A fully prefabricated track structure and method for integrated assembly of shield tunnels.

Abstract

This invention provides a fully prefabricated track structure and method for integrated assembly of shield tunnels, relating to the field of tunnel track bed construction technology. Addressing the problem of slow concrete mixing, transportation, and on-site pouring speeds in traditional cast-in-place track bed foundation construction, this invention utilizes prefabricated track bed foundations. On-site, prefabricated track bed slabs, prefabricated track bed foundations, and prefabricated shield tunnel segments are fixedly connected using connectors and grooves. The pre-reserved holes and grooves in the connectors serve as positioning points for the prefabricated track bed slabs and prefabricated track bed foundations, improving assembly accuracy and enabling locking components to maintain the stability of the connectors. This collaborative approach achieves a stable and reliable structure, preventing loosening of the connectors.

Description

Technical Field

[0001] This invention relates to the field of tunnel track bed construction technology, specifically to a fully prefabricated track structure and method for integrated assembly of shield tunnels. Background Technology

[0002] With the development of urban rail transit, the construction period of projects is affected by various constraints. In order to ensure the normal opening and operation of the construction line, the construction period of each process is compressed. Among them, the construction period of subway track and track bed is often compressed by 30% or more. Chinese patent (application number: 2022105210227) discloses a shield tunnel track bed connection structure and installation method, which establishes a stable connection between the cast-in-place track bed and the tunnel segments through connectors, reducing problems such as track bed separation. However, it still requires cast-in-place concrete, which makes the construction process more complicated and inconvenient to operate in narrow tunnel environments, resulting in low construction efficiency.

[0003] The inventors discovered that the track bed foundation structure in other precast slab track structures in the prior art still uses cast-in-place synthetic fiber concrete or steel fiber concrete, and does not have steel reinforcement to avoid the on-site steel reinforcement binding process. This does not comply with the requirement in GB50157-2013 "Code for Design of Metro" that ballastless track bed structures should use reinforced concrete structures. Traditional track slab construction requires steel reinforcement binding of the track bed foundation before construction, the erection of closed formwork around the perimeter, the installation of anti-buoyancy supports, and the use of self-compacting concrete for mixing, transportation, and pouring. The construction process is complex, especially for underground lines where the construction space in tunnels is small, which is not conducive to rapid pouring construction. In addition, the concrete is poured and cured in sections, which takes time. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a fully prefabricated track structure and method for integrated assembly of shield tunnels. The track slabs and foundations are prefabricated using modular components. On-site, the prefabricated track slabs, foundations, and shield tunnel segments are fixedly connected using connectors and grooves. The pre-reserved holes and grooves in the connectors serve as positioning points for the prefabricated track slabs and foundations, improving assembly accuracy and enabling locking components to maintain the stability of the connectors. This collaborative approach achieves a stable and reliable structure, preventing loosening of the connectors.

[0005] The first objective of this invention is to provide a fully prefabricated track structure for integrated assembly of shield tunnels, employing the following solution:

[0006] The system includes connectors, precast track slabs, precast track foundations, and channels for embedding tunnel segments. One end of the connector engages with the channel, and the other end passes through a pre-drilled connection hole in the precast track foundation. The top surface of the precast track foundation has a slot corresponding to the connection hole position. Fasteners fit into the slots to engage with the connectors and lock the position of the precast track foundation. The precast track slabs are supported on the precast track foundation. The precast track slabs have locking blocks corresponding to the slot positions for embedding into the slots. The locking blocks maintain the position of the connectors and fasteners.

[0007] Furthermore, along the tunnel ring upwards, the same precast track bed foundation is fitted with multiple connectors through multiple connection holes, with adjacent connectors arranged at intervals, and each connector is connected to the channel.

[0008] Furthermore, along the tunnel extension direction, at least one set of connectors is provided on the same precast track bed foundation; the channel is embedded in the segment and keeps its opening facing the tunnel axis, and the channel is connected to the anchor rods embedded in the segment.

[0009] Furthermore, the connector is a T-bolt, the head of the T-bolt is inserted into the groove and fixed, and the section of the T-bolt extending into the groove is threaded, and the fastener is engaged with the T-bolt through the thread.

