Cold region tunnel lining falling block rapid reinforcing structure based on cement-based tough material

Abstract

The utility model discloses a cold region tunnel lining falling block rapid reinforcing structure based on a cement-based tough material, which relates to the technical field of tunnel reinforcement, and comprises an existing tunnel lining structure, the inner side surface of the existing tunnel lining structure forms a reinforcing base surface after being cleaned, and the inner side of the existing tunnel lining structure is provided with a cement-based tough material section steel molded sleeve lining. A tunnel existing cable trough is formed in the side face of the tunnel pavement, the cement-based tough material profile steel molded sleeve lining comprises H-shaped steel arch frames arranged in the circumferential direction of the tunnel at the interval of 1 m, and a double-layer reinforcing mesh is arranged on the inner side of each H-shaped steel arch frame. Specifically, a steel formwork is fixed outside profile steel in a welding or bolted connection mode, the problems of uneconomy and low construction efficiency caused by a secondary lining pouring trolley and a full framing formwork are solved, and meanwhile the problem of formwork deformation possibly caused by small rigidity of a simple steel pipe framing formwork is solved.

Description

Technical Field

[0001] This utility model relates to the field of tunnel reinforcement technology, specifically a rapid reinforcement structure for lining spalling in cold regions based on cement-based tough materials. Background Technology

[0002] Currently, some highway tunnels operating in cold regions of my country are prone to sudden lining collapses due to factors such as long construction time leading to structural degradation, substandard construction quality, freeze-thaw cycles, and changes in tunnel geology and hydrology. This could endanger the safety of passing vehicles and maintenance personnel. How to quickly and safely reinforce the lining structure to prevent further structural instability and subsequent localized or large-scale collapses, while simultaneously restoring traffic flow as soon as possible, is a key issue that needs to be considered when reinforcing tunnels in cold regions that have experienced lining collapses.

[0003] Traditional cement-based concrete lining requires over 7 days of curing before formwork removal. The construction cost and time involved in using secondary lining trolleys or full-span scaffolding for formwork pouring of the inner lining concrete are significantly increased when reinforcing only one section (typically 6m, 9m, or 10m) of an operating tunnel experiencing slab collapse. Therefore, this utility model patent, based on materials, formwork, and the strength of the reinforced structure, provides a structurally safe and easily and quickly constructed reinforcement structure to restore tunnel structural safety and vehicle traffic as quickly as possible. Therefore, based on the above research and existing technology, a rapid reinforcement structure for slab collapse in cold-region tunnel linings based on cement-based tough materials is proposed to solve the aforementioned problems. Utility Model Content

[0004] The purpose of this invention is to provide a rapid reinforcement structure for lining collapse in cold regions based on cement-based tough materials, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A rapid reinforcement structure for slumping tunnel lining in cold regions based on cement-based tough materials includes: an existing tunnel lining structure, the inner surface of which is cleaned to form a reinforcement base surface; a cement-based tough material steel molded sleeve is provided on the inner side of the existing tunnel lining structure; and an existing cable trough for the tunnel is provided on the side of the tunnel pavement.

[0007] The cement-based tough material steel formwork lining includes H-shaped steel arches arranged at 1m intervals along the circumferential direction of the tunnel. The outer contour surface of the H-shaped steel arches is in close contact with the reinforced base surface of the existing tunnel lining structure. The inner side of the H-shaped steel arches is provided with a double-layer steel mesh.

[0008] The double-layer steel mesh includes inner circumferential steel bars, outer circumferential steel bars, inner longitudinal steel bars, and outer longitudinal steel bars;

[0009] Shear bars and L-shaped hoop bars are embedded in the existing lining structure of the tunnel. Cement-based tough concrete material is filled between the H-shaped steel arch and the reinforced base of the existing lining structure of the tunnel. Locking anchor rods are installed at the arch foot of the H-shaped steel arch.

[0010] Furthermore, the inner and outer circumferential reinforcing bars are made of φ20HRB400 steel bars with a circumferential spacing of 25cm, the inner and outer longitudinal reinforcing bars are made of φ14HRB400 steel bars with a longitudinal spacing of 25cm, and the double-layer steel mesh is fixed by tying with stirrups.

[0011] Furthermore, the shear reinforcement is φ14 steel bar with a circumferential spacing of 80cm and an insertion depth of not less than 15cm, and the L-shaped hoop reinforcement is φ14 steel bar with a circumferential spacing of 1m and an insertion depth of not less than 15cm.

