into the blast hole with a gun stick and vibrated tightly to seal the gun. The detonating cord shall not be damaged during the mud process;

In the eighth step, all the blasting hole charging and sealing work is completed, and the full-time blaster is connected to the line. After the line is connected, the bus bar and foot line are suspended in the air to prevent grounding;

The ninth step is to use the detonator to fire the cannon, and to blast in groups. Each group of blasting holes is connected in the way of "partial parallel connection, overall series connection", and each group of blasting holes is detonated, and the blasting holes are detonated in sequence from small to large;

Step 10: After the drilling and blasting of all the charges is completed, after the gun smoke is blown away, and after checking and confirming that there is no blast rejection, construct airtight walls at both ends of the withdrawal channel to close the withdrawal channel;

In the eleventh step, when the recovery of the working face advances to the position of the withdrawal channel, the recovery is stopped, the airtight walls at both ends of the withdrawal channel are removed, and the hydraulic support of the working face and other mining equipment are withdrawn from the withdrawal channel.

The deep hole pre-splitting drilling is drilled by the existing mining drilling equipment according to the design position and parameters, and the diameter of the hole is 75mm.

The explosive is a permitted emulsion explosive for third-grade coal mines, the size specification of the drug roll is Φ60×500mm, and the weight specification is 1.5 kg/roll.

The detonator is the 8# instantaneous power detonator permitted in coal mines, which can cause detonation immediately after being energized.

The detonating cord is a detonating cord permitted in coal mines, with Taian and RDX as the drug core, cotton thread and plastic braided silk as the wrapping material, and plastic as the moisture-proof layer. The specification is Φ6.5±0.3 mm, detonation velocity ≥ 6000m/s.

The gun stick is a Φ30 mm×2000 mm socketed bakelite gun stick, and the adjacent gun sticks are connected by a steel sleeve; a wooden gun stick head of Φ50 mm×500 mm is processed at the front end of the gun stick to increase the size of the gun stick and the explosive roll. and the contact area of the gun mud; a thin steel wire or nylon rope with a diameter of 3mm is fixed on the wooden gun stick head at the front end of the gun gun, and is used for pulling the gun gun when the gun gun is withdrawn from the drill hole during the charging and sealing process head to prevent the cannon stick from falling off at the socket.

The hole-sealing clay is a cylindrical strip-shaped clay made of sand and loess by a mining clay machine, which is used to seal the blast holes filled with explosives. The size of the clay is Φ60mm×200m, and the clay is uniform in texture. , Moderate hardness and softness, smooth surface, use gun sticks to send the clay into the blasting hole filled with explosives and vibrate it compactly to prevent open flames during the blasting process.

The sealing process of the blast hole is carried out twice, the first time the hole is sealed to a distance of 1m from the orifice; the second time the hole is sealed, the detonator and the detonating cord are bound firmly and then inserted into the hollow section of the hole and then sealed hole until the blast hole is completely sealed and compacted.

The detonator is a permitted detonator for coal mines, which is used for triggering electric detonators in underground coal mine blasting, and is suitable for mine environments with gas and coal dust explosion hazards.

The airtight walls at both ends of the retraction passage are temporary airtight walls built with masonry, and the walls are cut around to see the hard side and hard bottom. The vertical seams of the masonry walls are staggered, the horizontal seams are horizontal, arranged neatly, and the mortar is full , The wall is jointed or covered with fine gray mortar.

The beneficial effects of the present invention are as follows:

The above-mentioned technical solution provided by the present invention excavates the support of the working face and the retraction channel of other mining equipment in advance along the position of the stop production line, and cuts off the propagation path of the leading support pressure of the working face by pre-splitting the coal seam roof with deep holes, thus weakening the pressure on both sides. Faced with the influence of the main roadway in the mining area, the mining work has reduced the size of the protective coal pillar between the stop production line and the main roadway in the mining area. On the premise of ensuring the safety and stability of the main roadway in the mining area, the non-renewable coal resources have been improved. mining area recovery rate.

Compared with the prior art, the present invention calculates and determines the cycle of the old top of the mining face according to the structure of the roof and floor rock layers of the mining coal seam and the physical and mechanical properties of each rock layer to press the step distance, and doubles the cycle of the old roof of the coal seam of the mining face. The pressure step is used as the width of the protective coal pillar between the main roadway and the stop production line in the mining area, which reduces the loss of non-renewable coal resources due to the retention of protective coal pillars, improves the recovery rate of coal resources in the mining area, and reduces The amount of coal remaining in the goaf. By excavating the retraction channel of the working face support and other equipment in advance at the determined stop line position, arrange blast holes and pilot holes on the roof of the retraction channel, and fill the blasting holes with explosives to pre-split the coal seam roof. A pre-crack parallel to the roadway in the mining area is formed in the rock formation, which cuts off the propagating path of the advance support pressure of the mining face in the roof rock layer, weakens the influence of mining on the mining area roadway on both sides of the mining face, and can realize The safety and stability of the surrounding rock of the roadway in the mining area can be realized under the condition of protecting the coal pillar with a small width.

