Existing tunnel diameter expansion device and method without affecting vehicle traffic

Abstract

The present invention discloses an existing tunnel diameter expansion device and method that does not affect the passage of vehicles. The existing tunnel diameter expansion device that does not affect the passage of vehicles comprises a traveling trolley (3) and a lifting protection frame (1). The traveling trolley (3) comprises a left side support portion (301), a top working platform (302) and a right side support portion (303) connected in sequence from left to right. The left side support portion (301), the top working platform (302) and the right side support portion (303) form a driving passage (304). The top working platform (302) comprises a front section of the working platform (305). The lifting protection frame (1) and the front section of the working platform (305) are stacked up and down, and the lifting protection frame (1) can be lifted and lowered. A dome-shaped lifting frame is arranged at the front of the traveling trolley to form support for the front of the stratum to be expanded and excavated, so as to prevent the stratum disturbance in the excavation area in the middle of the trolley from causing the stratum in front of the trolley to collapse and hit the moving traffic vehicles.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, in particular to an existing tunnel diameter expansion device which does not affect the passage of vehicles, and also to an existing tunnel diameter expansion method which does not affect the passage of vehicles. Background Art

[0002] With the construction of various railway tunnels and highway tunnels around the world, the development of high-speed rail technology and the sharp increase in highway traffic, many old tunnels can no longer meet the existing needs. The existing conventional operation is to divert the line, abandon the original line, or close the line, and then resume traffic after the line reconstruction is completed, which puts great pressure on transportation and social and economic costs, and is not conducive to the needs of green environmental protection and ecological development. Therefore, it is extremely important to design an existing tunnel expansion device and its construction method that can not affect the passage of vehicles. Summary of the invention

[0003] In order to expand the diameter of an existing tunnel without affecting the passage of vehicles, the present invention provides an existing tunnel expansion device and method without affecting the passage of vehicles. The existing tunnel expansion device without affecting the passage of vehicles forms a driving passage for vehicles to pass through inside it, and a dome-shaped lifting frame is arranged at the front of the traveling trolley, which can form support for the front of the stratum to be expanded and excavated, so as to prevent the stratum disturbance in the expansion area in the middle of the trolley from causing the stratum in front of the trolley to collapse and hit the moving traffic vehicles. At the same time, an advance drilling rig, a demolition hammer and a segment assembly machine are configured, so that the expansion, trimming, segment installation and grouting operations of the existing tunnel can be completed while ensuring the passage of vehicles.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] The invention discloses an existing tunnel diameter enlarging device which does not affect the passage of vehicles, and comprises a traveling trolley and a lifting protection frame. The traveling trolley comprises a left side supporting part, a top working platform and a right side supporting part which are sequentially connected from left to right. The left side supporting part, the top working platform and the right side supporting part form a driving passage. The top working platform comprises a working platform front section. The lifting protection frame and the working platform front section are stacked up and down, and the lifting protection frame can be raised and lowered.

[0006] An existing tunnel diameter expansion method that does not affect the passage of vehicles, the existing tunnel diameter expansion method that does not affect the passage of vehicles adopts the above-mentioned existing tunnel diameter expansion device that does not affect the passage of vehicles, and the existing tunnel diameter expansion method that does not affect the passage of vehicles includes the following steps:

[0007] Step 1: the existing tunnel diameter expansion device that does not affect the passage of vehicles enters the original tunnel, the rear end of the lifting protection frame corresponds to the front end of the section to be demolished of the original tunnel, and the lifting protection frame rises and supports the front of the section to be demolished of the original tunnel;

[0008] Step 2, dismantling the section to be dismantled to form a newly excavated section of the newly excavated and enlarged tunnel;

[0009] Step 3, treating the surface of the newly excavated section to form a treated section;

[0010] Step 4: Install the segments in the treatment section.

[0011] The beneficial effects of the present invention are as follows: the existing tunnel expansion device and method that does not affect the passage of vehicles can effectively solve the gap in special construction machinery faced by tunnel expansion in soft or broken formations, and effectively solve the problems of inconvenient equipment and low operating efficiency in tunnel expansion in the prior art. It is not only suitable for mountain railway or highway tunnels, but also suitable for tunnel expansion construction operations in urban subway highway tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings in the specification, which constitute a part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0013] Figure 1 It is a schematic diagram of an existing tunnel diameter expansion device that does not affect the passage of vehicles as described in the present invention.

