A method for cleaning a shield cutter head

Abstract

The application provides a shield cutter cleaning method. The method specifically comprises directly ware-entering for cleaning the inside of the cutter, then disassembling the cover plate at the reserved opening of the screw machine, using a high-pressure water cutter to break the back area of the cutter, using a wind pick to break the area that cannot be broken after drilling and pre-splitting, and finally cleaning the outer arc surface of the cutter and the working face, which comprises removing the last ring of the shield tail pipe, planing an operation surface, then using a water drill to excavate a vertical channel, excavating forward along the tunneling direction to form a horizontal channel at the cutter working face, then drilling left and right along the edge of the cutter below the cutter to clean the edge of the cutter, and finally erecting a jack to assist the cutter to rotate and get rid of the trouble. The application effectively solves the problem that high-strength grouting material cannot be broken in a small and closed underground space, explosives cannot be used, and the cutter cannot quickly get rid of the trouble due to the limited conventional cleaning space.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction, and in particular to a method for cleaning the cutterhead of a TBM. Background Technology

[0002] With the development of urban construction in my country, underground projects such as underground rail transit and river-crossing tunnels are increasing, and the tunnel boring machine (TBM) advance distance is also getting longer. The shield tunneling method is a fully mechanized construction method for modern tunnel construction. Its main mechanical equipment is the TBM, which uses cutting tools to cut soil and break up rocks during tunnel excavation.

[0003] During tunnel boring machine (TBM) construction, multiple areas often operate simultaneously. Grouting may be performed on the ground near the TBM or behind the tunnel lining segments. Alternatively, if the TBM disturbs or damages structures above the cutterhead during excavation, grouting repairs are necessary. During grouting, grout may flow into the cutterhead and become trapped, filling the interior and space between the cutterhead and the soil chamber partition, rendering the cutterhead immobile. If the grout strength is low or if it is promptly detected and cleaned, the cutterhead can rotate using its own driving force. However, if the grout strength is too high, and it is not detected and cleaned before initial setting, the cutterhead is highly likely to become completely blocked and unable to rotate using its own power.

[0004] Currently, there is no specific and effective method for freeing the cutterhead from this situation. When the cutterhead becomes stuck due to this problem, the usual approach is to manually enter the soil chamber, clean the solidified grout, and then try rotating the cutterhead again. However, conventional cleaning methods cannot completely clean cutterheads with small opening ratios, especially TBM cutterheads. Due to the limited space behind the cutterhead, only small pneumatic picks can be used for demolition, and the demolition area is limited by the length of the pneumatic pick's chisel, resulting in a limited cleaning range and many areas that cannot be properly cleaned. For the outer arc surface and the front face of the cutterhead, there is no working space during the cleaning process. If the area after planing is used as the working surface and water-cooled drill is used to break downwards to create sufficient working space to clean the front face and outer arc surface of the cutterhead, it will also be limited by the limited working space at the 6 o'clock position inside the cutterhead. Using a small water-cooled drill to make downward holes and a small pneumatic pick to break to both sides for cleaning is inefficient and cannot meet the time requirements for cleaning work. Therefore, conventional cleaning methods cannot completely remove the slurry that has trapped the cutter head when the slurry has become stuck. Summary of the Invention

[0005] This invention addresses the problems existing in the prior art by providing a method for cleaning the cutterhead of a tunnel boring machine (TBM). This method can efficiently clean the grout material inside the cutterhead, the back plate of the cutterhead, the front face of the cutterhead-working face, and the outer arc surface of the cutterhead, enabling the cutterhead to quickly free itself and proceed with normal tunneling, thereby improving the efficiency of TBM construction, saving construction time, and reducing construction costs.

