Rapid tunneling method for basalt superhard rock in coal mine

Abstract

The invention discloses a coal mine basalt superhard rock rapid tunneling method which comprises the following steps: constructing a forepoling drill hole according to a forepoling drill hole design, and determining an allowable tunneling distance; according to the allowable tunneling distance, advanced pressure relief drilling parameters of the roadway tunneling face are designed; super-hard rock advanced pressure relief drilling is constructed, and after drilling construction is completed, the fully-mechanized excavating machine enters the field; cutting and rock drilling are conducted on the section of the roadway through a fully-mechanized coal winning machine, and a basalt super-hard rock stratum is And the advanced pressure relief drilling design of the roadway driving face is optimized. According to the method, a large number of pressure relief drill holes are constructed on the working face to destroy the rock compactness, the rock integrity of basalt on the tunneling face is reduced, an enough free face is added for drilling and cutting during tunneling of the roadheader, rapid tunneling of the super-hard rock is achieved, and the roadway tunneling efficiency and the single-entry level are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of rapid excavation of super-hard rock tunnels in coal mines, and in particular relates to a method for rapid excavation of super-hard basalt rocks in coal mines. Background Art

[0002] In some coal mine construction projects, the main tunnels, water storages and main mountain access roads of the mine construction projects are all arranged on the Emeishan basalt group at the bottom of the coal-bearing strata. The rock strength coefficient of the basalt group is relatively high. The conventional comprehensive mechanized excavation work efficiency is low and the single advance level is low, which seriously restricts the well construction period.

[0003] In view of the difficulty of excavating deep hard rock tunnels, many scholars have begun to optimize and adjust the equipment and technology of all-rock tunnel excavation. Drilling and blasting has always been the dominant method for excavation and mining of hard rock mine tunnels. In recent years, the blasting technology has also been optimized. Its main advantages are fast operation preparation, strong adaptability to rocks, flexible movement, and easy handling of geological faults and technical failures. However, there are still disadvantages such as low average excavation speed, difficulty in organizing multi-process cross-operation, serious blasting smoke hazards and high risk.

[0004] Therefore, in order to solve the hazards and shortcomings of blasting, mechanized mining technology of hard rock underground mines has gradually become the focus of scholars' research. Scholars have summarized the types of equipment for underground hard rock mechanized continuous mining, which are divided into drilling equipment, cutting disc roadheaders, rotary cutting disc roadheaders and cantilevered horizontal tunneling machines. In recent years, the cutterhead structure used by my country's roadheaders has been continuously improved, and the material has been continuously optimized, which has led to the continuous improvement of its overall performance, and the hard rock tunneling equipment and process technology have been optimized to a large extent. However, in order to achieve efficient tunneling of hard rock tunnels, it is difficult to achieve a good tunneling effect by only optimizing the cutterhead structure unilaterally. It is necessary to change the mechanical properties of the hard rock itself in the tunnel at the same time, that is, under the condition that the performance of the roadheader remains unchanged, the structure and strength of the rock and rock mass are changed to achieve the purpose of improving the working efficiency of the roadheader.

[0005] At present, efficient hard rock tunneling technologies all pre-treat the rock mass and then assist with mechanized cutting and breaking of the rock. In particular, hydraulic fracturing assisted mechanical rock breaking has a more obvious effect. It is a widely used and perfect fracturing technology, and has been successfully applied to shale oil, tight oil and gas and other fields. The conventional hydraulic fracturing excavation method requires first using a drilling rig to drill a hydraulic fracturing borehole into the hard rock, and then moving the hydraulic fracturing equipment to fracture the hard rock mass. After the fracturing is completed, the hydraulic fracturing equipment is removed and the excavation machine is pushed to the working face for excavation. However, this conventional hydraulic fracturing method is time-consuming and labor-intensive, and the hard rock roadway (tunnel) excavation equipment needs to be improved and optimized to achieve the goal of integrating hard rock hydraulic fracturing and excavation. Summary of the invention

[0006] The purpose of the present invention is to provide a method for rapid excavation of coal mine basalt superhard rock, so as to improve the excavation speed and work efficiency of the tunnel, reduce the excavation unit cost, and shorten the well construction period.