[0014] Figure 2 is along Figure 1 Schematic cross-sectional view along the AA direction.

[0015] Figure 3 is along Figure 1 Schematic cross-sectional view along the BB direction.

[0016] Figure 4 is along Figure 1 Schematic cross-sectional view in the CC direction.

[0017] Figure 5 is along Figure 1 Schematic cross-sectional view in the DD direction.

[0018] Figure 6 It is a cross-sectional schematic diagram after the segment assembly machine completes the installation of a ring of segments.

[0019] Figure 7 is along Figure 6 Schematic cross-sectional view along the EE direction.

[0020] Figure 8 It is a simplified schematic diagram of the traveling trolley.

[0021] Fig. 9 It is a schematic diagram of the front of the lifting protection frame supporting the section to be removed.

[0022] Fig.10It is a schematic diagram of treating the surface of a newly excavated section to form a treated section.

[0023] The following are the descriptions of the reference numerals:

[0024] 1. Lifting protection frame; 2. Personnel operating platform; 3. Traveling trolley; 4. Advanced drilling rig; 5. Demolition hammer; 6. Ladder for assembler; 7. Segment assembler; 8. Support structure for segment assembler; 9. Traveling wheels for trolley; 10. Traveling tracks for trolley; 11. Ladder for operating platform; 12. Platform lifting cylinder; 13. Dome lifting cylinder; 14. Original train track; 15. Train; 16. Original tunnel; 17. Newly excavated and enlarged tunnel; 20. Rotating mechanism for assembler; 21. Suction cup for assembler; 22. Segment; 23. Gap; 24. Long airbag;

[0025] 301, left side support; 302, top work platform; 303, right side support; 304, driving channel; 305, front section of work platform; 306, middle section of work platform; 307, rear section of work platform; 308, top external work platform; 309, external baffle;

[0026] 801, arc frame; 802, connecting beam;

[0027] 1601, section to be demolished;

[0028] 1701, newly excavated section; 1702, processed section;

[0029] 3011, left front pillar; 3012, left rear pillar;

[0030] 3031, right front pillar; 3032, right rear pillar. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] An existing tunnel expansion device that does not affect the passage of vehicles includes a traveling trolley 3 and a lifting protection frame 1. The traveling trolley 3 includes a left support portion 301, a top work platform 302 and a right support portion 303 connected in sequence from left to right. The left support portion 301, the top work platform 302 and the right support portion 303 form a driving passage 304. The top work platform 302 includes a work platform front section 305. The lifting protection frame 1 and the work platform front section 305 are stacked up and down. The lifting protection frame 1 can be raised and lowered. Figures 1 to 5 shown.

[0033] In this embodiment, the lifting protection frame 1 is a plate-like structure, and the cross section of the lifting protection frame 1 is an arc shape, and the arc extends in the front-to-back direction to form the lifting protection frame 1. In the direction from left to right, the middle part of the lifting protection frame 1 is higher than the left and right ends of the lifting protection frame 1, and the upper surface of the lifting protection frame 1 can match and abut with the upper part of the original tunnel 16. The lifting protection frame 1 can form a support for the front of the stratum to be expanded and excavated, so as to prevent the stratum disturbance in the expansion area in the middle of the trolley from causing the stratum in front of the trolley to collapse and hit the moving traffic vehicles (such as trains 15 or cars, etc.). Figure 1 and Figure 2 shown.

[0034] In this embodiment, along the direction from left to right, the width of the lifting protection frame 1 is greater than the width of the front section 305 of the work platform. Along the direction from front to back, the length of the lifting protection frame 1 is substantially the same as the length of the front section 305 of the work platform. The left and right sides of the lifting protection frame 1 are connected with a dome frame lifting cylinder 13, which is in an upright state and can be synchronously extended and retracted, so that the dome frame lifting cylinder 13 can make the lifting protection frame 1 rise and fall horizontally.

