A shield body of an integrated shield machine for urban rail transit station and tunnel and a construction method thereof

Abstract

The invention discloses a shield body of an integrated shield machine for urban rail transit stations and tunnels, comprising: a front shield, wherein the outer shield body of the front shield comprises a front shield shell, a front shield shell reducing block and a front shield shell partition plate, which are fixedly connected; the inner shield body of the front shield comprises a front shield inner partition plate, a front shield inner partition plate reducing block is arranged in the front shield inner partition plate, and the front shield inner partition plate reducing block is fixedly connected to the front shield shell partition plate; a middle shield, wherein the outer shield body of the middle shield comprises a middle shield shell, a middle shield shell reducing block and a middle shield shell partition plate, which are fixedly connected The inner shield body of the middle shield includes a middle shield inner partition plate, a middle shield inner partition reducing block is arranged in the middle shield inner partition plate, and the middle shield inner partition reducing block is fixedly connected to the middle shield outer shell partition; the tail shield, the front outer shield body of the tail shield includes a fixedly connected front outer shell of the tail shield, a front outer shell reducing block of the tail shield and a front outer shell partition of the tail shield, the front inner shield body of the tail shield includes a front inner partition plate of the tail shield, a front inner partition reducing block of the tail shield is arranged in the front inner partition plate of the tail shield, and the front inner partition reducing block of the tail shield is fixedly connected to the front outer shell partition of the tail shield.

Description

Technical Field

[0001] The present invention relates to the technical field of shield construction, and in particular to a shield body of an urban rail transit station-tunnel integrated shield machine and a construction method thereof. Background Art

[0002] The shield method refers to the construction method of underground space that uses the cutterhead and cutter at the front end of the shield machine to excavate the rock and soil, assemble prefabricated segments under the protection of the shield shell, and provide reaction force for the propulsion hydraulic cylinder, and snake forward in the stratum. With the vigorous development of my country's rail transit projects, the shield method has the advantages of safety and efficiency, and it has become a consensus on the choice of urban rail transit construction methods. In the construction of urban rail transit projects, the shield method is often used in sections, and the open-cut method is often used in stations. In the prosperous sections of the city, traffic congestion, dense pipelines, and limited sites lead to low applicability of the open-cut method, high risks of dark excavation, and the cover excavation method will also interfere with the environment to a certain extent. In view of the low degree of intensiveness, high safety risks, and long impact period of the above traditional construction methods of urban rail transit, research on station-tunnel integrated construction technology using the shield method has become a new development trend.

[0003] At present, the shield diameter changing methods mainly include: changing the diameter to adapt to different project diameters during the transfer process, assembling diameter-changing blocks outside the shield body after expanding the excavation to adapt to the different diameters of the previous and next projects during excavation, and changing the diameter of the non-closed shield body to adapt to the large and slow deformation support in areas with poor surrounding rock during excavation.

[0004] The Chinese patent with the publication number CN116398155A discloses an assembled shell-dismantling shield machine main body shield and its installation and disassembly method. The shield machine main body shield includes a front shield, a middle shield and a tail shield that are fixedly connected. The front shield is composed of a front shield outer shield body and a front shield inner shield body. The front shield inner shield body is fixed to the front shield outer shield body at the front. The middle shield is composed of a middle shield outer shield body and a middle shield inner shield body. The middle shield inner shield body is fixed to the middle shield outer shield body at the rear. The tail shield includes a tail shield body. The junction of the middle shield and the tail shield is provided with a M-beam and a M-beam outer partition. The front part of the annular M-beam outer partition is nested in the middle shield outer shell, and the rear end is fixed to the front end of the tail shield body. The invention adopts modular design, assembled construction, reasonable block setting, strong structural stability, and enables the front shield inner shield body to be transferred to the open space at the rear side for dismantling, avoiding the problems of narrow dismantling space, high dismantling difficulty and low dismantling efficiency caused by the main drive unit.

[0005] The Chinese patent with the publication number CN114183154A discloses a shield machine diameter-changing method capable of changing the excavation diameter in any proportion. The shield machine includes a variable diameter cutter head, a variable diameter front shield, a variable diameter middle shield, a tail shield, and a telescopic trolley for outriggers; it also includes a torsion beam, an active articulated oil cylinder, a folding shed type rubber articulated seal, a screw conveyor, a segment assembly machine, and a manhole. The shield machine of the present invention can quickly change the excavation diameter in any proportion within a certain range in the starting shaft and the tunnel; when transferring to another diameter or cross-section excavation, the cutter head, the shield body, and the rear supporting trolley can all be quickly changed in diameter, and only the newly manufactured folding shed type rubber articulated seal, the tail shield, etc. can adapt to the excavation of different diameters or cross-sections; the same shield machine can be used to excavate tunnels of different excavation diameters, which greatly reduces the equipment purchase and transformation costs and the shaft construction costs at the construction site, and greatly shortens the construction period, and has a high research value.

[0006] In the above scheme, when the excavation site is transferred to other diameters or cross-sections, the newly made folding shed type rubber articulated seal and tail shield can quickly change the diameter of the cutter head, shield body, and rear supporting trolley. However, it does not consider how to change the diameter during shield construction and how to dismantle the abandoned shell in the tunnel.

[0007] A Chinese patent with publication number CN116006197A discloses a variable diameter tunnel construction method, system and shield equipment. The variable diameter tunnel construction method includes: when the shield equipment completes the excavation and support of a first diameter tunnel through the first cutter disc and the first shield body of the variable diameter cutter disc assembly, multiple cutter disc blocks in the variable diameter cutter disc assembly are radially extended relative to the outer periphery of the first cutter disc to form a second cutter disc; the shield equipment continues to excavate and support along a preset excavation path through the second cutter disc and the first shield body to form a variable diameter operation space; in the variable diameter operation space, the first shield body of the shield equipment is assembled and adjusted to form a second shield body; and the shield equipment excavates and supports a second diameter tunnel through the second cutter disc and the second shield body.

[0008] In the above scheme, when the shield needs to change its diameter, it is necessary to reinforce the strata around the diameter change operation space, select different sizes of diameter change modules to cover the shield to achieve diameter change, and the diameter change module and the shield are detachably connected. The operation process is complicated and the safety risk is high, and how to dismantle the shell in the hole is not considered.

[0009] The Chinese patent with publication number CN213205678U discloses a shield with variable diameter, which solves the problems of small diameter change range and complex diameter change method of the shield in the prior art. The shield includes a central frame and a segmented outer shell that can be spliced ​​into a ring. The segmented outer shell is connected to the outer periphery of the central frame through a telescopic member, and two adjacent segmented outer shells are plugged in through a socket sealing connector. The shield adopts a segmented outer shell design and is connected to the central frame through a telescopic member. It can change the diameter in real time, has a flexible construction method, a large diameter change range, and can ensure that the shape does not change significantly, thereby ensuring the integrity of the shield. The socket sealing blocks at the overlapping parts of the shield body always maintain a staggered state to ensure the circumferential continuity of the shield body and reduce the intrusion of large particles of rock and soil debris into the shield body. The central frame is in a circumferentially closed ring state, which can not only provide support for the segmented outer shell, but also prevent small particles invading the shield body from causing harm to workers, thereby improving practical safety.