[0010] Furthermore, the top surface of the precast track bed foundation is provided with a groove, which fits with the bottom surface of the precast track bed slab and supports the precast track bed slab.

[0011] Furthermore, the locking block is located on the bottom surface of the precast track slab, and the shape of the locking block is adapted to the slot structure. When the locking block is embedded in the slot, the locking block abuts against the fastener and connector to press it tight.

[0012] Furthermore, along the tunnel extension direction, multiple precast track foundations are spliced ​​together in sequence. Each precast track foundation is fixed to the corresponding channel by connectors, and the splicing positions of adjacent precast track foundations are connected by tandem connectors.

[0013] Furthermore, along the tunnel extension direction, the end of the precast track bed foundation is provided with a series hole. One end of the series hole extends to the end face of the precast track bed foundation, and the other end forms an operating groove. One end of the series member passes through the series hole of one precast track bed foundation and extends into the operating groove, and the other end passes through the series hole of another precast track bed foundation and extends into the operating groove. The series member is arc-shaped.

[0014] A second objective of this invention is to provide a construction method utilizing a fully prefabricated track structure for integrated assembly of shield tunnels as described in the first objective, comprising:

[0015] After grasping the precast track bed foundation and aligning the connection holes with the channel, place it and arrange the connectors;

[0016] One end of the connector passes through the connecting hole and is inserted into the groove and locked in place, while the other end is located in the groove. Fasteners are installed in the groove to lock the position of the precast track bed foundation.

[0017] After all the connectors and fasteners for the precast track bed slab corresponding to the precast track bed foundation are installed, the locking blocks on the precast track bed slab are aligned with the corresponding holes and slots to install the precast track bed slab onto the track bed foundation.

[0018] Furthermore, multiple precast track bed foundations and corresponding precast track bed slabs are arranged along the tunnel extension direction. The joint positions of adjacent precast track bed foundations are spliced ​​together by tandem components, and waterproof elastic sealing gaskets are filled between adjacent precast track bed foundations.

[0019] Compared with the prior art, the advantages and positive effects of this invention are:

[0020] (1) To address the problem of slow concrete mixing, transportation and on-site pouring speed in the traditional cast-in-place track foundation construction process, the track foundation is prefabricated. On-site, the prefabricated track slab, prefabricated track foundation and shield tunnel prefabricated segments are fixedly connected by connectors and grooves. The pre-reserved holes and grooves in the connectors and structure are used as positioning points for the prefabricated track slab and prefabricated track foundation, which improves the assembly accuracy and can use locking parts to keep the connectors stable, thus achieving a stable and reliable structure and preventing the connectors from loosening.

[0021] (2) It realizes the prefabrication of structural unit production factory, mechanization of transportation and hoisting operations, and modular assembly on site. It has the characteristics of fast construction speed, high precision and good effect, which greatly shortens the time of traditional track bed foundation on site concrete mixing, transportation, pouring and curing.

[0022] (3) The prefabricated track bed foundation and prefabricated track bed slabs can be used in conjunction with mechanized construction. After the segments are assembled, the fully prefabricated track structure can be assembled and constructed simultaneously by mechanized methods. This can effectively overcome the problems that affect the construction speed and quality during the existing cast-in-place track bed foundation construction, such as long-distance transportation of concrete mixing, small space on the concrete pouring site, poor concrete compaction and difficulty in ensuring quality, time required for concrete curing, and the need for segmented construction. By adopting prefabricated track bed slabs and track bed foundations, the prefabricated assembly construction of all components of the track bed structure can be realized, achieving the effect of integrated rapid construction of shield tunnel assembly. Attached Figure Description

[0023] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary 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.

[0024] Figure 1This is a schematic diagram of the prefabricated track structure used for integrated assembly of shield tunnels in Embodiment 1 or 2 of the present invention.

[0025] Figure 2 This is a side view schematic diagram of the fully prefabricated track structure used for integrated assembly of shield tunnels in Embodiment 1 or 2 of the present invention.

[0026] Figure 3 This is a top view schematic diagram of the fully prefabricated track structure used for integrated assembly of shield tunnels in Embodiment 1 or 2 of the present invention.

[0027] Figure 4 This is a schematic diagram of the connection between the precast track bed foundation and the precast track bed slab in Embodiment 1 or 2 of the present invention.

