Shield tunneling machine split starting construction method

Abstract

The invention relates to the technical field of shield construction, in particular to a shield tunneling machine split starting construction method which comprises the following steps that S1, a front pilot tunnel and a rear pilot tunnel are constructed on the two sides of a shield well; s2, the machine head is set to be in a muddy water mode, a trailer is divided into at least two subgroups, the machine head and at least one subgroup are transported into the shield well, the remaining subgroups are left outside the shield well, and the machine head, the subgroups located in the shield well, the subgroups located outside the shield well and a mud treatment station communicate with one another through mud pipelines; s3, the machine head conducts empty pushing or tunneling towards the direction of the front pilot tunnel by the distance of at least one group, a hole opening of the front pilot tunnel is blocked, and at least one group is transported into the shield well; and S4, the step S3 is repeated until all the groups are transported into the shield well and connected with one another. The technical problems that the construction efficiency is low and potential safety hazards of subsequent construction can be increased due to the fact that an existing shield tunneling machine adopts an earth pressure mode for starting during drainage tunnel construction can be solved.

Description

Technical Field

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

[0002] Existing nuclear power plant drainage systems generally include shield shafts, drainage tunnels, and drainage risers. The shield shafts are located on land, and the drainage tunnels are connected to the shield shafts at one end and extend to the seabed at the other end, connecting to the marine environment through the drainage risers to discharge the cooling water from the shield shafts into the ocean. Since the drainage tunnels must pass through both land and seabed, earth pressure and slurry dual-mode shield tunneling machines are generally used for construction. Earth pressure mode is used for initiation and excavation in the land section to increase the excavation and excavation speed. After the shield machine has excavated to the sea area, it is switched to slurry mode to continue excavation, thereby improving pressure control accuracy and ensuring the safety of the excavation process.

[0003] The steps for initiating earth pressure testing (EPP) in the existing tunneling system are generally as follows: a pilot tunnel and a rear pilot tunnel are constructed at the bottom of the tunnel shaft, with the rear pilot tunnel being long enough to accommodate all the trailers of the tunnel boring machine (TBM); then, each trailer is transported to the rear pilot tunnel one by one, the TBM head is transported to the tunnel shaft, and the head is connected to each trailer to form a fully functional TBM; then, the TBM continues to excavate towards the pilot tunnel until the soil can provide sufficient reaction force for the TBM, thus completing the EPP initiation of the TBM.

[0004] However, earth pressure load (EPL) launching requires, on the one hand, the construction of a rear pilot tunnel at the bottom of the shield shaft large enough to accommodate all the trailers, and on the other hand, the repeated use of earth buckets to transport and stockpile soil from the shield shaft opening to the outside. This not only results in low construction efficiency but also occupies a huge amount of space (generally at least 11,000 square meters), making it unsuitable for projects with limited construction space. Furthermore, each trailer behind the shield machine's head will pass through the shield shaft opening one by one during the launching phase, requiring each trailer to be cut and modified individually to make way for the earth buckets, which can damage the overall structure of each trailer and increase safety hazards in subsequent construction. Therefore, there is an urgent need to design a new method for launching shield machines. Summary of the Invention

[0005] The purpose of this invention is to overcome the technical problem that the existing shield tunneling machine uses earth pressure mode for starting construction when constructing drainage tunnels, which not only results in low construction efficiency but also increases the safety hazards of subsequent construction, and to provide a method for split-type starting construction of shield tunneling machines.

[0006] In a first aspect, the present invention provides a method for the split-type launching construction of a tunnel boring machine, comprising the following steps: S1. Construct the front and rear pilot tunnels on opposite sides of the shield tunnel shaft, respectively; S2. Set the machine head to mud mode, divide the trailer into at least two groups, each group including at least one trailer; transport the machine head and at least one group into the shield shaft, leave the remaining groups outside the shield shaft, and connect the machine head, the groups inside the shield shaft, the groups outside the shield shaft and the mud treatment station through mud pipelines. S3. The machine head pulls the group located in the shield shaft to push or excavate at least one group's distance in the direction of the pilot tunnel, seals the entrance of the pilot tunnel, and transports at least one group into the shield shaft. S4. Repeat S3 until all groups are transported into the shield shaft and connected to each other, completing the launch of the tunnel boring machine.

