A construction method for tunnel excavation of a milling machine in a shallow buried water-rich layer of completely weathered granite

Abstract

The present invention provides a construction method for tunnel excavation by a milling machine in a shallow buried water-rich layer of completely weathered granite. The construction method for tunnel excavation by a milling machine in a shallow buried water-rich layer of completely weathered granite includes: using conduits for pre-support, directly pushing the conduits into a pilot hole by a pneumatic rock drill, and grouting the conduits; arranging a drainage device at the face of the tunnel along the advancing direction of the tunnel, and the position of the drainage device is set at the lower right of the face; part of the water flow is discharged through well point dewatering, the seepage phenomenon at the face is weakened, a milling machine is used to excavate the face, and during the construction process, measures such as hanging a mesh and spraying concrete to seal the face and adding the drainage device effectively control the landslide and collapse caused by the extrusion of the surrounding rock at the front of the face. The construction method for tunnel excavation by a milling machine in a shallow buried water-rich layer of completely weathered granite provided by the present invention has the advantages of accelerating the drainage efficiency, improving the construction progress, and ensuring the stability of the face.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel excavation, and in particular to a construction method for excavating a tunnel with a milling machine in a shallow-buried water-rich layer of completely weathered granite. Background Art

[0002] The completely weathered granite water-rich layer has the characteristics of large settlement deformation, large soil moisture content, poor self-stabilization ability, etc. Affected by groundwater, the geological conditions are complex, tunneling is prone to collapse, the safety risk is high, and the construction difficulty is great.

[0003] During the process of excavating a tunnel in the granite water-rich layer, a large amount of accumulated water will seep out from the heading face. In the prior art, the accumulated water is directly drained while excavating with a drainage pipe, resulting in a large overbreak, a large disturbance to the heading face, and the water on the heading face is drained to both sides with a drainage pipe, making the site muddy and the construction efficiency low; to ensure the stability of the surrounding rock of the tunnel in the completely weathered granite water-rich layer, reduce the disturbing force of the stratum during excavation, and improve the safety of tunnel construction, a construction method of using a milling machine in cooperation with well point dewatering is adopted, which effectively solves the overbreak and underbreak and safety of the milling machine in cooperation with manual excavation, reduces the construction cost, improves the construction progress, and ensures the stability of the heading face. However, during the process of using well point dewatering construction, one air compressor is connected to multiple drainage pipes. The internal suction of the drainage pipe farther away from the air compressor is smaller, but the drainage pipe farther away from the hollow pump is closest to the heading face and is installed later, and its internal water content is more, thus reducing the drainage efficiency inside the heading face.

[0004] Therefore, it is necessary to provide a new construction method for excavating a tunnel with a milling machine in a shallow-buried water-rich layer of completely weathered granite to solve the above technical problems. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a construction method for excavating a tunnel with a milling machine in a shallow-buried water-rich layer of completely weathered granite, which can accelerate the drainage efficiency, drain water first and then excavate, improve the construction progress, and ensure the stability of the heading face.

[0006] To solve the above technical problems, the construction method for excavating a tunnel with a milling machine in a shallow-buried water-rich layer of completely weathered granite provided by the present invention includes

[0007] S1: Pre-support the tunnel with conduits. The length of the conduits is 3.5 m, which are arranged in the arch part of the tunnel, and the circumferential spacing is 0.2 m to 0.4 m. Use a pneumatic rock drill to push the conduits into the soil layer through the guide holes, and use a grouting machine to inject ordinary cement-sodium silicate double liquid slurry into the interior of the soil layer through the conduits to form a pre-support;

[0008] S2: Drill holes along the advancing direction of the tunnel on both sides at the bottom of the tunnel heading face, install a drainage device, and introduce a 20 m long drainage pipe into the drilled holes to drain the water inside the rock layer behind the heading face;

[0009] S3: Use a milling excavator to excavate the heading face. For every 30 m of excavation, add a drainage pipe to achieve the purpose of draining water first and then excavating.