[0012] Furthermore, the anchor rod is a φ28 steel bar with a length of 2.5m. Two anchor rods are staggered at each arch foot on each side of the H-shaped steel arch frame. The anchor rod is fixedly connected to the H-shaped steel arch frame by stirrups.

[0013] Furthermore, the thickness of the cement-based tough concrete material is 30cm, and the H-shaped steel arch frame is made of HN300×150 steel.

[0014] Furthermore, the outer sidewall of the existing cable trough in the tunnel is cast together with the cement-based tough material steel formwork lining, and the H-shaped steel arch serves as the supporting skeleton for the casting template.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. Based on the existing research status of tough cement-based materials such as ECC, SHCC, UHPFRCC, and UHTCC, and combined with the stress characteristics of underground engineering structures, and taking into account certain economic factors, a new type of high-toughness cement-based material suitable for tunnel engineering in cold regions has been developed. This material is developed through means such as raw material substitution, admixtures, and optimized mix proportions. It changes the failure mode of traditional cement-based materials that develops a single macroscopic crack, and uniformly disperses the single macroscopic crack into saturated fine cracks. Under the ultimate tensile state, it can still control the crack width well, and has good low-temperature performance. It also has strain hardening and multi-crack characteristics.

[0017] 2. In this design scheme, the H-shaped steel arch frame serves as both the lining skeleton and the concrete pouring formwork skeleton. Specifically, the steel formwork is fixed by welding or bolting to the outside of the steel section, which solves the problems of uneconomical construction and low construction efficiency caused by the secondary lining pouring trolley and full-span scaffolding formwork. At the same time, it solves the problem of formwork deformation that may be caused by the low rigidity of simple steel pipe scaffolding formwork.

[0018] 3. The design of L-shaped hoop bars and L-shaped shear bars in this design scheme can effectively connect the steel arch frame with the existing lining structure and the steel mesh with the existing lining, increase the overall stiffness and strength of the reinforced structure, and give full play to the reinforcement effect of the composite lining.

[0019] 4. The lining reinforcement structure is composed of steel arch frame, double-layer steel mesh, hoop bars, shear bars and cement-based tough concrete. The reinforcement structure provides good support for the existing lining and surrounding rock, and has the characteristics of reasonable structure, strong operability and simple installation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cross-section of the reinforced structure of this utility model;

[0021] Figure 2 This is a schematic cross-sectional view of the reinforcement structure of this utility model;

[0022] Figure 3 This is a schematic diagram of the longitudinal arrangement of the H-shaped steel arch frame of this utility model;

[0023] Figure 4 This is a schematic diagram of the L-shaped hoop reinforcement structure of this utility model;

[0024] Figure 5 This is a schematic diagram of the longitudinal arrangement of the reinforcing steel mesh in the reinforcement structure of this utility model;

[0025] Figure 6 This is a schematic diagram of the longitudinal arrangement of shear reinforcement in this utility model.

[0026] In the diagram: 1. Existing tunnel lining structure; 2. Existing cable trough in the tunnel; 3. Tunnel pavement; 4. Cement-based tough concrete steel formwork lining; 5. Anchor bolts; 6. H-shaped steel arch; 7. Inner circumferential reinforcement; 8. Outer circumferential reinforcement; 9. Inner longitudinal reinforcement; 10. Outer longitudinal reinforcement; 11. Shear reinforcement; 12. Cement-based tough concrete material; 13. L-shaped hoop reinforcement; 14. Stirrups. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] In one typical implementation of this application, please refer to Figures 1-6A rapid reinforcement structure for slumping tunnel lining in cold regions based on cement-based tough materials includes an existing tunnel lining structure 1, the inner surface of which is cleaned to form a reinforcement base surface, a cement-based tough material steel molded sleeve 4 is provided on the inner side of the existing tunnel lining structure 1, and an existing tunnel cable trough 2 is provided on the side of the tunnel pavement 3.

[0029] The cement-based tough material steel formwork lining 4 includes H-shaped steel arch frames 6 arranged at 1m intervals along the tunnel circumference. The outer contour surface of the H-shaped steel arch frame 6 is in close contact with the reinforced base surface of the existing tunnel lining structure 1. The inner side of the H-shaped steel arch frame 6 is provided with a double layer of steel mesh.