[0035] In this embodiment, the top of the left support part 301 is connected and fixed to the left end of the top workbench 302, and the top of the right support part 303 is connected and fixed to the right end of the top workbench 302. The left support part 301 includes a left front column 3011, and the right support part 303 includes a right front column 3031. The left front column 3011 and the right front column 3031 are respectively located on the left and right sides of the front section 305 of the workbench, and the dome frame lifting cylinder 13 is located in the left front column 3011 and the right front column 3031. Figure 8 shown.

[0036] In this embodiment, the top work platform 302 is a plate-like structure, and the cross section of the top work platform 302 is an arc, and the arc extends along the front-back direction to form the top work platform 302. The axis of the lifting protection frame 1 coincides with the axis of the top work platform 302, and the lifting protection frame 1 and the front section 305 of the work platform can be stacked and matched and connected up and down, and the axis of the lifting protection frame 1 is parallel to the traveling direction of the traveling trolley 3.

[0037] In this embodiment, the top workbench 302 further includes a workbench middle section 306 and a workbench rear section 307. The workbench front section 305, the workbench middle section 306 and the workbench rear section 307 are arranged in sequence from front to rear. The left support portion 301 includes a left rear column 3012, and the right support portion 303 includes a right rear column 3032. The left rear column 3012 and the right rear column 3032 are respectively located on the left and right sides of the workbench rear section 307. Figure 8 shown.

[0038] In this embodiment, both left and right ends of the workbench rear section 307 are connected to a top external work platform 308, and the top external work platform 308 is a horizontal plate-shaped structure. In the front-to-back direction, the length of the top external work platform 308 is substantially the same as that of the workbench rear section 307. The middle section 306 of the work platform mainly corresponds to the section to be demolished. The left and right sides of the top work platform 302 are provided with outer baffles 309, and the left and right outer baffles 309 are correspondingly connected to the left and right ends of the top work platform 302. The height of the outer baffle 309 corresponds to the height of the left or right side of the top work platform 302. The outer baffle 309 is in an upright state, and the outer baffle 309 is parallel to the front and rear direction, along the front and rear direction; the length of the outer baffle 309 is basically the same as the length of the top work platform 302. The left and right sides are provided with outer baffles 309 and the top work platform 302 to form a closed cover. The function of the outer baffle 309 is to prevent the debris on the left and right sides of the demolition of the original tunnel from entering the driving channel 304, to separate the working area and the driving channel 304, and to protect the safety of vehicles inside the driving channel.

[0039] In this embodiment, personnel operating platforms 2 are provided outside the left and right ends of the middle section 306 of the work platform, and the personnel operating platforms 2 are located on the outside of the outer baffle 309. The personnel operating platform 2 is a flat structure, and one end of the personnel operating platform 2 is hinged to the middle section 306 of the work platform through a hinge shaft, and the axis of the hinge shaft is parallel to the travel direction of the walking trolley 3. The personnel operating platform 2 is connected to a platform lifting cylinder 12, and the platform lifting cylinder 12 can raise and lower the personnel operating platform 2. When the personnel operating platform 2 is in a raised state, the personnel operating platform 2 is in a horizontal state; when the personnel operating platform 2 is in a lowered state, the personnel operating platform 2 is in an upright state. In addition, operating platform ladders 11 can also be provided on the left and right sides of the middle section 306 of the work platform. The operator can stand on the personnel operating platform 2 to perform spraying operations to form a preliminary lining, or when the rock layer is broken, it can be reinforced by laying steel mesh after anchoring the top rock layer, such as Figure 3 shown.

[0040] In this embodiment, along the left-right direction, the distance between the left support part 301 and the right support part 303 is greater than the width of the original train track 14 or the original formed road in the original tunnel 16. Along the front-to-back direction, the length of the middle section 306 of the work platform is less than the length of the front section 305 of the work platform, and the length of the front section 305 of the work platform is less than the length of the rear section 307 of the work platform. A demolition hammer 5 is provided on the rear section 307 of the work platform, and an advance drill 4 is provided on the top external work platform 308. Both the demolition hammer 5 and the advance drill 4 can move forward and backward, and both the demolition hammer 5 and the advance drill 4 can adopt existing technology products. The advance drill 4 is used for drilling and blasting on intact rock formations or for performing advance grouting reinforcement operations in soft formations; the demolition hammer 5 is used for demolition of rock formations or concrete structures behind the lifting protection frame, and for trimming the boundary dimensions of tunnel formation, such as Figure 4 shown.

