Large-section tunnel deep-buried central drainage ditch precision blasting control method

Abstract

The application belongs to the technical field of tunnel construction, and particularly relates to a precise blasting control method for a large-section tunnel deep-buried central drainage ditch, which comprises the following steps: S1: simultaneously blasting and excavating the tunnel inverted arch and the central drainage ditch by using the method of borehole blasting, first marking the positions of the blasting boreholes on the ground uniformly through measurement and marking; S2: drilling boreholes at the positions marked in advance by using a drilling device, controlling the depth of the blast holes according to the actual shape of the inverted arch and the distance between the central drainage ditch and the ground during the drilling process, the depth of the blast holes increasing from both sides of the ground to the center, and the depth of the blast holes at the central drainage ditch being greater than that of the blast holes at other positions; S3: loading explosives into the blast holes according to the pre-designed explosive charge, then installing digital electronic detonators in the blast holes and plugging the blast holes, and carrying out the detonation operation after good related protection measures are taken, so that the tunnel inverted arch and the deep-buried central drainage ditch can be formed by one-time blasting.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel construction, and in particular relates to a precise blasting control method for a deep-buried central drainage ditch in a large-section tunnel. Background Art

[0002] There is generally varying degrees of groundwater distributed in the strata surrounding the tunnel, so a drainage system needs to be set up inside the tunnel. After the groundwater seeps out from the surrounding rock, it flows into the drainage ditches on both sides of the road surface or the central ditch in the middle of the road surface through longitudinal and transverse blind pipes, and finally drains out of the tunnel.

[0003] A Chinese patent, publication number CN113090325A, discloses a method for constructing tunnel drainage ditches. The method involves excavating a tunnel and initially supporting it to a set length, then vertically excavating a jacking pit at the tunnel base to serve as the starting pit. The jacking pit walls and bottom are hardened. Drain holes are installed in the jacking pit walls, and an annular sump is reserved at the bottom of the pit, within which drainage facilities are installed. Reaction blocks and jacking equipment are installed within the jacking pit, which pushes precast concrete pipes in sections along the tunnel's extension to the set length, forming a deep-buried drainage ditch. After the jacking is completed, rebar is tied within the jacking pit, and concrete is poured to seal the jacking pit opening. This method utilizes jacking technology to construct a deep-buried drainage ditch at the tunnel base, avoiding the damage to the tunnel's arch foot, crown, and initial support structure caused by open-cut construction.

[0004] In the current existing technology, during the tunnel construction process, it is usually necessary to add an inverted arch at the bottom of the tunnel. Only after the inverted arch is excavated can the blasting excavation of the deep-buried central drainage ditch be carried out. The process is relatively complicated and seriously affects the construction progress.

[0005] To this end, the present invention provides a precise blasting control method for a deep-buried central drainage ditch in a large-section tunnel. Summary of the Invention

[0006] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a method for precise blasting control of a deep-buried central drainage ditch in a large-section tunnel according to the present invention comprises the following steps:

[0008] S1: The tunnel invert and central drainage ditch are excavated simultaneously by drilling and blasting. First, the locations of the blasting holes are evenly marked on the ground by surveying and marking.

[0009] S2: Drill holes at pre-marked locations using drilling equipment. During the drilling process, the depth of the blastholes is controlled based on the actual shape of the invert and the distance between the central drainage ditch and the ground. The blasthole depth increases from both sides of the ground to the center, and the blasthole depth at the central drainage ditch is greater than that at other locations.

[0010] S3: Load explosives into the blasthole according to the pre-designed charge, then install digital electronic detonators inside the blasthole and seal the blasthole. After taking relevant protective measures, detonation is carried out. This allows the tunnel invert and the deep-buried central drainage ditch to be formed in one blast.

[0011] By drilling holes evenly on the ground and increasing the blasthole depth from both sides of the ground toward the center, the blasthole depth at the center of the ground is controlled to be greater than that at other locations. As a result, an inverted arch and a central drainage ditch can be formed simultaneously after blasting. By using this method, the tunnel inverted arch and the deep-buried central drainage ditch are simultaneously blasted and excavated, so that the tunnel inverted arch and the deep-buried central drainage ditch can be formed by blasting at one time, shortening the drainage ditch operation time, reducing the drainage ditch operation cost, and simplifying the tunnel excavation construction process.

