Process for carrying out large-dip-angle downhill tunneling construction in comprehensive mechanical mode

Abstract

The invention relates to the technical field of coal seam mining, in particular to a large-dip-angle downhill tunneling construction technology in a comprehensive mechanical mode, an open-off cut roadway is obtained through downhill tunneling construction of a roadheader, and the downhill tunneling construction comprises the steps that a working face is cut through a cutting part of the roadheader, construction operation without retreating the roadheader is adopted, and bottom coal is reserved on a roadway bottom plate during construction; the conveyor adopts a large-wrap-angle belt bracket, a conveyor rubber belt adopts a herringbone pattern rubber belt, after the fully-mechanized excavating machine finishes cutting, a rear support of the fully-mechanized excavating machine is supported to support a bottom plate, and meanwhile, a gun head of the fully-mechanized excavating machine presses the bottom plate or is directly inserted into a head-on coal wall; and supporting the top plate by matching with a hydraulic temporary supporting device of the fully-mechanized coal winning machine, shutting the fully-mechanized coal winning machine in a power failure manner, and finally supporting the head-on and the two sides. The device can prevent the roadheader from sliding down in a roadway during large-dip-angle construction, and solves the technical problem that discharging is difficult under a large slope.

Description

Technical Field

[0001] The invention relates to the technical field of coal seam mining, and in particular to a construction process for downhill excavation at a large dip angle using a comprehensive mechanized method. Background Art

[0002] With the promotion and application of modern mechanical products, the comprehensive excavation machine has become an irreplaceable mechanical product in the modern mine excavation production in the world with its advantages of fast excavation speed, high safety factor and low mining cost in coal tunnels. However, due to the different occurrence conditions of coal seams, it is impossible to use a complete set of comprehensive mechanized equipment for rapid excavation operations under many geological conditions. With the high-intensity mining in the coal mining industry in the past decade, while making great contributions, various mines are also facing problems such as poor resource occurrence, increasingly complex geological conditions, lack of skilled personnel, and aging equipment. In particular, the mine excavation profession has prominent problems such as serious aging of personnel, complex geological conditions, high labor intensity of employees, relatively low excavation efficiency, and relatively tight continuity. In order to ensure the recovery and mining of coal resources, the research and application of comprehensive mechanized construction technology for downhill with large slopes is extremely important.

[0003] Through the analysis of the main technical parameters of the tunnel boring machine and the downhill construction projects of mines that can be used as reference, it can be known that the tunnel boring machine is generally suitable for downhill tunneling in tunnels with a slope of less than 18°. If a downhill construction project with a large slope is encountered during the tunneling process, the drilling and blasting construction method is generally used. There are several difficulties in the use of comprehensive mechanized tunneling methods for downhill construction with large slopes. First, when the crawler of the tunnel boring machine walks directly on the bottom rock, because the crawler of the tunnel boring machine and the bottom plate of the tunnel are relatively hard and smooth, when the slope is large, the friction coefficient between the crawler and the bottom plate is small, resulting in a small friction between the crawler and the bottom plate, which causes the tunnel boring machine to slide down. Second, when the slope is large during downhill construction in the tunnel, the inclination angle of the tunnel boring machine itself is large. Because the mass of the tunnel boring machine itself is large (self-weight 72t), the downward component of the gravity of the tunnel boring machine itself is also large, which aggravates the slide of the tunnel boring machine.

[0004] At the same time, in terms of the discharge of coal gangue, it is difficult to discharge gangue with a belt conveyor. Due to the large slope, the gangue will continue to slide down on the belt during the discharge process, resulting in the inability to discharge the gangue normally. At the same time, the large slope is prone to flying gangue, and the management of preventing flying gangue is extremely difficult. Summary of the invention

[0005] In order to solve the technical problems such as sliding of the tunnel boring machine and difficulty in discharging coal gangue during downhill tunneling at a large angle, the present invention provides a comprehensive mechanized method for downhill tunneling at a large angle, which can prevent the tunnel boring machine from sliding down in the tunnel during construction at a large angle and solve the technical problem of difficulty in discharging materials on a large slope.

[0006] The present invention provides a comprehensive mechanized method for carrying out a high-angle downhill excavation construction process, wherein a cut-eye tunnel is obtained by using a comprehensive excavator for downhill excavation construction, the downhill excavation construction includes using a cutting part of the comprehensive excavator to cut the working face, and adopting a non-retracting machine construction operation, leaving bottom coal on the bottom plate of the tunnel during construction, and the cut coal gangue is transported out by a conveyor, the conveyor adopts a large-angle belt bracket, and the conveyor belt adopts a "human" shaped patterned belt. After the comprehensive excavator completes the cutting, the rear support of the comprehensive excavator is propped up to drag the bottom plate, and at the same time, the gun head of the comprehensive excavator is pressed against the bottom plate or directly inserted into the head coal wall, and the hydraulic temporary support device of the comprehensive excavator is used to support the top plate to prevent the comprehensive excavator from sliding down, and the comprehensive excavator is powered off and locked, and finally the head and two sides are supported.

