Fabricated tunnel structure suitable for existing operation line reconstruction and construction method

Abstract

The invention discloses an assembly type tunnel structure suitable for existing operation line reconstruction and a construction method, and relates to the technical field of rail transit, the assembly type tunnel structure comprises a plurality of symmetrical prefabricated pile foundations, the tops of the prefabricated pile foundations are connected with prefabricated bearing platform beams, and the tops of the prefabricated bearing platform beams are connected with a plurality of prefabricated reinforced concrete secondary lining straight walls; prefabricated drainage side ditches are arranged on the inner sides of the prefabricated bearing platform beams, an existing line rail assembly is arranged between the two sets of prefabricated drainage side ditches, and the top of the prefabricated reinforced concrete secondary lining straight wall is connected with an arc-shaped prefabricated cavity thin-wall arch crown component. Under the condition of not interrupting the operation of the existing line, on the basis that the line operation function can be continuously played, the transformation construction can be rapidly completed, and the influence period of the transformation construction is shortened.

Description

Technical Field

[0001] The present invention relates to the field of rail transit technology, and in particular to an assembled tunnel structure and a construction method suitable for the reconstruction of an existing operating line. Background Art

[0002] In the broad sense of existing rail transit projects, most of the project lines are laid in the main urban areas and core areas of the city, and some lines are laid in the sub-centers of the city or the connecting corridors between the main and sub-cities. The reasons for this are mostly related to the rapid pace of urbanization and the failure to steadily coordinate line planning with the speed of urban development.

[0003] The broad category of rail transit, namely national railways, local railways, intercity railways, urban and suburban railways, factory and mine dedicated lines, urban rail transit, scenic area rail transit, etc., has seriously affected the urban development and planning because most of its line track systems use roadbeds and cuttings to travel through the city, and have also brought varying degrees of impact and interference to the current traffic and environment. How to solve the above problems caused by existing line projects, how to propose technical innovation solutions to the existing broad rail transit, which is playing a transportation role, but has caused urban fragmentation and environmental impacts due to its narrow and long linear distribution, is particularly realistic. In some mountainous areas, there are also a large number of deep cutting line track systems, plank-type line open-hole roadbed track systems, etc., which have low resistance and protection capabilities against natural disasters. Line transportation is often interrupted due to falling rocks, floods, etc., and the same route uses a single track type of transportation, and no three-dimensional transportation has been formed. There is also a dilemma of waste of transportation resources and non-redevelopment.

[0004] For the above-mentioned problems caused by the distribution of near-ground lines of generalized rail transit projects, the method of interrupting operations and implementing technical transformation is often adopted. The problem brought about by this is that the cost of the transformation project is high and the economic losses caused by the interruption of operations are high, so that the impact on the status quo and implementation difficulty of the transformation of existing generalized rail transit near-ground line track projects that are really necessary and have a greater impact are enormous.

[0005] There are generally two implementation steps for similar project transformation technologies in China: 1. Operation interruption plan: within a certain period, the operation of the existing line will be interrupted, and the existing tracks will be dismantled and technically transformed at the original site. By means of roadbed and cutting transformation, open-cut to underground conversion, etc., the line shape and track elevation will be adjusted, and the near-ground line will be transformed into an underground line to eliminate the existing line's impact on urban space isolation and the environment, and finally resume line operation.

[0006] 2. Uninterrupted operation plan: Use new temporary side lines (sidewalks) to provide additional route directions, and partially transform the operating lines, that is, permanent line relocation plan, or use temporary relocation technical plan. This type of plan requires the relocation line construction to be carried out in advance, and the original line must be abandoned at the same time. As a temporary relocation plan, after the existing line is transformed, the temporary line needs to be dismantled and the site restored, which has a huge impact on the construction cost and construction period. As a permanent relocation plan, when the relocated line is completed and put into operation, the original existing line needs to be dismantled, modified and restored, and the construction investment, construction period and environmental impact are still huge.

[0007] In both schemes, when the near-ground line is transformed into a concealed underground line, a shallow buried line scheme is generally adopted to save construction investment. The reconstruction construction method is mostly to use the construction technology of on-site open-cut cast-in-place structure to carry out the overall construction of the new structure. The problem it brings is that the reconstruction construction period is long, which has a great impact on the cycle of resuming operation. In addition, during the on-site construction process, more land needs to be occupied to provide the site required during the construction process, and the construction site causes great interference and inconvenience to the surrounding environment.

[0008] Deficiencies of existing technical solutions: 1. Existing construction and implementation technology for converting existing line near-ground engineering into underground engineering: (1) At present, there are some cases in China where existing lines have been transformed into underground lines. Most of them are to build tunnel structures at the original site according to new construction projects without interrupting traffic operations, and then restore the line's traffic function after completion.

[0009] (2) In the implementation cases of existing line reconstruction, temporary bypass lines are used for short-term transitional traffic. After the construction of the original line site is completed, the traffic on the reconstructed line is restored and the temporary bypass line (bridge) project is abandoned.

[0010] (3) Use steel structure for temporary support of the arch construction, and construct the secondary casting structure on the temporary arch structure.

[0011] (4) Cast-in-place structure construction methods are often used, or tunnel construction trolleys are used for construction. The problem this brings is that it is necessary to erect temporary internal support (molding) structures within the clearance range of the tunnel to be renovated, which results in the need to interrupt the existing line's operating functions during construction.

[0012] 2. Problems with assembly technology and construction technology in existing line structure reconstruction projects (1) In prefabricated tunnels, "superimposed" and "composite" prefabricated structural technologies are mostly used. Their construction process and assembly technology both involve secondary construction, and the on-site construction cycle is long, the construction impact is large, and the construction quality and progress are greatly affected by external conditions and the labor of the work team.

[0013] (2) Prefabricated structural technology and components have not yet achieved full structural prefabrication and assembly, and are mostly prefabricated and assembled local structural components, resulting in low overall construction progress and efficiency. Prefabricated structures are used in some projects, but there are still "secondary pouring" and "overlapping construction", and prefabricated technology is still not perfect.

[0014] (3) The connection technology between prefabricated structural components mostly adopts the secondary casting node process of "wet joint", and the technology research and development of the quick connection system between prefabricated components is insufficient. The volume and lightweight technology innovation of prefabricated structural components are insufficient, the self-weight of the components is too large, and the construction is difficult.