[0007] The technical solution adopted by the present invention is a method for rapid excavation of basalt superhard rock in coal mines, comprising the steps of: Step 1: Design the exploratory drilling holes in front of the full-rock excavation working face in the non-coal formation, drill the holes before construction, explore the geological conditions ahead of the excavation, and determine the allowable excavation distance; Step 2: According to the allowable excavation distance, design the number, depth, orientation and inclination of the advance pressure relief drilling holes on the tunnel excavation face; Step 3: Construct the super-hard rock advance pressure relief drilling holes. After all the drilling holes are completed, clean up the site, vacate the drilling equipment, and move the tunnel boring machine into the site; Step 4: Use a multi-purpose excavator to cut and drill the tunnel section and excavate into the basalt super-hard rock layer; Step 5: Statistically analyze the time and efficiency of tunneling in super-hard basalt rock formations under the same progress, and optimize the design of advance pressure relief drilling holes in the tunnel excavation face.

[0008] Preferably, step one, design of exploratory drilling holes for the full-rock excavation working face in non-coal-bearing strata: for horizontal tunnels, the number of exploratory drilling holes shall not be less than 3, the position of one drilling end point shall be controlled at the front of the tunnel, and the other drilling end points shall be controlled at 5-8 meters outside the contour lines of both sides of the tunnel, and the advance distance shall not be less than 10 meters; for inclined tunnels, the number of exploratory drilling holes shall not be less than 3, the position of one drilling end point shall be controlled at the front of the tunnel, and the other drilling end points shall be controlled at a normal distance of 5-8 meters between the top and bottom plates of the tunnel, and the advance distance shall not be less than 10 meters.

[0009] Preferably, step two is the design of advance pressure relief drilling holes for the tunnel excavation face: along the two top corners of the tunnel section, the boundary of the tunnel section, and the middle of the tunnel section, directional pressure relief drilling holes are constructed in the pre-excavation direction, and the design depth of the drilling holes is equal to the allowable excavation distance of the forward drilling holes, the orientation of the drilling holes is consistent with the tunnel excavation orientation, and the inclination of the drilling holes is consistent with the inclination of the tunnel.

[0010] Preferably, in step one, a fast drilling device is used for forward drilling. The device is mainly composed of a crawler hydraulic drilling rig, a crawler clean water pump truck, a backwash filter station, a high-pressure rust-proof drill rod, and a high-energy hydraulic hammer. The equipment uses high-pressure water to drive the high-energy hydraulic hammer piston to reciprocate, generating high-frequency, large impact work to repeatedly impact the drill bit, thereby breaking the hard rock (f>10), and relying on pulsating impact to produce volume crushing instead of conventional rotary cutting. The drilling efficiency in hard rock is more than 3 times that of conventional rotary cutting drilling.

[0011] Preferably, the drilling rig adopts a longitudinal and transverse composite anchoring mechanism; the drilling rig has a propulsion stroke of 1000 mm and a lifting stroke of 500 mm.

[0012] Preferably, the crawler mud pump truck adopts a motor-direct-driven mud pump, the mud pump and the oil pump are connected in series as one, the outlet is equipped with an accumulator and an unloading valve assembly; and it is equipped with a precision backwashing filter station.

[0013] Preferably, the construction method of the step 4 excavator is: S1. First, drill and cut at the upper left corner of the cross section. When the cycle progress specified in the operating procedures is reached, swing left and right to cut out the groove first; S2, open a free surface along the groove, and then sweep down a step to cut the first strip; S3, cutting in strips from top to bottom until the bottom of the tunnel; S4, pick the top and brush the sides to make the tunnel contour smooth and the engineering appearance meet the standards; S5. Use the shovel of the tunnel boring machine to clean the bottom, making the bottom plate flat and free of loose gangue.

[0014] Preferably, in step S1, when the roof is intact, the circulation progress is 3.2 m. If the geological structure or the roof is broken, the circulation progress is reduced to 0.9 m.

[0015] Compared with the prior art, the beneficial effects of the present invention are: by using super-hard rock rapid drilling equipment to construct a large number of pressure-relieving boreholes on the working face to destroy the rock density, the rock integrity of the basalt on the excavation face is reduced, and sufficient free surface for drilling and cutting is increased during the excavation of the comprehensive excavation machine, thereby achieving super-hard rock rapid excavation and improving the tunnel excavation efficiency and single advance level.

