A method of constructing a tunnel lining structure

Abstract

The application provides a tunnel lining structure construction method, and belongs to the technical field of tunnel construction, and comprises the following steps: S1, installing an inverted arch formwork at the bottom of a tunnel, forming an inverted arch pouring cavity between the inverted arch formwork and the inner wall of the tunnel, and installing inverted arch anchor rods on the inverted arch formwork; pouring concrete between the inverted arch formwork and the bottom of the tunnel to form an inverted arch structure; S2, installing a track on the inverted arch structure, and matching the running wheels of a trolley with the track; S3, hoisting an arch wall formwork into position, installing arch wall anchor rods on the arch wall formwork by using the trolley, and forming an arch wall pouring cavity between the arch wall formwork and the inner wall of the tunnel; pouring concrete into the arch wall pouring cavity to form an arch wall; and S4, removing the arch wall formwork, the trolley and the track. The tunnel lining structure construction method shortens the waiting time for connection between processes, improves the construction efficiency, and guarantees the forming precision and appearance quality of the lining concrete.

Description

Technical Field

[0001] This application belongs to the field of tunnel construction technology, and more specifically, relates to a construction method for tunnel lining structures. Background Technology

[0002] Tunnel construction is typically divided into two stages: initial support and secondary lining. Initial support is carried out simultaneously with tunnel excavation to stabilize the surrounding rock in a timely manner. After the initial support is completed, the drainage system is constructed, and finally, the secondary lining is constructed to form the final load-bearing structure of the tunnel.

[0003] Currently, secondary tunnel lining commonly employs integral steel formwork lining trolleys for construction. These trolleys occupy most of the tunnel's internal passageway during pouring and curing, severely hindering the simultaneous execution of subsequent processes such as tunnel excavation and muck removal, resulting in a prolonged overall construction period. Furthermore, in existing methods, invert construction and arch wall construction are independent. After invert curing, temporary support structures for the trolley tracks must be installed before arch wall construction can proceed. The installation and removal of these temporary supports are cumbersome, further extending the construction period. Moreover, the lack of an effective rigid connection between the arch wall formwork and the invert makes it prone to floating and lateral displacement during pouring, affecting the quality of the lining. Summary of the Invention

[0004] The purpose of this application is to provide a construction method for tunnel lining structures to solve the technical problems in the prior art where the lining trolley occupies the passage space during tunnel construction, resulting in a long construction period, and the poor stability of the formwork affects the construction quality.

[0005] To achieve the above objectives, the technical solution adopted in this application is: to provide a construction method for a tunnel lining structure, comprising: S1: Install an invert arch formwork at the bottom of the tunnel, forming an invert arch casting cavity between the invert arch formwork and the inner wall of the tunnel, and install invert arch anchor bolts on the invert arch formwork; pour concrete between the invert arch formwork and the bottom of the tunnel, and remove the invert arch formwork after curing to form an invert arch structure; S2: Install a track for the trolley to travel on the inverted arch structure, and install the trolley inside the tunnel, with the trolley's wheels fitted onto the track. S3: The arch wall formwork is hoisted into place, and the arch wall anchor rods are installed on the arch wall formwork using the trolley, so that an arch wall casting cavity is formed between the arch wall formwork and the tunnel inner wall; concrete is poured into the arch wall casting cavity, and after curing, the arch wall is formed. The arch wall and the invert arch structure together constitute the tunnel inner lining structure. S4: Remove the arch wall template, the trolley, and the track.

[0006] In one possible implementation, in S1, before installing the inverted arch anchor bolts, the inverted arch steel mesh is first tied at the bottom of the tunnel; in S3, before or after installing the arch wall formwork, the arch wall steel mesh is tied on both sides and the top of the tunnel.

[0007] In one possible implementation, in S1, drilling is performed using a fixed anchor drilling jig to control the drilling angle, and the inverted arch anchor is fixed with an anchoring agent after drilling; in S3, after the arch wall template is installed, holes are drilled at the anchor hole positions of the arch wall template, and the arch wall anchor is fixed with an anchoring agent.

[0008] In one possible implementation, the invert arch template and / or the arch wall template are corrugated steel structures, and the invert arch template and / or the arch wall template are provided with casting holes and observation holes.

[0009] In one possible implementation, the inverted arch anchor and / or the arch wall anchor is a two-section structure, including a top rod and an anchoring section. The top rod and the anchoring section are connected by a sleeve. The top rod is provided with a support pad for supporting the formwork. When the formwork is removed, the top rod is removed along with the formwork, and the anchoring section remains in the surrounding rock.

[0010] In one possible implementation, there are multiple inverted arch anchors, which are divided into five groups, including two outer anchor groups symmetrically arranged on both sides of the bottom, two inner anchor groups symmetrically arranged between the two outer anchor groups, and a central anchor group arranged in the middle of the bottom.