[0006] To achieve the above-mentioned technical objectives, the present invention provides a method for cleaning a tunnel boring machine cutterhead, specifically including the following steps:

[0007] S1. Cleaning the inside of the cutter head: Directly enter the inside of the cutter head and use one or more of the following tools, such as an air gun, pneumatic pick, and water drill, to break up and clean the grout blocks in each compartment; at the same time, clean the inside of the roller cutter box in the area covered by the grouting material;

[0008] S2. Cleaning the back of the cutterhead: Remove the cover plate at the pre-reserved opening of the screw conveyor, and use a high-pressure water jet to break up the grout accumulated between the back of the cutterhead and the soil chamber partition. During the high-pressure water jet breaking process, add diamond powder to the water flow to increase the cutting force of the water jet. The breaking range of the high-pressure water jet is within 2 meters around the pre-reserved opening of the screw conveyor. The remaining solidified grout outside the 2-meter area around the pre-reserved opening of the screw conveyor is first drilled with an extended drill rod water-cooled drill, then pre-cracked with a hydraulic splitting rod, and finally broken up with an extended drill bit of a pneumatic pick. All the broken debris is transported out of the tunnel.

[0009] S3. Cleaning of the outer arc surface of the cutter head and the front surface of the cutter head - the working face:

[0010] (1) Remove the last ring segment of the shield tail and excavate an open working face at the shield tail;

[0011] (2) Use a large water-cooled drill to excavate downwards at the shield tail working face to form a vertical channel with a diameter greater than 1.5m;

[0012] (3) After the vertical passage is excavated, the horizontal passage is formed by excavating forward along the tunneling direction through the vertical passage to the cutterhead face;

[0013] (4) After the horizontal channel is excavated in step (3), water drills are used to drill holes and cores to remove all the concrete on the edge of the cutter head from the cutter head directly below the cutter head. Then, a pneumatic pick with an extended rod is used to break the grouting material on the front of the cutter head directly below the cutter head to complete the cutter head cleaning work.

[0014] S4. After the cutterhead cleaning is completed, set up a jack at the reserved opening of the auger on the back of the cutterhead to assist the cutterhead in rotating. If the cutterhead can rotate, the excavation is successful. If it cannot move, continue to dig to both sides below the front shield until the trapped area is cleaned up.

[0015] The preferred technical solution of the present invention is as follows: In step S1, the cleaning of the cutter box of the grouting material-wrapped area is specifically carried out by breaking the grout inside the cutter box with a pneumatic pick and removing the cutter, so as to avoid the solidified grout flowing into the cutter box from exerting tangential force on the cutter disc when the cutter disc rotates.

[0016] The preferred technical solution of the present invention is as follows: In step S2, an extended drill rod is used to drill a water-powered drill with a diameter of 5cm. The broken debris is bagged and then transported out of the tunnel by a battery-powered vehicle.

[0017] The preferred technical solution of the present invention is as follows: In step (1) of step S3, a 1.8*1.8m open working surface is excavated at the 6 o'clock position of the shield tail.

[0018] A further technical solution of the present invention: In step (2) of step S3, the diameter of the vertical channel is 1.6 to 2m; the excavation of the vertical channel is specifically carried out in two stages by drilling downwards through a water-powered drill at the tail of the shield. After drilling the water-powered drill, the rocks are pre-cracked by a splitting machine to break the large rocks into small pieces and transport them to the outside.

[0019] A further technical solution of the present invention: the excavation length of the horizontal channel in step (3) of step S3 is 8-9m; the specific excavation of the horizontal channel is carried out by building a support frame with steel pipes after the vertical channel working face is completed at the shield tail, and then a large water-powered drill is used to drill holes in the direction of excavation until it reaches the bottom of the cutterhead. After drilling holes around the perimeter, several holes are drilled in the middle, and then a rock splitter is used to break the large rocks into small pieces and remove them.

[0020] The preferred technical solution of the present invention is as follows: in step (3) of step S3, 32M Tefeng A-2 type teeth are welded onto the steel cylinder of the water-grinding drill by high-frequency induction heating.

[0021] The preferred technical solution of the present invention is as follows: In step (4) of step S3, after the working surface reaches directly below the cutter head, the area directly below the cutter head is hollowed out by drilling with a 165mm drill bit at an angle to both sides and upwards, with a single drilling depth of 45-60cm and a channel diameter of 1-1.2 meters, forming a channel with a diameter of 1-1.2 meters. After the channel is formed, the remaining residue on the edge of the cutter head is cleaned by using a pneumatic pick and a pneumatic pick reinforced long drill rod.