[0007] Furthermore, the maximum slope of the cut-eye tunnel is 40°. The invention is suitable for downhill excavation construction at a large slope and a large inclination angle, and has high construction efficiency.

[0008] Furthermore, the area cut by the tunnel boring machine on the working face is 27.5m 2 .

[0009] Furthermore, the thickness of the bottom coal left on the tunnel floor is 100~200mm. The effect is that, at this thickness, it can increase the friction of the tunnel boring machine and save the excavation space.

[0010] Furthermore, the support method for the head and two sides includes using short air-leg anchor drills and pneumatic drills to support the head and two sides of the tunnel, and the side anchors are constructed by directly following the head without dragging. The short air-leg anchor drill is particularly suitable for operations in narrow spaces, such as the head of the tunnel, because of its compact structure and flexible operation. Its power source is generally compressed air, which makes it more convenient and safe to use in environments such as underground mines. The short air-leg design enables the drill to drill close to the working surface, improving the operating efficiency and the timeliness of support. The pneumatic drill is also powered by compressed air and is suitable for drilling operations in a variety of rocks and coal seams. It has a simple structure, easy maintenance, and high drilling efficiency. It is a commonly used drilling tool in coal mines and tunnel engineering. The side anchor is constructed by directly following the head, that is, supporting while excavating, ensuring that the tunnel is immediately stabilized after excavation. This method effectively avoids the phenomenon of empty side over-distance caused by the excavation speed being faster than the support speed, and reduces the risk of tunnel collapse. At the same time, the close fit between the support structure and the excavation surface is ensured by the undelayed construction method.

[0011] Furthermore, the conveyor is equipped with a fully enclosed rock-blocking net, and a full-section rock-blocking door is set every 50 meters on the sidewalk. The rock-blocking door is in a normally closed state. After pedestrians pass through, the full-section rock-blocking door must be closed in time to prevent the rock from sliding down the sidewalk to the front. The effect is that it can significantly reduce the risk of injury to personnel and equipment caused by material splashing, scattering or accidental falling.

[0012] Furthermore, downhill excavation construction also includes material transportation, which includes using a monorail crane to transport the materials needed for production directly to the top of the cut eye, and then using an infinite rope winch in conjunction with a dry boat to transport the support materials and construction tools to the head. The purpose is to ensure that the materials can be transported to the construction site safely and efficiently.

[0013] Furthermore, a steel wire rope ladder is installed on the side of the sidewalk, and the joints of the ladders are fixed with U-shaped clips. A set of ground anchors is set every 50 meters to fix the ladders, and brown ropes are installed on the side of the sidewalk as handrails. The purpose is to improve the safety and convenience of people going up and down.

[0014] The beneficial effects of the present invention are: (1) The present invention aims to solve the problem of low friction between the crawler and the bottom plate rock of the excavator when going down a steep slope by leaving bottom coal on the bottom plate to solve the problem of smooth bottom plate, thereby increasing the friction of the bottom plate and preventing the excavator from sliding down. At the same time, after the excavator has completed cutting, the rear support of the excavator is propped up to hold the bottom plate, the gun head of the excavator is pressed against the bottom plate or directly inserted into the head coal wall, the hydraulic temporary support device of the excavator is used to support the top plate, and the excavator is powered off and locked to further prevent the excavator from sliding down.

[0015] (2) The conveyor of the present invention adopts a large wrap angle belt bracket, which allows the belt to be wrapped around the pulley at a larger angle (i.e., a large wrap angle). By increasing the contact area between the belt and the bracket, the stability of the conveyor belt when running at high speed and large slope is improved, and the belt is prevented from shifting or falling off. At the same time, the conveyor belt of the present invention adopts a "human" pattern belt, which can prevent the material from slipping during transportation, solves the problems in large slope, complex terrain and heavy load transportation, and improves the efficiency and safety of coal gangue transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a cross-sectional view of the envisioned structure of eye cutting according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0019] Example 1 The 4901 cut of the Great Wall Coal Mine in Etuokeqian Banner is the first working face of the nine layers in the eastern area of ​​the mine. The working face is located in the fourth mining area of ​​the +750 level in the eastern area of ​​the mine field. It is adjacent to the auxiliary transportation roadway of the 4903 fully mechanized mining working face in the east, the coal pillar of the coal seam outcrop in the west, the coal pillar of the ancient Great Wall in the south, and the 4901 working face in the north. The working face has a strike length of 270m, a ground elevation of 1238.7-1243.4m, an upper limit elevation of +1049m, a lower limit elevation of +928m, and a burial depth of 189.7-315.4m. Within the excavation range of this working face, the stratum strikes 181-193°, dips 91-103°, and dips 15-40°. The overall working face is a regular monocline structure. According to the actual exposure analysis of three-dimensional seismic data and adjacent excavation tunnels, there is no fault development within the excavation range.