[0015] (4) In some railway projects where ground lines are converted to open-cut tunnel projects, or where road cuttings and roadbed lines are converted to underground lines, connection technology for assembling small-sized tunnel segments is also used. Although this technology solves the structural technology and construction process problems of prefabricated structures to a certain extent, the degree of commonality of tunnel segments is limited by the cross-sectional shape and size of the open-cut tunnels. The degree of commonality and application of tunnel segments is not high and they are mostly used in specific single engineering projects. During the construction process, a construction trolley in the tunnel must be used to assist in the erection and installation of tunnel segments. This type of construction process and prefabricated technology system cannot be widely applied to existing operating line projects.

[0016] There is currently no effective solution to this type of technical problem in related projects. Summary of the invention

[0017] In view of the problems in the related technology, the present invention proposes an assembled tunnel structure and a construction method suitable for the reconstruction of existing operating lines, so as to overcome the above-mentioned technical problems existing in the existing related technology.

[0018] To this end, the specific technical solution adopted by the present invention is as follows: According to one aspect of the present invention, there is provided an assembled tunnel structure suitable for reconstruction of existing operating lines, comprising a plurality of symmetrical precast pile foundations, the tops of the precast pile foundations are connected to precast pedestal beams, the tops of the precast pedestal beams are connected to a plurality of precast reinforced concrete secondary lining vertical walls, precast drainage ditches are arranged on the inner sides of the precast pedestal beams, an existing line track assembly is arranged between two groups of precast drainage ditches, and the tops of the precast reinforced concrete secondary lining vertical walls are connected to arc-shaped precast hollow thin-walled arch components.

[0019] Furthermore, a top prestressed fastening and tensioning hole is provided at the inner top of the precast reinforced concrete second lining straight wall, and two symmetrical wall body prestressed fastening and tensioning holes are provided at the inner bottom of the precast reinforced concrete second lining straight wall.

[0020] Furthermore, the interior of the precast reinforced concrete second lining straight wall and the tops of the two wall prestressed fastening and tensioning holes are provided with wall body assembled shear tenons, and the top of the precast reinforced concrete second lining straight wall is provided with wall top assembled shear tenons.

[0021] Furthermore, a tunnel trackside maintenance corbel is provided on one side of the top of the precast reinforced concrete second lining straight wall, and an embedded bolt sleeve for arch assembly positioning and fastening bolts is provided on the side of the top of the precast reinforced concrete second lining straight wall away from the wall top assembly shear mortise.

[0022] Furthermore, a drainage ditch cover is provided at the top of the prefabricated drainage ditch.

[0023] Furthermore, the existing line track assembly includes an existing line roadbed disposed between two groups of prefabricated drainage ditches, and the existing line tracks are symmetrically disposed on the top of the existing line roadbed.

[0024] Furthermore, prestressed tensioning holes for the arch foot are opened on both sides of the inner bottom of the arc-shaped prefabricated hollow cavity thin-walled arch component, a prestressed tensioning hole for the middle part of the arch is opened in the middle part of the inner top of the arc-shaped prefabricated hollow cavity thin-walled arch component, and reserved holes for high-strength steel bolts matching the prefabricated reinforced concrete second lining straight wall are opened on both sides of the bottom of the arc-shaped prefabricated hollow cavity thin-walled arch component.

[0025] Furthermore, the arcuate outer walls on both sides of the bottom of the arc-shaped prefabricated cavity thin-walled arch component are provided with positioning and fastening bolt working grooves, and the two side walls of the positioning and fastening bolt working grooves are provided with a module longitudinal fastening connection bolt channel one, and the end face top of the arc-shaped prefabricated cavity thin-walled arch component is provided with a plurality of prefabricated arch assembly positioning and shear-resistant tenons, and the top of the arc-shaped prefabricated cavity thin-walled arch component is provided with an arch fastening and assembly work platform, and the inside of the arch fastening and assembly work platform is provided with a module longitudinal fastening connection bolt channel two.

[0026] Furthermore, a symmetrical prefabricated structure end face paving waterproof strip groove is opened inside the side wall at one end of the arc-shaped prefabricated cavity thin-walled arch component, a plurality of cavity thin-walled arch structure internal cavities matching with the prefabricated arch assembly positioning shear-resistant tenons are opened on the top of the end face of the arc-shaped prefabricated cavity thin-walled arch component, a plurality of prefabricated arch embedded multi-directional hanging rings are arranged on the top arc-shaped outer wall of the arc-shaped prefabricated cavity thin-walled arch component, vertical assembly positioning shear-resistant grooves for the arch feet matching with the wall top assembly shear-resistant tenons are opened on both sides of the bottom end of the arc-shaped prefabricated cavity thin-walled arch component, and the arch inner side embedded contact network mounting bolt sleeves are symmetrically arranged in the middle of the inner side of the arch of the arc-shaped prefabricated cavity thin-walled arch component.

[0027] According to another aspect of the present invention, there is also provided a method for constructing an assembled tunnel applicable to the reconstruction of an existing operating line, the method for constructing an assembled tunnel applicable to the reconstruction of an existing operating line comprising the following steps: S1. For the construction of prefabricated pile foundation, the longitudinal construction unit length shall be controlled according to the line power supply contact network pole spacing, and the existing equipment and facilities of the operating line electrical and power supply traction shall be kept unchanged; S2. After the prefabricated pile foundation construction is completed, the prefabricated cap beam is constructed and the reserved conditions for the installation of the prefabricated reinforced concrete secondary lining vertical wall are prepared; S3, install the prefabricated reinforced concrete secondary lining vertical wall, and after installation, backfill the soil outside the wall in steps; S4. After the backfill construction of the prefabricated reinforced concrete secondary lining vertical wall on both sides of the existing line subgrade is completed, a bridge gantry crane is set up on the outside of the wall; S5. Use a bridge gantry crane to hoist and install the arc-shaped prefabricated hollow thin-walled arch components in place, and install the circumferential installation seams of the arc-shaped prefabricated hollow thin-walled arch components and the circumferential installation seams of the prefabricated reinforced concrete secondary lining straight walls in a staggered manner; S6. After the installation of the arc-shaped prefabricated hollow thin-walled arch components and the prefabricated reinforced concrete secondary lining straight walls, the power equipment is relocated and reconstructed during the interruption of the existing line operation, and the abandoned power equipment is dismantled; S7. After the construction of all the modified tunnels is completed, the waterproofing and protective layer structures will be outsourced, and the backfill construction around the tunnel will be carried out according to the planning and design requirements.

[0028] The beneficial effects of the present invention are: 1. The new technology adopted by the present invention can enable the existing line to continue to play its line operation function without interrupting the operation of the existing line. Through a special prefabricated assembly technology and construction technology, combined with the technical characteristics of the renovation project to innovate the structural system and connection technology, the renovation construction can be completed more quickly and shorten the impact period of the renovation construction. It can achieve the transformation from "bright" to "dark", thereby providing more land space, forming a spatial composite transportation system or comprehensive development system, and breaking through the adverse effects of the block "gap" caused by the existing open rail transit line on the city.

