Adjustable prefabricated temporary supporting structure in tunnel

Abstract

The adjustable prefabricated temporary supporting structure in the tunnel comprises a primary supporting steel arch frame and further comprises a prefabricated temporary supporting wall, the prefabricated temporary supporting wall is vertically supported between the ground of an excavation area and the primary supporting steel arch frame, and the prefabricated temporary supporting wall comprises a plurality of prefabricated wall plates; a plurality of prefabricated wallboards are spliced and connected in the vertical direction and the horizontal direction to form the prefabricated temporary supporting wall. The construction method has the beneficial effects that the construction procedure is simplified; the safety is improved; dynamically adjusting the capability; cyclic utilization is realized; the method is environment-friendly.

Description

Technical Field

[0001] This application belongs to the field of tunnel construction technology, specifically relating to an adjustable prefabricated temporary support structure for tunnels, applicable to various tunnel excavation methods, such as the CD method, CRD method, and double-sidewall pilot tunnel method. Background Technology

[0002] Tunnel construction is characterized by complex surrounding rock conditions and high difficulty in deformation control. In tunnel excavation, especially for large-section tunnels with poor surrounding rock grades and complex geological environments, traditional construction methods typically employ steel profiles combined with shotcrete for temporary support. This approach involves lengthy construction procedures, significant safety hazards, and the use of shotcrete often results in the connection points being completely encased in concrete, requiring destructive removal later and preventing recycling. This increases construction costs, wastes substantial materials, generates significant construction waste, and is detrimental to environmental protection. Furthermore, traditional temporary support structures, due to their fixed dimensions, cannot be dynamically adjusted to accommodate the deformation of the initial tunnel support, thus failing to effectively reduce initial support deformation. To improve construction efficiency and ensure safety, there is an urgent need to design a dynamically adjustable prefabricated temporary support structure that simplifies procedures, improves construction stability, and allows for recycling. Utility Model Content

[0003] With the development of tunnel construction technology, construction techniques for complex geological conditions are constantly being innovated. However, existing construction methods and temporary support structures still have the following shortcomings in practice: (1) Low construction efficiency: Traditional steel supports require a long process time for cutting, welding and shotcreting operations, resulting in a long construction period and being easily affected by the skill level of workers. (2) Significant construction safety hazards: The deformation of the surrounding rock cannot be adjusted in time, which can easily lead to the failure of the support structure and increase the risk of collapse. (3) Serious material waste: Since the steel supports are covered with one-time shotcrete, most of the materials cannot be recycled when the structure is dismantled, resulting in resource waste. (4) Insufficient dynamic adjustment capability: Existing temporary support structures cannot be flexibly adjusted according to monitoring and measurement data, making it difficult to cope with the nonlinear deformation requirements of the surrounding rock.

[0004] The purpose of this application is to provide an adjustable prefabricated temporary support structure for tunnels, which solves the problems of long construction time, inability to be recycled, and inability to be dynamically adjusted in the existing temporary support structure process.

[0005] The objective of this application is achieved through the following technical solution:

[0006] An adjustable prefabricated temporary support structure for tunnels includes an initial support steel arch frame and a prefabricated temporary support wall. The prefabricated temporary support wall is vertically supported between the ground in the excavation area and the initial support steel arch frame. The prefabricated temporary support wall includes several prefabricated wall panels, which are assembled and connected in the vertical and horizontal directions to form the prefabricated temporary support wall.

[0007] Furthermore, initial support concrete is poured onto the initial support steel arch frame.

[0008] Furthermore, the initial support concrete is a sprayed concrete structure.

[0009] Furthermore, the prefabricated temporary support wall is positioned at the centerline of the tunnel.

[0010] Furthermore, the precast wall panel is a precast reinforced concrete structure.

[0011] Furthermore, the precast wall panel has vertical connecting plates at both ends, and the vertical connecting plates between two adjacent precast wall panels are connected and fixed by high-strength bolts. The precast wall panel has horizontal connecting plates on both sides, and the horizontal connecting plates between two adjacent precast wall panels are connected and fixed by high-strength bolts.

[0012] Furthermore, the bottom wall panel of the prefabricated wall panel is provided with an adjustable support assembly, and the top wall panel of the prefabricated wall panel is provided with an arch frame fixing assembly.

[0013] Furthermore, the adjustable support assembly includes an adjustable base and an adjustable sleeve. The adjustable base and the adjustable sleeve are threaded together. The adjustable base is supported on the ground of the excavation area, and the adjustable sleeve is installed on the bottom wall plate.

[0014] Furthermore, the bottom wall panel is provided with several adjustable sleeves.

[0015] Furthermore, the arch frame fixing assembly includes a wall panel fixing plate and an arch frame fixing plate. The wall panel fixing plate is connected to the arch frame fixing plate by high-strength bolts. The wall panel fixing plate is located on the top wall panel, and the arch frame fixing plate is located on the initial support steel arch frame.

[0016] Furthermore, the wall panel fixing plate is arranged horizontally or at an angle.