[0012] Preferably, the diameter of the blasthole is set to 60-90 mm, and the spacing between the blastholes is set to 400-500 mm.

[0013] Preferably, the drilling equipment in step S2 includes a vehicle body; a drill barrel is installed at the front end of the vehicle body through a bracket, and the drill barrel passes through the bracket and is arranged vertically; a drill bit is installed inside the drill barrel; a drive assembly is installed inside the drill barrel, and the drill bit is controlled by the drive assembly; the drive assembly can control the drill bit to rotate and move up and down inside the drill barrel; a protective sleeve is fixed to the bottom of the drill barrel, and the drill bit is located inside the protective sleeve during the drilling process; the drilling equipment is moved to a pre-marked position, and the drill bit is driven to rotate and controlled to move downward continuously by the drive assembly, so that the drill bit is drilled into the ground to form a blasthole, and in this process, by setting a protective sleeve, the slag and dust generated during drilling can be blocked inside the protective sleeve, avoiding the splashing of slag to cause harm to the construction workers, and also avoiding the problem of large amounts of dust being raised to pollute the environment.

[0014] Preferably, the protective sleeve is configured as a foldable elastic airbag structure, and the protective sleeve can be retracted; an air supply assembly is installed inside the drill barrel, and the air supply assembly is connected to the protective sleeve through a pipeline; when drilling, air can be supplied to the inside of the protective sleeve through the air supply assembly, thereby causing the protective sleeve to stretch downward and stick to the ground, thereby increasing the degree of blocking stone chips and dust, and further avoiding the problem of stone chips splashing and dust being raised. After drilling is completed, the air supply can be stopped, and the protective sleeve resets and shrinks to avoid affecting the normal movement of the drilling equipment.

[0015] Preferably, an elastic layer is fixed to the inner surface of the protective sleeve, and the elastic layer is made of rubber material; by arranging the elastic layer on the inner side of the protective sleeve, it can play a buffering role, avoiding the problem of splashing slag puncturing the protective sleeve and leaking air, thereby extending the service life of the protective sleeve.

[0016] Preferably, a piston cylinder is fixedly connected to the inside of the drill barrel near the protective sleeve; a piston plate is slidably connected to the inside of the piston cylinder, and the piston plate is made of magnetic material; an overflow hole is opened at the bottom of the drill barrel near the protective sleeve; clean water is added to the inside of the piston cylinder above the piston plate and is connected to the overflow hole through a hose; a magnetic block is fixed to the inside of the drill bit, and the magnetic block can generate attraction to the piston plate when it is close to the piston plate; after the drilling is completed, the driving assembly controls the drill bit to move up and retract into the inside of the drill barrel. Due to the attraction effect of the magnetic block on the piston plate, the drill bit will drive the piston plate to move upward through the magnetic block, and then the piston plate squeezes the water inside the piston cylinder and squeezes it downward through the hose and the overflow hole. The water flowing out of the overflow hole flushes the inner wall surface of the protective sleeve, thereby cleaning the dust and impurities adhering to the surface of the elastic layer, thereby improving the use effect of the protective sleeve.

[0017] Preferably, a water tank is fixedly connected to the inside of the drill barrel, and clean water is added to the water tank; the inside of the piston cylinder above the piston plate is connected to the water tank through a water supply pipe; a one-way valve is provided inside the hose and the water supply pipe; during the drilling operation, when the drill bit moves downward, the piston plate will be driven to move downward synchronously through the magnetic block, and then a negative pressure will be generated inside the piston cylinder above the piston plate, and the water inside the water tank will be sucked into the piston cylinder through the water supply pipe, and when the drill bit moves up, the water inside the piston cylinder will be squeezed downward, so that the cleaning work can be carried out in a cycle.