Description of drawings

Fig. 1 is a schematic plan view of the layout of the roadway in the mining area of the present invention and the mining working faces on both sides;

Fig. 2 is a schematic diagram of the arrangement of boreholes in the retraction channel at the production stop line of the present invention;

Fig. 3 is a schematic diagram of the gun stick of the present invention and its mutual socketing;

Fig. 4 is a schematic diagram of the connection between the detonating roll and the detonating cord of the present invention;

Fig. 5 is a schematic diagram of filling explosives and sealing holes in the blast holes of the present invention;

Fig. 6 is a schematic plan view of the arrangement of boreholes in the retraction channel of the fully mechanized caving face according to the embodiment of the present invention.

Among them: 1- mining area transportation up (down) hill; 2- mining area track up (down) hill; 3- mining face; 4- mined-out area; line; 7-retraction channel Ⅰ; 8-retraction channel Ⅱ; 9-coal seam direct roof; 10-coal seam old roof; 11-drilling; 12-wooden gun stick head; 13-wire rope; 15-bakelite gun stick; 16-detonating cord Ⅰ; 17-detonating powder roll; 18-detonating cord Ⅱ; 19-explosive roll; 20-sealing gun mud; 21-detonator; Put the working face; 24-air return roadway; 25 air inlet roadway.

Detailed ways

The present invention is further described in conjunction with examples.

A mine adopts the layout of the mining area towards the longwall working face. The 15# coal seam with an average thickness of 5.2m is mined by the fully mechanized top coal caving process, and the average inclination angle of the coal seam is 4°. A mining area transportation roadway is arranged at the central position of the mining area and a return air roadway in the mining area, which are respectively responsible for the transportation and ventilation tasks of the mining working faces on both sides of the mining area.

In the mining area, the average step distance between the old top cycle of the fully mechanized caving face was 13m, and the width of the protective coal pillar between the production stop line and the main road in the mining area was 80m. The impact is serious. When the mining face is close to the stop line, the large roadway in the mining area is seriously deformed, and the specific manifestations are roof separation, partial collapse and large-scale roof fall, which seriously threatens the safety and stability of the main roadway in the mining area. .

The inclined length of a fully mechanized caving face on one side of the mining area is 190m, and the strike length of the working face is 860m. According to geological drilling data, the immediate roof of the 15# coal seam is 4.2m thick sandy mudstone or mudstone, and the old roof is 5.6m thick K ₂ limestone. Calculate and determine the periodic pressure step distance of the old roof L=16m. Apply the technical solution provided by the present invention to determine the size of the protective coal pillar between the position of the stop line of the fully mechanized caving face and the main roadway in the mining area S=2L=2×16=32m.

After the mining roadway excavation of the fully-mechanized caving face and the installation of mining equipment such as open cut supports, excavate a retraction channel for support equipment parallel to the main roadway in the mining area along the coal seam floor at a distance of 32m from the main roadway in the mining area. The width is 2m, the height is 3.2m, the minimum height of the hydraulic support of the working face, and the length along the working face is 190m. The roof of the withdrawal channel and the side walls near the main road in the mining area are supported by high-strength rebar anchors of Φ22mm×2400mm and diamond-shaped metal mesh according to the row spacing of 900mm×900mm, and each anchor uses K2335 and Z2360 resin coils One piece of anchoring agent, the metal mesh is a diamond-shaped metal mesh with a mesh size of 50×50mm woven by No. 10 iron wire; the side wall of the withdrawal channel close to the mining face is selected according to the row spacing of 900mm×900mm FRP of Φ22mm×2000mm Anchor rods and flame-retardant plastic nets for mines with specifications and models of PP180MS are used for support.

When the excavation and support of the retraction channel is completed, drill holes are drilled at the center of the roof in the retraction channel 10m away from the return airway of the fully-mechanized working face. The hole diameter is 75mm, the drilling depth H=( h ₁ + h ₂ )÷sin45°=(4.2+5.6)÷sin45°=13.86m, and the distance between adjacent drilling holes is 5m. When the distance between the last borehole and the air inlet roadway of the fully mechanized caving face is 10m, stop drilling. A total of 35 drill holes were drilled in the retracement channel, and the numbers were 1#, 2#, 3#..., 34#, 35#.