[0007] Preferably, a screw conveyor is installed inside the machine head, with one end of the screw conveyor connected to the mud and water bin inside the machine head, and the other end of the screw conveyor connected to the slurry discharge pipe inside the machine head.

[0008] Preferably, the machine head is also equipped with a slurry return pipeline, which includes two inlet sections and one outlet section; each of the two inlet sections is equipped with a switch valve, one inlet section is connected to the slurry discharge pipeline, and the other inlet section is connected to the slurry inlet pipeline of the machine head; the outlet section is connected to the air cushion chamber of the machine head.

[0009] Preferably, a buffer tank is connected to the slurry return pipeline.

[0010] Preferably, a quarry box is also provided at the end of the screw conveyor away from the mud and water silo.

[0011] Preferably, an adjustable throttle valve is installed between the slurry discharge pipeline and the screw conveyor.

[0012] Preferably, in S2, a segmented mud pipeline is used to connect the group located inside the shield shaft and the group located outside the shield shaft; in S3, the mud pipeline is extended accordingly as the tunneling head advances.

[0013] Preferably, at least one booster pump is connected to the mud pipeline.

[0014] Preferably, before S3, the following step is also included: depositing gravel in the pilot hole.

[0015] Preferably, when the nose is thrusting in the pilot hole, S3 further includes the following steps: First, fill the lower part of the gap between the shield tunnel segment and the pilot tunnel with gravel and grout, and then grout the upper part of the gap between the shield tunnel segment and the pilot tunnel.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a method for the separate launching of a tunnel boring machine (TBM). The method uses a slurry-water method for launching, initially placing only a portion of the TBM head and trailer into the tunnel shaft, while leaving the other portion of the trailer outside. A complete slurry circulation is established between the TBM head, trailer, and slurry treatment station via slurry pipelines. This reduces the space occupied by the TBM within the tunnel shaft while ensuring the TBM remains fully functional for excavating towards the pilot tunnel. The TBM's excavation expands the space within the tunnel shaft. Once sufficient space is available inside the tunnel shaft, the remaining components are then placed in, thus successfully completing the TBM launch.

[0017] Compared to existing technologies, the mud generated by the tunnel boring machine in this invention can be continuously transported to the outside of the shield shaft through mud pipelines. This not only allows for a more continuous and efficient transfer of the slag generated by the tunnel boring machine, thereby improving the starting efficiency and starting speed, but also eliminates the need to cut and modify each trailer behind the tunnel boring machine, thus eliminating structural hazards caused by cutting and modification and ensuring the safety of this invention in subsequent construction. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the construction steps of a split-type tunnel boring machine launching method according to the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the construction steps of a method for the separate launching of a tunnel boring machine according to the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the construction steps of a method for the separate launching of a tunnel boring machine according to the present invention. Figure 3 ; Figure 4 This is a schematic diagram of the construction steps of a method for the separate launching of a tunnel boring machine according to the present invention. Figure 4 ; Figure 5 This is a partial cross-sectional view of the tunnel boring machine head in a split-type starting construction method according to the present invention. Figure 1 ; Figure 6 This is a partial cross-sectional view of the tunnel boring machine head in a split-type starting construction method according to the present invention. Figure 2 ; icon: 100 - Shield tunnel shaft; 110 - Pilot tunnel; 111 - Gravel tunnel; 120 - Rear pilot tunnel; 200-Head of machine; 210-Mud bin; 220-Air cushion bin; 230-Slurry discharge pipeline; 240-Slurry inlet pipeline; 250-Screw conveyor; 260-Quarry box; 270-Slurry return pipeline; 271-Inlet section; 272-Outlet section; 273-Switch valve; 274-Buffer tank; 300 - Trailer; 400 - Mud pipeline; 500 - Mud treatment station; 600 - Soil. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0020] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0021] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0022] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0023] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0024] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0025] Example 1 like Figures 1 to 6 As shown, a method for the separate launching of a tunnel boring machine includes the following steps: S1, such as Figure 1 As shown, soil 600 is excavated on both sides of the shield shaft 100 to form a front guide tunnel 110 and a rear guide tunnel 120, and the length of the rear guide tunnel 120 can be less than the length of the complete shield machine; and a launching base, guide platform structure, track and reaction support are set in the shield shaft 100; the launching base, guide platform structure, track and reaction support can all be used directly according to existing technology, so they will not be described in detail here.