[0018] Preferably, a water-passing shell is fixedly connected to the bottom of the drill tube near the inner side of the protective sleeve, and the water-passing shell is arranged in a circular shape; the side of the water-passing shell away from the protective sleeve is connected to the overflow hole, and the overflow hole is tangent to the water-passing shell; an opening is provided on the side of the water-passing shell close to the protective sleeve, and there is a gap between the opening and the elastic layer; a rotating column is rotatably connected inside the water-passing shell; a group of blades are evenly distributed on the circumference of the surface of the rotating column, and the blades can contact the elastic layer during the rotation of the rotating column; when water is squeezed downward through the overflow hole, the water flows into the water-passing shell and pushes the blades and the rotating column to rotate, and then the blades continuously move the elastic layer, causing the protective sleeve to shake continuously, and at the same time the water flows through the opening to flush the elastic layer, so that the dust and impurities on the surface of the elastic layer are quickly shaken off, further improving the cleaning efficiency of the elastic layer.

[0019] Preferably, a metal block is fixed to the surface of the elastic layer near the opening of the water flow shell, and the blades can contact the metal block during the rotation of the rotating column; by providing the metal block, the blades will act on the surface of the metal block during rotation instead of directly contacting the elastic layer. Since the elastic layer is a flexible material, this operation can reduce the degree of wear of the elastic layer and avoid the problem of high-frequency scraping of the elastic layer by the blades, which may cause rupture and damage to the elastic layer.

[0020] Preferably, a group of grooves are evenly opened on one side of the metal block close to the water flow shell; a pulley is rotatably connected to the inside of the groove through a rotating shaft, and the pulley protrudes from the surface of the metal block; the blade contacts the metal block during rotation, and by evenly distributing multiple pulleys on the surface of the metal block, the end of the blade will contact the pulley and drive the pulley to rotate, so that rolling friction is formed between the blade and the metal block, thereby reducing the friction resistance between the two, improving the smoothness of the rotation of the rotating column, and also reducing the degree of wear between the end of the blade and the metal block.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The present invention discloses a method for precise blasting control of a deep-buried central drainage ditch in a large-section tunnel. By uniformly drilling holes in the ground and increasing the blasthole depth from both sides of the ground toward the center, the blasthole depth at the center of the ground is controlled to be greater than the blasthole depths at other locations. As a result, an inverted arch and a central drainage ditch can be simultaneously formed after blasting. By using this method, the tunnel inverted arch and the deep-buried central drainage ditch are simultaneously blasted and excavated, so that the tunnel inverted arch and the deep-buried central drainage ditch can be formed by blasting at one time, shortening the drainage ditch operation time, reducing the drainage ditch operation cost, and simplifying the tunnel excavation construction process.

[0023] 2. The present invention describes a method for precise blasting control of a deep-buried central drainage ditch in a large-section tunnel. The method moves the drilling equipment to a pre-marked position, drives the drill bit to rotate through a driving assembly and controls it to move continuously downward, thereby drilling the drill bit into the ground to form a blasthole. In this process, a protective cover is provided to block the slag and dust generated during drilling inside the protective cover, thereby preventing the slag from splashing and causing harm to the construction workers, and also preventing the problem of large amounts of dust being raised and polluting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] Figure 1 It is a schematic flow chart of the method of the present invention;

[0026] Figure 2 It is a construction schematic diagram of the present invention;

[0027] Figure 3 is a perspective view of the drilling apparatus of the present invention;

[0028] Figure 4 It is a schematic structural diagram of the protective cover in the present invention;

[0029] Figure 5 yes Figure 4 A partial enlarged view of the middle part;

[0030] Figure 6 It is a schematic structural diagram of the metal block in the present invention;

[0031] In the figure: vehicle body 1, bracket 2, drill barrel 3, drill bit 4, protective sleeve 5, elastic layer 6, piston cylinder 7, piston plate 8, overflow hole 9, hose 10, magnetic block 11, water storage tank 12, water supply pipe 13, water flow housing 14, opening 15, rotating column 16, blades 17, metal block 18, rotating shaft 19, pulley 20. DETAILED DESCRIPTION

[0032] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0033] like Figures 1 to 2 As shown, a method for precise blasting control of a deep-buried central drainage ditch in a large-section tunnel comprises the following steps:

[0034] S1: The tunnel invert and central drainage ditch are excavated simultaneously by drilling and blasting. First, the locations of the blasting holes are evenly marked on the ground by surveying and marking.