[0030] The double-layer steel mesh includes inner circumferential steel bars 7, outer circumferential steel bars 8, inner longitudinal steel bars 9, and outer longitudinal steel bars 10;

[0031] Shear bars 11 and L-shaped hoop bars 13 are embedded in the existing lining structure 1 of the tunnel. Cement-based tough concrete material 12 is filled between the H-shaped steel arch frame 6 and the reinforced base surface of the existing lining structure 1 of the tunnel. Locking anchor rods 5 are installed at the arch foot of the H-shaped steel arch frame 6.

[0032] In this method, a cement-based tough steel molded lining 4 is installed inside the existing tunnel lining structure 1. The H-shaped steel arch frame 6 is in close contact with the existing tunnel lining structure 1. With the help of double-layer steel mesh, shear bars 11, L-shaped hoop bars 13 and anchor bolts 5, the lining slab collapse area can be quickly reinforced. This effectively prevents the lining structure from becoming more unstable and causing collapse, ensuring the safety of passing vehicles and maintenance personnel. At the same time, it provides a structural foundation for the subsequent restoration of vehicle traffic.

[0033] The inner circumferential reinforcement 7 and the outer circumferential reinforcement 8 are made of φ20HRB400 steel bars with a circumferential spacing of 25cm. The inner longitudinal reinforcement 9 and the outer longitudinal reinforcement 10 are made of φ14HRB400 steel bars with a longitudinal spacing of 25cm. The double-layer steel mesh is fixed by tying with stirrups 14.

[0034] During construction, the binding of reinforcing bars should be strictly carried out in accordance with the specifications to ensure the firmness and stability of the reinforcing mesh. Furthermore, the arrangement of this reinforcing mesh can form a good synergistic relationship with the cement-based tough concrete material 12. During concrete pouring, the reinforcing mesh can effectively restrain the deformation of the concrete, improve its crack resistance, and thus extend the service life of the reinforced structure.

[0035] In this method, the specific steel specifications and spacing of the double-layer steel mesh are clearly defined. φ20HRB400 steel bars are used as the inner circumferential steel bars 7 and the outer circumferential steel bars 8, and φ14HRB400 steel bars are used as the inner longitudinal steel bars 9 and the outer longitudinal steel bars 10. The circumferential and longitudinal spacing is 25cm, and they are fixed by tying with stirrups 14. This ensures that the double-layer steel mesh has sufficient strength and rigidity to effectively bear the load of the lining structure, while ensuring the convenience and economy of the steel mesh construction. It provides reliable skeleton support for the pouring of cement-based tough concrete material 12 and further enhances the overall performance of the reinforced structure.

[0036] Shear reinforcement 11 is φ14 steel bar with a circumferential spacing of 80cm and an insertion depth of not less than 15cm. L-shaped hoop reinforcement 13 is φ14 steel bar with a circumferential spacing of 1m and an insertion depth of not less than 15cm.

[0037] The specific specifications, spacing, and insertion depth of shear bars 11 and L-shaped hoop bars 13 were further clarified. The specifications of φ14 steel bars, shear bars 11 with a circumferential spacing of 80cm and an insertion depth of not less than 15cm, and L-shaped hoop bars 13 with a circumferential spacing of 1m and an insertion depth of not less than 15cm are ensured to guarantee a reliable connection between the new and old structures, effectively transfer loads, enhance the integrity of the reinforced structure, and make the new molded lining and the existing tunnel lining structure 1 closely integrated to form a collaborative whole, improve the reinforcement effect, and prevent local damage or overall instability caused by weak connection between the new and old structures.

[0038] The anchor rod 5 is a φ28 steel bar with a length of 2.5m. Two anchor rods are staggered at each arch foot on each side of the H-shaped steel arch frame 6. The anchor rod 5 is fixedly connected to the H-shaped steel arch frame 6 by stirrups 14.

[0039] Two staggered anchor bolts 5 are used to form a stable support system, effectively restraining the H-shaped steel arch 6 in all directions. During construction, professional anchor bolt installation equipment should be used to install the anchor bolts 5, ensuring that the installation angle and depth meet design requirements. The fixed connection between the stirrups 14 and the H-shaped steel arch 6 should be firm and reliable to guarantee the synergistic effect between the anchor bolts 5 and the H-shaped steel arch 6.