[0010] The above scheme is based on the idea that when a mountain tunnel encounters weak surrounding rock, in order to adapt to the slow stress release and large deformation in the area with poor surrounding rock, a shield with a large range of diameter changes is proposed to improve the efficiency of post-slow support. However, the shield is in a non-closed state after the diameter expansion, which is not suitable for strata with sand and soil, and it does not consider providing internal space by changing the diameter during construction to solve the problem of changing the size of the structural section and how to dismantle the shell in the tunnel. Summary of the invention

[0011] The object of the present invention is to provide a shield body of an urban rail transit station-tunnel integrated shield machine and a construction method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0012] To achieve the above-mentioned purpose, the present invention provides a shield body of an urban rail transit station-tunnel integrated shield machine, comprising:

[0013] The front shield comprises a front shield outer shield body and a front shield inner shield body, wherein the front shield outer shield body comprises a front shield outer shell, a front shield outer shell reducing block and a front shield outer shell partition plate which are fixedly connected, and the front shield inner shield body comprises a front shield inner partition plate, wherein a front shield inner partition plate reducing block is arranged in the front shield inner partition plate, and the front shield inner partition plate reducing block is fixedly connected to the front shield outer shell partition plate;

[0014] The middle shield comprises a middle shield outer shield body and a middle shield inner shield body, wherein the middle shield outer shield body comprises a middle shield outer shell, a middle shield outer shell reducing block and a middle shield outer shell partition plate which are fixedly connected, and the middle shield inner shield body comprises a middle shield inner partition plate, wherein a middle shield inner partition plate reducing block is arranged in the middle shield inner partition plate, and the middle shield inner partition plate reducing block is fixedly connected to the middle shield outer shell partition plate;

[0015] The tail shield comprises a front outer shield body and a front inner shield body, wherein the front outer shield body comprises a front outer shell of the tail shield, a reducing block of the front outer shell of the tail shield and a front outer shell partition of the tail shield, and the front inner shield body comprises a front inner partition block of the tail shield, a front inner partition block of the tail shield is provided with a reducing block of the front inner partition of the tail shield, and the reducing block of the front inner partition of the tail shield is fixedly connected to the front outer shell partition of the tail shield;

[0016] Among them, the front shield shell, the middle shield shell and the tail shield front shell are all block structures, and the front shield shell reducing block, the middle shield shell reducing block and the tail shield front shell reducing block can be respectively removed or filled between the adjacent blocks of the front shield shell, the middle shield shell and the tail shield front shell.

[0017] In a preferred embodiment, the front shield inner shield body also includes a front shield outer shell reducing hydraulic cylinder and a front shield inner baffle reducing hydraulic cylinder, the front shield inner baffle reducing hydraulic cylinder is connected to the front shield inner baffle reducing block, the front shield outer shell reducing hydraulic cylinder is fixedly connected to the middle part of the front shield outer shell reducing block, the front shield outer shell reducing block includes two symmetrically arranged front shield reducing connecting plates, the inner ends of the two front shield reducing connecting plates are rotatably connected through a rotating shaft, and the outer ends of the two front shield reducing connecting plates are respectively rotatably connected to adjacent blocks of the front shield outer shell through the rotating shaft; in the expanded diameter state, the front shield outer shell blocks and the adjacent front shield outer shell reducing blocks on both sides are sequentially spliced ​​to form a closed space, and in the reduced diameter state, the adjacent blocks of the front shield outer shell are sequentially spliced ​​to form a closed space.

[0018] In a preferred embodiment, the middle shield inner shield body further includes a middle shield outer shell reducing hydraulic cylinder and a middle shield inner partition reducing hydraulic cylinder, the middle shield outer shell reducing hydraulic cylinder is fixedly connected to the middle part of the middle shield inner partition reducing block, the middle shield inner partition reducing hydraulic cylinder is connected to the middle shield outer shell reducing block, the middle shield outer shell reducing block includes two middle shield reducing connecting plates symmetrically arranged, the inner ends of the two middle shield reducing connecting plates are rotatably connected through a rotating shaft, and the outer ends of the two middle shield reducing connecting plates are respectively rotatably connected to the adjacent blocks of the middle shield outer shell through the rotating shaft; in the expanded diameter state, the middle shield outer shell blocks and the adjacent middle shield inner partition reducing blocks on both sides are sequentially spliced ​​to form a closed space, and in the reduced diameter state, the adjacent blocks of the middle shield outer shell are sequentially spliced ​​to form a closed space.

[0019] In a preferred embodiment, the front inner shield body of the tail shield also includes a tail shield front outer shell reducing hydraulic cylinder and a tail shield front inner baffle reducing hydraulic cylinder, the tail shield front outer shell reducing hydraulic cylinder is fixedly connected to the middle part of the tail shield front outer shell reducing block, the tail shield front inner baffle reducing hydraulic cylinder is connected to the tail shield front inner baffle reducing block, the tail shield front outer shell reducing block includes two tail shield front reducing connecting plates symmetrically arranged, the inner ends of the two tail shield front reducing connecting plates are rotatably connected through a rotating shaft, and the outer ends of the two tail shield front reducing connecting plates are respectively rotatably connected to adjacent blocks of the tail shield front outer shell through the rotating shaft; in the expanded diameter state, the tail shield front outer shell and the adjacent tail shield front outer shell reducing blocks on both sides are sequentially spliced ​​to form a closed space, and in the reduced diameter state, the adjacent blocks of the tail shield front outer shell are sequentially spliced ​​to form a closed space.

[0020] In a preferred embodiment, the tail shield also includes a tail shield middle and a tail shield rear, the joint position of the tail shield middle and the tail shield rear is provided with a transition ring, the joint portion of the tail shield and the middle shield is provided with a M-beam, and when the tail shield is in a reduced diameter state, adjacent blocks of the outer shell of the tail shield are sequentially spliced ​​to form an enclosed space, and when it is in an expanded diameter state, the outer shell blocks of the tail shield and the adjacent diameter reducing blocks of the outer shell of the tail shield on both sides are sequentially spliced ​​to form an enclosed space.

[0021] In a preferred embodiment, when the tail shield is expanded, the transition ring between the middle and rear of the tail shield is removed and replaced with a sealing steel plate ring, and after the tail shield expansion is completed, the middle and rear flange of the tail shield is cut off and a shield tail brush is welded on the inner side of the middle and rear part of the tail shield.