[0011] In one possible implementation, in S2, the track is fixedly installed on the two support seats symmetrically installed on the inverted arch structure; the support seat includes a base plate and a support block fixedly installed on the base plate, the base plate is fixedly connected to the inverted arch structure, the support block is provided with a mounting surface, and the track is fixedly installed on the mounting surface; in S4, the support seats are also removed.

[0012] In one possible implementation, in S2, before installing the support base, an adjustable bearing mechanism is first installed on the arch structure; both ends of the arch wall template are respectively abutted against the two adjustable bearing mechanisms, and the installation position of the arch wall template is adjusted by adjusting the adjustable bearing mechanisms; the adjustable bearing mechanism includes an adjusting screw, an adjusting nut threaded onto the adjusting screw, and a force-applying component installed on the adjusting nut, one end of the adjusting screw is supported on the support base, and the other end extends toward the arch wall template, and the force-applying component is driven to move along the adjusting screw by rotating the adjusting nut, thereby adjusting the position of the arch wall template; in S4, the adjustable bearing mechanism is also removed.

[0013] In one possible implementation, the arch wall anchor is a rebar, and multiple rebars are pre-installed and spaced apart circumferentially along the arch wall template. One end of each rebar is detachably connected to the arch wall template, and the other end extends into the arch wall casting cavity. The rebar includes a reinforcing rod and a fastener for fixing the reinforcing rod to the arch wall template. The fastener is detachably connected to the arch wall template and includes a connecting sleeve, a connecting screw, and a locking nut. The connecting sleeve is located inside the arch wall casting cavity and has an internal thread section on its inner wall. The reinforcing rod is located below the connecting sleeve and its upper end is threaded to the connecting sleeve. The connecting screw is located above the connecting sleeve and its lower end is threaded to the connecting sleeve. The locking nut is located on the side of the arch wall template away from the arch wall casting cavity. In S4, when the arch wall template is removed, the connecting screw and the locking nut are removed together, and the reinforcing rod and the connecting sleeve remain inside the arch wall.

[0014] In one possible implementation, a vibrator is installed inside the arch formwork and / or the arch wall formwork, and the vibrator is turned on when pouring concrete.

[0015] The beneficial effects of the tunnel lining structure construction method provided in this application are as follows: Compared with the prior art, the tunnel lining structure construction method of this application first installs the invert arch formwork and arranges the invert arch anchor rods at the bottom of the tunnel, and then pours concrete to form an invert arch structure with exposed ends of the anchor rods. The invert arch structure is anchored to the bottom surrounding rock by the anchor rods, so that the invert arch structure has high structural stability from the beginning of its formation, providing a reliable foundation bearing surface for the subsequent direct installation of the track.

[0016] After the invert arch structure has been cured to the required standard, a track for the trolley to travel on is installed on the surface of the invert arch structure, and the trolley's wheels are installed in conjunction with the track. This method eliminates the cumbersome procedures of designing, installing, and dismantling temporary supports, eliminates the safety hazard of track unevenness caused by settlement or displacement of temporary supports, and also combines the invert arch construction and track installation procedures.

[0017] Next, the arch wall formwork is hoisted to the designed position. Using a trolley as a mobile operating platform, the arch wall anchor bolts are installed in place, forming a closed arch wall casting cavity between the arch wall formwork and the tunnel inner wall. Concrete is then poured to form the arch wall. The arch wall formwork is an independent component, and the trolley only provides positioning and support functions. This allows the arch wall formwork to be completely removed after this step of construction, and the trolley can also be moved out, realizing the recycling of equipment.

[0018] After the arch wall concrete has been cured to the required standard, the arch wall formwork, trolley and track will be removed, and the construction of the tunnel lining structure for this section will be completed.

[0019] This method integrates the track installation directly onto the invert arch structure. Track laying and trolley installation can proceed immediately after the invert arch is formed, significantly reducing the waiting time between processes and improving construction efficiency. Furthermore, by laying the track directly on the invert arch structure and installing the trolley on it, construction vehicles and equipment for subsequent processes such as tunnel excavation and muck removal can still pass normally through the same tunnel section throughout the entire cycle of arch wall concrete pouring and curing, shortening the overall tunnel construction cycle. The arch wall formwork is rigidly connected to the surrounding rock through arch wall anchors, and the arch wall anchors themselves achieve precise fit with the formwork through anchor holes, effectively resisting the lateral pressure and buoyancy of the concrete, ensuring the forming accuracy and appearance quality of the lining concrete. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 Structural schematic diagram of the tunnel lining structure construction method provided in the embodiments of this application. Figure 1 ; Figure 2 Structural schematic diagram of the tunnel lining structure construction method provided in the embodiments of this application. Figure 2 ; Figure 3 Structural schematic diagram of the tunnel lining structure construction method provided in the embodiments of this application. Figure 3 ; Figure 4 Structural schematic diagram of the tunnel lining structure construction method provided in the embodiments of this application. Figure 4 ; Figure 5 A schematic diagram showing the connection of the inverted arch anchor bolt, support seat, and trolley provided in an embodiment of this application; Figure 6 This is a schematic diagram illustrating the connection between the arch wall anchor and the arch wall formwork provided in an embodiment of this application. Figure 7 This is a schematic diagram showing the connection between the adjustable bearing mechanism and the support base provided in an embodiment of this application.