[0016] The present invention firstly utilizes a complete set of rapid drilling equipment consisting of a crawler hydraulic drilling rig, a crawler clean water pump truck, a backwashing filter station, a high-pressure rust-proof drill rod, a high-energy hydraulic hammer and other accessories to construct a pressure relief hole in the basalt. The performance from the hole mouth to the hole bottom is not attenuated and is not affected by the inclination of the borehole. The hard rock drilling speed is fast. The high-energy hydraulic hammer ultra-hard rock rapid drilling technology is used to drill a depth of 30m, the total drilling time is 1.65h, the efficiency is 18.18m / h, and the mechanical efficiency is 36.59m / h. The propulsion force required for drilling is small, the rotation speed is low, the straightness of the hole is good, and the hole tilting is effectively prevented. Special high-pressure and rust-proof drilling tools meet high water quality requirements. The construction conditions are environmentally friendly (relative to pneumatic hammers, there is no dust pollution) and are friendly to operators. Among them, high-pressure water is used to drive the high-energy hydraulic hammer piston to reciprocate, generating high-frequency, large impact energy (frequency ≥45Hz, single impact energy ≥150J) to repeatedly hit the drill bit, thereby breaking the hard rock (f>10). The pulsating impact produces volume crushing instead of conventional rotary cutting, and the drilling efficiency in hard rock is more than 3 times that of conventional rotary cutting drilling.

[0017] The present invention solves key technical problems such as the rapid excavation cycle of basalt, innovates the superhard rock excavation process, improves work efficiency and single-advance level, and constructs a superhard rock rapid excavation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flowchart of the method of the present invention; Figure 2 It is a schematic diagram of the layout of the advance drilling holes for the all-rock horizontal tunnel in the non-coal-bearing strata; Figure 3 It is a schematic diagram of the layout of the advance drilling holes for the all-rock inclined roadway in the non-coal-bearing strata; Figure 4 This is the construction flow chart of the tunnel boring machine; Figure 5 This is a schematic diagram of the construction of a tunnel boring machine; Figure 6 This is a schematic diagram of the rapid drilling equipment layout. DETAILED DESCRIPTION

[0019] The present invention will be further explained below in conjunction with the accompanying drawings to facilitate better understanding by those skilled in the art.

[0020] Example 1 like Figure 1-3 As shown, a method for rapid excavation of basalt superhard rock in a coal mine comprises the following steps: Step 1: According to the design of exploratory drilling holes in front of the full-rock excavation working face in non-coal strata, use rapid drilling equipment to construct exploratory drilling holes to explore the geological conditions ahead of excavation and determine the allowable excavation distance.

[0021] Design of exploratory drilling holes for all-rock excavation working face in non-coal strata: for horizontal tunnels, the number of exploratory drilling holes shall not be less than 3, and the position of the final hole point of one drilling hole shall be controlled at the front of the tunnel, and the final hole points of the other drilling holes shall be controlled at 5-8 meters outside the contour lines of the two sides of the tunnel, with an advance distance of not less than 10 meters; for inclined tunnels, the number of exploratory drilling holes shall not be less than 3, and the position of the final hole point of one drilling hole shall be controlled at the front of the tunnel, and the final hole points of the other drilling holes shall be controlled at a normal distance of 5-8 meters between the top and bottom plates of the tunnel, with an advance distance of not less than 10 meters.

[0022] Step 2: Based on the allowable excavation distance, design the number, depth, orientation and inclination of the advance pressure relief drilling holes on the tunnel excavation face.

[0023] Design of advance pressure relief drilling holes on tunnel excavation face: along the two top corners of the tunnel section, the boundary of the tunnel section, and the middle of the tunnel section, directional pressure relief drilling holes are constructed in the pre-excavation direction. The design depth of the drilling holes is equal to the allowable excavation distance of the forward drilling holes, the orientation of the drilling holes is consistent with the orientation of the tunnel excavation, and the inclination of the drilling holes is consistent with the inclination of the tunnel.

[0024] Step three: Use fast drilling equipment to construct super-hard rock advance pressure relief boreholes. After all the drilling holes are completed, clean up the site, vacate the drilling equipment, and enter the site with a tunnel boring machine.

[0025] Specifically, the complete set of ultra-hard rock rapid drilling equipment is mainly composed of a crawler hydraulic drilling rig, a crawler clean water pump truck, a backwashing filter station, a high-pressure rust-proof drill rod, and a high-energy hydraulic hammer. The equipment uses high-pressure water to drive the piston of the high-energy hydraulic hammer to reciprocate, generating high-frequency, large impact energy (frequency ≥ 45Hz, single impact energy ≥ 150J) to repeatedly hit the drill bit, thereby breaking the hard rock (f> 10). Relying on pulsating impact to produce volumetric crushing instead of conventional rotary cutting, the drilling efficiency in hard rock is more than three times that of conventional rotary cutting drilling.