[0020] The rock types of the tunnel roof from top to bottom are as follows: the basic roof is grayish white fine sandstone, calcareous cementation, the main components are feldspar and quartz, followed by muscovite, 4.0m thick, f=5.0; the direct roof is grayish black fine sandstone, mainly composed of quartz, feldspar and rock debris, 2.2m thick, f=5.0.

[0021] The rock types of the tunnel floor from top to bottom are: the direct bottom is gray-black siltstone, mainly composed of rock fragments and clay minerals, 1.34m thick, f=4.0; the basic bottom is gray-white fine sandstone, fine sand grain structure, calcareous cementation, locally containing siltstone, 3.22m thick, f=5.0.

[0022] According to the design, with the center line of the tunnel as the benchmark, the 4901 cut was constructed at a true azimuth of 101° along the 9th coal roof for 270m to penetrate the 4901 transport tunnel. The designed total length is 270m with an average slope of 28°. The slope of the cut gradually increases from top to bottom, with a section of 15-26° of 50.5m, 27-32° of 68m, 33-36° of 38.5m and 37-40° of 113m. Figure 1 A cross-sectional view of the envisioned structure of the 4901 cut eye is shown.

[0023] The 4901 eye-cutting excavation working face of the present invention adopts a top-down comprehensive mechanized excavation construction method, and the excavator used is the EBZ220H excavator of Shanghai Chuangli Group. The main technical parameters of the EBZ220H excavator are: overall length: 10.7m; overall width: 3.3m; overall height: 1.82m; machine weight: 72t; ground clearance: 190 (mm); undercover depth: 180mm; gantry height: 450mm; adaptable slope: ±18°; cutting hardness: ≤90MPa; total power: 367kW; positioning cutting height: 4.83m; positioning cutting width: 5.7m; positioning cutting section: 27.5m 2 .

[0024] The present invention provides a comprehensive mechanized method for high-angle downhill excavation construction, comprising: (1) Excavation construction: The tunneling tunnel is constructed by using a multi-purpose excavator to dig downhill to obtain the cut-eye tunnel. The digging construction includes cutting the working face with the cutting part of the multi-purpose excavator. The cross-sectional area of ​​the positioning cutting is 27.5m 2 The tunnel boring machine adopts the non-retracting construction operation. During the construction, the bottom coal is left on the bottom plate of the tunnel. The thickness of the bottom coal is 100~200mm. Under this thickness, the friction force of the tunnel boring machine can be increased, and the excavation space can be saved at the same time. (2) Material discharge: the cut and fallen coal gangue is transported out by a conveyor. The conveyor adopts a large wrap angle belt bracket. The large wrap angle belt bracket means that the belt is allowed to wrap around the pulley at a larger angle (i.e., a large wrap angle). By increasing the contact area between the belt and the bracket, the stability of the conveyor belt when running at high speed and large slope is improved, and the belt is prevented from deflecting or falling off. At the same time, the conveyor belt of the present invention adopts a "human" pattern belt, which can prevent the material from slipping during transportation, solves the problem of large slope, complex terrain and heavy load transportation, and improves the efficiency and safety of coal gangue transportation; (3) After the excavator has completed cutting, the rear support of the excavator is propped up to hold the bottom plate, and the gun head of the excavator is pressed against the bottom plate or directly inserted into the coal wall at the head. The excavator is equipped with a hydraulic temporary support device, which is lifted to hold the top plate to prevent the excavator from sliding down. The excavator is also powered off and locked to further prevent the excavator from sliding down. Then, support methods are applied to the head and two sides. The support methods include: using short air-leg anchor drills and pneumatic drills to support the head and two sides of the tunnel. The side anchors are constructed by directly following the head without dragging. (4) Material transportation: Under the condition of steep downhill slope, the sliding force of materials is large, and the difficulty of transporting support materials and construction tools increases significantly. The material transportation of the present invention includes using a monorail crane to directly transport the materials required for production to the top of the cut eye, and then using an infinite rope winch in combination with a dry boat to transport the support materials and construction tools to the front. The purpose is to ensure that materials can be transported to the construction site safely and efficiently; (5) Management of anti-flying waste rock: The 4901 cut uses a 125kW belt conveyor and a two-way transport of a multi-purpose excavator (the two-way transport equipment includes conveyors, belt conveyors, etc.). All are equipped with fully enclosed waste rock retaining nets to prevent waste rock from falling. A full-section waste rock retaining door is set every 50 meters on the sidewalk. The waste rock retaining door is in a normally closed state. After pedestrians pass through, the full-section waste rock retaining door must be closed in time to prevent waste rock from sliding down from the sidewalk to the front. This can significantly reduce the risk of injury to personnel and equipment caused by material splashing, scattering or accidental falling; (6) For pedestrian management on steep slopes, a steel wire rope ladder is installed on the side of the sidewalk for the convenience of pedestrians. The ladder is welded with a φ15.5mm steel wire rope and a 2-inch steel pipe. The steel wire rope ladder is rolled up in 30m rolls for easy transportation. The ladder is fixed with a U-shaped clip at the joint. A set of ground anchors is installed every 50m to fix the ladder. Brown ropes are installed on the side of the sidewalk as handrails to improve the safety and convenience of people going up and down.