[0026] S2. Set the engine head 200 to mud / water mode, and divide the trailer 300 into at least two groups, each group including at least one trailer 300; such as Figure 2 The machine head 200 and at least one group are transported one by one into the shield shaft 100, and the group is placed in the rear guide tunnel 120. The machine head 200 is placed below the shield machine shaft opening. The remaining group is left outside the shield shaft 100. The machine head 200, the group inside the shield shaft 100, the group outside the shield shaft 100, and the mud treatment station 500 outside the shield shaft 100 are interconnected through the mud pipeline 400, so that a complete mud circulation can be formed between the machine head 200, the group inside the shield shaft 100, the group outside the shield shaft 100, and the mud treatment station 500.

[0027] S3, such as Figure 3 As shown, the tunnel boring machine (TBM) head 200 pulls the tunnel segments located in the shield shaft 100 to push them in the pilot tunnel 110, or to excavate the soil 600 meters away from the rear pilot tunnel 120, until the TBM head 200 moves at least one tunnel segment's distance away from the rear pilot tunnel 120 and seals the entrance of the pilot tunnel 110. The specific method of moving the TBM head 200 is the same as the propulsion method of existing TBMs, that is, the shield segments are assembled at the tail of the TBM head 200, then the jacks are placed against the end faces of the shield segments, and then the jacks are extended to achieve the forward movement of the TBM head 200; subsequently, as... Figure 4As shown, at least one group is transported into the shield shaft 100 and connected to a group located in front of it; for example, the tunnel boring machine 200 advances forward a distance of one group and transports one group into the shield shaft 100; or the tunnel boring machine 200 advances forward a distance of two groups and transports one group into the shield shaft 100; or the tunnel boring machine 200 advances forward a distance of two groups and transports two groups into the shield shaft 100.

[0028] S4. Repeat S3 until all groups are transported into the shield shaft 100 and connected to each other (if there are only two groups, S3 only needs to be executed once), to complete the start of the shield machine. After that, the shield machine can continue to excavate along the predetermined route in slurry mode until the construction of the drainage tunnel is completed.

[0029] It is important to note that Figures 1 to 6 The shield shaft 100, trailer 300, machine head 200 and the pipeline system inside the machine head 200 are simplified schematic diagrams and are not intended to limit the specific shape of the shield shaft 100, trailer 300, machine head 200 and the pipeline system inside the machine head 200. Figures 5 to 6 The arrows in the diagram indicate the direction of mud flow.

[0030] This embodiment uses a slurry-water method for launch. At launch, only a portion of the tunnel boring machine (TBM) head 200 and trailer 300 are placed into the shield shaft 100, while the other portion of the trailer 300 remains outside the shield shaft 100. A complete slurry circulation is established between the TBM head 200, trailer 300, and slurry treatment station 500 through the slurry pipeline 400. This reduces the space occupied by the TBM within the shield shaft 100, thereby significantly reducing the requirements for the construction site for TBM launch. It also enables the TBM to have complete functionality to excavate towards the pilot tunnel 110, thus expanding the space within the shield shaft 100 through the TBM's excavation. Once there is sufficient space inside the shield shaft 100, the remaining portions are placed into the shield shaft 100, thus successfully completing the TBM launch.