[0041] In this embodiment, the lower end of the left support portion 301 includes a left lower cross beam, the lower end of the right support portion 303 includes a right lower cross beam, the lower end of the left front column 3011 and the lower end of the left rear column 3012 are both connected and fixed to the left lower cross beam, and the lower end of the right front column 3031 and the lower end of the right rear column 3032 are both connected and fixed to the right lower cross beam. The left lower cross beam and the right lower cross beam both extend in the front-to-back direction, and the traveling direction of the walking trolley 3 is the front-to-back direction. The lower end of the walking trolley 3 is provided with a trolley running wheel 9, the trolley running wheel 9 includes a brake mechanism, and the trolley running wheel 9 is connected to the left lower cross beam and the right lower cross beam.

[0042] In this embodiment, the rear end of the traveling trolley 3 is connected with the segment assembly machine support structure 8 and the segment assembly machine 7 in sequence. The segment assembly machine support structure 8 includes an arc frame 801 and a connecting beam 802. The segment assembly machine 7 is located on the arc frame 801, and the arc frame 801 is connected to the traveling trolley 3 through the connecting beam 802. The segment assembly machine 7 includes an assembly machine rotating mechanism 20 and an assembly machine suction cup 21, as shown in FIG. Figure 1 , Figure 5 and Fig. 9 shown.

[0043] The traveling trolley 3 is used to support the above-mentioned components, and utilizes its own closed structure to form a driving passage 304 that can cover the vehicles below, thereby ensuring the smooth and safe passage of the train 15 (or other vehicles) below; the segment assembler 7 is used to assemble the prefabricated segments 22 again in the formed expanded tunnel as a secondary lining to form the final tunnel shape; the segment assembler support structure 8 is used to support the segment assembler 7 and enable it to move circumferentially on the arc frame 801 to meet the circumferential segment laying of the tunnel after the expansion is completed.

[0044] The following is an existing tunnel diameter expansion method that does not affect the passage of vehicles. The existing tunnel diameter expansion method that does not affect the passage of vehicles adopts the above-mentioned existing tunnel diameter expansion device that does not affect the passage of vehicles. The existing tunnel diameter expansion method that does not affect the passage of vehicles includes the following steps:

[0045] Step 1: The existing tunnel expansion device that does not affect the passage of vehicles enters the original tunnel 16, the original train track 14 is located between the left support part 301 and the right support part 303, the train 15 can be located in the driving channel 304, the rear end of the lifting protection frame 1 corresponds to the front end of the section 1601 to be demolished of the original tunnel 16, and the lifting protection frame 1 is raised and supports the front of the section 1601 to be demolished of the original tunnel 16, as shown in FIG. Fig. 9 As shown;

[0046] First, the traveling trolley 3 is driven into the original tunnel 16 to be expanded. At this time, the lifting and protection frame 1 is in the retracted state, that is, the dome frame lifting cylinder 13 is in the retracted state, and the lifting and protection frame 1 is lowered. After reaching the designated position (the rear end of the lifting and protection frame 1 corresponds to the front end of the section to be demolished 1601 of the original tunnel 16), the piston rod of the dome frame lifting cylinder 13 is extended, and the lifting and protection frame 1 rises to hold the tunnel top in front of the section to be demolished 1601 tightly, preventing the demolition hammer 5 on the rear section 307 of the rear work platform or the advance drilling rig 4 from disturbing the rock layer in front of the section to be demolished 1601 during construction, causing collapse and hitting the vehicle moving forward under the traveling trolley 3.

[0047] Step 2, dismantling the section to be dismantled 1601 to form a newly excavated section 1701 of the newly excavated and enlarged tunnel 17;

[0048] Specifically, the demolition hammer operator drives the demolition hammer 5 forward to demolish the section to be demolished 1601, thereby achieving the hole diameter expansion operation.

[0049] In order to cope with the collapse caused by soft strata, between step 1 and step 2, the operator can drive the advance drilling rig 4 forward in advance and perform advance grouting reinforcement on the section to be demolished 1601 through the advance drilling rig 4; after the reinforcement is completed, the operator can drive the demolition hammer 5 forward, demolish the section to be demolished 1601, and expand the hole diameter; when the surrounding area of ​​the section to be demolished 1601 does not need to be reinforced, the demolition hammer operator can expand the hole diameter in the non-reinforced area to save process time.