[0010] The drainage device includes: a drainage mechanism; the drainage mechanism is arranged at the bottom end of the tunnel; a suction mechanism, the suction mechanism is connected to the drainage mechanism; a precipitation mechanism, the precipitation mechanism is arranged inside the tunnel, and the precipitation mechanism is communicated with the suction mechanism; an adjusting mechanism, the adjusting mechanism is installed at the connection between the suction mechanism and the drainage mechanism, the adjusting mechanism includes a second hose, a bracket, a cylinder, a third hose and a baffle, the side wall of the suction mechanism installs the bracket, and the top end of the bracket installs the cylinder; both ends of the second hose are respectively connected to the side wall of the cylinder and the side wall of the suction mechanism, both ends of the third hose are respectively connected to the top surface of the cylinder and the top end of the drainage mechanism; the inner side wall of the cylinder installs the baffle, and the baffle is slidably connected to the inside of the top end of the second hose; a collection mechanism, the collection mechanism is installed on the side wall of the cylinder.

[0011] Preferably, the drainage mechanism includes the drainage pipe and the filter pipe, the drainage pipe is inclined and arranged at the bottom of both sides of the tunnel heading face, and the end of the drainage pipe installs the filter pipe for sucking water.

[0012] Preferably, the suction mechanism includes an air compressor, a water pipe, a connecting sleeve and a connecting pipe. The air compressor is installed inside the tunnel, the water pipes are symmetrically installed at both ends of the air compressor. One end of one of the water pipes installs the connecting sleeve, and the connecting pipe is installed on the side wall of the connecting sleeve, and the drainage pipe is communicated with one of the connecting pipe and the water pipe.

[0013] Preferably, the side walls of the water pipe and the connecting pipe respectively install the brackets, the bottom end of the second hose is connected to the top end of one of the water pipe and the connecting pipe, and one end of the third hose is connected to the top end of the drainage pipe.

[0014] Preferably, the precipitation mechanism includes a sponge pad, a first hose, a floating ball, a sedimentation tank, a wire mesh and a fixing frame. The sedimentation tank is arranged at the bottom end of the tunnel, and the sponge pad is slidably connected inside the sedimentation tank; the wire mesh is installed on the top surface of the sponge pad, the side wall of another water pipe is slidably connected inside the sponge pad, and the floating ball is installed at the edge of the top surface of the sponge pad; the fixing frame is installed at the center of the top surface of the wire mesh, and the first hose is fixed inside the fixing frame.

[0015] Preferably, the collection mechanism includes a plug, a collection pipe and a connecting plate. The collection pipe is installed on the side wall of the cylinder, the bottom end of the collection pipe is threadedly connected with the plug, and the arc-shaped connecting plate is installed on the inner side wall of the cylinder.

[0016] Preferably, the collecting pipe, the connecting plate and the baffle are located on the same side of the cylinder body, and the inner diameter of the collecting pipe gradually decreases from the bottom end to the top end of the collecting pipe.

[0017] Compared with the related art, the full-weathered granite shallow-buried water-rich layer milling excavator tunnel excavation construction method provided by the present invention has the following beneficial effects:

[0018] The present invention provides a full-weathered granite shallow-buried water-rich layer milling excavator tunnel excavation construction method. Before excavating the tunnel face, the drainage mechanism is first inclined and driven into the lower part of the tunnel face, and the suction mechanism is opened to generate suction inside the drainage mechanism, sucking out the water inside the rock layer below and behind the tunnel face, facilitating the excavation inside the tunnel. When the tunnel is excavated for a certain distance, another drainage mechanism is driven into the tunnel to continue sucking the water inside the tunnel face; when one suction mechanism is connected to multiple drainage mechanisms, during the working process, water enters the inside of the third hose through the drainage mechanism, flows into the inside of the cylinder body, and accumulates continuously inside the cylinder body. The cylinder body is rotatably connected to the support. When the water slowly rises inside the cylinder body, the collection mechanism is installed on one side of the cylinder body, making the weight on one side of the cylinder body large, causing the cylinder body to slowly rotate towards the side with the large weight. The cylinder body drives the baffle to rotate. The baffle slowly rotates inside the second hose, and the gap between the baffle and the second hose increases, continuously increasing the suction inside the second hose, the cylinder body, the third hose and the drainage mechanism, quickly sucking the water inside the tunnel into the inside of the cylinder body. When the cylinder body is filled to 80% of its capacity with water, the center of gravity of the cylinder body moves upward, causing the cylinder body to flip, and the water inside the cylinder body is poured into the inside of the suction mechanism through the second hose. After the water is poured out of the cylinder body, the cylinder body reversely returns to its original position; during the use process, when the water content in the soil layer where the drainage mechanism is inserted is high, the rate of water flowing into the inside of the cylinder body is fast, the time for the water to fill the inside of the cylinder body is short, and the frequency of the cylinder body flipping is fast, thereby increasing the suction inside this drainage mechanism, quickly draining the water inside this soil layer, accelerating the drainage efficiency, improving the construction progress, and ensuring the stability of the tunnel face. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the full-weathered granite shallow-buried water-rich layer milling excavator tunnel excavation construction method provided by the present invention;