[0031] Compared to existing technologies that require repeated use of earth buckets to transfer excavated material inside and outside the shield shaft 100, in this embodiment, the mud generated by the excavator head 200 can be continuously transported to the outside of the shield shaft 100 through the mud pipeline 400. This not only allows for more continuous and efficient transfer of excavated material generated by the excavator head 200, thus improving launching efficiency and launching speed, but also reduces leakage of excavated material during transportation, thereby helping to maintain the cleanliness of the construction site. Furthermore, this embodiment eliminates the need to cut and modify each of the trailers 300 behind the excavator head 200 to reserve hoisting space for the earth bucket, thereby eliminating structural hazards caused by cutting and modification and ensuring the safety of this embodiment in subsequent construction.

[0032] When constructing drainage tunnels for nuclear power plant drainage systems, compared to existing technologies that start with earth pressure mode and then switch to slurry mode later, this embodiment uses slurry mode from the beginning for excavation, which can save the subsequent mode switching work, thereby improving the construction efficiency of drainage tunnels and reducing construction risks.

[0033] In an optional implementation, for a tunnel boring machine comprising ten trailers 300, S2 includes the following steps: The trailer 300 is divided into a first group and a second group, each consisting of five trailers 300. The trailer 300 in the first group includes a main control room, a grease system, a synchronous grouting system, an air compressor, an air tank, an electrical cabinet, a ring cooling system, a hydraulic pump station, a bentonite system, and a compensation cabinet. The trailer 300 in the second group includes a dryer, a pressure tank, an air compressor, an emergency generator, a pressure tank, a secondary air fan, a transformer, a sewage tank, a cable box, a pipeline storage area, a pipeline extension device, a slurry collection system, and a water pipe reel. The first group and the tunnel head 200 are then lowered into the shield shaft 100 one by one, leaving the second group outside the shield shaft 100. The tunnel head 200, the first group, the second group, and the mud treatment station 500 are interconnected through the mud pipeline 400, enabling a complete mud circulation among the tunnel head 200, the first group, the second group, and the mud treatment station 500.

[0034] S3 includes the following steps: the machine head 200 pulls the first group in the direction of the pilot tunnel 110 and pushes or excavates at least five trailer cars 300 away, transports the second group into the shield shaft 100 and connects it with the first group, thus completing the start of the shield machine.

[0035] This embodiment provides one specific grouping method for trailers 300, which enables the core components of the tunnel boring machine to be as close as possible to the head 200, thereby avoiding the negative impact of trailer grouping on the operating efficiency of the head 200; at the same time, since this embodiment only divides the trailers 300 into two groups, this embodiment can also reduce the number of cycles of S3 to a minimum, thereby helping to reduce the construction complexity of the initial construction.

[0036] In an optional embodiment, a screw conveyor 250 is installed inside the tunnel boring machine (TBM) head 200. One end of the screw conveyor 250 is connected to the slurry tank 210 inside the TBM head 200, and the other end of the screw conveyor 250 is connected to the slurry discharge pipe 230 inside the TBM head 200. The screw conveyor 250 can be an existing product, such as the screw conveyor 250 of the tunnel boring machine in earth pressure mode.

[0037] Compared to the existing technology that uses steel pipes to transfer mud between the mud tank 210 and the slurry discharge pipe 230, this embodiment uses a screw conveyor 250 to transfer mud between the mud tank 210 and the slurry discharge pipe 230. This allows larger-diameter slag to leave the mud tank 210 through the screw conveyor 250, thereby suppressing the stagnation phenomenon in the circulation system of the head 200 and helping to maintain the tunneling efficiency of the head 200.