[0026] Furthermore, the above-mentioned drilling rig adopts an overall narrow body all-round structural layout, and the main machine width is 1000mm, which is suitable for handling work in narrow tunnels of small and medium-sized coal mines; the drilling rig integrates horizontal azimuth adjustment, inclination adjustment, and hole opening height adjustment, and all actions are controlled by a hydraulic rotary turntable or cylinder. The inclination adjustment range is -90° to +90°, and the azimuth adjustment range is: 0 to 360°, which can meet the drilling needs of any azimuth and inclination; the drilling rig adopts longitudinal and transverse composite anchoring mechanisms, and the whole machine has high stability during deep hole drilling; the drilling rig has a propulsion stroke of 1000mm and a lifting stroke of 500mm; the drilling rig adopts a large-opening clamp, which can quickly load and unload the hydraulic impactor, shortening the hole opening auxiliary time, with low labor intensity for workers, and is safe and reliable.

[0027] The crawler mud pump truck adopts a motor-driven mud pump. The mud pump and the oil pump are connected in series. The outlet is equipped with an accumulator to reduce pressure pulsation. It is equipped with an unloading valve assembly, which can adjust the pump station flow and operating pressure in real time according to the working conditions of the hydraulic hammer. It is equipped with a hydraulically controlled ball valve to facilitate the switching of the pump truck working conditions, without the need to frequently start and stop the electromagnetic starter, reducing the equipment failure rate and improving work efficiency. It is equipped with a precision backwashing filter station, which can filter the underground water source with a filtration accuracy of 50μm and is installed on the crawler vehicle platform. The mud pump adopts an imported mud pump with the characteristics of small size, compact structure and long life. High-pressure sealed rust-proof drill rods are used. The drill rods have good sealing performance and can be sealed at a pressure of 20MPa to ensure that the power of the hammer head is not attenuated. The inner wall of the drill rod is treated with a special surface anti-rust treatment, which will not rust under various harsh working conditions and prevent rust from entering the sealing surface of the hydraulic hammer and affecting the sealing of the hydraulic hammer.

[0028] Step 4: Use a tunnel boring machine to cut and drill the tunnel section and dig into the super-hard basalt rock layer. The construction method of the tunnel boring machine is: S1. First, drill and cut at the upper left corner of the section. When the cycle progress specified in the operating procedures is reached, swing left and right to cut out the groove first. When the roof is intact, the cycle progress is 3.2m. If the geological structure or roof is broken, the cycle progress is reduced to 0.9m. S2, open a free surface along the groove, and then sweep down a step to cut the first strip; S3, cutting in strips from top to bottom until the bottom of the tunnel; S4, pick the top and brush the sides to make the tunnel contour smooth and the engineering appearance meet the standards; S5. Use the shovel of the tunnel boring machine to clean the bottom, making the bottom plate flat and free of loose gangue.

[0029] Step 5: Statistically analyze the time and work efficiency of conventional excavation methods in super-hard basalt formations under the same progress, and optimize the design of advance pressure relief drilling holes in the tunnel excavation face.

[0030] According to the calculation of 3.2m per cycle, the time taken for one cycle of cutting and drilling is counted and compared with the traditional cutting process of the tunnel boring machine. The data after comparison is used to verify the number of pressure relief holes in the early stage of construction. Therefore, the appropriate number of pressure relief holes can be selected to improve the single-entry level.

[0031] For tunneling in super-hard basalt rock formations, the traditional comprehensive excavation technology consumes an average of 6 cutting teeth per meter of tunnel, each cutting tooth costs 268 yuan, and the average material cost per meter of tunnel is 1,608 yuan, with a monthly single advance of 30 meters. The rapid excavation method for super-hard basalt rock is adopted. After the pressure relief hole is constructed in the basalt, the tunnel drilling is carried out. The monthly single advance is 100 meters, and the single advance efficiency is increased by 3 times. The average cutting tooth is consumed per meter of tunnel, and the economic cost is saved by 1,340 yuan per meter of tunnel, which greatly saves economic costs.

[0032] By comparing the excavation cycles, the rapid excavation method for basalt super-hard rock uses a set of super-hard rock rapid drilling technology equipment to construct pressure relief holes in the basalt and then use a comprehensive excavation machine for excavation. Compared with the traditional excavation technology, the single advance level is increased to 100m / month, and the excavation cycle is shortened by 35%.