[0022] The preferred technical solution of the present invention is as follows: In step S4, two 200-ton jacks are installed at the reserved opening position of the screw conveyor on the back of the cutter head to assist the rotation of the cutter head.

[0023] The beneficial effects of this invention are:

[0024] (1) This invention uses high-pressure, high-speed water flow and quartz sand to achieve high-efficiency breaking of slurry blocks in a limited space, solving the problem of the narrow space on the back of the cutter head that cannot be cleaned normally.

[0025] (2) The present invention opens a channel forward at the tail of the shield to reach the bottom of the cutter head to complete the cleaning, which solves the problem of low work efficiency due to limited space when drilling downward inside the cutter head to obtain the working surface. It can efficiently clean the slurry on the front and outer arc surfaces of the cutter head.

[0026] (3) During the process of the cutter head getting out of trouble, the present invention can also set up a central positioning bracket to set up multiple water drills to move forward synchronously to make holes; in response to the wear and consumption of water drill bits, the Li Yidao 32M Tefeng A-2 type feed 15mm-3 cutter head is used, and the water drill teeth are inserted by high frequency induction heating and powder welding, which improves the remanufacturing speed of water drills and ensures the construction progress.

[0027] (4) The present invention sets up two 200-ton jacks at the reserved opening position of the screw conveyor on the back of the cutter head to assist the rotation of the cutter head, which reduces the amount of grout cleaning work and shortens the extrication cycle.

[0028] This invention can efficiently clean the grout material inside the cutterhead, the back plate of the cutterhead, the front face of the cutterhead-working face, and the outer arc surface of the cutterhead, enabling the cutterhead to quickly escape and proceed with normal tunneling, improving the efficiency of shield tunneling, saving construction time, and reducing construction costs. It effectively solves the problem that explosives cannot be used to break and clean high-strength grout material in narrow and confined underground spaces, and that conventional cleaning tools are difficult to use due to space constraints, thus preventing the cutterhead from quickly escaping. Attached Figure Description

[0029] Figure 1 This is a frontal schematic diagram of the cutterhead encasing the grout in the embodiment;

[0030] Figure 2 This is a side view of the cutterhead encasing the grout in the embodiment;

[0031] Figure 3 This is a schematic diagram of the excavation channel from the tail of the shield to the cutterhead in the embodiment;

[0032] Figure 4 This is a schematic diagram of the shield tail excavating downwards in the embodiment;

[0033] Figure 5 This is a cross-sectional view of the horizontal forward excavation in the embodiment;

[0034] Figure 6 This is a schematic diagram showing the distance direction from the shield tail to the cutterhead excavation channel in the embodiment;

[0035] Figure 7 This is a schematic diagram of cleaning directly below the cutter head in the embodiment.

[0036] In the diagram: 1—Cuter head; 2—Grouting area; 3—Horizontal channel; 4—Vertical channel; 5—Water-ground drilling hole; 6—Working space directly below the cutter head. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments. The drawings are all embodiments, drawn in a simplified manner, and are only used to clearly and concisely illustrate the purpose of the embodiments of the present invention. The technical solutions shown in the drawings below are specific solutions of the embodiments of the present invention and are not intended to limit the scope of the claimed invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In this example, after the completion of the 396th ring tunneling on the right line of Zhenfeng Mountain, the tunnel boring machine (TBM) was shut down to facilitate grouting within the trolley for the water diversion tunnel. The bottom layer of the TBM's shutdown location consisted of slightly weathered tuff with a rock strength of 98 MPa and a burial depth of 167 meters. On the second day after the shutdown, the operator prepared to rotate the cutterhead to drain the water. However, the cutterhead torque reached its maximum limit of 19,500 kN·m, preventing it from rotating. After the water inside the chamber was pumped out, it was discovered that the lower 2 meters of the cutterhead were covered by grout (C50, initial setting time 3 hours, final setting time 10 hours, final setting strength 50 MPa). Figure 1 and Figure 2 As shown. The cutterhead used in this project is the DZ771 cutterhead, with a maximum excavation diameter of 8640 mm, covering an area approximately 2 meters deep and 7.36 meters wide. Figure 2 The cutterhead shown contains approximately 11 m³ of grout, and the volume between the back of the cutterhead and the soil chamber partition is approximately 3 m³. 3 The volume of the face of the tunnel face and the front of the cutterhead is approximately 1.5m³. 3 .