After all the boreholes have been drilled, water is sprinkled in the retraction channel to reduce dust, and it is ready to start loading explosives into the boreholes. Fill the holes with odd numbers (1#, 3#, ..., 35#) with explosives as blast holes, a total of 18 blast holes filled with explosives; drill holes with even numbers (2#, 4#... ..., 34#) are not filled with explosives, and provide free surfaces as pilot holes, a total of 17 drill holes without explosives.

The charge length of each blast hole is ( h2 ÷ _sin45 °)=5.6÷sin45°=7.92m, and it is designed to be loaded with 16 sections of emulsion explosive rolls permitted for Class III coal mines with a dimension of Φ60×500mm. Before loading the first roll of priming charge, put two detonating cords into the charge roll in advance. The coils are sent to the bottom of the blast hole; then the remaining 15 drug coils are loaded one by one. When the 16 drug coils are all loaded into the drilled hole, the prepared hole sealing mud is loaded into the blast hole with a gun stick and Vibrate and compact to a position 1m away from the orifice, connect the two detonators to the two detonating cords and bind them firmly, then insert them into the empty section of the hole, and then seal the hole with gun mud until the blast hole is completely sealed and compacted.

All the 18 blasting holes were charged and sealed, and the full-time blasters connected the lines. After the lines were connected, the busbars and foot lines were suspended in the air, and the three blasting holes were blasted in groups using the detonator. After the drilling and blasting of all the charge holes is completed, after the gun smoke is blown away, check and confirm that there is no blast rejection, and construct airtight walls at both ends of the withdrawal channel to close the withdrawal channel.

During the process of advancing the working face until it reaches the position of the retraction channel, a roadway surface displacement observation station is set up in the main roadway of the mining area to observe and record the displacement of the roof, floor and two sides of the main roadway in the mining area. According to the results of observation records, during the 8 months from the start of mining of the fully mechanized caving face to the advancement of mining to the stop production line, the displacement of the roof, floor and two sides of the main roadway in the mining area was less than 2 mm, and no local collapse or collapse occurred. The phenomenon of roof fall is almost not affected by the mining of the working face and remains stable.

This fully-mechanized caving face uses the specific technical scheme provided by the method of cutting the top and pressure relief roadway protection of the last mining withdrawal channel of the coal mining face to determine that the protective coal pillar between the stop production line and the main roadway of the mining area is 32m. Excavate support and other equipment retraction channels in advance at the position of the stop production line and implement deep pre-splitting blasting. Compared with the original 80m protective coal pillar, not only 48m more coal resources were recovered (actually more than 47,400 tons of raw coal were recovered), but also improved The recovery rate of the mining area; and through the arrangement of the roadway surface displacement observation station, the monitoring shows that the main roadway in the mining area is hardly affected by the mining of the working face and has always maintained a stable state, and the protection of the main roadway in the mining area has achieved good results.

Claims (10)

1. a kind of coal working face end adopts return channel and cuts top release shield lane method, it is characterised in that：Include the following steps：

The first step calculates the periodic weighting step pitch L for determining that stope pushes up always,, in formula, L is that exploiting field is big The periodic weighting step pitch that lane both sides stope pushes up always；h ₂For the thickness of coal seam main roof strata；qMade by gravity for overlying rock With and be applied to the uniform load on the main roof strata of coal seam；R_TFor the ultimate tensile strength of main roof strata；

Second step, the position of mining device return channel at the end of apart from the position of exploiting field main entry S=2L, determining working face extraction It sets, i.e., protection coal pillar width S=2L between working face the position of terminal mining line and exploiting field main entry；

Third walks, after installation is complete for the mining devices such as working face extraction tunnelling and open-off cut holder, in determining work Face the position of terminal mining line digs a force piece along seat earth according to the direction parallel with exploiting field main entry and other back production are set Standby return channel, return channel width are 2m, and return channel height is the minimum bearing height of working surface hydraulic support, is withdrawn Using anchor metal or anchor cable and metal mesh combined supporting, return channel is close to return for channel top plate and the lateral wall of close exploiting field main entry The lateral wall of mining face uses cleavable glass fibre reinforced plastics rockbolts and flame retardant plastics net combined supporting；

4th step sets depth since return channel one end is apart from the end positions 10m in return channel inner top panel centre position Hole pre-splitting hole, all drillings are biased to return channel and start to punch 45 ° of end, i.e., the angle between drilling and vertical direction is 45 °；It bores Bore dia Φ=75mm；Drilling depth H=（h ₁+h ₂）÷ sin45 °,h ₁For the thickness that back production coal seam is directly pushed up,h ₂For back production coal seam The thickness pushed up always；Spacing distance between adjacent drillingl=5m, when the last one drilling the return channel other end between away from When from less than 10m, stopping set drilling, all drillings set move towards in alignment along return channel, according to set priority Sequence is numbered to the drilling set successively according to since 1；