[0022] In a preferred embodiment, when the tail shield is reduced in diameter, a circular ring plate is welded on the front flange of the tail shield, and the connecting bolts of the front and middle of the tail shield are removed, and a new tail shield center and tail shield rear are installed behind the reduced diameter position of the front of the tail shield inside the circular ring plate.

[0023] The present invention also provides a construction method for a shield body of an urban rail transit station-tunnel integrated shield machine, which is used in the diameter expansion process of the shield body of the urban rail transit station-tunnel integrated shield machine, and comprises the following steps:

[0024] Step 1: According to the construction design drawings, the shield is manufactured at the manufacturer, transported to the construction site, assembled, debugged and excavated;

[0025] Step 2: When the shield needs to be expanded, the circulation system is started to keep the formation stable during the shield expansion process;

[0026] Step 3: Use the variable diameter cutterhead to expand the diameter, complete the cutterhead expansion, and continue to excavate until the front shield expansion space is met in the cutterhead expansion state;

[0027] Step 4: Extend the front ends of the front shield shell reducing hydraulic cylinder and the front shield inner baffle reducing hydraulic cylinder to push the front shield shell reducing block and the front shield inner baffle reducing block to expand the diameters respectively. At the same time, fill the front shield shell reducing block between adjacent blocks of the front shield shell, extend the front shield inner baffle reducing block to the expansion position and fill the gaps between adjacent front shield inner baffle reducing blocks to complete the expansion of the front shield.

[0028] Step 5: In the state of cutterhead expansion, the shield machine continues to excavate until the expansion space of the middle shield is met;

[0029] Step 6: Extend the front ends of the middle shield shell reducing hydraulic cylinder and the middle shield inner partition reducing hydraulic cylinder, respectively push the middle shield shell reducing block and the middle shield inner partition reducing block to expand the diameter, and at the same time, fill the middle shield shell reducing block between the adjacent blocks of the middle shield shell, extend the middle shield inner partition reducing block to the expansion position, and complete the expansion of the middle shield;

[0030] Step 7: In the state of cutterhead expansion, the shield machine continues to excavate until the expansion space in front of the tail shield and in the tail shield is met;

[0031] Step 8, remove the connecting bolts between the transition ring and the rear of the tail shield;

[0032] Step nine, remove the transition ring and replace it with a sealing steel plate ring;

[0033] Step ten, extend the front end of the tail shield front shell reducing hydraulic cylinder and the tail shield front inner baffle reducing hydraulic cylinder to push the tail shield front shell reducing block and the tail shield front inner baffle reducing block to expand the diameter, and at the same time, fill the tail shield front shell reducing block between the tail shield front shell blocks, fill the tail shield middle shell reducing block between the adjacent blocks of the tail shield middle shell, and extend the tail shield front inner baffle reducing block to the expansion position, so as to complete the expansion of the tail shield front and the tail shield middle;

[0034] Step 11, cut off the rear flange of the tail shield;

[0035] Step 12, weld the shield tail brush on the inner side of the rear middle part of the tail shield;

[0036] Step 13, discard the rear shield and the sealing steel plate ring into the stratum to complete the expansion of the entire shield machine;

[0037] Step 14. After the shield machine completes excavation in the expanded diameter state, first, pre-reinforce the front of the cutter head and around the shield body, then cut off the front shield outer shell partition, the middle shield outer shell partition, and the rear shield front outer shell partition, and then shrink the front shield inner shield body, the middle shield inner shield body, and the rear shield front inner shield body to the reduced diameter state, and finally remove the assembled modules inside the shield body and transport them to the starting well to hoist them out, and abandon the shield shell in the formation.

[0038] The present invention also provides a construction method for a shield body of an urban rail transit station-tunnel integrated shield machine, which is used in the diameter reduction process of the shield body of the urban rail transit station-tunnel integrated shield machine, and comprises the following steps:

[0039] Step 1: When the shield machine needs to shrink, start the circulation system to keep the ground stable during the shrinking process of the shield;

[0040] Step 2: Retract the variable diameter cutter disc to complete the cutter disc diameter reduction;

[0041] Step 3: shorten the front shield shell reducing hydraulic cylinder and the front shield inner partition reducing hydraulic cylinder, and at the same time, move the front shield shell reducing block out from between the adjacent blocks of the front shield shell, and retract the front shield inner partition reducing block into the front shield inner partition block to complete the front shield reduction;

[0042] Step 4: After the front shield is reduced in diameter, shorten the middle shield outer shell reducing hydraulic cylinder and the middle shield inner partition reducing hydraulic cylinder. At the same time, move the middle shield outer shell reducing block out from between the adjacent blocks of the middle shield outer shell, and retract the middle shield inner partition reducing block into the middle shield inner partition block to complete the middle shield reduction;

[0043] Step 5: Remove the bolts connecting the front and middle of the tail shield;

[0044] Step 6: Weld the annular plate on the front flange of the tail shield;

[0045] Step 7: Install a new tail shield center and tail shield rearward of the predetermined reduced diameter position on the inner side of the circular ring plate and in front of the tail shield;

[0046] Step 8: After the middle shield is reduced in diameter, shorten the tail shield front outer shell reducing hydraulic cylinder and the tail shield front inner partition reducing hydraulic cylinder. At the same time, move the tail shield front outer shell reducing block out of the adjacent blocks of the tail shield front outer shell, move the tail shield middle outer shell reducing block out of the middle outer shell blocks of the tail shield, and retract the tail shield front inner partition reducing block into the tail shield front inner partition block to complete the tail shield front and tail shield middle reduction;

[0047] Step 9: After the diameter reduction of the front and middle tail shield is completed, connect the front tail shield with the new middle tail shield using connecting bolts;

[0048] Step 10: Abandon the old tail shield in the stratum to complete the reduction of the entire shield body of the shield machine.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention divides the outer shell of the front shield, the middle shield and the rear shield into blocks, and accordingly sets the outer shell variable diameter block, the inner baffle variable diameter block and the outer shell variable diameter hydraulic cylinder and the inner baffle variable diameter hydraulic cylinder. Through modular design, the outer shell block is reasonably set, the structure is stable and the degree of intelligence is high. Under the condition of ensuring the continuous expansion / contraction of the cutter head, the shield body of the shield machine can be rapidly expanded / contracted in situ, and the internal space can be greatly changed, such as the case where the diameter changes by ≥2.5m, so as to quickly realize the change of the size of the structural section. It reduces the occupation of the construction area of ​​traditional stations and tunnels, the relocation of pipelines and the interference with the traffic on busy streets in the city, and avoids the problem of repeated transfer of shield machines during tunnel construction. At the same time, it reduces the abandoned length of the shield tail and the stratum reinforcement process, improves the application scope of the shield method, the applicability and construction efficiency of the shield machine, and promotes the green construction process of urban rail transit projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a diagram of the shield body of the shield machine in the reduced diameter state of the present invention;