[0035] S2: Drill holes at pre-marked locations using drilling equipment. During the drilling process, the depth of the blastholes is controlled based on the actual shape of the invert and the distance between the central drainage ditch and the ground. The blasthole depth increases from both sides of the ground to the center, and the blasthole depth at the central drainage ditch is greater than that at other locations.

[0036] S3: Load explosives into the blasthole according to the pre-designed charge, then install digital electronic detonators inside the blasthole and seal the blasthole. After taking relevant protective measures, detonation is carried out. This allows the tunnel invert and the deep-buried central drainage ditch to be formed in one blast.

[0037] By drilling holes evenly on the ground and increasing the blasthole depth from both sides of the ground toward the center, the blasthole depth at the center of the ground is controlled to be greater than that at other locations. As a result, an inverted arch and a central drainage ditch can be formed simultaneously after blasting. By using this method, the tunnel inverted arch and the deep-buried central drainage ditch are simultaneously blasted and excavated, so that the tunnel inverted arch and the deep-buried central drainage ditch can be formed by blasting at one time, shortening the drainage ditch operation time, reducing the drainage ditch operation cost, and simplifying the tunnel excavation construction process.

[0038] The diameter of the blastholes is set to 60-90 mm, and the spacing between the blastholes is set to 400-500 mm.

[0039] Example 1

[0040] like Figures 3 to 5 As shown, the drilling equipment in step S2 includes a vehicle body 1; a drill barrel 3 is installed at the front end of the vehicle body 1 through a bracket 2, and the drill barrel 3 passes through the bracket 2 and is arranged vertically; a drill bit 4 is installed inside the drill barrel 3; a driving assembly is installed inside the drill barrel 3, and the drill bit 4 is controlled by the driving assembly; the driving assembly can control the drill bit 4 to rotate and move up and down inside the drill barrel 3; a protective sleeve 5 is fixed to the bottom of the drill barrel 3, and the drill bit 4 is located inside the protective sleeve 5 during the drilling process; the drilling equipment is moved to a pre-marked position, and the drill bit 4 is driven to rotate and controlled to move downward continuously by the driving assembly, so that the drill bit 4 is drilled into the ground to form a blasthole, and in this process, by setting the protective sleeve 5, the slag and dust generated during drilling can be blocked inside the protective sleeve 5, so as to avoid the slag splashing to cause harm to the construction workers, and at the same time, it can also avoid the problem of large amounts of dust being raised to pollute the environment.

[0041] The protective sleeve 5 is configured as a foldable elastic airbag structure, and the protective sleeve 5 can be extended and retracted; an air supply component is installed inside the drill barrel 3, and the air supply component is connected to the protective sleeve 5 through a pipeline; when drilling, air can be supplied to the inside of the protective sleeve 5 through the air supply component, thereby prompting the protective sleeve 5 to stretch downward and stick to the ground, thereby improving the degree of blocking stone chips and dust, and further avoiding the problem of stone chips splashing and dust being raised. After drilling is completed, the air supply can be stopped, and the protective sleeve 5 resets and shrinks to avoid affecting the normal movement of the drilling equipment.

[0042] An elastic layer 6 is fixed to the inner surface of the protective sleeve 5, and the elastic layer 6 is made of rubber material; by arranging the elastic layer 6 on the inner side of the protective sleeve 5, a buffering effect can be played, thereby preventing the protective sleeve 5 from being punctured by flying slag and causing air leakage, thereby extending the service life of the protective sleeve 5.

[0043] A piston cylinder 7 is fixedly connected to the inside of the drill barrel 3 near the protective sleeve 5; a piston plate 8 is slidably connected to the inside of the piston cylinder 7, and the piston plate 8 is made of magnetic material; an overflow hole 9 is opened at the bottom of the drill barrel 3 near the protective sleeve 5; clean water is added to the piston cylinder 7 above the piston plate 8 and is connected to the overflow hole 9 through a hose 10; a magnetic block 11 is fixed to the inside of the drill bit 4, and the magnetic block 11 can generate attraction on the piston plate 8 when it is close to the piston plate 8; after the drilling is completed, the driving assembly controls the drill bit 4 to move up and retract into the drill barrel 3. Due to the attraction effect of the magnetic block 11 on the piston plate 8, the drill bit 4 will drive the piston plate 8 to move upward through the magnetic block 11, and then the piston plate 8 squeezes the water inside the piston cylinder 7 and squeezes it downward through the hose 10 and the overflow hole 9. The water flowing out of the overflow hole 9 flushes the inner wall surface of the protective sleeve 5, thereby cleaning the dust and impurities adhering to the surface of the elastic layer 6, thereby improving the use effect of the protective sleeve 5.

