A method for mud water shield tunneling through boulders without pressure and changing cutter by using precipitation and dark pier

Abstract

The application provides a method for mud water shield tunneling through boulder group without pressure obstacle clearing and cutter changing by using precipitation and hidden pier, which comprises the following steps: step 1) according to tunnel mileage, geological conditions and cutter wear period, presetting a hidden pier reinforcement area in the stratum, and arranging a plurality of precipitation wells along the two sides of the tunnel; step 2) formulating a coordinated plan; step 3) according to different working conditions, executing different operation processes: planned maintenance: when the shield machine normally tunnels to the hidden pier reinforcement area, performing overall maintenance; emergency obstacle clearing: when the shield machine tunnels in the non-hidden pier reinforcement area and the cutter fails due to encountering boulders, starting the precipitation well to reduce the pressure, and performing emergency maintenance; after the maintenance is completed, the shield machine resumes normal tunneling. According to the maintenance mileage, the hidden pier reinforcement area is preset to assist the planned maintenance, and the precipitation well is arranged to actively optimize the emergency obstacle clearing when the boulders are stuck, so that the reliability and safety of the shield operation are ensured.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) engineering technology, specifically to a method for clearing obstacles and changing cutterheads without pressure when using dewatering and hidden piers to enable slurry TBMs to pass through boulders. Background Technology

[0002] In the construction of urban rail transit, underground utility tunnels, and water diversion tunnels, the shield tunneling method is widely used due to its advantages such as safety and efficiency. However, shield tunneling often encounters complex geological conditions, among which, traversing boulders in water-rich sand layers is a global challenge. The boulders are strong and randomly distributed, which can easily lead to severe wear and breakage of the shield machine cutters, or even jamming of the cutterhead, making tunneling impossible.

[0003] Currently, the conventional methods for dealing with isolated rock formations mainly include:

[0004] (1) Ground pre-reinforcement and blasting clearing: Large-scale ground exploration and full-section reinforcement are required, followed by blasting through ground drilling to remove boulders. This method is inefficient, costly, and has a significant environmental impact when used in urban areas, making it difficult to guarantee the construction period.

[0005] (2) Pressurized entry operation of tunnel boring machine: When the tunnel boring machine reaches the cutter replacement mileage in the water-rich stratum and needs to replace the cutter, it is necessary to maintain high air pressure in the chamber to balance the external water and soil pressure. The operators need to work in a high-pressure environment, which is extremely risky, has strict requirements on equipment and personnel, low work efficiency, and poses huge safety hazards.

[0006] Therefore, how to enable tunnel boring machines to safely and efficiently traverse water-rich boulder strata without large-scale ground pretreatment and high-risk pressurized operations has become a pressing technical challenge in this field. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for clearing obstacles and replacing cutterheads without pressure by using dewatering and hidden blocks to facilitate the smooth progress of the tunnel boring machine (TBM) through a group of boulders. This method involves setting up a pre-defined reinforcement zone for hidden blocks based on the maintenance mileage to assist in planned maintenance, and setting up dewatering wells to proactively optimize emergency clearing when boulders become stuck.

[0008] To achieve the above objectives, the technical solution adopted by this invention is: a method for clearing obstacles and changing cutterheads without pressure using precipitation and concealed piers to achieve slurry shield tunneling through a group of isolated boulders, comprising the following steps:

[0009] Step 1) Calculate the planned maintenance mileage based on the tunnel mileage, geological conditions and tool wear cycle, and pre-set a hidden pier reinforcement zone in the strata at the end of or within the planned maintenance mileage. The hidden pier reinforcement zone forms a closed water-proof wall. Arrange several dewatering wells along both sides of the tunnel.

[0010] Step 2) Develop a collaborative plan: Develop a collaborative work plan, which includes determining the mileage of each underground pier, the number of each dewatering well, the triggering conditions for planned maintenance and emergency clearing, the dewatering operation time, the entry operation process, and the communication methods between the surface and underground.

[0011] Step 3) Execute different work procedures according to different working conditions:

[0012] Planned maintenance: When the tunnel boring machine is tunneling normally to the reinforced area of ​​the pier, according to the triggering conditions set in step 2), the cutterhead is cut into the water-isolated body of the pier to isolate the face in front of the cutterhead from the high water pressure outside. After confirming that the pressure inside the chamber is safe, the workers enter the chamber to carry out a comprehensive maintenance.