[0029] 2. The new structural system adopted in the present invention is an assembled tunnel structural system. The on-site construction stage has little impact on the operating line and the surrounding environment. The overall assembly construction speed is fast, and there is no driving interference to the operating line, thereby avoiding the process method of interrupting the operating function of the existing line and then implementing the transformation. It solves the structural system technology, construction process technology and process problems of transforming the existing line into an underground line, greatly reduces the construction impact, and avoids the project waste and excessive construction period caused by previous construction processes.

[0030] 3. The "open to dark" transformation project of the existing line using the technology described in the present invention can provide new land for development after the top of the underground line tunnel after the transformation is backfilled with soil, which can be used as a ground connecting strip platform on both sides of the original line, creating and providing the role of land development and realizing new development plans. It can also carry out integrated cover development at the same time, provide secondary development conditions above the line, and bring economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 This is a schematic diagram of a prefabricated tunnel structure suitable for reconstruction of an existing operating line according to an embodiment of the present invention; Figure 2 is a cross-sectional view of an assembled tunnel structure suitable for reconstruction of an existing operating line according to an embodiment of the present invention; Figure 3 is a side view of an assembled tunnel structure suitable for reconstruction of an existing operating line according to an embodiment of the present invention; Figure 4 It is a front view of a prefabricated reinforced concrete secondary lining straight wall in a prefabricated tunnel structure suitable for reconstruction of an existing operating line according to an embodiment of the present invention; Figure 5 It is a side view of a prefabricated reinforced concrete secondary lining straight wall in a prefabricated tunnel structure suitable for reconstruction of an existing operating line according to an embodiment of the present invention; Figure 6 It is a top view of an arc-shaped prefabricated cavity thin-walled arch component in a prefabricated tunnel structure suitable for reconstruction of an existing operating line according to an embodiment of the present invention; Figure 7 It is a cross-sectional view of an arc-shaped prefabricated cavity thin-walled arch member in a prefabricated tunnel structure suitable for reconstruction of an existing operating line according to an embodiment of the present invention; Figure 8 It is a side view of an arc-shaped prefabricated cavity thin-walled arch component in a prefabricated tunnel structure suitable for reconstruction of an existing operating line according to an embodiment of the present invention; Fig. 9 It is a schematic diagram of the internal cavity of a thin-walled vault structure of an assembled tunnel structure cavity applicable to the reconstruction of an existing operating line according to an embodiment of the present invention; Fig.10 It is a schematic diagram of assembling a longitudinal unit prefabricated vault using an existing power supply overhead line according to an embodiment of the present invention; Fig.11 is a schematic diagram of assembling a longitudinal construction unit during construction according to an embodiment of the present invention; Fig.12 According to an embodiment of the present invention, the existing contact network is removed to complete the last longitudinal "ring" structure and then poured; Fig.13 is a schematic diagram of the backfilling and removal effect after the vertical assembly is completed according to an embodiment of the present invention; Fig.14 is a flow chart of a prefabricated tunnel construction method applicable to the reconstruction of an existing operating line according to an embodiment of the present invention; Fig.15 This is one of the schematic diagrams of the transverse construction steps of the assembled tunnel structure according to an embodiment of the present invention; Fig.16 This is a second schematic diagram of the transverse construction sequence of the assembled tunnel structure according to an embodiment of the present invention; Fig.17 This is a third schematic diagram of the transverse construction steps of the assembled tunnel structure according to an embodiment of the present invention; Fig.18 This is a fourth schematic diagram of the transverse construction steps of the assembled tunnel structure according to an embodiment of the present invention; Fig.19 This is the fifth schematic diagram of the transverse construction steps of the assembled tunnel structure according to an embodiment of the present invention; Fig. 20 This is the sixth schematic diagram of the transverse construction steps of the assembled tunnel structure according to an embodiment of the present invention; Fig.21 This is the seventh schematic diagram of the transverse construction steps of the assembled tunnel structure according to an embodiment of the present invention; Fig. 22 This is the eighth schematic diagram of the transverse construction steps of the prefabricated tunnel structure according to an embodiment of the present invention.

[0033] In the figure: 1. Prefabricated pile foundation; 2. Prefabricated cap beam; 3. Prefabricated reinforced concrete secondary lining straight wall; 301. Top prestressed fastening and tensioning hole; 302. Wall prestressed fastening and tensioning hole; 303. Wall assembly shear tenon; 304. Wall top assembly shear tenon; 305. Tunnel trackside maintenance bracket; 306. Arch assembly positioning fastening bolts embedded bolt sleeve; 4. Prefabricated drainage ditch; 401. Drainage ditch cover; 5. Existing line track assembly; 501. Existing line roadbed; 502. Existing line track; 6. Arc-shaped prefabricated cavity thin-walled arch component; 601. Arch foot prestressed tensioning hole; 602. 02. Prestressed tensioning hole in the middle of the arch; 603. Reserved holes for steel bar bolts; 604. Positioning and fastening bolt operation groove; 605. One bolt hole for fastening and connecting the modules longitudinally; 606. Prefabricated arch assembly positioning and shear tenon; 607. Arch fastening and assembly operation platform; 608. Two bolt holes for fastening and connecting the modules longitudinally; 609. Waterproof rubber strip groove for paving the end face of the prefabricated structure; 6010. Internal cavity of the hollow thin-walled arch structure; 6011. Prefabricated arch embedded with multi-directional lifting rings; 6012. Vertical assembly and positioning shear groove at the arch foot; 6013. Embedded contact network installation bolt sleeve on the inner side of the arch. DETAILED DESCRIPTION

[0034] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0035] According to an embodiment of the present invention, a prefabricated tunnel structure and a construction method suitable for reconstruction of an existing operating line are provided.

[0036] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. Figure 1-Figure 9 As shown, according to an embodiment of the present invention, the prefabricated tunnel structure suitable for the reconstruction of existing operating lines includes a plurality of symmetrical prefabricated pile foundations 1, the tops of the prefabricated pile foundations 1 are connected with prefabricated pedestal beams 2, the tops of the prefabricated pedestal beams 2 are connected with a plurality of prefabricated reinforced concrete secondary lining straight walls 3, prefabricated drainage ditches 4 are arranged on the inner sides of the prefabricated pedestal beams 2, an existing line track assembly 5 is arranged between two groups of prefabricated drainage ditches 4, and the tops of the prefabricated reinforced concrete secondary lining straight walls 3 are connected with arc-shaped prefabricated cavity thin-walled arch components 6.