[0028] Figure 5 This is a schematic diagram of the connectors used in conjunction with the precast track bed foundation and tunnel segments in Embodiment 1 or 2 of the present invention.

[0029] In the figure, 1. Precast track foundation; 2. Segment; 3. Channel; 4. Anchor bolt; 5. Weld; 6. Connector; 7. Fastener; 8. Precast track slab; 9. Rail; 10. Hole and slot; 11. Connecting element; 12. Axis of symmetry; 13. Circumferential joint; 14. Inner wall of segment; 15. Sealing gasket; 16. Axial joint. Detailed Implementation

[0030] Example 1

[0031] In a typical embodiment of the present invention, such as Figures 1-5 As shown, a fully prefabricated track structure for integrated assembly of shield tunnels is presented.

[0032] like Figure 1 The prefabricated track structure shown is used for integrated assembly of shield tunnels. It forms an assembled track foundation structure by combining a prefabricated track bed foundation 1, prefabricated track bed slabs 8, and connectors 6, enabling rapid assembly of the track bed and track within the tunnel. Unlike existing technologies that establish a connection structure between the tunnel segments 2 and the cast-in-place track bed, this embodiment uses a prefabricated track bed foundation 1 structure, which saves on-site construction time. The position of the prefabricated track bed foundation 1 and the connectors 6 also serves as a positioning point, allowing the prefabricated track bed slabs 8 to be quickly positioned. After the prefabricated track bed slabs 8 are fitted with the prefabricated track bed foundation 1, the mating position locks the connectors 6, collaboratively completing the connection and strengthening of the three components, thus improving overall strength.

[0033] To address the slow speed of concrete mixing, transportation, and on-site pouring during the traditional cast-in-place track foundation construction process, the track bed and precast track bed slabs 8 are prefabricated. On-site, the precast track bed slabs 8, track bed, and segments 2 are fixed together using connectors 6 and grooves 3. The pre-reserved holes and grooves 10 of the connectors 6 serve as positioning points for the precast track bed slabs 8 and the precast track bed foundation 1, improving assembly accuracy and enabling the use of locking components to maintain the stability of the connectors 6. This collaborative approach achieves a stable and reliable structure and prevents the connectors 6 from loosening.

[0034] like Figure 1 As shown, the prefabricated track structure used for integrated assembly of shield tunnels mainly includes a prefabricated track bed foundation 1, a prefabricated track bed slab 8, and a connector 6. The prefabricated track bed foundation 1 is arranged inside the tunnel and fits against the bottom of the inner wall 14 of the tunnel segment. The prefabricated track bed foundation 1 is supported by the tunnel segment 2. The tunnel segment 2 has a pre-embedded channel 3. The connector 6 can engage with the channel 3, thereby fixing one end. The other end passes through the pre-set connection hole on the prefabricated track bed foundation 1 and is then fitted with a fastener 7. The fastener 7 is used to fix the prefabricated track bed foundation 1 to the tunnel segment 2. After the prefabricated track bed foundation 1 is fixed, the prefabricated track bed slab 8 is placed on the prefabricated track bed foundation 1, and the two are stably connected.

[0035] It is understood that in this embodiment, multiple segments 2 are provided along the circumferential direction and are spliced ​​into a ring, forming a circumferential joint 13 between adjacent segments 2; after forming a ring, the segments 2 are spliced ​​together sequentially along the axial direction, forming an axial joint 16 between adjacent rings.

[0036] Specifically, a channel 3 is pre-embedded in the segment 2. One end of the connector 6 engages with the channel 3, and the other end passes through the pre-reserved connection hole on the precast track bed foundation 1. The connector 6 forms a stable connection by engaging with the channel 3 at its end, which facilitates the subsequent tightening of the precast track bed foundation 1. The bottom surface of the precast track bed foundation 1 is attached to the inner wall 14 of the segment.

[0037] The top surface of the precast track bed foundation 1 is provided with a groove 10 corresponding to the connection hole position. The fastener 7 is fitted with the connector 6 in the groove 10 to lock the position of the precast track bed foundation 1. The precast track bed foundation 1 supports the precast track bed slab 8. The precast track bed slab 8 is provided with a locking block for embedding in the groove 10 corresponding to the position of the groove 10. The locking block maintains the position of the connector 6 and the fastener 7.