[0044] A water tank 12 is fixedly connected to the inside of the drill barrel 3, and clean water is added to the water tank 12; the inside of the piston cylinder 7 above the piston plate 8 is connected to the water tank 12 through a water supply pipe 13; both the hose 10 and the water supply pipe 13 are provided with a one-way valve; during the drilling operation, when the drill bit 4 moves downward, it will drive the piston plate 8 to move downward synchronously through the magnetic block 11, and then a negative pressure is generated inside the piston cylinder 7 above the piston plate 8, and the water inside the water tank 12 is sucked into the inside of the piston cylinder 7 through the water supply pipe 13, and when the drill bit 4 moves upward, the water inside the piston cylinder 7 is squeezed downward, so that the cleaning work can be carried out in a cycle.

[0045] The bottom of the drill tube 3 is fixedly connected to a water-passing shell 14 near the inner side of the protective sleeve 5, and the water-passing shell 14 is designed to be circular; the side of the water-passing shell 14 away from the protective sleeve 5 is connected to the overflow hole 9, and the overflow hole 9 is tangent to the water-passing shell 14; the side of the water-passing shell 14 close to the protective sleeve 5 is provided with an opening 15, and there is a gap between the opening 15 and the elastic layer 6; a rotating column 16 is rotatably connected inside the water-passing shell 14; a group of blades 17 are evenly distributed on the circumference of the surface of the rotating column 16, and the blades 17 can contact the elastic layer 6 during the rotation of the rotating column 16; when water is squeezed downward through the overflow hole 9, the water flows into the water-passing shell 14 and drives the blades 17 and the rotating column 16 to rotate, and then the blades 17 continuously move the elastic layer 6, causing the protective sleeve 5 to shake continuously, and at the same time, the water flows through the opening 15 to flush the elastic layer 6, so that the dust and impurities on the surface of the elastic layer 6 are quickly shaken off, further improving the cleaning efficiency of the elastic layer 6.

[0046] A metal block 18 is fixedly attached to the surface of the elastic layer 6 near the opening 15 of the water flow housing 14, and the blades 17 can contact the metal block 18 during the rotation of the rotating column 16. By providing the metal block 18, the blades 17 will act on the surface of the metal block 18 during rotation, rather than directly contacting the elastic layer 6. Since the elastic layer 6 is made of a flexible material, this operation can reduce the degree of wear on the elastic layer 6 and avoid the problem of the blades 17 scraping the elastic layer 6 at a high frequency, causing the elastic layer 6 to be broken or damaged.

[0047] Example 2

[0048] like Figure 6 As shown, in contrast to Example 1, another embodiment of the present invention is as follows: a group of grooves are evenly opened on one side of the metal block 18 close to the water-passing shell 14; a pulley 20 is rotatably connected to the inside of the groove via a rotating shaft 19, and the pulley 20 protrudes from the surface of the metal block 18; the blade 17 contacts the metal block 18 during rotation, and by evenly distributing a plurality of pulleys 20 on the surface of the metal block 18, the end of the blade 17 contacts the pulley 20 and drives the pulley 20 to rotate, so that rolling friction is formed between the blade 17 and the metal block 18, thereby reducing the frictional resistance between the two, improving the smoothness of the rotation of the rotating column 16, and also reducing the degree of wear between the end of the blade 17 and the metal block 18.