[0051] Figure 2 This is a diagram of the shield body of the shield machine in the state of front shield expansion of the present invention;

[0052] Figure 3 This is a shield diagram of the shield machine in the expanded diameter state of the front shield and the middle shield of the present invention;

[0053] Figure 4 This is a diagram of the shield body of the shield machine in the expanded state before the shield tail brush is welded;

[0054] Figure 5 This is a diagram of the shield body of the shield machine in the expanded state after the shield tail brush is welded;

[0055] Figure 6 It is a diagram of the shield body of the shield machine in the tail shield middle and rear of the tail shield in the reduced diameter state;

[0056] Figure 7 This is a diagram of the shield body of the shield machine in the state where the front shield is in a reduced diameter state;

[0057] Figure 8 This is a shield diagram of the shield machine in the state where the front shield and the middle shield of the present invention are in a reduced diameter state;

[0058] Fig. 9 It is a shield body diagram of the shield machine in the front-reduced state of the middle shield, front shield and tail shield of the present invention;

[0059] Fig.10 It is a front view of the front shield and the middle shield of the present invention in a reduced diameter state;

[0060] Fig.11 It is a front view of the front shield and the middle shield of the present invention in the expanded state;

[0061] Fig.12 It is a front view of the middle shield and the tail shield of the present invention in the front reduced diameter state;

[0062] Fig.13 It is a front view of the middle shield and the tail shield of the present invention in the front diameter expansion state;

[0063] Fig.14 It is a front view of the tail shield of the present invention in a reduced diameter state;

[0064] Fig.15 It is a front view of the tail shield of the present invention in the expanded state;

[0065] Fig.16 It is a structural schematic diagram of the front shield shell reducing block of the present invention in a reduced diameter state;

[0066] Fig.17 It is a schematic plan view of the structure of the front shield shell reducing block in the expanded state of the present invention.

[0067] Description of reference numerals:

[0068] 1. Front shield outer shield body; 101. Front shield outer shell; 102. Front shield outer shell reducing block; 103. Front shield outer shell partition; 2. Front shield inner shield body; 201 Front shield inner partition block; 202. Front shield inner partition reducing block; 203. Front shield outer shell reducing hydraulic cylinder; 204. Front shield inner partition reducing hydraulic cylinder; 4. Middle shield outer shield body; 401. Middle shield outer shell; 402. Middle shield outer shell reducing block; 403. Middle shield outer shell partition; 5. Middle shield inner shield body; 501. Middle shield inner partition block; 502. Middle shield inner partition reducing block; 503. Middle shield outer shell reducing hydraulic cylinder; 504. Middle shield inner partition reducing hydraulic cylinder; 6. M-beam; 7. Tail shield front outer shield body; 701. Tail shield front outer shell; 702, the reducing block of the front outer shell of the tail shield; 703, the bulkhead of the front outer shell of the tail shield; 8, the front inner shield body of the tail shield; 801, the front inner bulkhead plate of the tail shield; 802, the reducing block of the front inner bulkhead of the tail shield; 803, the reducing hydraulic cylinder of the front outer shell of the tail shield; 804, the reducing hydraulic cylinder of the front inner bulkhead of the tail shield; 805, the front and rear flanges of the tail shield; 9, the middle of the tail shield; 901, the middle outer shell of the tail shield; 902, the reducing block of the middle outer shell of the tail shield; 903, the front flange of the middle of the tail shield; 904, the rear flange of the middle of the tail shield; 10, the transition ring; 11, the rear of the tail shield; 1101, the rear outer shell of the tail shield; 1102, the rear flange of the tail shield; 12, the anchor bolt; 13, the connecting bolt; 14, the sealing steel plate ring; 15, the shield tail brush; 16, the circular ring plate. DETAILED DESCRIPTION

[0069] The technical solutions in the embodiments of the present invention are described clearly and completely below. The embodiments of the present invention and all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0070] Example 1

[0071] like Figures 1 to 17 As shown, the shield body of the urban rail transit station-tunnel integrated shield machine of the present invention includes: a front shield, a middle shield, and a tail shield. The front shield includes a front shield outer shield body 1 and a front shield inner shield body 2, the middle shield includes a middle shield outer shield body 4 and a middle shield inner shield body 5, and the tail shield includes a tail shield front outer shield body 7 and a tail shield front inner shield body 8.

[0072] The front shield outer shield body 1 includes a front shield outer shell 101, a front shield outer shell reducing block 102 and a front shield outer shell partition 103 which are fixedly connected. The front shield inner shield body 2 includes a front shield inner partition block 201, a front shield inner partition reducing block 202, a front shield outer shell reducing hydraulic cylinder 203 and a front shield inner partition reducing hydraulic cylinder 204. The front shield inner partition block 201 is provided with a front shield inner partition reducing block 202, and the front shield inner partition reducing block 202 is fixedly connected to the front shield outer shell partition 103 through an anchor bolt 12. The middle shield outer shield body 4 includes a middle shield outer shell 401, a middle shield outer shell reducing block 402 and a middle shield outer shell partition 403 which are fixedly connected. The middle shield inner shield body 5 includes a middle shield inner partition block 501, a middle shield inner partition reducing block 502 is provided in the middle shield inner partition block 501, and the middle shield inner partition reducing block 502 is fixedly connected to the middle shield outer shell partition 403. The front outer shield body 7 of the tail shield includes a front outer shell 701 of the tail shield, a diameter reducing block 702 of the front outer shell of the tail shield and a partition plate 703 of the front outer shell of the tail shield. The front inner shield body 8 of the tail shield includes a front inner partition plate 801 of the tail shield. The front inner partition plate 801 is provided with a diameter reducing block 802 of the front inner partition of the tail shield. The diameter reducing block 802 of the front inner partition of the tail shield is fixedly connected to the front outer shell partition plate 703 of the tail shield. The front outer shell diameter reducing block 102 of the front shield, the middle outer shell diameter reducing block 402 of the middle shield, and the front outer shell diameter reducing block 702 of the tail shield are all hinge-type folding structures. The front outer shell diameter reducing block 102 is movably arranged between adjacent front inner partition diameter reducing blocks 202 of the front shield, the middle outer shell diameter reducing block 402 is movably arranged between adjacent middle inner partition diameter reducing blocks 502 of the middle shield, and the front outer shell diameter reducing block 702 of the tail shield is movably arranged between adjacent front inner partition diameter reducing blocks 802 of the tail shield. The front shield shell 101, the middle shield shell 401, and the rear shield front shell 701 are all block structures, and the front shield shell reducing block 102, the middle shield shell reducing block 402, and the rear shield front shell reducing block 702 can be respectively removed or filled between adjacent blocks of the front shield shell 101, the middle shield shell 401, and the rear shield front shell 701.