[0038] In this embodiment, the slot 10 serves as both a space to accommodate the end of the connector 6 and the fastener 7, and a positioning and fixing structure for the precast track bed slab 8 to cooperate with the precast track bed foundation 1. The locking block cooperates with the slot 10 to form a positioning block and positioning groove structure, achieving the effect of rapid positioning. The locking block cooperates with the slot 10 to form a protrusion and a recess structure, achieving the effect of limiting the axial position and circumferential position.

[0039] It should be noted that after the locking block is inserted into the slot 10, it can contact the end of the connector 6 and the fastener 7, keeping the connector 6 in position to prevent it from shifting and keeping the fastener 7 in position to prevent it from loosening. Especially when working in the subway, it can prevent the problem of loosening and falling off caused by high-frequency vibration.

[0040] like Figure 2 , Figure 3 As shown, for the arrangement of the channels 3 on the segment 2, channels 3 are provided along the ring upward of the segment 2, and channels 3 are also provided along the tunnel axis. Multiple channels 3 can be arranged in a crisscross pattern on the same segment 2 to meet different arrangement requirements when installing the connector 6.

[0041] Specifically, along the tunnel circumferential direction, the same precast track bed foundation 1 is fitted with multiple connectors 6 through multiple connection holes, with adjacent connectors 6 arranged at intervals, and each connector 6 is connected to the channel 3; along the tunnel extension direction, the same precast track bed foundation 1 is provided with at least one set of connectors 6; such as Figure 5 As shown, the channel 3 is embedded in the segment 2 and keeps its opening facing the tunnel axis. The channel 3 is connected to the anchor rod 4 embedded in the segment 2.

[0042] Combination Figure 5 The channel 3 is pre-embedded in the segment 2. The bottom surface of the channel 3 is connected to the anchor rod 4. The end of the anchor rod 4 is welded to the channel 3, and the connection position forms a weld 5. When making the segment 2, the channel 3 and the anchor rod 4 are buried together in the segment 2.

[0043] In addition, the connector 6 is a rod-shaped structure. In this embodiment, the connector 6 is a T-bolt. The head of the T-bolt is inserted into the groove 3 and fixed. The section of the T-bolt extending into the groove 10 is threaded. The fastener 7 is threaded to the T-bolt. The fastener 7 is an anti-slip nut.

[0044] It is understandable that, in order to make the locking part cooperate with the connecting part 6 and the fastener 7, a receiving groove can be provided at the position of the locking part mating hole groove 10, so that the connecting part 6 and the fastener 7 can be inserted into the receiving groove and the position of the connecting part 6 and the fastener 7 can be constrained to prevent them from loosening and falling off.

[0045] like Figure 1 As shown, a groove is provided on the top surface of the precast track bed foundation 1. The groove fits the bottom surface of the precast track bed slab 8 and supports the precast track bed slab 8. The locking block is located on the bottom surface of the precast track bed slab 8. The shape of the locking block is adapted to the structure of the slot 10. When the locking block is embedded in the slot 10, the locking block abuts against the fastener 7 and the connector 6 to press it tight.

[0046] In accordance with the assembled multiple tunnel segments 2, multiple precast track foundations 1 are spliced ​​sequentially along the tunnel extension direction. Each precast track foundation 1 is fixed to the corresponding channel 3 by a connector 6, and the splicing positions of adjacent precast track foundations 1 are connected by a series connector 11.

[0047] like Figure 2 , Figure 4 As shown, along the tunnel extension direction, the end of the precast track bed foundation 1 is provided with a series hole. One end of the series hole extends to the end face of the precast track bed foundation 1, and the other end forms an operating groove. One end of the series member 11 passes through the series hole of one precast track bed foundation 1 and extends into the operating groove, and the other end passes through the series hole of another precast track bed foundation 1 and extends into the operating groove. The series member 11 is arc-shaped.

[0048] It is understood that in this embodiment, both the precast track bed foundation 1 and the precast track bed slab 8 are axisymmetric structures, and their axis of symmetry 12 is coplanar and perpendicular to the tunnel axis.

[0049] The tandem component 11 adopts an arc-shaped screw with threaded sections at both ends. After the threaded sections extend into the operating groove, they are tightened with nuts to lock the adjacent precast track bed foundations 1 together.