[0037] It needs to be explained that the precast pile foundation 1 is a pile foundation, which is constructed by in-situ static pressure of precast pipe piles. The pile head part of the precast pile foundation 1 is inserted and embedded with the precast pedestal beam 2. The precast pedestal beam 2 is a pedestal strip beam, which is prefabricated and assembled in longitudinal sections, and the joints are treated with local post-casting strips.

[0038] It needs to be explained that the precast reinforced concrete secondary lining vertical wall 3 is installed by crane lifting, and forms a grouting and inserting connection with the precast pedestal beam 2 through the reserved holes. After the precast reinforced concrete secondary lining vertical wall 3 and the precast pedestal beam 2 are in place, post-grouting operation is required. Grouting is performed at the bottom of the precast reinforced concrete secondary lining vertical wall 3. A sleeve is reserved at the bottom of the precast reinforced concrete secondary lining vertical wall 3, and the reserved inserting bars of the precast pedestal beam 2 are inserted into place through holes. After that, the UHPC grouting process is carried out in the sleeve. After the strength is met, the entire construction of the bottom precast pile foundation 1, precast pedestal beam 2 and precast reinforced concrete secondary lining vertical wall 3 is completed.

[0039] It should be explained that the precast reinforced concrete second lining straight wall 3 and the arc-shaped precast cavity thin-walled arch member 6 adopt a vertical staggered assembly connection structure. The top of the precast reinforced concrete second lining straight wall 3 is assembled with a shear convex tenon 304, which is designed as a half-side convex tenon. When two adjacent precast reinforced concrete second lining straight walls 3 are assembled, an integral upper convex tenon is formed to be engaged with the groove of the arc-shaped precast cavity thin-walled arch member 6. After the arc-shaped precast cavity thin-walled arch member 6 is installed, the joints of the two groups of adjacent precast reinforced concrete second lining straight walls 3 at the lower part can be positioned and squeezed to avoid the generation of relative displacement, which is more conducive to the assembly structure to form a whole without generating relative difference deformation.

[0040] Preferably, a top prestressed fastening and tensioning channel 301 is provided at the inner top of the precast reinforced concrete second lining straight wall 3, and two symmetrical wall body prestressed fastening and tensioning channels 302 are provided at the inner bottom of the precast reinforced concrete second lining straight wall 3.

[0041] It should be explained that the precast reinforced concrete secondary lining vertical wall 3 is the side wall of the lower structure, which plays the role of load bearing and later retaining and waterproofing. The precast reinforced concrete secondary lining vertical wall 3 is a precast module, which is connected to the precast cap beam 2 by a grouting sleeve combined with the tooth groove at the bottom of the wall, and is a steel bar through-type equivalent cast-in-place structure.

[0042] Preferably, the interior of the precast reinforced concrete second lining straight wall 3 and the tops of the two wall prestressed fastening and tensioning holes 302 are provided with wall body assembling shear tenons 303, and the top of the precast reinforced concrete second lining straight wall 3 is provided with wall top assembling shear tenons 304.

[0043] Preferably, a tunnel trackside maintenance corbel 305 is provided on one side of the top of the precast reinforced concrete second lining straight wall 3, and an arch assembly positioning fastening bolt embedded bolt sleeve 306 is provided on the side of the top of the precast reinforced concrete second lining straight wall 3 away from the wall top assembly shear tenon 304.

[0044] It needs to be explained that the trackside maintenance corbel 305 in the tunnel is a corbel on the inner wall of the tunnel, and its structure meets the safety limits of trains running in the tunnel. Its function is to serve as a track platform for the maintenance trolley invented later during the inspection and installation of the arch in the tunnel, and to provide a running surface. In addition, it can also be used as a path for laying pipelines in the tunnel, and as a support for installing the tunnel lighting system.

[0045] It needs to be explained that the embedded bolt sleeve 306 of the arch assembly positioning fastening bolt is a connecting bolt sleeve pre-embedded in the component, and the contact network installation bolt sleeve 6013 is embedded on the inner side of the arch for rapid connection and assembly, as well as subsequent rapid installation and construction of the contact network in the tunnel.

[0046] Preferably, a drainage ditch cover plate 401 is provided at the top of the prefabricated drainage ditch 4 .

[0047] Preferably, the existing line track assembly 5 includes an existing line roadbed 501 arranged between two groups of prefabricated drainage ditches 4, and the existing line tracks 502 are symmetrically arranged on the top of the existing line roadbed 501.

[0048] Preferably, both sides of the inner bottom of the arc-shaped prefabricated cavity thin-walled arch component 6 are provided with arch foot prestressed tensioning holes 601, the middle part of the inner top of the arc-shaped prefabricated cavity thin-walled arch component 6 is provided with arch middle prestressed tensioning holes 602, and both sides of the bottom of the arc-shaped prefabricated cavity thin-walled arch component 6 are provided with high-strength steel bolt reserved holes 603 that match the prefabricated reinforced concrete second lining straight wall 3.

[0049] It needs to be explained that the reserved holes 603 for high-strength steel bar bolts serve as a leveling, positioning, and fastening connection system for the preliminary assembly of the arch structure and the side wall structure, and the prestressed tensioning holes 601 at the arch foot and the prestressed tensioning holes 602 in the middle of the arch serve as a fine leveling, extrusion, and precise connection and fastening system for the longitudinal connection of the arch prefabricated components.

[0050] It should be explained that the arc-shaped prefabricated hollow thin-walled vault member 6 is a prefabricated arc-shaped vault structure, which adopts an inner cavity structure and an "arc-shaped" structure to minimize the problem of excessively large component design cross-sections caused by the upper covering soil load and the large span. The "arch" can save the height of the prefabricated reinforced concrete secondary lining straight wall 3 while meeting the operating space in the tunnel, thereby saving a series of costs such as component manufacturing, transportation, and hoisting. The arc-shaped prefabricated hollow thin-walled vault member 6 arc-shaped vault structure can also convert the large bending moment internal force generated by the upper load into the horizontal thrust of the "arch feet" at both ends. The horizontal thrust is transmitted to the prefabricated reinforced concrete secondary lining straight wall 3, which can offset or reduce the thrust deformation load caused by the outer soil of the prefabricated reinforced concrete secondary lining straight wall 3, which is more in line with the force balance principle of the overall structure.