[0013] Emergency Clearance: When the tunnel boring machine encounters a boulder and discovers a cutter malfunction during tunneling in a non-reinforced area, the triggering conditions set in step 2) are used to determine the number of the dewatering well to be opened based on the current mileage and immediately start dewatering. In a short time, the water level near the machine head is lowered to below the center line of the cutterhead or to a preset safe position. After the water pressure stabilizes and reaches normal pressure, the workers enter the chamber to carry out emergency repairs.

[0014] Step 4) After the planned maintenance or emergency clearing operation is completed and safety is confirmed by inspection, the dewatering operation is adjusted or stopped, and the tunnel boring machine resumes normal tunneling.

[0015] Preferably, during planned maintenance, if the residual water pressure inside the cutterhead-reinforced block still exceeds the preset value, the dewatering wells near the block reinforcement area will be activated to further reduce the residual water pressure.

[0016] Preferably, the reinforced area of ​​the concealed pier is constructed using interlocking piles or mixing piles to form a closed water-proof wall, the extent of which must completely enclose the tunnel excavation section and leave a safety margin.

[0017] Preferably, the location and number of precipitation wells are determined based on hydrogeological conditions to enable the rapid formation of precipitation funnels.

[0018] Preferably, during planned maintenance, staff enter the warehouse to perform a comprehensive inspection, replacement, and maintenance of the cutting tools.

[0019] Preferably, during emergency clearance operations, staff enter the warehouse to remove stuck boulders or replace damaged tools.

[0020] Preferably, ground staff control the working status of the dewatering wells, underground staff complete the maintenance inside the well, and ground and underground staff cooperate through communication.

[0021] This invention has outstanding substantive features and significant progress compared to the prior art. Specifically, this invention has the following advantages:

[0022] 1. Extremely high safety: It fundamentally avoids high-risk pressurized entry operations. All entry operations are carried out in normal pressure or safe low-pressure environments, which greatly protects the life safety of operators and reduces occupational risks such as gas poisoning and decompression sickness.

[0023] 2. High construction efficiency: The normal pressure working environment makes operations such as cutterhead replacement and obstacle clearing simpler and faster, without the need for a long pressurization and depressurization process. Personnel working time is not limited, which can greatly shorten downtime and improve overall tunneling efficiency.

[0024] 3. Significant economic benefits: It eliminates the need for expensive and time-consuming full-linebed reinforcement or ground blasting for obstacle removal, and also saves on complex pressurized operation equipment and high maintenance and medical costs. Through localized and precise geological modification, cost optimization is achieved.

[0025] 4. Strong adaptability: This method is applicable to various shield tunneling machine types such as slurry and earth pressure balance tunneling machines. It is especially suitable for conventional shield tunneling machines encountering extremely water-rich boulder formations, thus improving the adaptability of ordinary shield tunneling machines.

[0026] 5. Green and low-carbon: It reduces the environmental impact and energy consumption caused by large-scale ground operations, which is in line with the concept of green construction. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating the process of using precipitation and hidden piers to achieve unpressurized obstacle clearing and cutterhead replacement of a slurry shield tunnel through a group of isolated rocks in this invention.

[0028] Figure 2 This is a schematic diagram of the plan layout of the hidden pier reinforcement area in this invention.

[0029] The area shown in the diagram for the reinforcement of the end of the shutdown and renovation project is the same as the area for the reinforcement of the hidden pier; J1-J8 in the diagram are all dewatering wells.

[0030] Figure 3 This is a schematic diagram of the plan layout of the dewatering wells in this invention.

[0031] In the diagram, J1-J6, G1, and G2 are all precipitation wells.

[0032] Figure 4 This is a schematic diagram of the tunnel boring machine cutting into the pier to change cutters in this invention.

[0033] Figure 5 This is a flowchart of the general atmospheric pressure tool changing process. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In the description of the present invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention through specific circumstances.

[0035] like Figures 1-5 As shown, a method for clearing obstacles and changing cutterheads without pressure using a slurry shield tunneling machine to pass through a group of isolated rocks by utilizing precipitation and hidden piers is presented. The core idea of ​​this invention is "reverse modification of the strata", that is, without changing the shield machine itself, but by pre-setting "safety islands" (hidden pier reinforcement zones) and "emergency drainage systems" (precipitation wells) in the strata, conditions for the shield machine to operate under normal pressure are created.