[0022] The following are the labeling elements in the figure: 10. Invert arch formwork; 11. Invert arch casting cavity; 12. Invert arch anchor bolt; 13. Invert arch structure; 14. Top rod; 15. Anchoring section; 16. Support pad; 20. Track; 21. Trolley; 22. Support seat; 23. Base plate; 24. Support block; 25. Mounting surface; 30. Arch wall formwork; 31. Arch wall casting cavity; 32. Arch wall; 33. Arch wall anchor bolt; 34. Reinforcing rod; 35. Connecting cylinder; 36. Connecting screw; 37. Locking nut; 38. L-shaped connecting plate; 40. Adjustable bearing mechanism; 41. Adjusting screw; 42. Adjusting nut; 43. Force application component; 44. Limiting plate; 45. Support plate; 46. Blocking component. Detailed Implementation

[0023] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0024] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0025] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0027] Please see Figures 1 to 7 The construction method for a tunnel lining structure provided in this application is now described. A construction method for a tunnel lining structure includes: S1: Install the invert arch formwork 10 at the bottom of the tunnel, forming an invert arch casting cavity 11 between the invert arch formwork 10 and the inner wall of the tunnel, and install invert arch anchor rods 12 on the invert arch formwork 10; pour concrete between the invert arch formwork 10 and the bottom of the tunnel, and remove the invert arch formwork 10 after curing to form an invert arch structure 13. S2: Install a track 20 on the invert arch structure 13 for the trolley 21 to travel on, and install the trolley 21 in the tunnel, with the wheels of the trolley 21 being installed on the track 20. S3: The arch wall formwork 30 is hoisted into place, and the arch wall anchor rod 33 is installed on the arch wall formwork 30 using the trolley 21, so that the arch wall formwork 30 and the tunnel inner wall form an arch wall casting cavity 31; concrete is poured into the arch wall casting cavity 31, and after curing, an arch wall 32 is formed. The arch wall 32 and the invert arch structure 13 together constitute the tunnel inner lining structure. S4: Remove arch wall formwork 30, trolley 21 and track 20.

[0028] Compared with existing technologies, the tunnel lining structure construction method provided in this application first installs the invert arch formwork 10 at the bottom of the tunnel and arranges the invert arch anchor bolts 12. After pouring concrete, an invert arch structure 13 with exposed anchor bolt ends is formed. The invert arch structure 13 is anchored to the surrounding rock at the bottom by the anchor bolts, so that the invert arch structure 13 has high structural stability from the beginning of its formation, providing a reliable foundation bearing surface for the subsequent direct installation of the track 20.

[0029] After the invert arch structure 13 has been cured to the required standard, a track 20 for the trolley 21 to travel on is installed on the surface of the invert arch structure 13, and the wheels of the trolley 21 are installed in conjunction with the track 20. This method eliminates the cumbersome procedures of designing, installing and dismantling temporary supports, eliminates the safety hazard of uneven track 20 caused by settlement or displacement of temporary supports, and also combines the invert arch construction and track 20 installation procedures.

[0030] Next, the arch wall formwork 30 is hoisted to the designed position. Using the trolley 21 as a mobile operating platform, the arch wall anchor bolts 33 are installed in place, forming a closed arch wall casting cavity 31 between the arch wall formwork 30 and the tunnel inner wall. Concrete is then poured to form the arch wall 32. The arch wall formwork 30 is an independent component, and the trolley 21 only provides positioning and support functions. This allows the arch wall formwork 30 to be completely removed after this step of construction, and the trolley 21 can also be moved out, realizing the recycling of equipment.

[0031] After the concrete of the arch wall 32 has reached the required standard, the arch wall formwork 30, the trolley 21 and the track 20 will be removed, completing the construction of the tunnel lining structure for this section.

[0032] In this manner, the track 20 is directly integrated into the invert arch structure 13. Once the invert arch is formed, the track 20 can be laid and the trolley 21 installed, significantly shortening the waiting time between processes and improving construction efficiency. Furthermore, by directly laying the track 20 on the invert arch structure 13 and installing the trolley 21 on it, construction vehicles and equipment for subsequent processes such as tunnel excavation and muck removal can still pass normally through the same tunnel section throughout the entire period of concrete pouring and curing of the arch wall 32, shortening the overall tunnel construction cycle. The arch wall formwork 30 is rigidly connected to the surrounding rock through arch wall anchors 33, and the arch wall anchors 33 themselves achieve precise fit with the formwork through anchor holes on the formwork, effectively resisting the lateral pressure and buoyancy of the concrete, ensuring the forming accuracy and appearance quality of the lining concrete.