[0038] In optional implementations, such as Figure 6 As shown, the machine head 200 is also equipped with a return slurry pipeline 270, which includes two inlet sections 271 and one outlet section 272. Each of the two inlet sections 271 is equipped with a switch valve 273, which can be an existing product, including but not limited to gate valves, butterfly valves or ball valves. One inlet section 271 is connected to the discharge slurry pipeline 230, and the other inlet section 271 is connected to the slurry inlet pipeline 240 of the machine head 200. The outlet section 272 is connected to the air cushion chamber 220 of the machine head 200.

[0039] As the tunnel boring machine 200 advances, it pulls the groups located inside the shield shaft 100 to move, causing changes in the relative positions of the groups inside and outside the shield shaft 100. In order to maintain the continuity of the mud pipeline 400, it is necessary to continuously adjust the mud pipeline 400 as the tunnel boring machine 200 advances. Therefore, it is sometimes necessary to temporarily disconnect the mud pipeline 400, which can easily lead to the mud remaining inside the mud pipeline 400 being directly discharged into the tunnel and causing pollution.

[0040] Therefore, in this embodiment, a return slurry pipeline 270 is added inside the head 200. When the mud pipeline 400 is normally connected, the switch valves 273 of the two inlet sections 271 are closed, and the return slurry pipeline 270 is isolated from the mud pipeline 400, which can prevent the return slurry pipeline 270 from affecting the operation of the mud pipeline 400. When the mud pipeline 400 is disconnected, the switch valves 273 of the two inlet sections 271 are opened, so that the residual mud in the inlet pipeline 240 and the outlet pipeline 230 can enter the return slurry pipeline 270, and then enter the air cushion chamber 220 of the head 200 through the outlet section 272. Thus, it can rejoin the mud circulation after the mud pipeline 400 is connected, thereby realizing the reuse of residual mud and reducing mud leakage and pollution.

[0041] In an optional embodiment, a negative pressure device can be connected to the return slurry pipeline 270 to actively draw the residual slurry inside the slurry pipeline 400 into the air cushion chamber 220; the negative pressure device includes, but is not limited to, a centrifugal pump, a vacuum pump, or an air lift pump; or a compressed air pipeline can be set near the inlet section 271 to create a negative pressure at the inlet of the inlet section 271 by blowing compressed air into the inlet section 271, thereby drawing the slurry into the inlet section 271.

[0042] In an optional embodiment, a buffer tank 274 is connected to the return slurry pipeline 270, which can both separate gas from the slurry and absorb pressure fluctuations in the return slurry pipeline 270, thereby reducing the risk of damage to the return slurry pipeline 270 under pressure fluctuations. The buffer tank 274 can be an existing product, including but not limited to a pneumatic buffer tank 274 or a membrane buffer tank 274.

[0043] In an optional embodiment, a quarry 260 is also provided at the end of the screw conveyor 250 away from the slurry tank 210; for example... Figure 6 As shown, the quarry box 260 is located at the lower part of the screw conveyor 250 away from the mud and water tank 210. So when large-diameter slag is conveyed to the end of the screw conveyor 250 away from the mud and water tank 210, the large-diameter slag will fall into the quarry box 260 under the action of gravity. Then, the large-diameter slag can be discharged from the screw conveyor 250 by opening the door panel at the bottom of the quarry box 260.

[0044] This embodiment can collect large-diameter slag from the screw conveyor 250 for subsequent centralized processing and prevent slag from accumulating at the outlet of the screw conveyor 250, which would cause blockage of the screw conveyor 250.

[0045] In an alternative implementation, additional quarry boxes 260 may be installed at other locations in the mud pipeline 400 to further concentrate large-diameter slag and reduce the risk of large-diameter slag clogging the mud pipeline 400.

[0046] In an optional embodiment, an adjustable throttle valve is installed between the slurry discharge pipeline 230 and the screw conveyor 250. This allows for the creation of varying degrees of plugging effect in front of the screw conveyor 250 by changing the opening of the throttle valve, thereby assisting the head 200 in achieving pressure balance. The throttle valve can be an existing product, including but not limited to gate valves, ball valves, or butterfly valves.