[0050] At the same time, such as Figure 2 , Figure 4 As shown, multiple precast track bed foundations 1 and corresponding precast track bed slabs 8 are arranged along the tunnel extension direction. The joint positions of adjacent precast track bed foundations 1 are spliced ​​by connecting parts 11, and waterproof elastic sealing gaskets 15 are filled between adjacent precast track bed foundations 1.

[0051] The precast track slab 8 is a precast structure with a steel rail 9 on top and a raised structure that matches the groove at the bottom; at the same time, the precast track slab 8 is also equipped with fasteners that match the steel rail 9.

[0052] The bottom mating parts of the precast track bed foundation 1 and the precast track bed slab 8 are all reinforced concrete structures precast in the factory or on the construction site; the waterproof elastic sealing gasket 15 is an elastic sealing material to prevent dust, debris, water and other substances from entering the gaps between the precast track bed foundation 1, the gap between the precast track bed foundation 1 and the tunnel segment 2, and the gap between the precast track bed foundation 1 and the station floor structure.

[0053] Example 2

[0054] In another typical embodiment of the present invention, such as Figures 1-5 As shown, a construction method for a fully prefabricated track structure for integrated assembly of shield tunnels is presented.

[0055] Construction methods for fully prefabricated track structures used in the integrated assembly of shield tunnels include:

[0056] After grabbing the precast track bed foundation 1 and aligning the connecting holes with the channel 3, place it and arrange the connecting parts 6;

[0057] One end of the connector 6 passes through the connecting hole and then inserts into the channel 3 and is locked in place. The other end is located in the hole groove 10. Fasteners 7 are installed in the hole groove 10 to lock the position of the precast track bed foundation 1.

[0058] The precast track slab 8 is equipped with all the connecting parts 6 and fasteners 7 corresponding to the precast track foundation 1. The locking blocks on the precast track slab 8 are aligned with the corresponding holes and slots 10 to install the precast track slab 8 onto the track bed.

[0059] Specifically, it includes the following steps:

[0060] The precast track bed foundation unit 1 is prefabricated in the factory. After the shield tunnel segment 2 containing the pre-embedded channel 3 is constructed, the precast track bed foundation unit 1 is transported to the construction site by transportation equipment. The assembly equipment picks it up and places it in the corresponding structural position of the shield tunnel segment 2. The precast track bed foundation 1 is arranged in the pre-embedded channel 3 in the middle of the circumference of the corresponding segment 2 through the pre-reserved connection hole for T-bolts to pass through. The head of the T-bolt passes through the pre-reserved connection hole of the precast track bed foundation 1 and is inserted into the pre-embedded channel 3 of the shield tunnel segment 2. After rotating 90 degrees, the T-bolt is fastened to the T-connector 6 in the slot at the end of the pre-reserved connection hole by fastener 7, so as to realize the reliable connection between the shield tunnel segment 2 and the precast track bed foundation 1.

[0061] After aligning the longitudinal series holes of adjacent precast track bed foundations 1, insert the series connector 11, and tighten the two ends of the series connector 11 with nuts to achieve a reliable longitudinal connection between the precast track bed foundations 1.

[0062] Install the waterproof elastic sealing gasket 15 between the precast track bed foundation 1 units, and install the precast track bed slab 8 system and rails 9 and fasteners above the precast track bed foundation 1.

[0063] The precast track bed foundation unit is prefabricated in a factory, ensuring high quality and precision. Mechanized transportation and hoisting operations greatly reduce the labor intensity of workers. On-site modular assembly significantly reduces construction steps. It features fast construction speed, high precision, and good results. It greatly shortens the time for on-site concrete mixing, transportation, pouring, and curing of traditional track bed foundations. It can be combined with the mechanized equipment for assembling tunnel segments 2 to achieve mechanized assembly and construction of the track bed foundation immediately after the segments 2 are assembled. It can effectively overcome the disadvantages of existing cast-in-place track bed foundation construction, such as multiple construction steps, high labor intensity of manual main operations, difficulty in controlling construction precision, and slow construction speed. It realizes the rapid construction of the precast assembly of the last part of the cast-in-place track bed foundation structure in the precast track bed slab system.