[0039] Because the area enclosed by the cutterhead is located at the bottom of the cutterhead and between the back of the cutterhead and the soil chamber partition, the internal space of the cutterhead is relatively ample, and a relatively rich variety of tools can be used. However, cleaning the slurry accumulated between the back of the cutterhead and the soil chamber wall is difficult due to the limited space; only a small pneumatic pick can be used for this purpose, and the cleaning area is limited by the length of the pick's rod. This leaves 0.5m above and 2.5m to the left and right, which cannot be cleaned. There is no working space on the outer arc surface of the cutterhead and the front of the cutterhead-face during the initial operation. If, after cleaning the inside of the cutterhead, the No. 8 bucket is planed out, and the planed area is used as a working surface to break downwards with a water-cooled drill to create sufficient working space for cleaning the front and outer arc surface of the cutterhead, this would be limited by the narrow working space at the 6 o'clock position inside the cutterhead. Using a small water-cooled drill to drill downwards and a small pneumatic pick to break out to the sides is inefficient and cannot meet the time requirements for the cleaning work.

[0040] In response to the above situation, the project team used the method described in this invention to clean the cutter head. The specific cleaning process is as follows:

[0041] S1. Inside the cutter head, air guns, pneumatic picks, and water drills are used to break up the slurry blocks in each compartment to reduce the mass imbalance of the cutter head caused by solidification. At the same time, the cutter box in the wrapped area is cleaned, and the slurry accumulated in the cutter box is broken up by pneumatic picks to remove the cutter cutters, so as to prevent the solidified slurry flowing into the cutter box from exerting tangential force on the cutter head when it rotates.

[0042] S2. Cleaning the back of the cutterhead: Remove the cover plate at the pre-reserved opening of the screw conveyor, and use a high-pressure water jet to break up the grout between the back of the cutterhead and the soil chamber partition. Then, manually bag the broken debris and transport it to an electric vehicle to be transported out of the tunnel. During the use of the high-pressure water jet, an appropriate amount of corundum is added to the water flow to increase the cutting force of the water jet and break up the grout. After the grout is broken up within a 2-meter radius around the pre-reserved opening of the screw conveyor, the breaking effect gradually weakens as it moves towards the edge of the cutterhead and cannot meet the requirements. Therefore, a 5cm hole is first drilled in the remaining solidified grout using an extended drill rod water-cooled drill, then a hydraulic splitting rod is used for pre-splitting, and finally, an extended drill bit is used to break it up. The grout is then manually cleaned and transported out.

[0043] S3. Cleaning of the outer arc surface of the cutter head and the front of the cutter head - the working face;

[0044] (1) Remove the last ring segment of the shield tail, and then excavate a 1.8*1.8m free face at the 6 o'clock position of the shield tail.

[0045] (2) At the shield tail free face, use a large water-cooled drill to excavate downwards for 1.8m to form a vertical passage, such as... Figure 3 As shown; the excavation of the vertical tunnel is specifically carried out in two stages by drilling downwards using a water-cooled drill at the tail of the shield. A schematic diagram of the excavation is shown below. Figure 4 As shown ( Figure 4 The marked 5 in the text refers to the holes made by the water-grinding drill downwards. After the water-grinding drill is completed, the stone is pre-cracked by the splitting machine. When the splitting rod is pressed, the large stone in the middle is broken off. The large stone is then broken into smaller pieces and transported to the outside.