[0051] It needs to be explained that the prestressed tensioning channel 601 at the foot of the arch is a prestressed channel after the longitudinal assembly of the arch structure, which is used for the longitudinal non-bonded post-tensioning operation after the construction section is completed. It plays a role in squeezing the assembly joints of several arch structures, namely the arc-shaped prefabricated hollow thin-walled arch components 6, to form an integral force-bearing unit, and at the same time, the waterproof structure is squeezed at the connection joints to play a water-stopping role. The waterproof extrusion rubber strip is paved at the waterproof rubber strip groove 609 on the end face of the prefabricated structure, that is, a groove is reserved on the side section concrete surface of the arc-shaped prefabricated hollow thin-walled arch component 6. After the arc-shaped prefabricated hollow thin-walled arch component 6 is manufactured, a rubber waterproofing strip is paved in the waterproof rubber strip groove 609 on the end face of the prefabricated structure. After longitudinal extrusion and tensioning through the prestressed tensioning channel 601 at the foot of the arch, the rubber strip is squeezed and densely, and at the same time, the concrete surface bonding between the arc-shaped prefabricated hollow thin-walled arch components 6 can be completed.

[0052] It should be explained that the prestressed tensioning holes 601 at the foot of the arch and the prestressed tensioning holes 602 in the middle of the arch are prestressed tensioning structures after multiple groups of arc-shaped prefabricated hollow thin-walled arch components 6 are installed in place and initially tightened. The prestressed tensioning holes 601 at the foot of the arch are prestressed tensioning holes at the arch feet of the two ends of the arc-shaped prefabricated hollow thin-walled arch components 6, and the prestressed tensioning holes 602 in the middle of the arch are prestressed tensioning holes in the center direction of the upper part of the arch. After a longitudinal construction unit has completed the initial assembly of multiple groups of prefabricated arc-shaped prefabricated hollow thin-walled arch components 6, the prestressed steel bars (strands) are bundled through the prestressed tensioning holes 601 at the foot of the arch and the prestressed tensioning holes 602 in the middle of the arch, and the non-bonded post-tensioning construction is carried out. The prestress is locked after the component joints are detected and positioned and measured. Each construction unit shall not exceed 50m, depending on the specific project conditions.

[0053] It is necessary to explain and illustrate that the reserved holes 603 for steel bar bolts are reserved holes for steel bar bolts on the top surface of the arc-shaped prefabricated hollow thin-walled arch member 6 and the prefabricated reinforced concrete second lining straight wall 3, and are used for the vertical fastening construction of the arc-shaped prefabricated hollow thin-walled arch member 6 and the prefabricated reinforced concrete second lining straight wall 3 after the arc-shaped prefabricated hollow thin-walled arch member 6 is placed on the top surface of the prefabricated reinforced concrete second lining straight wall 3 on both sides, so as to meet the component connection and water stop sealing effect. At the top of the prefabricated reinforced concrete second lining straight wall 3, that is, the top of the wall, the shear-resistant convex tenon 304 is assembled, and the convex tenon is used to position with the groove on the bottom surface of the arc-shaped prefabricated hollow thin-walled arch member 6, and the fitting surface is designed with a reserved horizontal groove channel for laying rubber water stop strips, which is the same as the method and function of laying waterproof strip channels 609 on the end surface of the prefabricated structure.

[0054] Preferably, the arcuate outer walls on both sides of the bottom of the arc-shaped prefabricated cavity thin-walled arch component 6 are provided with positioning and fastening bolt working grooves 604, and the two side walls of the positioning and fastening bolt working grooves 604 are provided with module longitudinal fastening and connecting bolt channels 605, and the top of the end face of the arc-shaped prefabricated cavity thin-walled arch component 6 is provided with a plurality of prefabricated arch assembly positioning and shear-resistant tenons 606, and the top of the arc-shaped prefabricated cavity thin-walled arch component 6 is provided with an arch fastening and connecting assembly work platform 607, and the arch fastening and connecting assembly work platform 607 is provided with module longitudinal fastening and connecting bolt channels 608.

[0055] It needs to be explained that the longitudinal fastening bolt hole 605 between modules and the arch fastening assembly work platform 607 are both used as the coarse adjustment preliminary positioning fastening connection system for the longitudinal connection of the arch structure; the longitudinal fastening bolt hole 608 between modules is used as the fine leveling, extrusion and precise connection fastening system for the longitudinal connection of the arch components.

[0056] It needs to be explained that the module longitudinal fastening connection bolt channel 605 is a steel bar bolt connection structure when two adjacent arc-shaped prefabricated cavity thin-walled arch components 6 are doubled along the line direction. Positioning fastening bolt working grooves 604 are reserved on the outer sides of the arch feet at both ends of the arc-shaped prefabricated cavity thin-walled arch components 6. The module longitudinal fastening connection bolt channel 605 is reserved on the wing arm walls on both sides of the positioning fastening bolt working groove 604. When two adjacent arc-shaped prefabricated cavity thin-walled arch components 6 are in place, the steel bar bolts are inserted to apply a predetermined torque to the bolts and nuts to form an initial tensioning and tightening effect.

[0057] It needs to be explained that the prefabricated arch assembly positioning shear-resistant tenon 606 is a mortise and tenon structure when the arc-shaped prefabricated cavity thin-walled arch components 6 are assembled adjacent to each other, and the two sides of the arc-shaped prefabricated cavity thin-walled arch components 6 are designed according to the groove and tenon structure respectively. The two adjacent groups of arc-shaped prefabricated cavity thin-walled arch components 6 can form a mortise and tenon engagement when horizontally spliced, providing overall connection performance, shear resistance, deformation coordination performance and positioning and installation functions.

[0058] It needs to be explained that the arch fastening connection assembly work platform 607 and the module longitudinal fastening connection bolt channel 608 are the preliminary fastening structural connection system for the adjacent components on the outer side of the top of the arc-shaped prefabricated cavity thin-walled arch component 6. When the adjacent arc-shaped prefabricated cavity thin-walled arch components 6 are assembled, the bolts are installed and fastened through the installation bolt working groove reserved in the module longitudinal fastening connection bolt channel 608 on the top. The bolt holes are connected to the arch fastening connection assembly work platform 607, and the function and method are the same as the module longitudinal fastening connection bolt channel 605 connection system.

[0059] It should be explained that when the arc-shaped prefabricated hollow thin-walled arch components 6 are assembled adjacently, the longitudinal horizontal assembly and tightening construction is completed through the initial fastening connection system at the arch and the arch foot, that is, the module longitudinal fastening connection bolt hole 1 605, the arch fastening connection assembly work platform 607, and the final tensioning and locking system of the construction unit, the arch foot prestressing tensioning hole 601, and the arch middle prestressing tensioning hole 602. The corresponding fastening operation groove, that is, the structural positioning fastening bolt operation groove 604 and the module longitudinal fastening connection bolt hole 2 608, after the construction unit is completed, the concrete post-casting construction is carried out on the outside of the arch to fill the operation groove, and play the role of prestressing the steel bar holes and steel bars and sealing and waterproofing.