[0047] In an optional implementation, the number of throttle valves is at least two to achieve graded control of the soil plug effect, and each throttle valve can serve as a backup for the others, thereby improving the safety redundancy of the entire system.

[0048] In an optional embodiment, the mud pipeline 400 may adopt a combined structure, a flexible structure or a telescopic structure to maintain the connection of the mud pipeline 400 when the relative positions of the groups located inside the shield shaft 100 and the groups located outside the shield shaft 100 change as the tunneling head 200 advances.

[0049] In an optional implementation, in S2, a segmented mud pipeline 400 is used to connect the group located inside the shield shaft 100 and the group located outside the shield shaft 100. The connection method between two adjacent segments of the mud pipeline 400 includes, but is not limited to, flange connection, welding or clamp connection. In S3, the mud pipeline 400 is extended in response to the tunneling of the machine head 200.

[0050] Compared to using a flexible structure, this embodiment can better maintain the shape of the mud pipeline 400, thereby reducing mud pressure fluctuations caused by the shaking of the mud pipeline 400, and thus enabling this embodiment to deliver mud more stably and reliably.

[0051] In an optional embodiment, at least one booster pump is connected to the mud pipeline 400 to increase the mud flow rate and flushing effect within the mud pipeline 400. This ensures normal circulation of the mud within the extended mud pipeline 400 while suppressing negative phenomena such as cutterhead cake formation and soil stagnation. The booster pump can be an existing product, including but not limited to centrifugal pumps, multistage pumps, or screw pumps.

[0052] In an optional embodiment, the following steps are included before S3: piling up gravel 111 in the pilot tunnel 110; the specific amount of gravel 111 piled up depends on the friction required by the tunnel boring machine.

[0053] When the tunnel boring machine (TBM) head 200 pushes empty inside the pilot tunnel 110, there is no soil pressure on the front of the head 200, resulting in insufficient compression of the rubber waterstop strips on the shield segments, thus leading to poor waterproofing of the tunnel. Therefore, in this embodiment, gravel 111 is piled up in the pilot tunnel 110. When the head 200 advances into the pilot tunnel 110, the gravel 111 can directly fill the gap between the shield segments and the pilot tunnel 110, and also provide more friction between the head 200 and the pilot tunnel 110 to compress the rubber waterstop strips, thereby improving the sealing and waterproofing effect of the tunnel.

[0054] In an optional implementation, after a specified number of shield tunnel segments are assembled inside the machine head 200 and the shield tunnel segments are pushed to the end face of the reaction support, the shield tunnel segments are fixedly connected to the reaction support, and the gap between the shield tunnel segments and the inner wall of the pilot tunnel 110 is sealed with cotton wool and shotcrete, thereby sealing the entrance of the pilot tunnel 110. This not only enhances the sealing of the tunnel to prevent water or soil 600 in the tunnel from flowing back into the shield shaft 100, but also ensures that the front chamber of the shield machine can build up pressure in slurry mode, thereby ensuring the smooth progress of subsequent tunneling work.

[0055] In an optional implementation, the cotton wadding and shotcrete cover at least the length of four rings of shield tunnel segments to ensure reliable sealing.

[0056] In an optional embodiment, the shotcrete used to seal the entrance of the pilot tunnel 110 has a strength grade greater than or equal to C25.

[0057] In an optional embodiment, after sealing the opening of the pilot tunnel 110, an exhaust hole is set at the top of the opening of the pilot tunnel 110, and an openable exhaust valve is connected to the exhaust hole to release the gas accumulated inside the tunnel and regulate the air pressure inside the tunnel, thereby reducing the risk of overpressure accidents.

[0058] In an optional implementation, when the nose cone 200 is thrusting empty within the pilot hole 110, S3 further includes the following steps: First, fill the lower part of the gap between the shield tunnel segment and the pilot tunnel 110 (for example, the part below the 3 o'clock to 9 o'clock direction) with gravel 111 and grout. Then, grout the upper part of the gap between the shield tunnel segment and the pilot tunnel 110 (for example, the part above the 3 o'clock to 9 o'clock direction).