[0073] Furthermore, the front shield inner baffle reducing hydraulic cylinder 204 is connected to the front shield inner baffle reducing block 202, the front shield outer shell reducing hydraulic cylinder 203 is fixedly connected to the middle part of the front shield outer shell reducing block 102, and the front shield outer shell reducing block 102 includes two front shield reducing connecting plates 1021 symmetrically arranged in a hinge structure, the inner ends of the two front shield reducing connecting plates 1021 are rotatably connected through a rotating shaft 1022, and the outer ends of the two front shield reducing connecting plates 1021 are rotatably connected to adjacent blocks of the front shield outer shell 101 through rotating shafts. When the front shield is expanded, the front ends of the front shield shell reducing hydraulic cylinder 203 and the front shield inner baffle reducing hydraulic cylinder 204 extend out, respectively pushing the front shield shell reducing block 102 and the front shield inner baffle reducing block 202 to the expansion position, and filling the front shield shell reducing block 102 between the adjacent blocks of the front shield shell 101, so that in the expansion state, the front shield shell 101 blocks and the front shield shell reducing blocks 102 adjacent on both sides are sequentially spliced ​​to form a closed space. When the front shield shrinks in diameter, the front ends of the front shield shell reducing hydraulic cylinder 203 and the front shield inner baffle reducing hydraulic cylinder 204 retract, respectively pulling the front shield shell reducing block 102 and the front shield inner baffle reducing block 202 to shrink in diameter, the front shield shell reducing block 102 moves out from between adjacent blocks of the front shield shell 101, and the front shield inner baffle reducing block 202 retracts into the front shield inner baffle block 201, so that in the reduced diameter state, the adjacent blocks of the front shield shell 101 are sequentially spliced ​​to form a closed space.

[0074] Furthermore, the middle shield inner shield body 5 also includes a middle shield outer shell reducing hydraulic cylinder 503 and a middle shield inner partition reducing hydraulic cylinder 504. The middle shield outer shell reducing hydraulic cylinder 503 is fixedly connected to the middle of the middle shield inner partition reducing block 502. The middle shield inner partition reducing hydraulic cylinder 504 is connected to the middle shield outer shell reducing block 402. The middle shield outer shell reducing block 402 includes two symmetrically arranged middle shield reducing connecting plates. The inner ends of the two middle shield reducing connecting plates are rotatably connected through a rotating shaft, and the outer ends of the two middle shield reducing connecting plates are rotatably connected to the adjacent blocks of the middle shield outer shell 401 through the rotating shaft. When the middle shield is expanded, the front ends of the middle shield shell reducing hydraulic cylinder 503 and the middle shield inner baffle reducing hydraulic cylinder 504 extend out, respectively pushing the middle shield shell reducing block 402 and the middle shield inner baffle reducing block 502 to the expansion position, and filling the middle shield shell reducing block 402 between the adjacent blocks of the middle shield shell 401, so that in the expansion state, the middle shield shell 401 blocks and the middle shield inner baffle reducing blocks 502 adjacent on both sides are sequentially spliced ​​to form a closed space. When the middle shield shrinks, the front ends of the middle shield outer shell reducing hydraulic cylinder 503 and the middle shield inner partition reducing hydraulic cylinder 504 are retracted respectively, pulling the middle shield outer shell reducing block 402 and the middle shield inner partition reducing block 502 to shrink, moving the middle shield outer shell reducing block 402 out from between the adjacent blocks of the middle shield outer shell 401, and retracting the middle shield inner partition reducing block 502 into the middle shield inner partition block 501, so that in the shrinking state, the adjacent blocks of the middle shield outer shell 401 are spliced ​​in sequence to form a closed space.

[0075] Furthermore, the front inner shield body 8 of the tail shield also includes a front outer shell reducing hydraulic cylinder 803 of the tail shield and a front inner baffle reducing hydraulic cylinder 804 of the tail shield. The front outer shell reducing hydraulic cylinder 803 of the tail shield is fixedly connected to the middle part of the front outer shell reducing block 702 of the tail shield. The front inner baffle reducing hydraulic cylinder 804 of the tail shield is connected to the front inner baffle reducing block 802 of the tail shield. The front outer shell reducing block 702 of the tail shield includes two symmetrically arranged front reducing connecting plates of the tail shield. The inner ends of the two front reducing connecting plates of the tail shield are rotatably connected through a rotating shaft, and the outer ends of the two front reducing connecting plates of the tail shield are rotatably connected to the adjacent blocks of the front outer shell 701 of the tail shield through the rotating shaft respectively. When the tail shield is expanded, the front ends of the tail shield front shell reducing hydraulic cylinder 803 and the tail shield front inner baffle reducing hydraulic cylinder 804 extend out, respectively pushing the tail shield front shell reducing block 702 and the tail shield front inner baffle reducing block 802 to the expansion position, and filling the tail shield front shell reducing block 702 between the adjacent blocks of the tail shield front shell 701, so that in the expansion state, the tail shield front shell 701 and the tail shield front shell reducing blocks 702 adjacent to each other on both sides are sequentially spliced ​​to form a closed space. When the tail shield is reduced in diameter, the front ends of the tail shield front shell reducing hydraulic cylinder 803 and the tail shield front inner baffle reducing hydraulic cylinder 804 are retracted respectively, pulling the tail shield front shell reducing block 702 and the tail shield front inner baffle reducing block 802 to reduce their diameters, moving the tail shield front shell reducing block 702 out from between adjacent blocks of the tail shield front shell 701, and retracting the tail shield front inner baffle reducing block 802 into the tail shield front inner baffle block 801, so that in the reduced diameter state, the adjacent blocks of the tail shield front shell 701 are spliced ​​in sequence to form a closed space.

[0076] Example 2

[0077] On the basis of Example 1, the tail shield further includes a tail shield middle 9 and a tail shield rear 11, a transition ring 10 is provided at the joint of the tail shield middle 9 and the tail shield rear 11, a M-shaped beam 6 is provided at the joint of the tail shield and the middle shield, and the M-shaped beam 5 is fixedly arranged at the inner cavity of the middle shield inner partition plate and the tail shield front inner partition plate to form an effective support. The tail shield middle 9 includes a tail shield middle shell 901, and when the tail shield middle 9 is in a reduced diameter state, the adjacent blocks of the tail shield middle shell 901 are sequentially spliced ​​to form a closed space, and when it is in an expanded diameter state, the blocks of the tail shield middle shell 901 and the tail shield middle shell reducer blocks 902 adjacent to both sides are sequentially spliced ​​to form a closed space.