[0017] The beneficial effects of this application are:

[0018] 1. Simplified construction process: The prefabricated modular design is adopted, and high-strength bolts are used to connect the temporary support structures and the initial support, reducing the conventional shotcrete construction process for temporary support structures. This makes installation convenient, construction speed fast, and reduces safety hazards during tunnel construction.

[0019] 2. Improved safety: As it is a prefabricated structure, it can provide sufficient support strength after installation, which can reduce the settlement and deformation of the surrounding rock around the tunnel.

[0020] 3. Dynamic adjustment capability: The precast structure has a pre-reserved sleeve at the bottom and an adjustable base support. Different stresses can be applied to the temporary support by adjusting the height of the base support. The stress of the temporary support structure can also be adjusted according to the monitoring and measurement data of the initial support of the tunnel, thereby reducing the deformation of the surrounding rock and ensuring construction safety.

[0021] 4. Recycling: The supporting structure is connected by high-strength bolts, which makes it easy to disassemble and recycle, reducing material waste and construction costs.

[0022] 5. Environmentally friendly: Reduces construction waste and conforms to the concept of green construction.

[0023] The aforementioned main solution and its various further alternatives can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application; furthermore, the (non-conflicting alternatives) can also be freely combined with each other and with other alternatives. Those skilled in the art, after understanding this solution, will realize from the prior art and common general knowledge that there are many combinations, all of which are technical solutions to be protected in this application, and will not be exhaustively listed here. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of this application.

[0025] Figure 2 This is a schematic diagram of the longitudinal section structure of the prefabricated temporary support wall in this application.

[0026] Figure 3 This is a schematic diagram of the cross-sectional structure of the prefabricated temporary support wall in this application.

[0027] Figure 4 This is a schematic diagram showing the connection between the prefabricated temporary support wall and the initial support steel arch frame in this application.

[0028] In the diagram: 1-Upper left excavation area, 2-Lower left excavation area, 3-Upper right excavation area, 4-Lower right excavation area, 5-Initial support steel arch frame, 6-Initial support concrete, 7-Precast temporary support wall, 71-Precast wall panel, 72-Vertical connecting plate, 73-Horizontal connecting plate, 74-High-strength bolt, 75-Bottom wall panel, 76-Adjustable bottom support, 77-Adjustable sleeve, 78-Top wall panel, 79-Wall panel fixing plate, 51-Arch frame fixing plate. Detailed Implementation

[0029] The present application will be further described below with reference to specific embodiments and accompanying drawings.

[0030] Example

[0031] refer to Figures 1-4 As shown, an adjustable prefabricated temporary support structure for tunnels includes an initial support steel arch 5, an initial support concrete 6, and a prefabricated temporary support wall 7.

[0032] The initial support steel arch frame 5 is a support skeleton that matches the tunnel profile. Initial support concrete 6 is poured on the initial support steel arch frame 5, and the initial support concrete 6 is a shotcrete structure. The initial support steel arch frame 5 and the initial support concrete 6 form an integral support and enclosure for the tunnel profile.

[0033] The precast temporary support wall 7 is vertically supported between the ground in the excavation area and the initial support steel arch 5. The precast temporary support wall 7 is supported at the centerline of the tunnel, which strengthens the initial support structure. At the same time, the precast wall itself has excellent strength, thus reducing the amount of concrete spraying work for the initial support wall.

[0034] The prefabricated temporary support wall 7 includes several prefabricated wall panels 71. The prefabricated wall panels 71 are prefabricated reinforced concrete structures. Several prefabricated wall panels 71 are assembled and connected in the vertical and horizontal directions to form the prefabricated temporary support wall 7. Therefore, the size or quantity of the prefabricated wall panels 71 can be designed by the support height. Moreover, the assembled structure is convenient for subsequent dismantling, avoids violent destruction during construction, and is conducive to the reuse of components.

[0035] The precast wall panel 71 has vertical connecting plates 72 at both ends. The vertical connecting plates 72 between two adjacent precast wall panels 71 are connected and fixed by high-strength bolts 74. The vertical connecting plates 72 are pre-embedded or welded to the precast wall panel 71 in the future to achieve the connection and fixation of two adjacent precast wall panels 71 in the vertical direction.

[0036] Horizontal connecting plates 73 are provided on both sides of the precast wall panel 71. The horizontal connecting plates 73 between two horizontally adjacent precast wall panels 71 are connected and fixed by high-strength bolts 74. The horizontal connecting plates 73 are pre-embedded or welded to the precast wall panel 71 in the future to achieve the connection and fixation of two horizontally adjacent precast wall panels 71.

[0037] The bottom wall panel 75 of the precast wall panel 71 is provided with an adjustable support assembly at its bottom. The adjustable support assembly is used to adjust the bottom support height, thereby ensuring that the precast wall panel 71 is firmly supported between the ground and the steel arch frame. The top wall panel 78 of the precast wall panel 71 is provided with an arch frame fixing assembly at its top. The arch frame fixing assembly is used to fix the precast wall panel 71 and prevent the wall panel from tilting or leaning.