[0050] The advance drilling machine 4 can move forward and backward on the traveling trolley 3. An advance drilling machine 4 is arranged on the left and right sides of the traveling trolley 3 and on the two top external working platforms 308. The advance drilling machine arm has 6 degrees of freedom, and the arm can be extended and retracted to meet the operations of advance drilling, advance grouting reinforcement and anchoring at various angles on one side. The demolition hammer 5 is arranged in the top center area of ​​the traveling trolley (i.e., the top working platform 302), and can move along the front and rear direction of the traveling trolley 3. The demolition hammer arm is retractable to meet the demolition work of the top and side areas. Auxiliary equipment can be used to carry out demolition work on the uncovered areas at the bottom of both sides of the tunnel, such as Fig.10 shown.

[0051] Step 3, treating the surface of the newly excavated section 1701 to form a treated section 1702;

[0052] The travel direction of the trolley 3 is parallel to the axis direction of the original tunnel 16. When the trolley 3 enters the tunnel to be expanded (i.e., the original tunnel 16), the personnel operating platform 2 is in a lowered state. After the trolley 3 is completed, the wheels can be locked by its own brake mechanism to prevent the trolley from slipping during operation. The trolley 3 of the existing tunnel expansion device that does not affect the passage of vehicles adopts a self-driving mode, and can rely on its own trolley running wheels 9 to drive itself to move on the trolley running track 10. The original train track 14 is located between the two trolley running tracks 10. Fig.10 shown.

[0053] After the section to be demolished 1601 is demolished, if it is necessary to process the surface of the newly excavated section 1701, for example, to reinforce the broken surrounding rock or soft stratum area after the expansion construction is completed (i.e., to reinforce the surface of the newly excavated section 1701), the personnel operating platform 2 is raised, and the operator can stand on the raised personnel operating platform 2 to reinforce the stratum by drilling holes, driving anchor rods, or laying steel mesh.

[0054] Step 4: Install the pipe segment 22 in the processing section 1702;

[0055] The assembling machine 7 at the rear of the trailer can grab the prefabricated segments 22 to complete the assembly of a whole ring of segments; when several rings of complete segments are assembled, the operator will insert the sealed long strip airbag 24 into the gap 23 between the last segment and the stratum along the circumference of the newly excavated and expanded tunnel 17, inflate the long strip airbag 24, and tighten the gap to prevent leakage during the grouting process. After the above measures are completed, grouting is performed into the gap 23 between the strata through the grouting holes of the segments 22, thereby completing the grouting of the gap between the segments 22 and the stratum. After the grouting is completed, the air in the sealed airbag 24 can be removed first, and then the sealed airbag can be removed, and then the next ring of segments can be assembled, and so on. Figure 6 and Figure 7 shown.

[0056] For the sake of easy understanding and description, absolute positional relationships are used in this invention for expression. Without special instructions, the directional term "up" herein refers to Figure 2 the upper side direction in Figure 2 the lower side direction in Figure 2 the left side direction in Figure 2 the right side direction in Figure 2 the direction perpendicular to the paper surface of Figure 2 and pointing outside the paper surface, and the directional term "back" refers to the direction perpendicular to the paper surface of

[0057] As described above, the above are only specific embodiments of the present invention and cannot be used to limit the scope of the invention implementation. Therefore, the replacement of equivalent components or the equivalent changes and modifications made according to the protection scope of the present invention patent should still fall within the scope covered by this patent. In addition, the technical features in the present invention, between technical features, between technical features and technical solutions, between technical solutions and technical solutions, and between embodiments and embodiments can be freely combined and used.