[0078] When the tail shield is expanded, the transition ring 10 between the tail shield middle 9 and the tail shield rear 11 is removed and replaced with a blocking steel plate ring 14. After the tail shield is expanded, the tail shield middle rear flange 904 is cut off and a shield tail brush 15 is welded to the inner side of the rear part of the tail shield middle 9. When the tail shield is reduced, a circular ring plate 16 is welded to the tail shield middle front flange 903, the connecting bolts between the tail shield front and the tail shield middle 9 are removed, and a new tail shield middle 9 and tail shield rear 11 are installed behind the reduced diameter position of the tail shield front inside the circular ring plate 16.

[0079] Furthermore, the circulation system can be used to stabilize the formation during the shield expansion / contraction process.

[0080] Furthermore, the front shield shell reducing block 102, the middle shield shell reducing block 402, the tail shield front shell reducing block 702, and the tail shield middle shell reducing block 902 can also adopt an N-fold design to ensure that the length after folding does not affect the extension and retraction of the propulsion hydraulic cylinder.

[0081] Example 3

[0082] The present invention also provides a construction method for a shield body of an urban rail transit station-tunnel integrated shield machine, which is used in the diameter expansion process of the shield body of the urban rail transit station-tunnel integrated shield machine, and comprises the following steps:

[0083] Step 1: According to the construction design drawings, the shield is manufactured at the manufacturer, transported to the construction site for lowering, assembly, debugging and excavation.

[0084] Step 2: When the shield needs to be expanded, the circulation system is started to keep the formation stable during the shield expansion process.

[0085] Step three, use the variable diameter cutterhead to expand the excavation diameter, complete the cutterhead diameter expansion, and continue to excavate until the front shield diameter expansion space is met while the cutterhead diameter is expanded.

[0086] Step 4: Extend the front ends of the front shield shell reducing hydraulic cylinder 203 and the front shield inner baffle reducing hydraulic cylinder 204 to push the front shield shell reducing block 102 and the front shield inner baffle reducing block 202 to expand the diameters respectively. At the same time, fill the front shield shell reducing block 102 between adjacent blocks of the front shield shell 101, extend the front shield inner baffle reducing block 202 to the expansion position and fill the gaps between adjacent front shield inner baffle reducing blocks 202 to complete the expansion of the front shield.

[0087] Step 5: When the cutterhead is expanding, the shield machine continues to excavate until the expansion space of the middle shield is met.

[0088] Step six, extend the front ends of the middle shield shell reducing hydraulic cylinder 503 and the middle shield inner partition reducing hydraulic cylinder 504, respectively push the middle shield shell reducing block 402 and the middle shield inner partition reducing block 502 to expand the diameter, and at the same time, fill the middle shield shell reducing block 402 between the adjacent blocks of the middle shield shell 401, extend the middle shield inner partition reducing block 502 to the expansion position, and complete the expansion of the middle shield.

[0089] Step seven, in the state of cutterhead expansion, the shield machine continues to excavate until the expansion space in front of the tail shield and in the middle of the tail shield is met.

[0090] Step eight, remove the connecting bolts 13 between the transition ring 10 and the rear shield 11.

[0091] Step nine, remove the transition ring 10 and replace it with a sealing steel plate ring 14.

[0092] Step ten, extend the front ends of the tail shield front shell reducing hydraulic cylinder 803 and the tail shield front inner baffle reducing hydraulic cylinder 804 to push the tail shield front shell reducing block 702 and the tail shield front inner baffle reducing block 802 to expand the diameter; at the same time, fill the tail shield front shell reducing block 702 between the blocks of the tail shield front shell 701, fill the tail shield middle shell reducing block 902 between the adjacent blocks of the tail shield middle shell 901, and extend the tail shield front inner baffle reducing block 802 to the expansion position to complete the expansion of the tail shield front and tail shield middle 9.

[0093] Step 11: Cut off the rear flange 904 in the tail shield.

[0094] Step 12: Weld the shield tail brush 15 on the inner side of the rear portion of the tail shield 9.

[0095] Step thirteen, discard the tail shield 11 and the plugging steel plate ring 14 into the stratum to complete the expansion of the entire shield machine.

[0096] Step 14, after the shield machine completes excavation in the expanded diameter state, first, pre-reinforce the front of the cutterhead and around the shield body, then cut off the front shield outer shell partition 103, the middle shield outer shell partition 403, and the rear shield front outer shell partition 703, and then shrink the front shield inner shield body 1, the middle shield inner shield body 5, and the rear shield front inner shield body 8 to the reduced diameter state, and finally remove the assembled modules in the shield body and transport them to the starting well for hoisting, and abandon the shield shell in the formation.

[0097] Example 4

[0098] The present invention also provides a construction method for a shield body of an urban rail transit station-tunnel integrated shield machine, which is used in the diameter reduction process of the shield body of the urban rail transit station-tunnel integrated shield machine, and comprises the following steps:

[0099] Step 1: When the shield machine needs to shrink in diameter, start the circulation system to keep the ground stable during the shrinking process of the shield.

[0100] Step 2: Retract the variable diameter cutter disc to complete the cutter disc diameter reduction.

[0101] Step 3: shorten the front shield shell reducing hydraulic cylinder 203 and the front shield inner partition reducing hydraulic cylinder 204. At the same time, move the front shield shell reducing block 102 out from between the adjacent blocks of the front shield shell 101, and retract the front shield inner partition reducing block 202 into the front shield inner partition block 201 to complete the front shield reduction.

[0102] Step 4: After the front shield is reduced in diameter, the middle shield outer shell reducing hydraulic cylinder 503 and the middle shield inner partition reducing hydraulic cylinder 504 are shortened. At the same time, the middle shield outer shell reducing block 402 is moved out from between the adjacent blocks of the middle shield outer shell 401, and the middle shield inner partition reducing block 502 is retracted into the middle shield inner partition block 501 to complete the middle shield reduction.

[0103] Step 5: Remove the connecting bolts 13 between the front and middle of the tail shield.

[0104] Step 6: Weld the annular plate 16 onto the front flange 903 in the tail shield.

[0105] Step 7: Install new tail shield middle 9 and tail shield rear 11 on the inner side of the circular ring plate 16 and behind the predetermined reduced diameter position of the tail shield front.

[0106] Step 8: After the middle shield is reduced in diameter, the tail shield front shell reducing hydraulic cylinder 803 and the tail shield front inner partition reducing hydraulic cylinder 804 are shortened. At the same time, the tail shield front shell reducing block 702 is moved out between the adjacent blocks of the tail shield front shell 701, and the tail shield middle shell reducing block 902 is moved out between the blocks of the tail shield middle shell 901, and the tail shield front inner partition reducing block 802 is retracted into the tail shield front inner partition block 801, completing the reduction of the tail shield front and the tail shield middle 9.

[0107] Step 9: After the tail shield front and tail shield middle 9 are reduced in diameter, the tail shield front and the new tail shield middle 9 are connected with the connecting bolts 13.

[0108] Step 10: Abandon the old tail shield 9 in the stratum to complete the reduction of the shield body of the entire shield machine.