5th step, after the completion of all drillings are all set, the watering and lowering dust in return channel prepares to start to load into drilling fried Medicine loads explosive, as blast hole in the drilling that number is odd number；Explosive is not loaded in the drilling that number is even number, is made The scope of freedom is provided for pilot hole, guiding roof strata moves towards cracking, i.e. deep hole blasting shape in roof strata along return channel At precracking it is parallel with exploiting field main entry；

6th step loads explosive into blast hole using Uncoincided charge mode, is ignited using double detonator, double primacords, 2 thunders Pipe is connected outside blast hole using parallel way, and every 3 blast holes are one group and using being connected in series with, if blast hole is less than 3 When be individually for one group, it is good to blow out bus insulation, hanging to hang；

7th step, using tamper by the explosive needed for each blast hole by volume load hole and shifting bottom hole onto, explosive payload it is small can To be once packed into, loaded length is the drillable length that range is pushed up in coal seam always, i.e. loaded length is（h ₂÷sin45°）；

Before filling first volume priming, first two primacords to be filled in powder stick in advance, the length that primacord stretches into powder stick is 200mm, Blend compounds band, which twines, is made primer [cartridge], then this powder stick is sent to blast hole bottom hole with tamper；Then gradually it is packed into remaining medicine Ready sealing of hole stemming is packed into blast hole and vibration compacting by volume after loaded length reaches design requirement, then with tamper；

8th step, all blast hole powder charge sealing of hole work are completed, and on line, after connection is good, busbar and payment to a porter are hanging, prevent from connecing Ground；

9th step, is blown out using initiator, by group blasting in groups, using " local parallel is totally connected " between every group of blast hole Mode on line, one group of charging hole of detonating every time, detonates successively from small to large by charging hole sequence；

Tenth step, all powder charge drillhole blastings finish, and wait for that blasting fume dispels, and check after confirming without misfire condition, in return channel two End construction fire dam closes return channel；

11st step when working face extraction is advanced into return channel position, stops back production, removes the closed of return channel both ends Wall withdraws from working surface hydraulic support and other mining devices from return channel.

2. a kind of coal working face end according to claim 1 adopts return channel and cuts top release shield lane method, feature exists In：The a diameter of 75mm of deep hole presplitting Completion of Drilling Hole.

3. a kind of coal working face end according to claim 1 adopts return channel and cuts top release shield lane method, feature exists In：The explosive is three-grade coal mine allowable emulsified explosive, and powder stick dimensions is 60 × 500mm of Φ, weight specification 1.5kg/ Volume.

4. a kind of coal working face end according to claim 1 adopts return channel and cuts top release shield lane method, feature exists In：The detonator is allowed for use in coal mines 8# instant electric detonators.

5. a kind of coal working face end according to claim 1 adopts return channel and cuts top release shield lane method, feature exists In：The primacord is coal permissible detonating cord, and ether peace, hexogen explosive are medicine core, with the works such as cotton thread and plastic knitting silk Wrap is formed by damp-proof layer of plastics, and specification is 6.5 ± 0.3mm of Φ, explosion velocity >=6000m/s.

6. a kind of coal working face end according to claim 1 adopts return channel and cuts top release shield lane method, feature exists In：The tamper is the socket bakelite tamper of Φ 30 mm × 2000 mm, is connected by steel bushing between adjacent tamper；Tamper front end The wooden tamper head of Φ 50 mm × 500 mm is processed, the contact area of tamper and explosive cartridge and stemming is increased；Before tamper The finer wire or nylon rope of an a diameter of 3mm are fixed on the wooden tamper head at end.

7. a kind of coal working face end according to claim 1 adopts return channel and cuts top release shield lane method, feature exists In：The sealing of hole stemming is the cylindric strip stemming made by mining Stemming machine sand and loess, stemming dimensions For Φ 60mm × 200m.

8. a kind of coal working face end according to claim 1 adopts return channel and cuts top release shield lane method, feature exists In：The sealing of hole process of the blast hole carries out at twice, and first sealing of hole is at away from aperture 1m for the first time；When second of sealing of hole, by thunder Dead band sealing of hole again is filled in hole after pipe, primacord binding securely, until blast hole all full tampings of envelope.

9. a kind of coal working face end according to claim 1 adopts return channel and cuts top release shield lane method, feature exists In：The initiator is allowed for use in coal mines initiator.

10. a kind of coal working face end according to claim 1 adopts return channel and cuts top release shield lane method, feature exists In：The fire dam of the return channel two ends is the temporary airtight wall of masonry bond.