[0033] The above-described embodiments are only for describing the preferred implementation of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit and principles of the present invention, various modifications and improvements made by those skilled in the art to the technical solution of the present invention should all fall within the scope of protection determined by the claims of the present invention.

Claims

1. A method for rapid excavation of basalt superhard rock in coal mines, It is characterized in that Includes steps: Step 1: Design the exploratory drilling holes in front of the full-rock excavation working face in the non-coal formation, drill the holes before construction, explore the geological conditions ahead of the excavation, and determine the allowable excavation distance; Step 2: According to the allowable excavation distance, design the number, depth, orientation and inclination of the advance pressure relief drilling holes on the tunnel excavation face; Step 3: Construct the super-hard rock advance pressure relief drilling holes. After all the drilling holes are completed, clean up the site, vacate the drilling equipment, and move the tunnel boring machine into the site; Step 4: Use a multi-purpose excavator to cut and drill the tunnel section and excavate into the basalt super-hard rock layer; Step 5: Statistically analyze the time and efficiency of tunneling in super-hard basalt rock formations under the same progress, and optimize the design of advance pressure relief drilling holes in the tunnel excavation face.

2. A method for rapid excavation of coal mine basalt superhard rock according to claim 1, It is characterized in that The step one is to design the exploratory drilling holes for the full-rock excavation working face in non-coal-bearing strata: for horizontal tunnels, the number of exploratory drilling holes shall not be less than 3, and the position of the final drilling point of one hole shall be controlled in front of the tunnel, and the final drilling points of the other holes shall be controlled 5-8 meters outside the contour lines of the two sides of the tunnel, and the advance distance shall not be less than 10 meters; for inclined tunnels, the number of exploratory drilling holes shall not be less than 3, and the position of the final drilling point of one hole shall be controlled in front of the tunnel, and the final drilling points of the other holes shall be controlled at a normal distance of 5-8 meters between the top and bottom plates of the tunnel, and the advance distance shall not be less than 10 meters.

3. A method for rapid excavation of coal mine basalt superhard rock according to claim 1, It is characterized in that The second step is to design advance pressure relief drilling holes on the tunnel excavation face: along the two top corners of the tunnel section, the boundary of the tunnel section, and the middle of the tunnel section, directional pressure relief drilling holes are constructed in the pre-excavation direction. The design depth of the drilling holes is equal to the allowable excavation distance of the forward drilling holes, the orientation of the drilling holes is consistent with the tunnel excavation orientation, and the inclination of the drilling holes is consistent with the inclination of the tunnel.

4. A method for rapid excavation of coal mine basalt superhard rock according to claim 1, It is characterized in that The step 1 uses a fast drilling equipment to construct a pre-exploration borehole. The equipment is mainly composed of a crawler hydraulic drilling rig, a crawler clean water pump truck, a backwash filter station, a high-pressure rust-proof drill rod, and a high-energy hydraulic hammer. The equipment uses high-pressure water to drive the high-energy hydraulic hammer piston to reciprocate, generating high-frequency, large impact work to repeatedly impact the drill bit, thereby breaking the hard rock.

5. A method for rapid excavation of coal mine basalt superhard rock according to claim 4, It is characterized in that The crawler hydraulic drilling rig adopts longitudinal and transverse composite anchoring mechanism; the drilling rig has a propulsion stroke of 1000mm and a lifting stroke of 500mm.

6. A method for rapid excavation of coal mine basalt superhard rock according to claim 5, It is characterized in that The crawler mud pump truck adopts a motor-driven mud pump. The mud pump and oil pump are connected in series as one. The outlet is equipped with an accumulator and an unloading valve assembly; it is also equipped with a precision backwashing filter station.

7. A method for rapid excavation of coal mine basalt superhard rock according to claim 1, It is characterized in that In the fourth step, the construction method of the excavator is as follows: S1. First, drill and cut at the upper left corner of the cross section. When the cycle progress specified in the operating procedures is reached, swing left and right to cut out the groove first; S2, open a free surface along the groove, and then sweep down a step to cut the first strip; S3, cutting in strips from top to bottom until the bottom of the tunnel; S4, pick the top and brush the sides to make the tunnel contour smooth and the engineering appearance meet the standards; S5. Use the shovel of the tunnel boring machine to clean the bottom and make the bottom plate flat and free of loose gangue.

8. A method for rapid excavation of coal mine basalt superhard rock according to claim 7, It is characterized in that In step S1, when the roof is intact, the circulation progress is 3.2 m. If the geological structure or the roof is broken, the circulation progress is reduced to 0.9 m.

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