[0109] The shield expansion / contraction structure of the present invention is easy to operate, has a large expansion / contraction range, and can ensure that the shape does not change significantly. The shield shell is always in a closed ring state, and can be abandoned and disintegrated in the expanded state, thereby reducing the occupation of traditional station and tunnel construction areas, pipeline relocation and interference with traffic in busy urban streets, avoiding the problem of repeated transfer of shield machines during tunnel construction, and reducing the discarded length of the tail shield and the pre-reinforcement process of the stratum. The shield body of the present invention has a mud-water balance function. When the shield body expands and contracts, the circulation system can be used to maintain the stability of the stratum. The present invention improves the application scope of the shield method, the applicability and construction efficiency of the shield machine, and promotes the green construction process of urban rail transit projects.

[0110] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A shield body of an integrated shield machine for urban rail transit stations and tunnels, characterized in that: include: A front shield, comprising a front shield outer shield body (1) and a front shield inner shield body (2), wherein the front shield outer shield body (1) comprises a front shield outer shell (101), a front shield outer shell reducing block (102) and a front shield outer shell partition (103) which are fixedly connected, and the front shield inner shield body (2) comprises a front shield inner partition block (201), a front shield inner partition reducing block (202) is arranged in the front shield inner partition block (201), and the front shield inner partition reducing block (202) is fixedly connected to the front shield outer shell partition (103); A middle shield, comprising a middle shield outer shield body (4) and a middle shield inner shield body (5), wherein the middle shield outer shield body (4) comprises a middle shield outer shell (401), a middle shield outer shell reducing block (402) and a middle shield outer shell partition (403) which are fixedly connected, and the middle shield inner shield body (5) comprises a middle shield inner partition block (501), a middle shield inner partition reducing block (502) is arranged in the middle shield inner partition block (501), and the middle shield inner partition reducing block (502) is fixedly connected to the middle shield outer shell partition (403); A tail shield, comprising a tail shield front outer shield body (7) and a tail shield front inner shield body (8), wherein the tail shield front outer shield body (7) comprises a tail shield front outer shell (701), a tail shield front outer shell reducing block (702) and a tail shield front outer shell partition (703) which are fixedly connected, and the tail shield front inner shield body (8) comprises a tail shield front inner partition block (801), a tail shield front inner partition reducing block (802) is arranged in the tail shield front inner partition block (801), and the tail shield front inner partition reducing block (802) is fixedly connected to the tail shield front outer shell partition (703); The front shield shell (101), the middle shield shell (401), and the tail shield front shell (701) are all block structures, and the front shield shell reducing block (102), the middle shield shell reducing block (402), and the tail shield front shell reducing block (702) can be respectively removed or filled between adjacent blocks of the front shield shell (101), the middle shield shell (401), and the tail shield front shell (701); The front shield inner shield body further comprises a front shield outer shell variable diameter hydraulic cylinder (203) and a front shield inner baffle variable diameter hydraulic cylinder (204); the front shield inner baffle variable diameter hydraulic cylinder (204) is connected to the front shield inner baffle variable diameter block (202); the front shield outer shell variable diameter hydraulic cylinder (203) is fixedly connected to the middle of the front shield outer shell variable diameter block (102); the front shield outer shell variable diameter block (102) comprises two symmetrically arranged front shield variable diameter connecting plates (1021); the inner ends of the two front shield variable diameter connecting plates (1021) are rotatably connected via a rotating shaft; the outer ends of the two front shield variable diameter connecting plates (1021) are rotatably connected to adjacent blocks of the front shield outer shell (101) via a rotating shaft; in an expanded state, the front shield outer shell (101) blocks and the adjacent front shield outer shell variable diameter blocks (102) on both sides are sequentially spliced ​​to form a closed space; in a reduced state, the adjacent blocks of the front shield outer shell (101) are sequentially spliced ​​to form a closed space.

2. The shield body of the urban rail transit station-tunnel integrated shield machine according to claim 1 is characterized by: The middle shield inner shield body (5) further comprises a middle shield outer shell variable diameter hydraulic cylinder (503) and a middle shield inner baffle variable diameter hydraulic cylinder (504); the middle shield outer shell variable diameter hydraulic cylinder (503) is fixedly connected to the middle part of the middle shield inner baffle variable diameter block (502); the middle shield inner baffle variable diameter hydraulic cylinder (504) is connected to the middle shield outer shell variable diameter block (402); the middle shield outer shell variable diameter block (402) comprises two symmetrically arranged middle shield variable diameter connecting plates; the inner ends of the two middle shield variable diameter connecting plates are rotatably connected via a rotating shaft; the outer ends of the two middle shield variable diameter connecting plates are respectively rotatably connected to adjacent blocks of the middle shield outer shell (401) via a rotating shaft; in an expanded diameter state, the middle shield outer shell (401) blocks and the middle shield inner baffle variable diameter blocks (502) adjacent to each other on both sides are sequentially spliced ​​to form a closed space; in a reduced diameter state, the adjacent blocks of the middle shield outer shell (401) are sequentially spliced ​​to form a closed space.

3. The shield body of the urban rail transit station-tunnel integrated shield machine according to claim 2 is characterized in that: The tail shield front inner shield body (8) further comprises a tail shield front outer shell variable diameter hydraulic cylinder (803) and a tail shield front inner baffle variable diameter hydraulic cylinder (804); the tail shield front outer shell variable diameter hydraulic cylinder (803) is fixedly connected to the middle of the tail shield front outer shell variable diameter block (702); the tail shield front inner baffle variable diameter hydraulic cylinder (804) is connected to the tail shield front inner baffle variable diameter block (802); the tail shield front outer shell variable diameter block (702) comprises two tail shield front variable diameter connecting plates symmetrically arranged; the inner ends of the two tail shield front variable diameter connecting plates are rotatably connected via a rotating shaft; the outer ends of the two tail shield front variable diameter connecting plates are respectively rotatably connected to adjacent blocks of the tail shield front outer shell (701) via the rotating shaft; in the expanded diameter state, the tail shield front outer shell (701) and the adjacent tail shield front outer shell variable diameter blocks (702) on both sides are sequentially spliced ​​to form a closed space; in the reduced diameter state, the adjacent blocks of the tail shield front outer shell (701) are sequentially spliced ​​to form a closed space.

4. The shield body of the urban rail transit station-tunnel integrated shield machine according to claim 3 is characterized in that: The tail shield further comprises a tail shield middle (9) and a tail shield rear (11), a transition ring (10) is provided at the joint of the tail shield middle (9) and the tail shield rear (11), a M-shaped beam (6) is provided at the joint of the tail shield and the middle shield, and when the tail shield middle (9) is in a reduced diameter state, adjacent blocks of the tail shield middle shell (901) are sequentially spliced ​​to form a closed space, and when the tail shield middle (9) is in an expanded diameter state, blocks of the tail shield middle shell (901) and adjacent tail shield middle shell reducing blocks (902) on both sides are sequentially spliced ​​to form a closed space.