[0036] Includes the following steps:

[0037] Step 1) Based on the tunnel mileage, geological conditions, and predicted tool wear cycle, a submerged pier reinforcement zone is pre-planned at regular intervals along the tunnel axis. The submerged piers utilize techniques such as interlocking piles and mixing piles to form a closed, waterproof wall, whose area must completely enclose the tunnel excavation section with a safety margin. Simultaneously, dewatering wells are installed on both sides of the tunnel. The layout and performance of these wells must be determined through hydrogeological calculations to ensure the rapid formation of dewatering funnels.

[0038] Step 2) Develop a collaborative plan: Compile a detailed collaborative work plan table, specifying the mileage of each underground pier, the corresponding dewatering well number, the triggering conditions for planned maintenance and emergency clearing, the dewatering operation time, the entry operation process, and the communication methods between the ground and underground.

[0039] Step 3) Execute different work procedures according to different working conditions:

[0040] Planned maintenance: When the tunnel boring machine (TBM) has reached the location of the pier, the cutterhead will be inserted into the pier's water-blocking structure. Utilizing the water-blocking properties of the pier and the TBM's own sealing capabilities, the face in front of the cutterhead will be isolated from the high external water pressure. If necessary, dewatering wells near the pier can be activated to further reduce residual water pressure. After confirming safety, personnel can enter the chamber under normal or low pressure to safely and efficiently conduct a comprehensive inspection, replacement, and maintenance of the cutterheads.

[0041] Emergency Clearance: When the tunnel boring machine (TBM) is excavating in a non-hidden pier area, if any abnormal situation occurs such as cutter head damage, breakage, or isolated boulders jamming the cutterhead, the emergency response should be activated immediately. Based on the mileage of the TBM head, the nearest dewatering well group should be quickly activated to forcefully pump water down to below the center line of the cutterhead or to a safe position within a short period. Once the water pressure stabilizes at atmospheric pressure, personnel can quickly enter the tunnel to clear any stuck boulders or replace damaged cutters.

[0042] Step 4) After the planned maintenance or emergency clearing operation is completed and safety is confirmed by inspection, the ground control personnel are notified to adjust or stop the dewatering, and the tunnel boring machine resumes normal tunneling.

[0043] This method actively and locally modifies the geological environment to adapt it to the operational needs of the tunnel boring machine, thereby fundamentally avoiding the high risks of pressurized tunneling, significantly improving construction efficiency, and reducing project costs.

[0044] Application Experiment Case Description:

[0045] 1. Project Overview: The shield tunnel section of this project traverses a water-rich sandy gravel stratum with dense boulders and abundant groundwater. Two slurry shield tunneling machines will be used for construction.

[0046] 2. Implementing the method of the present invention:

[0047] Step S1: A total of 15 hidden pier reinforcement zones are pre-planned along the tunnel axis of the two shield tunnel sections. Each hidden pier is formed by 19 plain concrete interlocking cast-in-place piles, with a reinforcement depth extending 3 meters below the tunnel floor. At the same time, 50 dewatering wells are installed on both sides of the tunnel. The well depth is determined based on hydrogeological calculations, and the designed water output of a single well is 40 m³ / h.

[0048] Step S2: The tunnel boring machine proceeds normally.

[0049] Step S3 - Planned Maintenance: When the tunnel boring machine (TBM) reaches the preset pier mileage, it cuts into the pier. Because the nearby water pressure is not within a safe range, nearby dewatering wells are simultaneously activated to assist in dewatering. After confirming that the chamber is at normal pressure, the cutterhead is opened for replacement. The entire process is safe and smooth, taking only 1 / 3 of the time of traditional pressurized cutterhead replacement.

[0050] Step S3 - Emergency Clearance: During one tunneling operation, the cutterhead was jammed by a large boulder in a non-hidden pier area. The emergency dewatering plan was immediately activated, and the corresponding dewatering wells were opened. The water head was lowered to a safe level within 4 hours. Personnel entered the chamber at normal pressure and successfully removed the boulder in 6 hours, avoiding a potential downtime of several weeks.