[0060] Preferably, a symmetrical prefabricated structure end face paving waterproof rubber strip groove 609 is opened inside the side wall of one end of the arc-shaped prefabricated cavity thin-walled arch component 6, a plurality of cavity thin-walled arch structure internal cavities 6010 that cooperate with the prefabricated arch assembly positioning shear-resistant tenons 606 are opened on the top of the end face of the arc-shaped prefabricated cavity thin-walled arch component 6, a plurality of prefabricated arch embedded multi-directional hanging rings 6011 are arranged on the top arc-shaped outer wall of the arc-shaped prefabricated cavity thin-walled arch component 6, vertical assembly positioning shear-resistant grooves 6012 of the arch foot that cooperate with the wall top assembly shear-resistant tenons 304 are opened on both sides of the bottom end of the arc-shaped prefabricated cavity thin-walled arch component 6, and the inner middle part of the inner arch of the arc-shaped prefabricated cavity thin-walled arch component 6 is symmetrically provided with arch inner embedded contact network mounting bolt sleeves 6013.

[0061] It should be explained that the prefabricated arch embedded multi-directional lifting ring 6011 is a pre-embedded universal lifting ring system for the lifting of the arc-shaped prefabricated cavity thin-walled arch component 6. The universal lifting ring system is arranged at the solid concrete structure position of the arc-shaped prefabricated cavity thin-walled arch component 6 to ensure the bearing capacity of the component lifting. A single arc-shaped prefabricated cavity thin-walled arch component 6 has a total of six universal lifting ring lifting points arranged on the outside.

[0062] It should be explained that the internal cavity system structure of the arc-shaped prefabricated cavity thin-walled arch component 6 is divided into the cavity structure shown in the cross section and the longitudinal section. The minimum thickness of all side wall concrete structures shall not be less than 250mm to meet the waterproof and strength requirements. The cavity design is carried out along the shape of the arc-shaped prefabricated cavity thin-walled arch component 6. The cavity design not only reduces the deadweight of the component, but also has no effect on the stress of the component. A prefabricated arch embedded multi-directional lifting ring 6011 embedded universal lifting ring system is set at the cavity (indicated by dotted lines) and the cavity interval of the internal cavity 6010 of the cavity thin-walled arch structure.

[0063] According to another embodiment of the present invention, Fig.12 As shown, a prefabricated tunnel construction method applicable to the reconstruction of an existing operating line is also provided, and the prefabricated tunnel construction method applicable to the reconstruction of an existing operating line comprises the following steps: S1. During the construction of prefabricated pile foundation 1, the length of the longitudinal construction unit shall be controlled according to the distance between the poles of the urban rail contact network along the line direction, and the existing equipment and facilities of the electrical and power supply traction of the operating line shall be kept unchanged; It needs to be explained that for the construction of prefabricated pile foundation 1 (or bored pile construction on the roadbed side), the length of the longitudinal construction unit is controlled according to the spacing of the poles of the electrified railway or urban rail contact network along the line direction, and the existing equipment and facilities of the electrical power supply remain unchanged.

[0064] S2. After the construction of the prefabricated pile foundation 1 is completed, the prefabricated cap beam 2 is constructed, and the installation reservation conditions of the prefabricated reinforced concrete secondary lining vertical wall 3 are prepared; S3, installing the prefabricated reinforced concrete secondary lining vertical wall 3, after installation, backfilling the soil outside the wall in steps; S4. After the backfilling of the prefabricated reinforced concrete secondary lining vertical walls 3 on both sides of the existing line roadbed 501 (road cutting) is completed, a bridge gantry crane (or truck crane) is erected; S5, hoisting and installing the arc-shaped prefabricated hollow thin-walled arch member 6 in place by means of a bridge gantry crane, and installing the circumferential installation seam of the arc-shaped prefabricated hollow thin-walled arch member 6 and the circumferential installation seam of the prefabricated reinforced concrete secondary lining straight wall 3 in a staggered alignment manner; It should be explained that the arc-shaped prefabricated hollow thin-walled arched top component 6 and the prefabricated reinforced concrete secondary lining straight wall 3 are vertically connected by "positioning pins" and high-strength steel bar fastening bolts for rough positioning and fine adjustment and fastening. The arc-shaped prefabricated hollow thin-walled arched top component 6 is connected along the line direction by "mortise and tenon grooves", high-strength steel bar pre-tightening bolts, and tensioned prestressed tendons of multiple components in series for longitudinal component connection.

[0065] S6, after the arc-shaped prefabricated hollow thin-walled arch components 6 and the prefabricated reinforced concrete secondary lining straight wall 3 are installed and constructed, the power equipment is relocated and transformed during the interruption of the existing line operation, and the abandoned power equipment is dismantled; It needs to be explained that for the components of the electrified railway and urban rail contact power supply system, after the prefabrication and assembly of the longitudinal units in the above-mentioned construction section, the power equipment will be relocated and renovated during the "window period" when the existing line operation is interrupted, and the contact network and other power supply, signal equipment and cables will be hung at the reserved installation area on the inner wall of the tunnel.

[0066] S7. After the construction of all the modified tunnels is completed, the waterproofing and protective layer structure will be outsourced, and the backfill construction around the tunnel will be carried out according to the planning requirements and design requirements, and the overall development function can also be realized.

[0067] What needs to be explained is that the abandoned power equipment will be dismantled, and the final "ring" structure will be cast in place between the completed longitudinal construction units along the line, that is, in the section after the removal of the abandoned power poles and signal equipment. After the construction of all the modified tunnels is completed, the waterproofing and protective layer structure will be outsourced, and then the surrounding soil backfilling construction of the tunnel will be carried out according to the planning and design requirements to complete the transformation of the existing "open line" into a "hidden line".

[0068] It needs to be explained that Figure 13-Figure 20 Shown is the construction sequence of the cross section of the structure of the present invention.

[0069] It should be explained that all construction processes are carried out under operating line conditions, and traffic will not be interrupted during construction. Under electrified line conditions, electrified contact wire construction and access construction are carried out only after the top arch of the closed arch structure is completed, using the nighttime non-operating "window period".

[0070] It needs to be explained that the "original technical solution" referred to below is: an assembled construction structure system with overall prefabrication of non-standard components and post-casting technology using steel bars as the connecting link.