[0033] Please see Figures 1 to 4 As a specific implementation of the tunnel lining structure construction method provided in this application, in S1, before installing the invert arch anchor rods 12, the invert arch steel mesh is first tied at the bottom of the tunnel; in S3, before or after installing the arch wall formwork 30, the arch wall steel mesh 32 is tied on both sides and the top of the tunnel. The tying of the steel mesh is an important part of the load-bearing system of the lining structure. Tying the invert arch steel mesh before installing the invert arch anchor rods 12 facilitates the positioning and fixing of the steel mesh, and also allows the invert arch anchor rods 12 to pass through the mesh gaps and anchor into the surrounding rock, forming a spatially staggered arrangement of the anchor rods and the steel mesh. After pouring, the two together constitute the load-bearing skeleton of the invert arch structure 13.

[0034] By installing steel mesh in the invert arch and arch wall 32 respectively, both the formed invert arch structure 13 and arch wall 32 possess good bending and crack resistance. As a secondary reinforcing bar in the lining concrete, the steel mesh can effectively restrain temperature cracks and shrinkage cracks in the concrete, improving the integrity and durability of the structure.

[0035] For the invert arch, the steel mesh and the invert arch anchor 12 together form a bottom reinforcement layer, enhancing the invert arch's ability to withstand surrounding rock pressure and train loads. For the arch wall 32, the steel mesh and the arch wall anchor 33 or rebar together constitute an arch-shaped load-bearing system, improving the structural safety reserve of the arch wall 32. This implementation method further ensures the long-term operational safety of the tunnel lining structure.

[0036] As a specific implementation of the tunnel lining structure construction method provided in this application, in S1, drilling is performed using a fixed anchor drilling jig to control the drilling angle, and after drilling, the invert arch anchor 12 is fixed with an anchoring agent; in S3, after the arch wall formwork 30 is installed, holes are drilled at the anchor hole positions of the arch wall formwork 30, and the arch wall anchor 33 is fixed with an anchoring agent. During bottom construction, the drilling jig is first fixed at the designed position at the bottom of the tunnel. The jig is equipped with guide holes, the angle of which is determined according to the stress requirements of the surrounding rock and the anchor arrangement design.

[0037] Construction workers drill through the guide hole with a drill rod, allowing for precise control of the borehole entry angle and ensuring the anchor rod is anchored into the surrounding rock in the designed direction. After drilling, anchoring agent is injected from the bottom to the opening of the hole, and then the anchor rod is inserted into the hole. Once the anchoring agent has cured, the anchor rod is firmly anchored to the surrounding rock. During the construction of the arch wall 32, drilling is carried out after the arch wall formwork 30 is installed. Anchor rod holes are pre-drilled on the arch wall formwork 30, and the drill rod drills directly through these holes into the surrounding rock. The positioning and angle of the anchor rod holes are precisely controlled by the anchor rod holes on the formwork.

[0038] The anchoring effect of anchor bolts is closely related to the drilling angle. If the drilling angle deviates from the design value, the anchor bolt will not be able to bear the surrounding rock load in the optimal direction, and may even weaken the anchoring effect and cause the anchor bolt to fail. The design of the drilling jig and pre-drilled holes in the template fundamentally solves the angle control problem, ensuring that the force direction of the anchor bolt matches the deformation direction of the surrounding rock.

[0039] Please see Figures 1 to 4 As a specific implementation of the tunnel lining structure construction method provided in this application, the invert arch formwork 10 and / or the arch wall formwork 30 are corrugated steel structures, and the invert arch formwork 10 and / or the arch wall formwork 30 are pre-reserved with pouring holes and observation holes. The corrugation direction of the corrugated steel structure extends along the tunnel length direction, and the bending stiffness and deformation resistance of the corrugated steel plate are much higher than those of ordinary flat steel plates.

[0040] When the formwork is subjected to lateral pressure and buoyancy during concrete pouring, the corrugated structure can distribute the local load to the entire formwork surface, effectively resisting formwork deformation. Simultaneously, the textured surface of the corrugated steel plate creates a naturally rough surface on the poured concrete, which is beneficial for the adhesion of subsequent waterproofing or decorative layers. The pouring holes on the formwork are used to inject concrete into the pouring cavity, while the observation holes are used to monitor the flow and compaction of the concrete in real time during construction, ensuring pouring quality.