[0020] Figure 2 is Figure 1 the cross-sectional view of the tunnel shown;

[0021] Figure 3 is Figure 1 the top view of the sponge pad structure shown in the figure;

[0022] Figure 4 is Figure 1 the enlarged schematic view of the structure at location A shown in the figure;

[0023] Figure 5 is Figure 4 the schematic view of the internal structure of the cylinder shown in the figure;

[0024] Figure 6 is Figure 1 the schematic view of the structure of the drainage mechanism shown in the figure. The reference numerals in the figure are: 1, tunnel; 2, conduit; 3, drainage mechanism; 31, drain pipe; 32, filter pipe; 4, suction mechanism; 41, air compressor; 42, water pipe; 43, connecting sleeve; 44, connecting pipe; 5, sedimentation mechanism; 51, sponge pad; 52, first hose; 53, float; 54, sedimentation tank; 55, wire mesh; 56, fixing bracket; 6, adjusting mechanism; 61, second hose; 62, bracket; 63, cylinder; 64, third hose; 65, baffle; 7, collection mechanism; 71, plug; 72, collection pipe; 73, connecting plate; 100, drainage device.

[0025] Specific embodiments

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 Among them, Figure 1 is the structural schematic diagram of the construction method for the tunnel excavation of the full-weathered granite shallow-buried water-rich layer milling excavator provided by the present invention; Figure 2 is Figure 1 the cross-sectional view of the tunnel shown in the figure; Figure 3 is Figure 1 the top view of the sponge pad structure shown in the figure; Figure 4 is Figure 1 the enlarged schematic view of the structure at location A shown in the figure; Figure 5 is Figure 4 the schematic view of the internal structure of the cylinder shown in the figure; Figure 6 is Figure 1 the schematic view of the structure of the drainage mechanism shown in the figure. The construction method for the tunnel excavation of the full-weathered granite shallow-buried water-rich layer milling excavator includes:

[0028] ​S1: Conduct pre - support using the conduit 3 with a length of 3.5 m. Set it at the arch part in the tunnel, with a circumferential spacing of 0.2 m - 0.4 m. Use a pneumatic rock drill to push the conduit 3 into the hole, and use a grouting machine to inject ordinary cement - water glass double - liquid grout through the conduit 3 into the interior of the soil layer to form pre - support;

[0029] S2: Drill holes along both sides of the bottom of the tunnel face of the tunnel 1 in the advancing direction of the tunnel 1, and set a drainage device 100. Insert the 20 - m - long drain pipe 31 into the drilled holes to drain the water inside the rock layer behind the tunnel face;

[0030] S3: Use a milling machine to excavate the tunnel face. For every 30 - m excavation, add a drain pipe 31; thus achieving the purpose of draining water first and then excavating;