[0040] The document specifies the exact specifications, length, arrangement, and connection method of the anchor bolts 5 with the H-shaped steel arch frame 6. Two anchor bolts 5, each with a diameter of φ28 steel bars and a length of 2.5m, are staggered at each arch foot and fixedly connected to the H-shaped steel arch frame 6 via stirrups 14. This provides stable lateral support for the H-shaped steel arch frame 6, prevents lateral displacement or deformation at the arch foot, enhances the overall stability and deformation resistance of the reinforced structure, and ensures the safety of the reinforced structure during construction and use.

[0041] The cement-based tough concrete material 12 is poured to a thickness of 30cm. The H-shaped steel arch 6 is made of HN300×150 steel, and its dimensions and performance were selected based on the actual needs of the tunnel lining slumping reinforcement project in cold regions. It has sufficient strength and rigidity to withstand the load of the tunnel structure. During construction, the installation of the H-shaped steel arch 6 should be strictly carried out in accordance with the design requirements to ensure its accurate positioning and firm installation.

[0042] The design specifies that the pouring thickness of the cement-based tough concrete material 12 is 30cm, and that the H-shaped steel arch 6 is made of HN300×150 steel. This design ensures that the lining structure has sufficient thickness and strength to meet the structural requirements for the reinforcement of tunnel lining slumps in cold regions. At the same time, the size and performance of the HN300×150 steel can match the double-layer steel mesh, shear bars 11, L-shaped hoop bars 13 and other structures to form a stable and reliable reinforcement system, providing strong protection for the safety and stability of the tunnel structure.

[0043] The outer sidewall of the existing cable trough 2 in the tunnel is cast together with the cement-based tough material steel formwork lining 4, and the H-shaped steel arch 6 also serves as the supporting skeleton for the casting formwork.

[0044] In this method, by casting the outer sidewall of the existing cable trough 2 in the tunnel together with the cement-based tough steel formwork lining 4, and using the H-shaped steel arch frame 6 as the supporting framework for the casting formwork, the construction steps can be reduced, construction efficiency can be improved, the construction period can be shortened, and construction costs can be reduced. At the same time, the integrity and stability of the reinforced structure are ensured, providing strong support for the rapid reinforcement and restoration of traffic in the tunnel.

[0045] As a preferred embodiment of this example, please refer to [link / reference]. Figures 1-6 The specific reinforcement methods are as follows:

[0046] Step 1: Conduct a detailed survey of the section where the tunnel lining has collapsed, measure the clear cross-section of the existing tunnel lining structure 1, determine the reinforcement range, and prepare construction materials such as H-shaped steel arch frame 6 (HN300×150), inner circumferential reinforcing bars 7, outer circumferential reinforcing bars 8, inner longitudinal reinforcing bars 9, outer longitudinal reinforcing bars 10, φ28 anchor bolts 5, and cement-based tough concrete material 12; clean up the construction site, set up safety warning signs, and prepare a traffic diversion plan.

[0047] Step 2: Roughen the inner surface of the existing tunnel lining structure 1, remove loose concrete, form a reinforced base surface, retain the inner sidewalls of the tunnel pavement 3 and the existing cable trough 2, remove only the outer small sidewall of the existing cable trough 2, and remove the lining concrete that has loosened and is about to fall off the arch.

[0048] Step 3: Based on the measurement results, cold-bend HN300×150 H-shaped steel arch frames 6 to ensure that the H-shaped steel arch frames 6 are in maximum close contact with the existing lining surface. Erect the H-shaped steel arch frames 6 at 1m intervals along the tunnel circumference. Reliably connect them by welding steel plates and bolts. Set "V-shaped" φ22 longitudinal connecting bars between the H-shaped steels, with a circumferential spacing of 1m. The connecting bars are staggered on the upper and lower edges of the web of the H-shaped steels. Install φ28 locking anchor rods 5 on both sides of the H-shaped steel arch feet, 2 rods on each side, staggered vertically, with a length of 2.5m. They are supported by ring stirrups 14 and share the force with the H-shaped steel arch frames 6.

[0049] Step 4: Insert L-shaped hoop bars 13 into the existing tunnel lining structure 1 with a circumferential spacing of 1m and staggered arrangement on the left and right sides, with an insertion depth of not less than 15cm. Insert shear bars 11 into the lining position of the adjacent H-shaped steel arch frame 6 at the centerline, with a circumferential spacing of 80cm and an insertion depth of not less than 15cm.