[0041] Please see Figures 1 to 7As a specific embodiment of the tunnel lining structure construction method provided in this application, the inverted arch anchor 12 and / or the arch wall anchor 33 are two-section structures, including a top rod 14 and an anchoring section 15. The top rod 14 and the anchoring section 15 are connected by a sleeve. The top rod 14 is provided with a support pad 16 for supporting the formwork. When the formwork is removed, the top rod 14 is removed along with the formwork, and the anchoring section 15 remains in the surrounding rock. The anchoring section 15 is a permanent component, with its lower end anchored into the surrounding rock and its upper end connected to the top rod 14 through a sleeve. The top rod 14 is a detachable component, which passes through the anchor hole on the formwork and uses the support pad 16 to press and fix the formwork. The inner wall of the sleeve is provided with internal threads, which respectively mate with the external threads at the upper end of the anchoring section 15 and the lower end of the top rod 14. During installation, first anchor section 15 is anchored into the surrounding rock. The sleeve is then screwed onto the upper end of anchor section 15. Next, the lower end of the top rod 14 is passed through the anchor hole in the template and screwed into the upper end of the sleeve. The axial tension of the anchor rod can be adjusted by rotating the top rod 14 or the sleeve, ensuring the template is firmly pressed against the surrounding rock surface. The support pad 16 is located between the outer surface of the template and the head of the top rod 14, increasing the pressing area of ​​the anchor rod on the template and preventing localized pressure indentation of the template.

[0042] Since the top rod 14 and the sleeve are detachable components, after the concrete curing is completed, simply loosening the top rod 14 will release the constraint on the formwork. The top rod 14 will be removed along with the formwork, while the anchoring section 15 will remain permanently in the surrounding rock. This structure avoids the cumbersome cutting process required by traditional anchor bolts and also avoids disturbance to the surrounding rock caused by cutting.

[0043] A hexagonal or square head can be provided at the upper end of the top rod 14 for easy wrench operation; the outer wall of the sleeve can be provided with an anti-loosening structure to prevent the sleeve from loosening during concrete vibration; a rubber gasket can be added between the support block 16 and the template to further protect the template surface and enhance the sealing.

[0044] Please see Figures 1 to 4 As a specific implementation of the tunnel lining structure construction method provided in this application, there are multiple inverted arch anchors 12, which are divided into five groups, including two outer anchor groups symmetrically arranged on both sides of the bottom, two inner anchor groups symmetrically arranged between the two outer anchor groups, and a middle anchor group arranged in the middle position of the bottom.

[0045] The anchor bolts are divided into five functional groups. The two outer anchor bolt groups are arranged at the left and right edges of the invert arch. This area is the transition zone between the invert arch and the surrounding rock of the side wall. It bears the pressure of the surrounding rock and the vertical load and horizontal thrust transmitted by the subsequent arch wall formwork 30. The anchoring force of the outer anchor bolt groups mainly provides lateral restraint.

[0046] The two inner anchor bolt groups are located inside the outer anchor bolt groups, close to the middle of the invert arch but at a certain distance from the outer group. This area mainly corresponds to the installation position of the support seat 22 and the track 20. The inner anchor bolt groups are specifically designed to bear the dynamic load generated when the trolley 21 passes through and the reciprocating force transmitted by the track 20.

[0047] The central anchor group is located in the geometric center of the invert arch, which is the part of the invert arch structure that bears the maximum bending moment. The central anchor group mainly strengthens the bending resistance and structural integrity of the mid-span region of the invert arch.

[0048] The design of five sets of anchor bolts, rather than a uniform arrangement, ensures that the anchor bolt positions are precisely matched with the structural stress requirements, avoiding wasted anchor bolts or stress gaps. The outer and inner sets form multiple layers of circumferential constraints, effectively suppressing the lateral extrusion deformation of the invert arch under the pressure of the surrounding rock; the presence of the middle set ensures the structural safety of the weakest area in the invert arch span.

[0049] Among them, the two outer anchor bolt groups are used to fix and connect to both ends of the arch wall formwork 30, and the two inner anchor bolt groups are used to fix and connect to the track 20 or the support seat 22. The outer anchor bolt groups mainly bear the vertical pressure and horizontal thrust transmitted by the subsequent arch wall formwork 30, the inner anchor bolt groups are specifically used to bear the dynamic load of the support seat 22 and the track 20, and the middle anchor bolt group strengthens the bending resistance of the mid-span of the invert arch.

[0050] L-shaped connecting plates 38 are set at both ends of the arch wall template 30. The L-shaped connecting plates 38 achieve a rigid connection between the arch wall template 30 and the inverted arch structure 13 through the outer anchor bolt group.

[0051] Please see Figure 1 and Figure 2 As a specific implementation of the tunnel lining structure construction method provided in this application, in S2, the track 20 is fixedly installed on the two support seats 22 by symmetrically installing two support seats 22 on the invert arch structure 13; the support seat 22 includes a base plate 23 and a support block 24 fixedly installed on the base plate 23, the base plate 23 is fixedly connected to the invert arch structure 13, the support block 24 is provided with an installation surface 25, and the track 20 is fixedly installed on the installation surface 25; in S4, the support seats 22 are also removed.