[0049] Working principle: by drilling holes evenly on the ground and making the depth of the blastholes increase from both sides of the ground to the center, the depth of the blastholes at the center of the ground is controlled to be greater than the depth of the blastholes at other positions, so that an inverted arch and a central drainage ditch can be formed at the same time after blasting. By using this method, the tunnel inverted arch and the deep-buried central drainage ditch are blasted and excavated simultaneously, so that the tunnel inverted arch and the deep-buried central drainage ditch can be blasted and formed at one time, shortening the drainage ditch operation time, reducing the drainage ditch operation cost, and simplifying the tunnel excavation construction process; the drilling equipment is moved to a pre-marked position, and the drill bit 4 is driven by the driving assembly to rotate and control it to move downward continuously, so that the drill bit 4 is drilled into the ground to form a blasthole, and in this process, the protective sleeve 5 is set to prevent the slag generated during drilling from being The dust is blocked inside the protective sleeve 5, so that the splashing of slag does not cause harm to the construction workers, and the problem of large amounts of dust being raised and polluting the environment can also be avoided. When drilling, air can be supplied to the inside of the protective sleeve 5 through the air supply component, thereby causing the protective sleeve 5 to stretch downward and stick to the ground, thereby improving the degree of blocking the slag and dust, and further avoiding the problem of slag splashing and dust being raised. After the drilling is completed, the air supply can be stopped, and the protective sleeve 5 can be reset and contracted to avoid affecting the normal movement of the drilling equipment. By arranging an elastic layer 6 on the inside of the protective sleeve 5, a buffering effect can be played, so that the splashing slag does not puncture the protective sleeve 5 and leaks, thereby extending the service life of the protective sleeve 5. After the drilling is completed, the driving component controls the drill bit 4 to move up and retract into the drill barrel. 3, due to the attraction effect of the magnetic block 11 on the piston plate 8, the drill bit 4 will drive the piston plate 8 to move upward through the magnetic block 11, and then the piston plate 8 squeezes the water inside the piston cylinder 7 and squeezes it downward through the hose 10 and the overflow hole 9. The water flowing out of the overflow hole 9 washes the inner wall surface of the protective sleeve 5, thereby cleaning the dust and impurities adhering to the surface of the elastic layer 6, and improving the use effect of the protective sleeve 5; during the drilling operation, when the drill bit 4 moves downward, it will drive the piston plate 8 to move downward synchronously through the magnetic block 11, and then negative pressure will be generated inside the piston cylinder 7 above the piston plate 8, and the water inside the water tank 12 will be sucked into the piston cylinder 7 through the water supply pipe 13, and when the drill bit 4 moves upward, the water inside the piston cylinder 7 will be squeezed downward to This cycle allows the cleaning process to be carried out in a circular manner. When water is squeezed downward through the overflow hole 9, the water flows into the water-passing housing 14 and drives the blades 17 and the rotating column 16 to rotate. The blades 17 then continuously move the elastic layer 6, causing the protective cover 5 to continuously vibrate. At the same time, the water flows through the opening 15 to flush the elastic layer 6, thereby quickly shaking off dust and impurities on the surface of the elastic layer 6, further improving the cleaning efficiency of the elastic layer 6. By providing the metal block 18, the blades 17 act on the surface of the metal block 18 during rotation, rather than directly contacting the elastic layer 6. Since the elastic layer 6 is made of a flexible material, this operation can reduce the degree of wear on the elastic layer 6 and avoid the problem of the blades 17 scraping the elastic layer 6 at a high frequency, causing the elastic layer 6 to be broken or damaged.During rotation, blades 17 contact metal block 18. By evenly distributing multiple pulleys 20 on the surface of metal block 18, the ends of blades 17 contact and rotate pulleys 20, creating rolling friction between blades 17 and metal block 18. This reduces frictional resistance between them, improves the smoothness of rotation of rotating column 16, and also reduces wear on the ends of blades 17 and metal block 18.

[0050] The above-mentioned front, back, left, right, up and down are all based on the Figure 1 As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0051] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention.

