CN116591707A - Steep coal seam open-cut tunnel structure and construction method of inclined tunnel and pilot tunnel - Google Patents

Abstract

The application discloses a steep coal seam open-cut tunnel structure, which comprises a return air tunnel, a transport tunnel and an installation chamber, wherein N near-horizontal pilot tunnels along the trend of a coal seam are arranged between the transport tunnel and an open-cut area, N gently-inclined tunnels are arranged in the open-cut area along the inclined direction of the coal seam, and each inclined tunnel is communicated with the tail end of the corresponding pilot tunnel to form a coal transportation, pedestrian and ventilation channel. The construction method of inclined drift and pilot tunnel comprises the following steps: the pilot tunnel and the inclined drift adopt small-section one-step tunneling to form a drift, and the construction is performed by a drilling and blasting method; the inclined roadway is brushed from top to bottom to form a cutting hole, and coal generated by brushing is conveyed to a conveying roadway along the inclined roadway and the pilot tunnel. The application designs the whole open-cut hole into multi-section construction, and then spreads and brushes from top to bottom, thereby greatly reducing the impact force of high-speed rolling of the coal in the steeply inclined coal seam, reducing the accident of flying gangue injury, and fully ensuring the ventilation safety of the inclined drift and pilot tunnel.

Description

Steep coal seam open-cut tunnel structure and construction method of inclined tunnel and pilot tunnel

Technical Field

The application relates to the technical field of open-cut eyes of fully mechanized coal mining faces of steeply inclined coal seams, in particular to an open-cut eye roadway structure of the steeply inclined coal seams and a construction method of inclined drift and pilot tunnel.

Background

Coal is the main energy source in China, and the yield of coal in 2022 years is 45.6 hundred million. The reserve of the steep and large-dip coal seam accounts for about 20% of the total reserve of coal in China, and the steep and large-dip coal seam accounts for 50% in western China, and half of the reserve of the steep and large-dip coal seam is high in industrial utilization value, so that the mining of the steep and large-dip coal seam is significant in guaranteeing coal supply.

The intelligent fully-mechanized mining face is a rectangular roadway with a large section, and compared with the construction of the cutting hole of the near horizontal coal seam and the gently inclined coal seam, the cutting hole of the steeply inclined coal seam is particularly difficult to construct. Because the drop of the open-cut hole of the steeply inclined coal seam is very high, the coal seam is tunneled from bottom to top along the inclined direction of the coal seam, and the problems of single-hole ventilation, reduced labor intensity of personnel operation, high-altitude falling of a large amount of coal in the tunnelling and roadway expanding processes, injury of people due to gangue flying, side caving, high safety risk and the like are solved. In order to ensure the safety of open-cut construction and solve the problems, a new open-cut roadway structure and a construction method need to be developed.

Disclosure of Invention

The application aims to provide a steep coal seam open-cut tunnel structure, which solves the problems of high altitude falling, gangue flying injury, side wall caving, high safety risk and the like of a large amount of coal in the processes of single-hole ventilation, tunneling and roadway expanding and brushing when the existing steep coal seam open-cut tunnel is tunneled from bottom to top.

In order to achieve the above purpose, the present application provides the following technical solutions:

the utility model provides a steep coal seam open-cut tunnel structure, includes return air lane, transportation lane and installation chamber, arrange N along the nearly horizontal pilot tunnel of coal seam trend between transportation lane and the open-cut area, open-cut area has arranged N inclined drifts of gentle slope along the coal seam incline direction, and every inclined drifts all communicates with the pilot tunnel end that corresponds, forms coal transportation, pedestrian and ventilation's passageway.

Furthermore, the pilot tunnel and the inclined drift are rectangular sections with small sections, and are supported by adopting I-steel and two rows of single struts in a combined way.

The application further aims at providing a construction method of an inclined drift and pilot tunnel of a steep coal seam open-cut tunnel structure, which comprises the following steps:

the pilot tunnel and the inclined drift adopt small-section one-step tunneling to form a drift, and the construction is performed by a drilling and blasting method;

the inclined roadway is brushed from top to bottom to form a cutting hole, and coal generated by brushing is conveyed to a conveying roadway along the inclined roadway and the pilot tunnel.

The beneficial effects of the application are as follows:

compared with the prior true inclined open-cut construction of the steep coal seam, the fall is very high, and the condition that coal falls aloft and a large amount of flying gangue is generated easily when tunneling is carried out from bottom to top. The application designs the whole open-cut hole into multi-section construction, and then brushes the multi-section construction from top to bottom, so that the impact force of high-speed rolling of the coal in the steeply inclined coal seam is greatly reduced, the fly waste rock is reduced by combining the I-steel and two rows of single struts in a combined supporting mode, pedestrians and coal chute are effectively separated, the operation environment is safer, the damage and knock-down of the existing supporting caused by the falling impact of the coal can be reduced, and the coal chute is controllable; and after the pilot tunnel is constructed in a sectional mode, an open-cut air inlet channel can be additionally arranged, so that ventilation safety is ensured.

Drawings

FIG. 1 is a schematic diagram of a steeply inclined seam open-cut roadway structure according to an embodiment of the present application;

fig. 2 is a cross-sectional view of an open-cut eye support.

Reference numerals in the drawings of the specification include: 1. a return airway; 2. a transport lane; 3. installing a chamber; 4. conducting cave; 5. inclined drift.

Detailed Description

The application is described in further detail below with reference to the attached drawings and embodiments:

example 1

Taking a coal mine with a stone cave ditch of a Sichuan coal industry group as an example, the mine adopts a footrill and inclined shaft exploitation mode, the mine production capacity is 300kt/a, the mine belongs to a low-gas mine, the main stone gate takes east as a 32-mining area, the trend is 2300m, the west as a 31-mining area, and the trend is 2000m. The geological structure of the mining area is a simple monoclinic structure.