[0052] The support base 22 is an intermediate force-transmitting component connecting the track 20 and the invert arch structure 13. The base plate 23 is a flat steel plate, which is fixedly connected to the invert arch structure 13 through the exposed ends of the invert arch anchor rods 12 or independent fasteners. The base plate 23 has a large area, which can distribute the load transmitted by the track 20 to the invert arch structure 13. The support block 24 is fixedly welded or bolted to the upper surface of the base plate 23. The height of the support block 24 is determined according to the design elevation of the track 20. The top surface of the support block 24 is a horizontal mounting surface 25, which extends along the length of the tunnel, providing a flat and continuous installation reference for the track 20. The track 20 is fixed to the mounting surface 25 by standard fasteners such as pressure plates and bolts. During dismantling, the track 20 is removed first, and then the connection between the base plate 23 and the invert arch is loosened, so that the support base 22 can be removed as a whole.

[0053] As an independent prefabricated component, the support base 22 can be mass-produced in the factory, ensuring controllable dimensional accuracy and welding quality. During on-site installation, only the base plate 23 needs to be aligned and fixed, eliminating the need for on-site welding and enabling rapid installation. The large area of ​​the base plate 23 ensures a reliable connection between the support base 22 and the inverted arch structure 13, effectively bearing the vertical load and horizontal braking force during the movement of the trolley 21, preventing settlement or displacement of the support base 22. The horizontal mounting surface 25 provides a precise installation reference for the track 20, ensuring the straightness of the track 20 and the parallelism between the two tracks 20. The support base 22 can be completely removed in S4, realizing the temporary and recyclable nature of the track 20 system and reducing the cost of construction facilities.

[0054] A set of blocking members 46 is set on the inner side of the two support seats 22 on the invert arch structure 13. The blocking members 46 are usually made of steel bars, etc., and are fixed to the invert arch body by pre-embedding or expansion bolts. They are located between the two support seats 22, and the inner end face of the bottom plate 23 of the support seat 22 is in close contact with the outer end face of the blocking member 46.

[0055] Please see Figures 1 to 3 , Figure 5 and Figure 7As a specific implementation of the tunnel lining structure construction method provided in this application, in S2, before installing the support seat 22, an adjustable bearing mechanism 40 is first installed on the invert arch structure 13; the two ends of the arch wall template 30 are respectively abutted against the two adjustable bearing mechanisms 40, and the installation position of the arch wall template 30 is adjusted by adjusting the adjustable bearing mechanisms 40; the adjustable bearing mechanism 40 includes an adjusting screw 41, an adjusting nut 42 threadedly connected to the adjusting screw 41, and a force-applying member 43 installed on the adjusting nut 42. One end of the adjusting screw 41 is supported on the support seat 22, and the other end extends toward the arch wall template 30. By rotating the adjusting nut 42, the force-applying member 43 is driven to move along the adjusting screw 41, thereby adjusting the position of the arch wall template 30; in S4, the adjustable bearing mechanism 40 is also removed.

[0056] The adjustable bearing mechanism 40 is a template position fine-tuning device. The adjusting screw 41 is a horizontally positioned long threaded rod, one end of which is supported on the support base 22 by a limiting plate 44 or a support plate 45, and the other end extends towards the end of the arch wall template 30. An adjusting nut 42 is threadedly connected to the adjusting screw 41, and a force-applying component 43 is fixedly installed at the end of the adjusting nut 42 facing the arch wall template 30, its end face directly abutting against the end of the arch wall template 30. When the adjusting nut 42 is rotated, it moves axially along the adjusting screw 41, causing the force-applying component 43 to move synchronously. The end face of the force-applying component 43 then pushes the end of the arch wall template 30 to displace horizontally. Because the motion of the threaded transmission is precisely controllable, the template position can be precisely fine-tuned by controlling the number of rotations of the adjusting nut 42. After adjustment, the self-locking characteristic of the thread automatically locks the template in that position, eliminating the need for an additional locking device.

[0057] A limiting plate 44 is vertically welded to the side of the support base 22 near the adjustable bearing mechanism 40. The limiting plate 44 has sufficient thickness and bending strength. At the same time, a support plate 45 with an area larger than the cross-sectional area of ​​the screw is welded to the end of the adjusting screw 41 that is supported by the support base 22.