[0052] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for precise blasting control of a deep-buried central drainage ditch in a large-section tunnel, characterized by: The following steps are involved: S1: The tunnel invert and central drainage ditch are excavated simultaneously by drilling and blasting. First, the locations of the blasting holes are evenly marked on the ground by surveying and marking. S2: Drill holes at pre-marked locations using drilling equipment. During the drilling process, the depth of the blastholes is controlled based on the actual shape of the invert and the distance between the central drainage ditch and the ground. The blasthole depth increases from both sides of the ground to the center, and the blasthole depth at the central drainage ditch is greater than that at other locations. S3: Load explosives into the blasthole according to the pre-designed charge, then install digital electronic detonators inside the blasthole and seal the blasthole. After taking relevant protective measures, detonation is carried out. This allows the tunnel invert and the deep-buried central drainage ditch to be formed in one blast. The drilling equipment in step S2 comprises a vehicle body (1); a drill barrel (3) is mounted on the front end of the vehicle body (1) via a bracket (2), and the drill barrel (3) passes through the bracket (2) and is vertically arranged; a drill bit (4) is mounted inside the drill barrel (3); a drive assembly is mounted inside the drill barrel (3), and the drill bit (4) is controlled by the drive assembly; the drive assembly can control the drill bit (4) to rotate and move up and down inside the drill barrel (3); a protective sleeve (5) is fixed to the bottom of the drill barrel (3), and the drill bit (4) is located inside the protective sleeve (5) during the drilling process; A piston cylinder (7) is fixedly connected to the inside of the drill barrel (3) near the protective sleeve (5); a piston plate (8) is slidably connected to the inside of the piston cylinder (7), and the piston plate (8) is made of magnetic material; an overflow hole (9) is opened at the bottom of the drill barrel (3) near the protective sleeve (5); clean water is added to the inside of the piston cylinder (7) above the piston plate (8) and is connected to the overflow hole (9) through a hose (10); a magnetic block (11) is fixedly connected to the inside of the drill bit (4), and the magnetic block (11) can generate an attractive force on the piston plate (8) when it is close to the piston plate (8); A water tank (12) is fixedly connected to the interior of the drill tube (3), and clean water is added to the interior of the water tank (12); the interior of the piston cylinder (7) above the piston plate (8) is connected to the water tank (12) via a water supply pipe (13); both the hose (10) and the water supply pipe (13) are provided with a one-way valve; An elastic layer (6) is fixedly connected to the inner surface of the protective sleeve (5), and the elastic layer (6) is made of rubber material; A water-passing shell (14) is fixedly connected to a position at the bottom of the drill tube (3) near the inner side of the protective sleeve (5), and the water-passing shell (14) is arranged in a circular shape; the side of the water-passing shell (14) away from the protective sleeve (5) is communicated with the overflow hole (9), and the overflow hole (9) is tangent to the water-passing shell (14); an opening (15) is provided on the side of the water-passing shell (14) near the protective sleeve (5), and a gap exists between the opening (15) and the elastic layer (6); a rotating column (16) is rotatably connected inside the water-passing shell (14); a group of blades (17) are evenly distributed on the circumference of the surface of the rotating column (16), and the blades (17) can contact the elastic layer (6) during the rotation of the rotating column (16).

2. The method for precise blasting control of a deep-buried central drainage ditch in a large-section tunnel according to claim 1 is characterized by: The diameter of the blastholes is set to 60-90 mm, and the spacing between the blastholes is set to 400-500 mm.

3. The method for precise blasting control of a deep-buried central drainage ditch in a large-section tunnel according to claim 1 is characterized by: The protective sleeve (5) is configured as a foldable elastic airbag structure, and the protective sleeve (5) is capable of expansion and contraction; an air supply component is installed inside the drill pipe (3), and the air supply component is connected to the protective sleeve (5) through a pipeline.

4. The method for precise blasting control of a deep-buried central drainage ditch in a large-section tunnel according to claim 1 is characterized by: A metal block (18) is fixedly connected to a position on the surface of the elastic layer (6) close to the opening (15) of the water-passing housing (14), and the blades (17) can contact the metal block (18) during the rotation of the rotating column (16).

5. The method for precise blasting control of a deep-buried central drainage ditch in a large-section tunnel according to claim 4 is characterized by: A group of grooves are evenly formed on one side of the metal block (18) close to the water flow housing (14); a pulley (20) is rotatably connected to the inside of the groove via a rotating shaft (19), and the pulley (20) protrudes from the surface of the metal block (18).

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