[0059] This embodiment can further fill the gap between the shield tunnel segments and the pilot tunnel 110, thereby improving the tunnel's sealing performance and suppressing the displacement and deformation of the shield tunnel segments.

[0060] In an optional embodiment, the pea gravel 111 is sprayed using a concrete spraying machine. The pea gravel 111 material is made of smooth pea gravel 111 with a diameter of 5 mm to 8 mm and mixed with a certain amount of sand. The spraying pressure is 0.2 MPa to 0.3 MPa.

[0061] In an optional embodiment, the lower part of the gap between the shield tunnel segment and the pilot tunnel 110 is grouted with cement-water glass double liquid; the upper part of the gap between the shield tunnel segment and the pilot tunnel 110 is grouted with inert grout, which is a mixture including fly ash, bentonite, sand and water, but without cement and lime.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for a shield machine split launching construction, characterized in that, The method comprises the following steps: S1, constructing a front pilot hole (110) and a rear pilot hole (120) on opposite sides of a shield well (100); S2, setting a machine head (200) to a slurry mode, dividing a trailer (300) into at least two groups, each group comprising at least one trailer (300), transporting the machine head (200) and at least one group into the shield well (100), leaving the remaining groups outside the shield well (100), and connecting the machine head (200), the group inside the shield well (100), the group outside the shield well (100), and a slurry treatment station (500) to each other through a slurry pipeline (400); S3, pulling the group inside the shield well (100) by the machine head (200) to push or dig at least one group distance in the direction of the front pilot hole (110), blocking the opening of the front pilot hole (110), and transporting at least one group into the shield well (100); S4, repeating S3 until all groups are transported into the shield well (100) and connected to each other, and completing the launching of the shield machine.

2. The method according to claim 1, wherein, The machine head (200) is provided with a screw conveyor (250), one end of the screw conveyor (250) is communicated with a slurry bin (210) in the machine head (200), and the other end of the screw conveyor (250) is communicated with a slurry discharge pipeline (230) in the machine head (200).

3. The method according to claim 2, wherein, The machine head (200) is further provided with a slurry return pipeline (270), the slurry return pipeline (270) comprises two inlet sections (271) and an outlet section (272); each of the two inlet sections (271) is provided with a switch valve (273), one inlet section (271) is communicated with the slurry discharge pipeline (230), and the other inlet section (271) is communicated with a slurry inlet pipeline (240) of the machine head (200); the outlet section (272) is communicated with an air cushion bin (220) of the machine head (200).

4. The method according to claim 3, wherein, The slurry return pipeline (270) is connected with a buffer tank (274).

5. The method of claim 2, wherein, A stone collecting box (260) is further arranged at the end of the screw conveyor (250) away from the slurry bin (210).

6. The method of claim 2, wherein, An adjustable throttle valve is arranged between the slurry discharge pipeline (230) and the screw conveyor (250).

7. The method according to any one of claims 1 to 6, wherein, The segmented slurry pipeline (400) is used to connect the group inside the shield well (100) and the group outside the shield well (100) in S2; and the slurry pipeline (400) is lengthened in S3 with the digging of the machine head (200).

8. The method according to any one of claims 1 to 6, wherein, At least one booster pump is connected in the slurry pipeline (400).

9. The method of claim 1 to 6, wherein, The method further comprises the following steps before S3: piling up pea gravel (111) in the front pilot hole (110).

10. The method of claim 1 to 6, wherein, When the machine head (200) is pushed in the front pilot hole (110), S3 further comprises the following steps: First, filling pea gravel (111) and grouting in the lower part of the gap between the shield segment and the front pilot hole (110), and then grouting in the upper part of the gap between the shield segment and the front pilot hole (110).

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