[0046] (3) Figure 3 As shown, after the vertical tunnel is excavated, the tunnel is excavated forward along the tunneling direction until the cutterhead face is reached, forming a horizontal tunnel. The excavation length is 8m, and the excavation distance is as follows. Figure 6 As shown; the specific excavation of the horizontal passage is carried out after the vertical passage working face is excavated at the tail of the shield. A support frame is erected using steel pipes to support a large water-powered drill bit to drill holes in the direction of excavation until it reaches below the cutterhead. A schematic diagram of the horizontal forward excavation is shown below. Figure 5 As shown ( Figure 5The circles indicated by reference numeral 5 in the attached diagram are all holes drilled forward by the water-grinding drill. After drilling around the perimeter, several holes are drilled in the center. Then, a splitting rod is used to squeeze the large rock in the center, which is broken into smaller pieces and removed. The bottom layer of the excavation is slightly weathered tuff with a strength of 98MPa. During the drilling process of the large water-grinding drill, the drill bit wears a lot. The drill barrel is repaired on-site by welding 32M Tefeng A-2 type teeth to the water-grinding drill barrel using high-frequency induction heating.

[0047] (4) After the horizontal channel is excavated in step (3), such as Figure 7 As shown, water-cooled drills were used to drill holes and core samples from the cutterhead directly below it, moving along the edge to the left and right to remove all the concrete from the cutterhead edge. This provided ample working space and surface for the cutterhead cleaning work. After reaching the area directly below the cutterhead, holes were drilled diagonally upwards and to the sides using 165mm drill bits, with a single hole depth of 50cm and a channel diameter of 1.1 meters, to hollow out the area directly below the cutterhead and form a 1.1-meter diameter channel. After forming the channel, a pneumatic pick and a reinforced long drill rod were used to clean up any remaining debris from the cutterhead edge.

[0048] S4. Set up two 200-ton jacks at the reserved opening on the back of the cutterhead to assist the cutterhead in rotating. If the cutterhead can rotate, the escape is successful. If it cannot move, continue to dig to both sides below the front shield until the trapped area is cleared.

[0049] In this embodiment, the cutterhead removal was completed on December 15, 2022. The internal slurry was completely removed, and the cutterhead back plate, the front face of the cutterhead, and the outer arc surface of the cutterhead were all cleared. At 22:44 that evening, driven by the cutterhead motor and pushed by the auxiliary jacks at the auger, the cutterhead began to rotate. After the test rotation, the auxiliary jack supports at the bottom of the cutterhead were removed. At 00:40 on December 16, the cutterhead rotated once in both directions. Trial excavation began at 01:56. By 01:17, the cumulative advance was 75mm, the cutterhead speed was 3.6 r / min, the thrust gradually increased from 20000kN to 45000kN, and the cutterhead torque was 1600kNm. After the installation of the props and the restoration of the shield tail, excavation began at 21:00 on December 19. The excavation speed was continuous, and the thrust gradually decreased to normal values, indicating a successful extrication.

[0050] In this embodiment, high-pressure, high-velocity water flow and quartz sand were used to efficiently break up slurry blocks in a limited space. However, as the breaking distance increased, the operational intensity decreased significantly, failing to meet the cleaning requirements. Drilling downwards inside the cutterhead to obtain the working surface was inefficient due to space constraints. The final solution involved creating a channel forward from the shield tail to reach directly below the cutterhead for cleaning. A central positioning support was installed, allowing multiple water-grinding drills to simultaneously drill holes. To address the wear and tear of the water-grinding drill bits, the team used a Li Yidao 32M Tefeng A-2 type feed 15mm-3 cutter head. High-frequency induction heating and powder welding were used to insert the drill teeth, improving the remanufacturing speed of the water-grinding drill and ensuring the construction progress.