Claims

1. An existing tunnel diameter expansion device that does not affect vehicle traffic, characterized in that: The existing tunnel diameter expansion device that does not affect the passage of vehicles comprises a traveling trolley (3) and a lifting protection frame (1), the traveling trolley (3) comprises a left side support portion (301), a top working platform (302) and a right side support portion (303) connected in sequence from left to right, the left side support portion (301), the top working platform (302) and the right side support portion (303) enclose a vehicle passage (304), the top working platform (302) comprises a working platform front section (305), the lifting protection frame (1) and the working platform front section (305) are stacked up and down, and the lifting protection frame (1) can be raised and lowered; The lifting protection frame (1) is a plate-like structure. The cross section of the lifting protection frame (1) is arc-shaped. From left to right, the middle of the lifting protection frame (1) is higher than the left and right ends of the lifting protection frame (1). The upper surface of the lifting protection frame (1) can match and abut against the upper part of the inner surface of the original tunnel (16). The left support part (301) includes a left front column (3011), and the right support part (303) includes a right front column (3031). The left front column (3011) and the right front column (3031) are respectively located on the left and right sides of the front section (305) of the workbench, and the dome frame lifting cylinder (13) is located in the left front column (3011) and the right front column (3031). The top working platform (302) is a plate-shaped structure, the cross section of the top working platform (302) is arc-shaped, and the lifting protection frame (1) and the front section (305) of the working platform can be matched and connected; The top workbench (302) also includes a middle section (306) and a rear section (307) of the workbench. The front section (305) of the workbench, the middle section (306) of the workbench and the rear section (307) of the workbench are arranged in sequence from front to back. The left and right ends of the rear section (307) of the workbench are both connected to a top external work platform (308), and the top external work platform (308) is a horizontal plate-like structure.

2. The existing tunnel diameter expansion device that does not affect vehicle traffic according to claim 1 is characterized in that: In the direction from left to right, the width of the lifting protection frame (1) is greater than the width of the front section (305) of the workbench. The left and right sides of the lifting protection frame (1) are both connected with a dome frame lifting cylinder (13), and the dome frame lifting cylinder (13) can lift the lifting protection frame (1).

3. The existing tunnel diameter expansion device that does not affect vehicle traffic according to claim 1 is characterized in that: A personnel operating platform (2) is provided outside the left and right ends of the middle section (306) of the work platform. The personnel operating platform (2) is a flat plate structure. One end of the personnel operating platform (2) is hinged to the middle section (306) of the work platform. The personnel operating platform (2) is connected to a platform lifting cylinder (12). The platform lifting cylinder (12) can raise and lower the personnel operating platform (2). When the personnel operating platform (2) is in a raised state, the personnel operating platform (2) is in a horizontal state; when the personnel operating platform (2) is in a lowered state, the personnel operating platform (2) is in an upright state.

4. The existing tunnel diameter expansion device that does not affect vehicle traffic according to claim 1 is characterized in that: Along the front-to-back direction, the length of the middle section (306) of the work platform is smaller than the length of the front section (305) of the work platform, and the length of the front section (305) of the work platform is smaller than the length of the rear section (307) of the work platform. A demolition hammer (5) is provided on the rear section (307) of the work platform, and an advance drill (4) is provided on the top outer work platform (308). Both the demolition hammer (5) and the advance drill (4) can move forward and backward.

5. The existing tunnel diameter expansion device that does not affect vehicle traffic according to claim 1 is characterized in that: A trolley walking wheel (9) is provided at the lower end of the traveling trolley (3); a segment assembly machine support structure (8) and a segment assembly machine (7) are sequentially connected to the rear end of the traveling trolley (3); the segment assembly machine support structure (8) comprises an arc frame (801) and a connecting beam (802); the segment assembly machine (7) is located on the arc frame (801); and the arc frame (801) is connected to the traveling trolley (3) via the connecting beam (802).

6. A method for expanding the diameter of an existing tunnel without affecting the passage of vehicles, characterized in that: The existing tunnel diameter expansion method that does not affect the passage of vehicles adopts the existing tunnel diameter expansion device that does not affect the passage of vehicles according to claim 1, and the existing tunnel diameter expansion method that does not affect the passage of vehicles includes the following steps: Step 1, the existing tunnel diameter expansion device that does not affect the passage of vehicles enters the original tunnel (16), the rear end of the lifting protection frame (1) corresponds to the front end of the section to be demolished (1601) of the original tunnel (16), and the lifting protection frame (1) rises and supports the front of the section to be demolished (1601) of the original tunnel (16); Step 2, dismantling the section to be dismantled (1601) to form a newly excavated section (1701) of a newly excavated and enlarged tunnel (17); Step 3, treating the surface of the newly excavated section (1701) to form a treated section (1702); Step 4: Install the pipe segment (22) in the processing section (1702).

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