[0031] Among them, the drainage device 100 includes: a drainage mechanism 3; the drainage mechanism 3 is arranged at the bottom end of the tunnel 1; a suction mechanism 4, the suction mechanism 4 is connected to the drainage mechanism 3; a sedimentation mechanism 5, the sedimentation mechanism 5 is arranged inside the tunnel 1, and the sedimentation mechanism 5 is communicated with the suction mechanism 4; a regulating mechanism 6, the regulating mechanism 6 is installed at the connection between the suction mechanism 4 and the drainage mechanism 3. The regulating mechanism 6 includes a second hose 61, a bracket 62, a cylinder 63, a third hose 64 and a baffle 65. The side wall of the suction mechanism 4 installs the bracket 62, and the top of the bracket 62 installs the cylinder 63; both ends of the second hose 61 are respectively connected to the side wall of the cylinder 62 and the side wall of the suction mechanism 4, and both ends of the third hose 64 are respectively connected to the top surface of the cylinder 63 and the top end of the drainage mechanism 3; the inner side wall of the cylinder 63 installs the baffle 65, and the baffle 65 is slidably connected to the inside of the top end of the second hose 61; a collection mechanism 7, the collection mechanism 7 is installed on the side wall of the cylinder 63.

[0032] Specifically, the drainage mechanism 3 includes the drain pipe 31 and the filter pipe 32. The drain pipe 31 is inclined and arranged inside the bottom of both sides of the tunnel face. The end of the drain pipe 31 installs the filter pipe 32 for water absorption, so as to facilitate the inclined insertion of the drain pipe 31 into the soil layer, enabling the water inside the soil layer to be sucked into the inside of the drain pipe 31 through the filter pipe 32 and reducing the moisture in the soil layer.

[0033] Specifically, the suction mechanism 4 includes an air compressor 41, a water pipe 42, a connecting sleeve 43, and a connecting pipe 44. The air compressor 41 is installed inside the tunnel 1. The water pipes 42 are symmetrically installed at both ends of the air compressor 41. One end of one of the water pipes 42 is installed with the connecting sleeve 43, and the connecting pipe 44 is installed on the side wall of the connecting sleeve 43. And the drain pipe 31 communicates with one of the connecting pipe 44 and the water pipe 42. To facilitate the operation of the air compressor 41 to generate suction force inside the water pipe 42, the connecting pipe 44, and the drain pipe 31, so as to facilitate the suction of water into the water pipe 42 and the connecting pipe 44, and to facilitate the use of the connecting sleeve 43 to splice the connecting pipe 44 and increase the length of the connecting pipe 44.

[0034] Specifically, the brackets 62 are respectively installed on the side walls of the water pipe 42 and the connecting pipe 44. The bottom end of the second hose 61 is connected to the top end of one of the water pipe 42 and the connecting pipe 44, and one end of the third hose 43 is connected to the top end of the drain pipe 31. To facilitate the use of the second hose 61 to communicate the cylinder body 63 with one of the water pipe 42 and the connecting pipe 44, and to use the third hose 43 to communicate the cylinder body 63 with the drain pipe 31, so that water sequentially passes through the drain pipe 31, the third hose 53, the cylinder body 63, and the second hose 61 and enters the water pipe 42 and the connecting pipe 44.

[0035] Specifically, the precipitation mechanism 5 includes a sponge pad 51, a first hose 52, a floating ball 53, a sedimentation tank 54, a wire mesh 55 and a fixing bracket 56. The sedimentation tank 54 is provided at the bottom end of the tunnel 1, and the sponge pad 51 is slidably connected inside the sedimentation tank 54; the wire mesh 55 is installed on the top surface of the sponge pad 51, and the side wall of another water pipe 42 is slidably connected inside the sponge pad 51, and the floating ball 53 is installed at the edge of the top surface of the sponge pad 51; the fixing bracket 56 is installed at the center of the top surface of the wire mesh 55, and the first hose 52 is fixed inside the fixing bracket 56. To facilitate the water inside the soil layer to enter the inside of the sedimentation tank 54 through the water pipe 42, the water contacts the sponge pad 51, and the wire mesh 55 is installed on the sponge pad 51 to increase the weight of the sponge pad 51, so that the water penetrates the sponge pad 51 and contacts the first hose 52, and the impurities in the water remain below the sponge pad 51, so that the sediment settles at the bottom end of the sedimentation tank 54. The first hose 52 is connected to a water pump, so that the first hose 52 pumps out the filtered water from the inside of the sedimentation tank 54; as the sediment settles at the bottom end of the sedimentation tank 54, the sediment squeezes the sponge pad 51 upward, and the wire mesh 55 fixes the sponge pad 51 to prevent the sponge pad 51 from bending and shrinking, and penetrates the sponge pad 51 to contact the floating ball 53, so that the floating ball 53 rises, and the floating ball 53 drives the edge of the sponge pad 51 to move, so that the sponge pad 51 slides linearly close to the side wall of the sedimentation tank 54, so that the sponge pad 51 keeps the sediment below the sponge pad 51 and improves the sedimentation effect.