[0058] Please see Figures 1 to 4 , Figure 6As a specific embodiment of the tunnel lining structure construction method provided in this application, the arch wall anchor 33 is a rebar installation. Multiple rebars are pre-installed and spaced apart circumferentially along the arch wall template 30. One end of each rebar is detachably connected to the arch wall template 30, and the other end extends into the arch wall casting cavity 31. The rebar installation includes a reinforcing rod 34 and fasteners for fixing the reinforcing rod 34 to the arch wall template 30. The fasteners are detachably connected to the arch wall template 30 and include a connecting sleeve 35, a connecting screw 36, and a locking nut 37. The connecting cylinder 35 is located inside the arch wall casting cavity 31 and has an internal thread section on its inner wall. The reinforcing rod 34 is located below the connecting cylinder 35 and its upper end is threaded to the connecting cylinder 35. The connecting screw 36 is located above the connecting cylinder 35 and its lower end is threaded to the connecting cylinder 35. The locking nut 37 is located on the side of the arch wall template 30 away from the arch wall casting cavity 31. In step S4, when the arch wall template 30 is removed, the connecting screw 36 and the locking nut 37 are removed together, and the reinforcing rod 34 and the connecting cylinder 35 are left inside the arch wall 32.

[0059] Rebar anchoring is a key component used to strengthen the structural strength of the arch wall 32. The rebar anchoring is arranged radially and evenly along the circumference of the arch wall template 30, and the extension direction of each rebar anchoring is consistent with the radial direction of the arch wall template 30. Each rebar anchoring consists of four parts: the reinforcing rod 34 is a steel bar or threaded steel bar, which is the main load-bearing component of the rebar anchoring; the connecting cylinder 35 is a steel cylinder with internal threads on the inner wall, which serves as a transition piece between the reinforcing rod 34 and the connecting screw 36; the connecting screw 36 is an externally threaded rod that passes through the rebar anchoring hole on the template and connects the reinforcing rod 34 to the template; the locking nut 37 is screwed onto the exposed end of the connecting screw 36 to lock the entire rebar anchoring assembly onto the template.

[0060] During installation, the reinforcing rod 34 and connecting cylinder 35 are pre-assembled on the ground or in the factory before the arch wall formwork 30 is installed. Then, the connecting bolt 36 is passed through the rebar holes in the formwork and screwed into the upper end of the connecting cylinder 35. Finally, the locking nut 37 is tightened to fix the rebar to the formwork. At this time, the reinforcing rod 34 and connecting cylinder 35 are located inside the formwork (i.e., inside the arch wall casting cavity 31), the connecting bolt 36 penetrates the formwork, and the locking nut 37 is located outside the formwork. When pouring concrete, the reinforcing rod 34 and connecting cylinder 35 are embedded in the arch wall 32 concrete. When removing the formwork, simply unscrew the locking nut 37, and the connecting bolt 36 can be unscrewed from the connecting cylinder 35 and removed along with the formwork, while the reinforcing rod 34 and connecting cylinder 35 remain permanently inside the arch wall 32 concrete.

[0061] The rebar is precisely positioned and fixed in its designed location during the formwork installation stage. After the concrete is poured, the rebar is naturally embedded, eliminating the need for secondary drilling and grouting. The rebar is firmly connected to the formwork before concrete pouring, allowing for precise control of its position and angle. It will not shift due to concrete flow during pouring, ensuring uniform distribution and accurate positioning of the rebar within the arch wall 32, thus significantly improving the load-bearing capacity of the arch wall 32. The connecting bolts 36 and locking nuts 37 can be reused after formwork removal, reducing material consumption. The reinforcing rods 34 and connecting cylinders 35 are retained within the arch wall 32 as permanent reinforcing bars, sharing the operational load with the arch wall 32's steel mesh.

[0062] As a specific implementation of the tunnel lining structure construction method provided in this application, a vibrator is installed inside the invert arch formwork 10 and / or the arch wall formwork 30, and the vibrator is turned on when pouring concrete.

[0063] The vibrator is a supporting compaction device for the formwork system. It is a high-frequency attached vibrator, fixed to the inner surface of the formwork (facing the pouring cavity) by bolts or magnetic bases. Multiple vibrators are arranged at regular intervals along the longitudinal and circumferential directions of the formwork to ensure that the vibration energy covers the entire pouring area. During concrete pouring, when the concrete reaches the corresponding height, the vibrator at the corresponding position is activated. The high-frequency vibration force generated by the vibrator is directly transmitted to the concrete mixture inside the formwork through the formwork panel, causing the aggregate in the concrete to rearrange and air bubbles to be expelled, thereby achieving concrete compaction. The timing and duration of vibrator activation are flexibly controlled according to the concrete pouring speed, slump, and formwork position. Intermittent vibration is usually used to avoid excessive compaction that could lead to concrete segregation.

[0064] Corrugated steel formwork, as a rigid formwork, can effectively transfer the vibration energy of the vibrator to the concrete in the pouring cavity, with minimal vibration energy loss and a wide coverage area. Through proper arrangement and control of the vibrator, air bubbles inside the concrete are fully expelled, reducing surface defects such as honeycomb and pitting, improving the density and strength of the concrete, and also enhancing the appearance quality and waterproofing performance of the lining structure. The vibrator is installed and removed together with the formwork, without adding any extra construction steps.