[0071] Prefabricated component lightweight index: 70%-85% of components in the same part of the same type of structure; The lifting weight of the vault component module is 70% of the lifting weight of the flat roof component or solid component under the original technical conditions; The time required for connecting and installing components can shorten the on-site construction period by 70%-80% compared with cast-in-place construction technology; There is no need to close the existing line, and the traffic on the existing line will not be interrupted. The interruption time caused to the traffic is "zero". When the train passes through the construction section, it only needs to reduce the speed to the safe speed. The construction period of a single kilometer of double-line cast-in-place open-cut tunnel structure is generally sixteen months. After adopting the technology of the present invention, the operating efficiency can be improved by sixteen months due to uninterrupted traffic. Within the single-kilometer construction and reconstruction length, the economic indicators of operating income can be increased by sixteen months.

[0072] The construction site, including storage, lifting and other site areas, is 50%-60% of the existing closed cast-in-place technical construction site; On-site construction emissions (wastewater, construction waste) are approximately 10% of the cast-in-place construction technology solution and 20% of the existing prefabricated wet joint (post-casting) process technology; On-site construction can save more than 80% of labor compared to cast-in-place construction; at the same construction rate, it can save more than 20% of labor compared to existing prefabricated construction technology.

[0073] On-site lifting, installation and other construction are affected by seasons and climate, with the degree of influence being 40% compared to the original technical solution.

[0074] In summary, with the help of the above technical scheme of the present invention, the speed and efficiency of on-site assembly construction can be improved. Through the investigation of existing prefabricated hoisting construction, the existing automobile crane (gantry crane) is used for lifting. When the structural system and components are invented, the present invention introduces the "weight limit design concept", that is, the maximum component weight is less than 40t (previously similar structures were basically 50t-70t), which can be completed by a single automobile crane. This makes the hoisting construction more flexible, reduces the lifting weight, and the prefabricated component transport flatbed truck is also more miniaturized, making it easier to store prefabricated components in prefabrication plants and construction sites. According to the general hoisting construction equipment and construction process, it only takes less than one hour to hoist a single component into place and install and assemble, which greatly reduces the installation time, and there is no need to pour concrete at the node. Compared with general similar structures, the lifting and installation time of a single component is reduced by more than two hours. After the node connection of the present invention is installed, the self-stabilization of the structure can be achieved through preliminary tightening, which can shorten the total time of mold making, pouring, and early concrete reaching the standard by more than five days. In summary, from the hoisting and installation process to the node connection, the construction period is significantly shortened. The use of the component construction and manufacturing technology of the present invention can greatly improve the strength and deformation resistance of the arch structure components, greatly reduce the cross-sectional size of the components, and further achieve lightweight components, with a lightweight ratio of more than 20%. During the transportation stage of large components, the transportation efficiency can be improved, and the transportation route plan is more diversified. During the component hoisting construction, because the components adopt lightweight design innovations, the lifting weight is reduced by more than 20% compared with previous components, which can improve the lifting efficiency, improve the hoisting safety, and make the component installation more accurate. The prefabricated components manufactured with high-precision templates have a processing accuracy of within ±1mm error, and the joint accuracy during the installation stage can better guarantee the installation margin control. The process technology achieves fast construction speed without interrupting the operation of the existing line, and all construction is carried out outside the safety control limit range of the existing line.

[0075] The present invention innovatively develops the module division method of the prefabricated structure and the design of prefabricated components, so that the tunnel structure has a lighter prefabricated assembly module, which can solve the problem that similar structural systems cannot be assembled and constructed with large components due to the limitations of construction site conditions, and enriches the technical application scenarios of existing line reconstruction projects and fully assembled tunnel structures. For the on-site assembly construction link, because the prefabricated component modules are lighter, miniaturized lifting equipment and hoisting equipment can be used, which does not occupy more construction sites, has a smaller operating turning radius, and is more flexible in construction organization and construction procedures, which can improve construction safety and assembly accuracy. By adopting new technologies such as node fastening connection technology, tongue-and-groove bite technology, toothed shear grooves, high-molecular polymer rubber strip caulking extrusion precision control, and upper prefabricated component secondary counterweight, the overall stability of the structure and the assembly and splicing construction efficiency are improved. The present invention adopts a dry connection system, an initial fastening connection system with high precision requirements, a series of connection systems such as "mortise and tenon" type structural component bite extrusion connection, prestressed tensioning leveling and pre-compression connection, high-strength bolt connection splicing, and limit slot shear transmission structure, to achieve full structural assembly and construction. The above connection method requires the use of prefabricated components with a manufacturing error within ±1.0mm, a positioning accuracy within 5mm, and a component connection accuracy within 2mm after extrusion and tightening. The efficient assembly accuracy (non-stressed joint width + 2mm) is achieved. The width of the force-transmitting joint after extrusion and tightening is 1mm. The polymer rubber bonding extrusion tape is laid on the component bonding surface. By applying pressure to extrude the tape, the component installation control accuracy requirements are met. This technology requires that the manufacturing and processing of prefabricated components must reach the manufacturing accuracy of the shield segment level, which can further improve the overall assembly structure quality compliance rate and develop and innovate a new modular structural system for the fully assembled design and construction of elevated structures and rail transit structures. The overall structural framework system of the present invention has clear force and clear force transmission, which solves the problem of large eccentric component force caused by the side soil pressure and water pressure of the underground structure on the side wall. By adding an arched vault structure, the large deformation caused by the load above the vault structure is reduced, and at the same time, the load above the arch is converted into the thrust of the arch foot to offset the strength and deformation problems of the side wall caused by the lateral water and soil pressure. Through the staggered splicing and longitudinal tensioning of the vault and the side wall, as well as the mortise and tenon limiter and other comprehensive technical systems, the assembled structure is better formed into an overall force structure, the deformation is more coordinated, and the probability of relative deformation and damage of a single component is avoided. The overall structural system realizes the most optimized fully assembled assembly structure. The results of the present invention can further optimize the performance of the overall structure with lightweight, and the prefabricated component module is smaller in size, which is more convenient for manufacturing, urban transportation, and on-site hoisting, and can better ensure the accuracy of hoisting and fine-tuning construction operations. It provides more possible application scenarios for the application of prefabricated rail transit technology.