[0036] Specifically, the collection mechanism 7 includes a screw plug 71, a collection pipe 72 and a connecting plate 73. The collection pipe 72 is installed on the side wall of the cylinder body 63, and the bottom end of the collection pipe 72 is threadedly connected to the screw plug 71, and the arc-shaped connecting plate 73 is installed on the inner side wall of the cylinder body 63. To facilitate the sediment to slide downward along the side wall of the cylinder body 63 when the cylinder body 63 is turned over, so that the sediment slides and contacts the connecting plate 73, so that the sediment slides into the inside of the collection pipe 72, reducing the sediment flowing into the inside of the second hose 61, and as the sediment accumulates inside the collection pipe 72, the weight of one end of the cylinder body 63 increases, facilitating the turning over of the cylinder body 63. After using it for a period of time, turn the screw plug 71 to open the collection pipe 72 and clean the sediment inside the collection pipe 72.

[0037] Specifically, the collecting pipe 72, the connecting plate 73, and the baffle 65 are located on the same side of the cylinder body 63. To increase the weight on one side of the cylinder body 63 and facilitate the flipping of the cylinder body 63, the inner diameter of the collecting pipe 72 gradually decreases from the bottom end to the top end of the collecting pipe 72, so as to keep the sediment inside the collecting pipe 72 and prevent the sediment from being discharged from the inside of the collecting pipe 72.