[0064] At the same time, by combining the existing technology of precast slab track bed 8, the effect of rapid construction of all components of the track bed structure by prefabrication and assembly has been achieved. This maximizes the rapid and efficient construction of the track bed structure and establishes a rapid construction system for the full prefabrication and assembly of the main components of shield tunnels. This is in line with the industry's green development concept of prefabrication industrialization, assembly, energy conservation and emission reduction, and promotes the high-quality and sustainable development of prefabricated track bed 8 in the field of urban rail transit from the source.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fully prefabricated track structure for integrated assembly of shield tunnels, characterized in that, The system includes connectors, precast track slabs, precast track foundations, and channels for embedding tunnel segments. One end of the connector engages with the channel, and the other end passes through a pre-drilled connection hole in the precast track foundation. The top surface of the precast track foundation has a slot corresponding to the connection hole position. Fasteners fit into the slots and engage with the connectors to lock the position of the precast track foundation. The precast track slabs are supported on the precast track foundation. The precast track slabs have locking blocks corresponding to the slot positions for embedding into the slots. The locking blocks maintain the position of the connectors and fasteners. The top surface of the precast track bed foundation is provided with a groove, which fits with the bottom surface of the precast track bed slab and supports the precast track bed slab; The locking block is located on the bottom surface of the precast track slab. The shape of the locking block is adapted to the slot structure. When the locking block is embedded in the slot, the locking block abuts against the fastener and connector to press it tight. A receiving groove is provided at the position of the locking part mating hole groove, so that the connector and fastener can be inserted into the receiving groove and the position of the connector and fastener can be constrained to prevent them from loosening and falling off.

2. The fully prefabricated track structure for integrated assembly of shield tunnels as described in claim 1, characterized in that, Along the tunnel ring, the same precast track bed foundation is connected to multiple connectors through multiple connection holes. Adjacent connectors are arranged at intervals, and each connector is connected to the channel.

3. The fully prefabricated track structure for integrated assembly of shield tunnels as described in claim 2, characterized in that, Along the tunnel extension direction, at least one set of connectors are provided on the same precast track bed foundation; the channel is embedded in the segment and keeps the opening facing the tunnel axis, and the channel is connected to the anchor rod embedded in the segment.

4. The fully prefabricated track structure for integrated assembly of shield tunnels as described in claim 1, characterized in that, The connector is a T-bolt. The head of the T-bolt is inserted into the groove and fixed. The section of the T-bolt extending into the groove is threaded. The fastener is engaged with the T-bolt through the thread.

5. The fully prefabricated track structure for integrated assembly of shield tunnels as described in claim 1, characterized in that, Along the tunnel's extension direction, multiple precast track bed foundations are spliced ​​together in sequence. Each precast track bed foundation is fixed to the corresponding channel by connectors, and adjacent precast track bed foundations are connected by tandem connectors.

6. The fully prefabricated track structure for integrated assembly of shield tunnels as described in claim 5, characterized in that, Along the tunnel extension direction, the end of the precast track bed foundation is provided with a series hole. One end of the series hole extends to the end face of the precast track bed foundation, and the other end forms an operating groove. One end of the series member passes through the series hole of one precast track bed foundation and extends into the operating groove, and the other end passes through the series hole of another precast track bed foundation and extends into the operating groove. The series member is arc-shaped.

7. A construction method for a fully prefabricated track structure for integrated assembly of shield tunnels as described in any one of claims 1-6, characterized in that, include: After grasping the precast track bed foundation and aligning the connection holes with the channel, place it and arrange the connectors; One end of the connector passes through the connecting hole and is inserted into the groove and locked in place, while the other end is located in the groove. Fasteners are installed in the groove to lock the position of the precast track bed foundation. All the connecting parts and fasteners corresponding to the precast track bed slab are installed. The locking blocks on the precast track bed slab are aligned with the corresponding holes and slots to install the precast track bed slab onto the track bed.

8. The construction method as described in claim 7, characterized in that, Multiple precast track bed foundations and corresponding precast track bed slabs are arranged along the tunnel extension direction. The joints of adjacent precast track bed foundations are spliced ​​together by tandem components, and waterproof elastic sealing gaskets are filled between adjacent precast track bed foundations.

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