5. The shield body of the urban rail transit station-tunnel integrated shield machine according to claim 4 is characterized in that: When the tail shield is expanded, the transition ring (10) between the tail shield center (9) and the tail shield rear (11) is removed and replaced with a blocking steel plate ring (14), and after the tail shield is expanded, the tail shield center rear flange (904) is cut off and a tail brush (15) is welded on the inner side of the rear part of the tail shield center (9).

6. The shield body of the urban rail transit station-tunnel integrated shield machine according to claim 4 is characterized in that: When the tail shield is reduced in diameter, a circular plate (16) is welded to the front flange (903) of the tail shield, and the connecting bolts between the front and middle parts of the tail shield (9) are removed, and a new middle part of the tail shield (9) and a rear part of the tail shield (11) are installed behind the reduced diameter position of the front part of the tail shield inside the circular plate (16).

7. A construction method for a shield body of an integrated shield machine for urban rail transit station and tunnel, which is used in the diameter expansion process of the shield body of an integrated shield machine for urban rail transit station and tunnel as claimed in claim 4, characterized in that: The steps include: Step 1: According to the construction design drawings, the shield is manufactured at the manufacturer, transported to the construction site, assembled, debugged and excavated; Step 2: When the shield needs to be expanded, the circulation system is started to keep the formation stable during the shield expansion process; Step 3: Use the variable diameter cutterhead to expand the diameter, complete the cutterhead expansion, and continue to excavate until the front shield expansion space is met in the cutterhead expansion state; Step 4, extending the front ends of the front shield shell reducing hydraulic cylinder (203) and the front shield inner baffle reducing hydraulic cylinder (204), respectively pushing the front shield shell reducing block (102) and the front shield inner baffle reducing block (202) to expand the diameters; at the same time, filling the front shield shell reducing block (102) between adjacent blocks of the front shield shell (101), extending the front shield inner baffle reducing block (202) to the expansion position and filling the gap between adjacent front shield inner baffle reducing blocks (202), thereby completing the expansion of the front shield; Step 5: In the state of cutterhead expansion, the shield machine continues to excavate until the expansion space of the middle shield is met; Step 6, extending the front ends of the middle shield shell reducing hydraulic cylinder (503) and the middle shield inner baffle reducing hydraulic cylinder (504), respectively pushing the middle shield shell reducing block (402) and the middle shield inner baffle reducing block (502) to expand the diameters, and at the same time, filling the middle shield shell reducing block (402) between adjacent blocks of the middle shield shell (401), extending the middle shield inner baffle reducing block (502) to the expansion position, and completing the expansion of the middle shield; Step 7: In the state of cutterhead expansion, the shield machine continues to excavate until the expansion space in front of the tail shield and in the tail shield (9) is met; Step 8, removing the connecting bolts (13) between the transition ring (10) and the rear shield (11); Step nine, removing the transition ring (10) and replacing it with a sealing steel plate ring (14); Step 10, extending the front ends of the tail shield front shell reducing hydraulic cylinder (803) and the tail shield front inner baffle reducing hydraulic cylinder (804) to push the tail shield front shell reducing block (702) and the tail shield front inner baffle reducing block (802) to expand the diameter, and at the same time, filling the tail shield front shell reducing block (702) between the tail shield front shell (701) blocks, filling the tail shield middle shell reducing block (902) between the adjacent blocks of the tail shield middle shell (901), and extending the tail shield front inner baffle reducing block (802) to the expansion position, completing the expansion of the tail shield front and tail shield middle (9); Step 11, cut off the rear flange (904) in the tail shield; Step 12, welding the shield tail brush (15) on the inner side of the rear portion of the tail shield (9); Step 13, discarding the rear shield (11) and the plugging steel plate ring (14) into the stratum to complete the expansion of the entire shield machine; Step 14: After the shield machine has completed excavation in the expanded state, first, pre-reinforce the front of the cutterhead and the shield body, then cut off the front shield outer shell partition (103), the middle shield outer shell partition (403), and the rear shield front outer shell partition (703), and then shrink the front shield inner shield body (1), the middle shield inner shield body (5), and the rear shield front inner shield body (8) to the reduced diameter state, and finally remove the assembled modules in the shield body, transport them to the starting well and hoist them out, and abandon the shield shell in the formation.

8. A construction method for a shield body of an integrated shield machine for urban rail transit station and tunnel, which is used in the diameter reduction process of the shield body of an integrated shield machine for urban rail transit station and tunnel as claimed in claim 4, characterized in that: The steps include: Step 1: When the shield machine needs to shrink, start the circulation system to keep the ground stable during the shrinking process of the shield; Step 2: Retract the variable diameter cutter disc to complete the cutter disc diameter reduction; Step 3: shorten the front shield shell reducing hydraulic cylinder (203) and the front shield inner baffle reducing hydraulic cylinder (204), and at the same time, move the front shield shell reducing block (102) out from between adjacent blocks of the front shield shell (101), and retract the front shield inner baffle reducing block (202) into the front shield inner baffle block (201), thereby completing the front shield reduction; Step 4: After the front shield is reduced in diameter, the middle shield outer shell reducing hydraulic cylinder (503) and the middle shield inner baffle reducing hydraulic cylinder (504) are shortened. At the same time, the middle shield outer shell reducing block (402) is moved out from between the adjacent blocks of the middle shield outer shell (401), and the middle shield inner baffle reducing block (502) is retracted into the middle shield inner baffle block (501), thereby completing the reduction of the middle shield; Step 5: Remove the connecting bolts (13) between the front and middle of the tail shield (9); Step 6: Weld the annular plate (16) onto the front flange (903) in the tail shield; Step 7: Install a new tail shield middle (9) and tail shield rear (11) on the inner side of the circular plate (16) and behind the predetermined reduced diameter position of the tail shield front; Step 8: After the middle shield is reduced in diameter, the tail shield front outer shell reducing hydraulic cylinder (803) and the tail shield front inner baffle reducing hydraulic cylinder (804) are shortened. At the same time, the tail shield front outer shell reducing block (702) is moved out between the adjacent blocks of the tail shield front outer shell (701), the tail shield middle outer shell reducing block (902) is moved out between the blocks of the tail shield middle outer shell (901), and the tail shield front inner baffle reducing block (802) is retracted into the tail shield front inner baffle block (801), thereby completing the reduction of the tail shield front and tail shield middle (9); Step 9: After the diameter reduction of the front tail shield and the middle tail shield (9) is completed, the front tail shield is connected to the new middle tail shield (9) using connecting bolts (13); Step 10: Abandon the old tail shield (9) in the stratum to complete the reduction of the shield body of the entire shield machine.

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