[0038] The working principle of the tunneling construction method for a full-weathered granite shallow buried water-rich layer milling excavator provided by the present invention is as follows: The conduit 3 is directly pushed into the guide hole on the arch of the tunnel 1 by a pneumatic rock drill, and a common cement-sodium silicate double-fluid slurry is injected into the interior of the soil layer through the conduit 3 by a grouting machine to form a pre-support. Before the excavation of the heading face, the drain pipe 31 is obliquely driven into the interior of the tunnel 1 to achieve the purpose of draining water first and then excavating. The second hose 61 is used to connect the cylinder body 63 with the water pipe 42, and the third hose 43 is used to connect the cylinder body 63 with the drain pipe 31. A sedimentation tank 54 is dug out inside the tunnel 1, and the air compressor 41 is connected with the sedimentation tank 54. The device is externally powered, the air compressor 41 is turned on, so that suction is generated inside the drain pipe 31, the water inside the soil layer is sucked into the interior of the drain pipe 31 through the filter pipe 32, the moisture in the soil layer is reduced, the water below the heading face is sucked out, and the milling excavator excavates the heading face. When the tunnel 1 is excavated for a certain distance, another drain pipe 31 is driven into the tunnel interior. The connecting sleeve 43 is used to fix one end of the connecting pipe 44 to one end of the water pipe 42, and the other end of the connecting pipe 44 is sealed. Then, the second hose 61 and the third hose 64 are used to connect the connecting pipe 44 with this drain pipe 31, so that the drain pipe 31 extracts the moisture inside the heading face. As the tunnel is excavated, the connecting pipe 43 is continuously used to connect the connecting pipe 44, so that the connecting pipe 44 is connected with the drain pipe 31, so that the drain pipes 31 are equidistantly installed at the bottom of the tunnel 1 to drain the moisture inside the tunnel 1.When one of the air compressors 41 provides suction for multiple drain pipes 31, during operation, water enters the interior of the third hose 64 through the drain pipe 31, causing the water to flow into the interior of the cylinder 63. The water undergoes preliminary sedimentation inside the cylinder 63 and accumulates continuously inside the cylinder 63. The cylinder 63 is rotatably connected to the bracket 62. When the water level inside the cylinder 62 slowly rises, a collection pipe 72 is installed on one side of the cylinder 62, making the upper side of the cylinder 62 heavier, causing the cylinder 62 to slowly rotate towards the heavier side. The cylinder 62 drives the baffle 65 to rotate. The baffle 65 slowly rotates inside the second hose 61, increasing the gap between the baffle 65 and the second hose 61, and also increasing the gap at the connection between the second hose 61 and the cylinder 63. Continuously increasing the suction of the air compressor 41 on the interiors of the second hose 61, the cylinder 63, the third hose 64, and the drain pipe 31, quickly sucking the water inside the tunnel 1 into the interior of the cylinder 63. Since during the drainage process of the drain pipe 31, the water in the rock formation cannot fill the drain pipe 31 completely, that is, there is a part of water and a part of air in the drain pipe. When the cylinder 63 is filled up faster, it proves that the water-vapor ratio in the drain pipe is larger, that is, the water volume in the rock formation corresponding to this drain pipe is larger. When the interior of the cylinder 63 is filled to 80% full with water, the center of gravity of the cylinder 63 moves upward, causing the cylinder 63 to flip, and the water inside the cylinder 63 pours into the interior of the water pipe 42 and the connecting pipe 44 through the second hose 61. After the water is poured out from the interior of the cylinder 63, the cylinder 63 reverses and resets. During use, when the water content in the soil layer where the drain pipe 31 is inserted is high, the rate at which the water flowing into the interior of one cylinder 63 corresponding to this drain pipe 31 fills up is fast, the time for the water to fill the interior of the cylinder 63 is short, and the flipping frequency of the cylinder 63 is high. The gap at the connection between the second hose 61 and the cylinder 63 is increased multiple times, thereby increasing the suction inside this drain pipe 31, quickly draining the water inside this soil layer, accelerating the drainage efficiency, improving the construction progress, ensuring the stability of the heading face, without the need to increase too many air compressors 41, achieving the effect of voltage division on the drain pipe 31. When the water content in the rock formation corresponding to the drain pipe 31 is large, the suction assigned to this drain pipe 31 is large, effectively saving energy consumption. When the cylinder 63 flips, the sediment slides downward along the side wall of the cylinder 63, making the sediment slide into contact with the connecting plate 73 and then slide into the interior of the collection pipe 72, reducing the sediment flowing into the interior of the water pipe 42 and the connecting pipe 44 and preventing blockage. After using for a period of time, rotate the plug 71 to open the collection pipe 72 and clean the sediment inside the collection pipe 72.The water inside the soil layer enters the inside of the sedimentation tank 54 through the water pipe 42. The water contacts the sponge pad 51. The wire mesh 55 is installed on the sponge pad 51 to increase the weight of the sponge pad 51, so that the water penetrates the sponge pad 51 and contacts the first hose 52. The impurities in the water remain below the sponge pad 51, and the sediment settles at the bottom of the sedimentation tank 54. The first hose 52 is connected to a water pump, so that the first hose 52 pumps out the filtered water from the inside of the sedimentation tank 54, reducing the sedimentation time. As the sediment settles at the bottom of the sedimentation tank 54, the sediment presses the sponge pad 51 upward. The wire mesh 55 fixes the sponge pad 51 to prevent the sponge pad 51 from bending and shrinking. Moreover, the water penetrates the sponge pad 51 and contacts the floating ball 53, causing the floating ball 53 to rise. The floating ball 53 drives the edge of the sponge pad 51 to move, so that the sponge pad 51 slides straight upward close to the side wall of the sedimentation tank 54, causing the sponge pad 51 to leave the sediment below the sponge pad 51, increasing the sedimentation effect and preventing too much sediment from touching the sponge pad 51.