31111 is an intelligent fully-mechanized mining face, K10 and K11 coal laminated layers are mined, the inclination angle of the coal layer is 55-68 degrees, the average mining height is 3.6m, the mining difficulty is high, and the mining face belongs to a typical steeply-inclined medium-thickness coal layer fully-mechanized mining face.

As shown in fig. 1, the steeply inclined coal seam open-cut tunnel structure comprises a return air tunnel 1, a transport tunnel 2 and an installation chamber 3. The method is characterized in that a drilling and blasting method is adopted for construction, a small section is detonated into a roadway at one time, two approximately horizontal pilot tunnels 4 along the trend of a coal seam are arranged between a conveying roadway 2 and an open-cut hole area, a prop and materials are conveyed by a prop returning winch during tunneling of the pilot tunnels 4, the drilling and blasting method is adopted for construction, the small section is detonated into the roadway at one time, and a gently inclined roadway 5 is tunneled from the tail end of the pilot tunnels 4. And then spreading and brushing the inclined roadway 5 from top to bottom, and conveying the coal generated by spreading and brushing to the conveying roadway 2 along the inclined roadway 5 and the pilot tunnel 4. Wherein, the total length of the enlarging brush of the inclined drift No. 1 is 26m (true inclination), the total length of the pilot drift No. 1 is 78.5m, the length of the inclined drift No. 2 is 22m, and the length of the pilot drift No. 2 is 48.5m. The inclined drift and the pilot tunnel are rectangular sections, and are supported by adopting I-steel and two rows of single struts in a combined way, wherein the spacing between the struts is 800mm, and the row spacing is 1000mm. The open-cut hole is subjected to brushing construction by adopting a drilling and blasting method, the shape of the section of the open-cut hole brushing is designed into a rectangular section, and the anchor net cable injection full section support is arranged as shown in fig. 2: 6 is a hollow grouting anchor cable with phi 22.4mm, the length is 8.0m, and the interval is 1.8m;7 is an anchor rod with the diameter of 22mm, the length of 2.4m and the interval distance of 0.9m;8 is a phi 20mm full-thread anchor rod, the length is 1.8m, the row spacing is 0.9m, and the spacing is 1.1m; the supporting roof anchor net is formed by processing reinforcing steel bars with the diameter of 6mm, the mesh specification is length, width, 100mm, and the mesh size is length, width, 2000mm, 1000mm; the supporting coal wall anchor net adopts a No. 10 lead wire net, the grid is 80mm multiplied by 80mm, the width of the net sheet is 1.0m, and the length is more than or equal to 20m; seven rows of DW40-25/110TL or DW45-20/110TL single hydraulic prop are used for reinforcing and supporting, the row spacing of the single hydraulic prop is 1.0m, and the column spacing is 0.9m. The clear width of the open-cut eye expanding brush is 8500mm or more, the length 7438mm of the bracket, the safe distance from the front end of the bracket to the roadway wall is 500mm, and the safe distance from the tail end of the bracket to the roadway wall is 560mm. The clear height of the open-cut hole expanding brush is 3500mm (tunneling along the coal seam, bottom along with the shed) which is more than 1700mm of the support height and 218mm of the ballast bed height. The open-cut eye is specially provided with a pedestrian passage, and the material passage is provided with a group of gangue blocking barriers every 5m.

The construction time of the open-cut inclined drift and pilot tunnel is 2022, 6 months, 24 days, 2022, 7 months, 8 days, 2022, 7 months, 18 days, 2022, 8 months and 2 days, and the actual production days are 20 days. The average progress per shift is 5 m/shift, and the construction efficiency is high. The construction time of open-cut eye expanding brushing is 2022, 8, 17, 2022, 9, 30, wherein the effective expanding brushing time is calculated to be about 35 days due to the influence of checking, early warning, removing people and the like, the expanding brushing efficiency can reach 2.1 m/day, and the expanding brushing efficiency is high.

The foregoing is merely exemplary of the present application, and specific technical solutions and/or features that are well known in the art have not been described in detail herein. It should be noted that, for those skilled in the art, several variations and modifications can be made without departing from the technical solution of the present application, and these should also be regarded as the protection scope of the present application, which does not affect the effect of the implementation of the present application and the practical applicability of the patent. The protection scope of the present application is subject to the content of the claims, and the description of the specific embodiments and the like in the specification can be used for explaining the content of the claims.

Claims (3)

1. The utility model provides a steep coal seam open-cut eye tunnel structure, includes return air lane (1), transportation lane (2) and installation chamber (3), its characterized in that: n approximately horizontal pilot tunnels (4) along the trend of the coal bed are arranged between the transportation roadway (2) and the open-cut hole area, N inclined roadways (5) which incline slowly are arranged in the open-cut hole area along the coal bed in an inclined mode, and each inclined roadway (5) is communicated with the tail end of the corresponding pilot tunnel (4) to form a channel for coal transportation, pedestrians and ventilation.

2. The steeply inclined seam open-cut eye roadway structure of claim 1, wherein: the pilot tunnel (4) and the inclined drift (5) are rectangular sections with small sections, and are supported by I-steel and two rows of single struts in a combined mode.

3. The construction method of the inclined drift and pilot tunnel of the steep coal seam open-cut tunnel structure is characterized by comprising the following steps of:

the pilot tunnel and the inclined drift adopt small-section one-step tunneling to form a drift, and the construction is performed by a drilling and blasting method;

the inclined roadway is brushed from top to bottom to form a cutting hole, and coal generated by brushing is conveyed to a conveying roadway along the inclined roadway and the pilot tunnel.