[0076] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An assembled tunnel structure suitable for reconstruction of an existing operating line, comprising a plurality of symmetrical prefabricated pile foundations (1), characterized in that: The tops of the prefabricated pile foundations (1) are connected to prefabricated pedestal beams (2), the tops of the prefabricated pedestal beams (2) are connected to a plurality of prefabricated reinforced concrete secondary lining vertical walls (3), prefabricated drainage side ditches (4) are arranged on the inner sides of the prefabricated pedestal beams (2), an existing track assembly (5) is arranged between two groups of the prefabricated drainage side ditches (4), and the tops of the prefabricated reinforced concrete secondary lining vertical walls (3) are connected to arc-shaped prefabricated hollow thin-walled arch components (6).

2. The assembled tunnel structure suitable for reconstruction of existing operating lines according to claim 1 is characterized in that: The inner top of the precast reinforced concrete second lining straight wall (3) is provided with a top prestressed fastening and tensioning hole (301), and the inner bottom of the precast reinforced concrete second lining straight wall (3) is provided with two symmetrical wall body prestressed fastening and tensioning holes (302).

3. The assembled tunnel structure suitable for reconstruction of existing operating lines according to claim 2 is characterized in that: Wall body assembly shear-resistant tenons (303) are provided inside the precast reinforced concrete second lining straight wall (3) and at the tops of the two wall body prestressed fastening and tensioning holes (302), and wall top assembly shear-resistant tenons (304) are provided at the top of the precast reinforced concrete second lining straight wall (3).

4. The assembled tunnel structure suitable for reconstruction of existing operating lines according to claim 3 is characterized in that: A tunnel trackside maintenance bracket (305) is provided on one side of the top of the precast reinforced concrete secondary lining vertical wall (3), and a vault assembly positioning fastening bolt pre-embedded bolt sleeve (306) is provided on one side of the top of the precast reinforced concrete secondary lining vertical wall (3) away from the wall top assembly shear resistant tenon (304).

5. The assembled tunnel structure suitable for reconstruction of existing operating lines according to claim 4 is characterized in that: A drainage ditch cover plate (401) is provided at the top of the prefabricated drainage ditch (4).

6. The assembled tunnel structure suitable for reconstruction of existing operating lines according to claim 5 is characterized in that: The existing line track assembly (5) comprises an existing line roadbed (501) arranged between two groups of prefabricated drainage ditches (4), and existing line tracks (502) are symmetrically arranged at the top of the existing line roadbed (501).

7. The assembled tunnel structure suitable for reconstruction of existing operating lines according to claim 6 is characterized in that: Both sides of the inner bottom of the arc-shaped prefabricated hollow thin-walled arch component (6) are provided with arch foot prestressed tensioning holes (601), the middle part of the inner top of the arc-shaped prefabricated hollow thin-walled arch component (6) is provided with an arch middle prestressed tensioning hole (602), and both sides of the bottom of the arc-shaped prefabricated hollow thin-walled arch component (6) are provided with high-strength steel bar bolt reserved holes (603) that match the prefabricated reinforced concrete second lining straight wall (3).

8. The assembled tunnel structure suitable for reconstruction of existing operating lines according to claim 7 is characterized in that: The arc-shaped outer walls on both sides of the bottom of the arc-shaped prefabricated hollow thin-walled arch component (6) are provided with positioning and fastening bolt operation grooves (604), and the two side walls of the positioning and fastening bolt operation groove (604) are provided with module longitudinal fastening connection bolt holes (605), and the top of the end surface of the arc-shaped prefabricated hollow thin-walled arch component (6) is provided with a plurality of prefabricated arch assembly positioning anti-shear tenons (606); A dome fastening and connecting assembly operation platform (607) is arranged at the top of the arc-shaped prefabricated hollow thin-walled dome component (6), and two module longitudinal fastening and connecting bolt holes (608) are provided inside the dome fastening and connecting assembly operation platform (607).

9. The assembled tunnel structure suitable for reconstruction of existing operating lines according to claim 8 is characterized in that: A symmetrical prefabricated structural end face waterproofing strip paving groove (609) is provided inside the side wall at one end of the arc-shaped prefabricated hollow thin-walled arch component (6); a plurality of hollow thin-walled arch structure internal cavities (6010) matching the prefabricated arch assembly positioning anti-shear tenons (606) are provided at the top of the end face of the arc-shaped prefabricated hollow thin-walled arch component (6); and a plurality of prefabricated arch pre-embedded multi-directional lifting rings (6011) are provided at the top arc-shaped outer wall of the arc-shaped prefabricated hollow thin-walled arch component (6); Both sides of the bottom end of the arc-shaped prefabricated hollow thin-walled arch component (6) are provided with arch foot vertical assembly positioning shear grooves (6012) that match the wall top assembly shear tenons (304), and arch inner side embedded contact network installation bolt sleeves (6013) are symmetrically arranged in the middle of the inner side of the arch inside the arc-shaped prefabricated hollow thin-walled arch component (6).

10. A method for constructing an assembled tunnel suitable for the reconstruction of an existing operating line, used to realize the construction of an assembled tunnel structure suitable for the reconstruction of an existing operating line as claimed in any one of claims 1 to 9, characterized in that: The prefabricated tunnel construction method applicable to the reconstruction of existing operating lines comprises the following steps: S1. For the construction of prefabricated pile foundation (1), the length of the longitudinal construction unit shall be controlled according to the spacing of the overhead contact poles along the line direction, and the existing equipment and facilities of the operating line electrical and power supply traction shall be kept unchanged; S2. After the construction of the prefabricated pile foundation (1) is completed, the prefabricated cap beam (2) is constructed, and the installation conditions for the prefabricated reinforced concrete secondary lining vertical wall (3) are reserved; S3, installing the prefabricated reinforced concrete secondary lining vertical wall (3), and after the installation is completed, backfilling the soil outside the wall in steps; S4, after the backfilling of the prefabricated reinforced concrete secondary lining vertical wall (3) on both sides of the existing line roadbed (501) is completed, a bridge gantry crane is set up on the outer side of the wall; S5, hoisting and installing the arc-shaped prefabricated hollow thin-walled arch member (6) in place by means of a bridge gantry crane, and installing the circumferential installation seam of the arc-shaped prefabricated hollow thin-walled arch member (6) and the circumferential installation seam of the prefabricated reinforced concrete secondary lining straight wall (3) in a staggered manner; S6. After the arc-shaped prefabricated hollow thin-walled arch components (6) and the prefabricated reinforced concrete secondary lining straight walls (3) are installed and constructed, the power equipment is relocated and transformed during the interruption of the operation of the existing line, and the abandoned power equipment is dismantled; S7. After the construction of all the modified tunnels is completed, the waterproofing and protective layer structures will be outsourced, and the backfill construction around the tunnel will be carried out according to the planning and design requirements.

Images