[0051] Step S4: After each operation, the tunnel boring machine successfully resumed tunneling.

[0052] 3. Implementation Results: The successful application of this construction method has successfully overcome the challenges posed by dense clusters of boulders, achieved safe and rapid tunneling, ensured the construction period, and yielded significant economic and social benefits, thus verifying the advanced nature, practicality, and reliability of this invention.

[0053] Finally, it should be noted that: the preferred embodiments of this patent have been described in detail above, but this patent is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this patent.

Claims

1. A method for clearing obstacles and changing cutterheads without pressure using precipitation and concealed piers to achieve slurry shield tunneling through a group of isolated rocks, characterized in that: Includes the following steps: Step 1) Calculate the planned maintenance mileage based on the tunnel mileage, geological conditions and tool wear cycle, and pre-set a hidden pier reinforcement zone in the strata at the end of or within the planned maintenance mileage. The hidden pier reinforcement zone forms a closed water-proof wall. Arrange several dewatering wells along both sides of the tunnel. Step 2) Develop a collaborative plan: Develop a collaborative work plan, which includes determining the mileage of each underground pier, the number of each dewatering well, the triggering conditions for planned maintenance and emergency clearing, the dewatering operation time, the entry operation process, and the communication methods between the surface and underground. Step 3) Execute different work procedures according to different working conditions: Planned maintenance: When the tunnel boring machine is tunneling normally to the reinforced area of ​​the pier, according to the triggering conditions set in step 2), the cutterhead is cut into the water-isolated body of the pier to isolate the face in front of the cutterhead from the high water pressure outside. After confirming that the pressure inside the chamber is safe, the workers enter the chamber to carry out a comprehensive maintenance. Emergency Clearance: When the tunnel boring machine encounters a boulder and discovers a cutter malfunction during tunneling in a non-reinforced area, the triggering conditions set in step 2) are used to determine the number of the dewatering well to be opened based on the current mileage and immediately start dewatering. In a short time, the water level near the machine head is lowered to below the center line of the cutterhead or to a preset safe position. After the water pressure stabilizes and reaches normal pressure, the workers enter the chamber to carry out emergency repairs. Step 4) After the planned maintenance or emergency clearing operation is completed and safety is confirmed by inspection, the dewatering operation is adjusted or stopped, and the tunnel boring machine resumes normal tunneling.

2. The method for non-pressurized obstacle clearing and cutterhead replacement of slurry shield tunneling through a group of isolated boulders using precipitation and concealed piers as described in claim 1, characterized in that: During planned maintenance, if the residual water pressure inside the water-blocking body of the cutterhead is still higher than the preset value, the dewatering wells near the reinforced area of ​​the water-blocking body will be activated to further reduce the residual water pressure.

3. The method for non-pressurized obstacle clearing and cutterhead replacement of slurry shield tunneling through a group of boulders using precipitation and concealed piers as described in claim 1, characterized in that: The reinforced area of ​​the concealed pier is constructed using interlocking piles or mixing piles to form a closed water-proof wall. Its area must completely enclose the tunnel excavation section and leave a safety margin.

4. The method for non-pressurized obstacle clearing and cutterhead replacement of slurry shield tunneling through a group of boulders using precipitation and concealed piers as described in claim 1, characterized in that: The location and number of precipitation wells are determined based on hydrogeological conditions to ensure the rapid formation of precipitation funnels.

5. The method for non-pressurized obstacle clearing and cutterhead replacement of slurry shield tunneling through a group of boulders using precipitation and concealed piers as described in claim 1, characterized in that: During planned maintenance, staff enter the warehouse to perform a comprehensive inspection, replacement, and maintenance of the cutting tools.

6. The method for non-pressurized obstacle clearing and cutterhead replacement of slurry shield tunneling through a group of boulders using precipitation and concealed piers as described in claim 1, characterized in that: During emergency clearance operations, staff enter the warehouse to remove stuck boulders or replace damaged tools.

7. The method for clearing obstacles and changing cutterheads without pressure using precipitation and concealed piers to achieve slurry shield tunneling through a group of isolated boulders, as described in claim 1, is characterized in that: Ground staff control the working status of the dewatering wells, while underground staff complete maintenance inside the well. Ground and underground staff coordinate and cooperate through communication.

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