[0065] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method of constructing a tunnel lining structure, characterized by, include: S1: Install an invert arch formwork at the bottom of the tunnel, forming an invert arch casting cavity between the invert arch formwork and the inner wall of the tunnel, and install invert arch anchor bolts on the invert arch formwork; Concrete is poured between the invert arch formwork and the bottom of the tunnel. After curing, the invert arch formwork is removed to form the invert arch structure. S2: Install a track for the trolley to travel on the inverted arch structure, and install the trolley inside the tunnel, with the trolley's wheels fitted onto the track. S3: The arch wall formwork is hoisted into place, and the arch wall anchor rods are installed on the arch wall formwork using the trolley, so that an arch wall casting cavity is formed between the arch wall formwork and the tunnel inner wall; concrete is poured into the arch wall casting cavity, and after curing, the arch wall is formed. The arch wall and the invert arch structure together constitute the tunnel inner lining structure. S4: Remove the arch wall template, the trolley, and the track.

2. The construction method for the tunnel lining structure as described in claim 1, characterized in that, In S1, before installing the inverted arch anchor rod, the inverted arch steel mesh is tied at the bottom of the tunnel; in S3, before or after installing the arch wall formwork, the arch wall steel mesh is tied on both sides and the top of the tunnel.

3. The tunnel lining structure construction method as described in claim 2, characterized in that, In S1, drilling is performed using a fixed anchor drilling jig to control the drilling angle, and the inverted arch anchor is fixed with an anchoring agent after drilling. In S3, after the arch wall template is installed, holes are drilled at the anchor hole positions of the arch wall template, and the arch wall anchor is fixed with an anchoring agent.

4. The construction method for the tunnel lining structure as described in claim 1, characterized in that, The inverted arch template and / or the arch wall template are corrugated steel structures, and the inverted arch template and / or the arch wall template are provided with casting holes and observation holes.

5. The construction method for the tunnel lining structure as described in claim 1, characterized in that, The arch anchor and / or the arch wall anchor is a two-section structure, including a top rod and an anchoring section. The top rod and the anchoring section are connected by a sleeve. The top rod is provided with a support pad for supporting the formwork. When the formwork is removed, the top rod is removed along with the formwork, and the anchoring section is left in the surrounding rock.

6. The construction method for the tunnel lining structure as described in claim 1, characterized in that, The inverted arch anchor bolts are multiple, and the multiple inverted arch anchor bolts are divided into five groups, including two outer anchor bolt groups symmetrically arranged on both sides of the bottom, two inner anchor bolt groups symmetrically arranged between the two outer anchor bolt groups, and a middle anchor bolt group arranged in the middle position of the bottom.

7. The construction method for the tunnel lining structure as described in claim 1, characterized in that, In S2, the track is fixedly installed on the two support seats by symmetrically installing two support seats on the arch structure; the support seat includes a base plate and a support block fixedly installed on the base plate, the base plate is fixedly connected to the arch structure, the support block is provided with a mounting surface, and the track is fixedly installed on the mounting surface; in S4, the support seats are also removed.

8. The construction method for the tunnel lining structure as described in claim 7, characterized in that, In S2, before installing the support base, an adjustable bearing mechanism is first installed on the arch structure; both ends of the arch wall template are respectively abutted against the two adjustable bearing mechanisms, and the installation position of the arch wall template is adjusted by adjusting the adjustable bearing mechanisms; the adjustable bearing mechanism includes an adjusting screw, an adjusting nut threaded onto the adjusting screw, and a force-applying component installed on the adjusting nut. One end of the adjusting screw is supported on the support base, and the other end extends toward the arch wall template. By rotating the adjusting nut, the force-applying component is driven to move along the adjusting screw, thereby adjusting the position of the arch wall template; in S4, the adjustable bearing mechanism is also removed.

9. The construction method for the tunnel lining structure as described in claim 1, characterized in that, The arch wall anchor is a rebar, and multiple rebars are pre-installed and spaced apart circumferentially along the arch wall template. One end of each rebar is detachably connected to the arch wall template, and the other end extends into the arch wall casting cavity. The rebar includes a reinforcing rod and a fastener for fixing the reinforcing rod to the arch wall template. The fastener is detachably connected to the arch wall template and includes a connecting cylinder, a connecting screw, and a locking nut. The connecting cylinder is located inside the arch wall casting cavity and has an internal thread section on its inner wall. The reinforcing rod is located below the connecting cylinder and its upper end is threaded to the connecting cylinder. The connecting screw is located above the connecting cylinder and its lower end is threaded to the connecting cylinder. The locking nut is located on the side of the arch wall template away from the arch wall casting cavity. In S4, when the arch wall template is removed, the connecting screw and the locking nut are removed together, and the reinforcing rod and the connecting cylinder are left inside the arch wall.

10. The construction method for the tunnel lining structure as described in any one of claims 1-9, characterized in that, A vibrator is installed inside the arch formwork and / or the arch wall formwork, and the vibrator is turned on when pouring concrete.

Images