[0051] The above description is merely one embodiment of the present invention, and while it is detailed and specific, it should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for cleaning a tunnel boring machine cutterhead, characterized in that, Specifically, the following steps are included: S1. Cleaning the inside of the cutter head: Directly enter the inside of the cutter head and use one or more of the following tools, such as an air gun, pneumatic pick, and water drill, to break up and clean the grout blocks in each compartment; at the same time, clean the inside of the roller cutter box in the area covered by the grouting material; S2. Cleaning the back of the cutterhead: Remove the cover plate at the pre-reserved opening of the screw conveyor, and use a high-pressure water jet to break up the grout accumulated between the back of the cutterhead and the soil chamber partition. During the high-pressure water jet breaking process, add diamond powder to the water flow to increase the cutting force of the water jet. The breaking range of the high-pressure water jet is within 2 meters around the pre-reserved opening of the screw conveyor. The remaining solidified grout outside the 2-meter area around the pre-reserved opening of the screw conveyor is first drilled with an extended drill rod water-cooled drill, then pre-cracked with a hydraulic splitting rod, and finally broken up with an extended drill bit of a pneumatic pick. All the broken debris is transported out of the tunnel. S3. Cleaning of the outer arc surface of the cutter head and the front surface of the cutter head - the working face: (1) Remove the last ring segment of the shield tail and excavate an open working face at the shield tail; (2) Use a large water-cooled drill to excavate downwards at the shield tail working face to form a vertical channel with a diameter greater than 1.5m; (3) After the vertical passage is excavated, the horizontal passage is formed by excavating forward along the tunneling direction through the vertical passage to the cutterhead face; (4) After the horizontal channel is excavated in step (3), water drills are used to drill holes and cores along the edge of the cutter head to remove all the concrete on the edge of the cutter head. Then, the grouting material on the front of the cutter head is broken up by a pneumatic pick with an extended rod to complete the cutter head cleaning work. S4. After the cutterhead cleaning is completed, set up a jack at the reserved opening of the auger on the back of the cutterhead to assist the cutterhead in rotating. If the cutterhead can rotate, the excavation is successful. If it cannot move, continue to dig to both sides below the front shield until the trapped area is cleaned up.

2. The method for cleaning a tunnel boring machine cutterhead according to claim 1, characterized in that: In step S1, the cleaning of the cutter box in the area covered by the grout is specifically carried out by using a pneumatic pick to break up the grout inside the cutter box and remove the cutter head, so as to prevent the solidified grout from flowing into the cutter box from exerting tangential force on the cutter head when it rotates.

3. The method for cleaning a tunnel boring machine cutterhead according to claim 1, characterized in that: In step S2, an extended drill rod and a water-powered drill with a hole diameter of 5cm are used. The broken debris is bagged and transported out of the tunnel by an electric vehicle.

4. The method for cleaning a tunnel boring machine cutterhead according to claim 1, characterized in that: In step (1) of step S3, a 1.8*1.8m open working surface is excavated at point 6 on the shield tail.

5. The method for cleaning a tunnel boring machine cutterhead according to claim 1, characterized in that: In step (2) of step S3, the diameter of the vertical channel is 1.6 to 2m. The excavation of the vertical channel is carried out in two stages by drilling downwards through a water-powered drill at the tail of the shield. After drilling the water-powered drill, the rocks are pre-cracked by a splitting machine to break the large rocks into smaller pieces and transport them to the outside.

6. The method for cleaning a tunnel boring machine cutterhead according to claim 1, characterized in that: In step (3) of step S3, the excavation length of the horizontal channel is 8-9m. The specific excavation of the horizontal channel is carried out by building a support frame with steel pipes after the vertical channel working face is completed at the shield tail. The large water-powered drill is used to drill holes in the direction of excavation until it reaches the bottom of the cutterhead. After drilling holes around the perimeter, several holes are drilled in the middle. Then, a rock splitter is used to break the large rocks into small pieces and remove them.

7. The method for cleaning a tunnel boring machine cutterhead according to claim 1, characterized in that: In step (4) of step S3, after the working surface reaches directly below the cutter head, the area directly below the cutter head is hollowed out by drilling with a 165mm drill bit at an angle to both sides and upwards, with a single drilling depth of 45-60cm and a channel diameter of 1-1.2 meters, forming a channel with a diameter of 1-1.2 meters. After the channel is formed, the remaining residue on the edge of the cutter head is cleaned up by using a pneumatic pick and a pneumatic pick reinforced long drill rod.

8. The method for cleaning a tunnel boring machine cutterhead according to claim 1, characterized in that: In step S4, two 200-ton jacks are installed at the reserved opening on the back of the cutter head to assist in the rotation of the cutter head.

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