[0025] The method of the present invention is used to construct downhill cutting, which changes the traditional downhill excavation construction process with a large slope. Compared with the blasting speed, the machine excavation footage speed is increased from 80 meters / month to 115 meters / month. After the construction of the cutting, at least 30 days of construction period are saved. According to the attendance of 50 people / day and 350 yuan / worker, it is estimated that the salary expenditure can be saved by 525,000 yuan. At the same time, according to the calculation of 22.8 yuan / kg of mineral water gel explosives and 42 yuan / piece of detonators, it is estimated that 468,500 yuan of blasting costs can be saved, and the links of dismantling and transporting the excavator are eliminated, which saves 3 days of construction time and 106,800 yuan of dismantling and transporting the excavator.

[0026] The present invention eliminates various safety risks caused by blasting at the source, improves the safety of construction, and at the same time, comprehensive mechanized excavation increases the excavation rate, reduces the labor intensity of employees, ensures efficient advance, ensures the continuity of mine production, and saves time for normal mine production.

[0027] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention.

Claims

1. A comprehensive mechanized method for high-angle downhill excavation construction process, characterized in that: The eye tunnel is obtained by downhill excavation by a multi-purpose excavator. The downhill excavation construction includes cutting the working face with the cutting part of the multi-purpose excavator, and the machine is not retreated for construction. During construction, bottom coal is left on the bottom plate of the tunnel, and the cut coal gangue is transported out by a conveyor. The conveyor adopts a large-angle belt bracket, and the conveyor belt adopts a "human" shaped patterned tape. After the multi-purpose excavator completes the cutting, the rear support of the multi-purpose excavator is propped up to hold the bottom plate, and the gun head of the multi-purpose excavator is pressed against the bottom plate or directly inserted into the head coal wall. The hydraulic temporary support device of the multi-purpose excavator is used to support the top plate, and the multi-purpose excavator is powered off and locked. Finally, the head and both sides are supported.

2. A comprehensive mechanized construction process for high-angle downhill excavation as claimed in claim 1, characterized in that: The maximum slope of the cut-eye tunnel is 40°.

3. A comprehensive mechanized construction process for high-angle downhill excavation as claimed in claim 1, characterized in that: The area cut by the tunnel boring machine is 27.5m 2 .

4. A comprehensive mechanized construction process for high-angle downhill excavation as claimed in claim 1, characterized in that: The thickness of the bottom coal left on the tunnel floor is 100~200mm.

5. A comprehensive mechanized construction process for high-angle downhill excavation as claimed in claim 1, characterized in that: The support methods for the head and both sides include using short air-leg anchor drilling rigs and pneumatic drills to support the head and both sides of the tunnel. The side anchors are constructed by directly following the head without lagging behind.

6. A comprehensive mechanized construction process for high-angle downhill excavation as claimed in claim 1, characterized in that: The conveyor is equipped with a fully enclosed rock-blocking net, and a full-section rock-blocking door is set every 50m on the sidewalk side.

7. A comprehensive mechanized construction process for high-angle downhill excavation as claimed in claim 1, characterized in that: Downhill excavation construction also includes material transportation. Material transportation includes using a monorail crane to transport the materials needed for production directly to the top of the cut eye, and then using an endless rope winch in conjunction with a dry boat to transport the support materials and construction tools to the head.

8. A comprehensive mechanized construction process for high-angle downhill excavation as claimed in claim 6, characterized in that: A wire rope ladder is installed on the sidewalk. The joints between the ladders are fixed with U-shaped clips. A set of ground anchors is installed every 50 meters to fix the ladder. Brown ropes are installed on the side of the sidewalk as handrails.

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