[0039] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied to other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A construction method for tunnel excavation by a milling excavator in a shallow buried water-rich layer of completely weathered granite, characterized in that, Including: S1: Pre-support the tunnel using conduits. The length of the conduits is 3.5 m, which are set at the arch part inside the tunnel, with a circumferential spacing of 0.2 m to 0.4 m. Use a pneumatic rock drill to push the conduits into the soil layer through the pilot holes, and use a grouting machine to inject ordinary cement-sodium silicate double-fluid slurry through the conduits into the interior of the soil layer to form pre-support; S2: Drill holes on both sides at the bottom of the tunnel face along the advancing direction of the tunnel, install drainage devices, and introduce 20-m-long drain pipes into the drilled holes to drain the water inside the rock layer behind the tunnel face; S3: Use a milling machine to excavate the tunnel face. For every 30 m of excavation, add one more drain pipe, so as to achieve the purpose of draining water first and then excavating; Among them, the drainage device includes: A drainage mechanism; the drainage mechanism is arranged at the bottom end of the tunnel; A suction mechanism, the suction mechanism is connected to the drainage mechanism; A precipitation mechanism, the precipitation mechanism is arranged inside the tunnel, and the precipitation mechanism is communicated with the suction mechanism; An adjustment mechanism, the adjustment mechanism is installed at the connection between the suction mechanism and the drainage mechanism. The adjustment mechanism includes a second hose, a bracket, a cylinder, a third hose and a baffle. The bracket is installed on the side wall of the suction mechanism, and the top end of the bracket is installed with the cylinder; both ends of the second hose are respectively connected to the side wall of the cylinder and the side wall of the suction mechanism, and both ends of the third hose are respectively connected to the top surface of the cylinder and the top end of the drainage mechanism; the baffle is installed on the inner side wall of the cylinder, and the baffle is slidably connected to the inside of the top end of the second hose; A collection mechanism, the collection mechanism is installed on the side wall of the cylinder.

2. The tunneling construction method of a full-weathered granite shallow buried water-rich layer milling excavator according to claim 1, characterized in that, The drainage mechanism includes the drain pipe and the filter pipe. The drain pipe is inclined and arranged at the bottom of both sides of the tunnel face, and the end of the drain pipe is installed with the filter pipe for water absorption.

3. The construction method for tunnel excavation by a milling and digging machine in a shallow buried water-rich layer of completely weathered granite according to claim 2, characterized in that, The suction mechanism includes an air compressor, a water pipe, a connecting sleeve and a connecting pipe. The air compressor is installed inside the tunnel, and the water pipes are symmetrically installed at both ends of the air compressor. One end of one of the water pipes is installed with the connecting sleeve, and the connecting pipe is installed on the side wall of the connecting sleeve, and the drain pipe is communicated with one of the connecting pipe and the water pipe.

4. The construction method for tunnel excavation of a full-weathered granite shallow buried water-rich layer milling excavator according to claim 3, characterized in that, Supports are respectively installed on the side walls of the water pipe and the connecting pipe. The bottom end of the second hose is connected to the top end of one of the water pipe and the connecting pipe, and one end of the third hose is connected to the top end of the drain pipe.

5. The tunneling construction method of a full-weathered granite shallow buried water-rich layer milling excavator according to claim 3, characterized in that, The precipitation mechanism includes a sponge pad, a first hose, a floating ball, a sedimentation tank, a wire mesh and a fixing frame. The sedimentation tank is provided at the bottom end of the tunnel, and the sponge pad is slidably connected to the inside of the sedimentation tank; the wire mesh is installed on the top surface of the sponge pad, and the sponge pad is slidably connected to the side wall of the other water pipe, and the floating ball is installed at the edge of the top surface of the sponge pad; the fixing frame is installed at the center of the top surface of the wire mesh, and the first hose is fixed inside the fixing frame.

6. The tunneling construction method of a full-weathered granite shallow buried water-rich layer milling excavator according to claim 1, characterized in that, The collection mechanism includes a plug, a collection pipe and a connecting plate. The collection pipe is installed on the side wall of the cylinder, the bottom end of the collection pipe is threadedly connected with the plug, and the arc-shaped connecting plate is installed on the inner side wall of the cylinder.

7. The construction method for tunnel excavation of a full-weathered granite shallow buried water-rich layer milling excavator according to claim 6, characterized in that, The collecting pipe, the connecting plate and the baffle are located on the same side of the cylinder body, and the inner diameter of the collecting pipe gradually decreases from the bottom end of the collecting pipe towards the top end of the collecting pipe.

Images