[0050] Step 5: The circumferential main reinforcement uses outer circumferential steel bars 8, and the longitudinal reinforcement uses outer longitudinal steel bars 10, with a mesh spacing of 25cm×25cm; the circumferential main reinforcement uses inner circumferential steel bars 7 of φ20HRB400 steel bars, and the longitudinal reinforcement uses inner longitudinal steel bars 9 of φ14HRB400 steel bars, with a mesh spacing of 25cm×25cm. The longitudinal steel bars are broken at the H-beams, and the ends are reliably welded to the H-beams; the double-layer steel mesh is tied and fixed with stirrups 14.

[0051] Step 6: Use the H-shaped steel arch frame 6 as the template skeleton, and weld or bolt the steel template to the outside of it; check the template installation quality to ensure that the pouring space thickness is 30cm; pour the cement-based tough concrete material 12 in one go, and at the same time pour the small side wall on the outside of the cable trough; use an immersion vibrator to fully vibrate to ensure that the concrete is dense.

[0052] Step 7: After pouring, cover and cure to maintain a moist environment; remove the formwork after the cement-based tough concrete material reaches the design strength; restore the function of the tunnel cable trough and clean the construction site.

[0053] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. A rapid reinforcement structure for spalling tunnel lining in cold regions based on cement-based toughness materials, characterized in that, include: The tunnel has an existing lining structure (1), and its inner surface is cleaned to form a reinforced base surface. The inner side of the tunnel has a cement-based tough material steel molded sleeve (4), and the side of the tunnel road surface (3) has an existing cable trough (2). The cement-based tough material steel formwork lining (4) includes H-shaped steel arch frames (6) arranged at 1m intervals along the tunnel circumference. The outer contour surface of the H-shaped steel arch frame (6) is in close contact with the reinforced base surface of the existing tunnel lining structure (1). The inner side of the H-shaped steel arch frame (6) is provided with a double-layer steel mesh. The double-layer steel mesh includes inner circumferential steel bars (7), outer circumferential steel bars (8), inner longitudinal steel bars (9), and outer longitudinal steel bars (10); Shear bars (11) and L-shaped hoop bars (13) are embedded in the existing lining structure (1) of the tunnel. Cement-based tough concrete material (12) is filled between the H-shaped steel arch frame (6) and the reinforced base surface of the existing lining structure (1) of the tunnel. Locking anchor rods (5) are provided at the arch foot of the H-shaped steel arch frame (6).

2. The rapid reinforcement structure for spalling tunnel lining in cold regions based on cement-based tough materials according to claim 1, characterized in that: The inner circumferential reinforcing bars (7) and the outer circumferential reinforcing bars (8) are made of φ20HRB400 steel bars with a circumferential spacing of 25cm. The inner longitudinal reinforcing bars (9) and the outer longitudinal reinforcing bars (10) are made of φ14HRB400 steel bars with a longitudinal spacing of 25cm. The double-layer steel mesh is tied and fixed by stirrups (14).

3. The rapid reinforcement structure for spalling tunnel lining in cold regions based on cement-based tough materials according to claim 2, characterized in that: The shear reinforcement (11) is a φ14 steel bar with a circumferential spacing of 80cm and an implantation depth of not less than 15cm. The L-shaped hoop reinforcement (13) is a φ14 steel bar with a circumferential spacing of 1m and an implantation depth of not less than 15cm.

4. The rapid reinforcement structure for spalling tunnel lining in cold regions based on cement-based tough materials according to claim 3, characterized in that: The anchor rod (5) is a φ28 steel bar with a length of 2.5m. Two anchor rods are staggered at each arch foot of the H-shaped steel arch frame (6). The anchor rod (5) is fixedly connected to the H-shaped steel arch frame (6) by stirrups (14).

5. The rapid reinforcement structure for spalling tunnel lining in cold regions based on cement-based tough materials according to claim 4, characterized in that: The thickness of the cement-based tough concrete material (12) is 30cm, and the H-shaped steel arch frame (6) is made of HN300×150 steel.

6. The rapid reinforcement structure for spalling tunnel lining in cold regions based on cement-based tough materials according to claim 5, characterized in that: The outer sidewall of the existing cable trough (2) in the tunnel is cast together with the cement-based tough material steel formwork lining (4), and the H-shaped steel arch frame (6) also serves as the supporting skeleton for the casting template.

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