[0038] The adjustable support assembly includes an adjustable base 76 and an adjustable sleeve 77. The adjustable base 76 and the adjustable sleeve 77 are threaded together. The adjustable base 76 is supported on the ground of the excavated area, and the adjustable sleeve 77 is welded to the bottom wall plate 75. The support height can be changed by rotating the adjustable base 76. Several evenly distributed adjustable sleeves 77 are provided on the bottom wall plate 75 to ensure uniform and balanced support.

[0039] The arch frame fixing assembly includes a wall panel fixing plate 79 and an arch frame fixing plate 51. The wall panel fixing plate 79 is connected to the arch frame fixing plate 51 by high-strength bolts 74. The wall panel fixing plate 79 is welded to the top wall panel 78, and the arch frame fixing plate 51 is welded to the initial support steel arch frame 5, thus achieving a fixed connection between the wall panel and the steel arch frame. The bolted connection facilitates subsequent dismantling, avoiding the need for structural damage to achieve dismantling during the pouring connection. The wall panel fixing plate 79 can be arranged horizontally or inclined to adapt to different support positions in the tunnel.

[0040] The workflow of this application specifically includes the following steps:

[0041] 1. Main tunnel advance support: Before the tunnel excavation begins, advance support is carried out on the main tunnel, using advanced small pipes or large pipe roofs, to ensure the stability of the surrounding rock mass and lay the foundation for subsequent excavation work.

[0042] 2. Excavation of the Upper Left Excavation Zone 1: Excavation will begin in the upper bench area of ​​the left-side cavern. During this stage, initial support for the upper left excavation zone must be constructed simultaneously, including the installation of steel arches, temporary supports, and shotcrete to ensure rock stability during excavation. The temporary supports in the upper left excavation zone are connected to the steel arches using high-strength bolts. Temporary pads are placed at the bottom of the supports to support the surrounding rock after excavation in the upper left excavation zone.

[0043] 3. Excavation of the Lower Left Excavation Zone 2: When the excavation of the upper bench on the left side reaches 5-10 meters, the length of the bench can be adjusted according to the strength of the surrounding rock or monitoring data. Excavation of the lower left excavation zone will commence, and initial support will be constructed, including the installation of steel arches, temporary supports, and shotcrete. The temporary supports in the lower left excavation zone should be connected to the corresponding temporary supports in the upper left excavation zone using high-strength bolts. Adjustable base supports will be installed at the bottom of the temporary supports. The height of the base supports will be adjusted by adjusting the adjustable bolts according to design calculations or test results. The base supports will rest on the initial support of the lower left excavation zone of the tunnel.

[0044] 4. Excavation of the upper right excavation zone 3: After the overall advance of the left tunnel reaches 5 to 10 meters, the excavation of the upper right excavation zone will begin, and the initial support of the upper right excavation zone will be implemented, including the installation of steel arch frames and shotcrete, to ensure the stability of the right tunnel.

[0045] 5. Excavation of the lower right excavation zone 4: When the excavation of the upper right bench reaches 5 to 10 meters, the excavation of the lower right excavation zone will be carried out, and the initial support of the lower right excavation zone will be implemented.

[0046] 6. Cyclic Excavation: The excavation of each section should be carried out alternately and cyclically, and the front and rear steps should be maintained at all times during the construction process to ensure the safety of tunnel construction.

[0047] 7. Tunnel secondary lining construction: After the initial support deformation has converged and stabilized, the temporary support is removed and the secondary lining construction of the tunnel is carried out.

[0048] The foregoing basic examples and their further alternative examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed in this application. In the scheme of this application, each alternative example can be arbitrarily combined with any other basic example and alternative example.

[0049] The above description is merely a preferred embodiment of this application and is 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. An adjustable prefabricated temporary support structure for tunnels, comprising an initial support steel arch frame (5), characterized in that: It also includes a prefabricated temporary support wall (7), which is vertically supported between the ground of the excavation area and the initial support steel arch frame (5). The prefabricated temporary support wall (7) includes several prefabricated wall panels (71), which are assembled and connected in the vertical and horizontal directions to form the prefabricated temporary support wall (7).

2. The adjustable prefabricated temporary support structure in the tunnel according to claim 1, characterized in that: The initial support steel arch frame (5) is filled with initial support concrete (6); the initial support concrete (6) is a sprayed concrete structure.

3. The adjustable prefabricated temporary support structure in the tunnel according to claim 1, characterized in that: The prefabricated temporary support wall (7) is located at the centerline of the tunnel.

4. The adjustable prefabricated temporary support structure in the tunnel according to claim 1, characterized in that: The precast wall panel (71) is a precast reinforced concrete structure.

5. The adjustable prefabricated temporary support structure in a tunnel according to claim 1 or 4, characterized in that: The precast wall panel (71) has vertical connecting plates (72) at both ends. The vertical connecting plates (72) between two adjacent precast wall panels (71) are connected and fixed by high-strength bolts (74). The precast wall panel (71) has horizontal connecting plates (73) on both sides. The horizontal connecting plates (73) between two adjacent precast wall panels (71) are connected and fixed by high-strength bolts (74).

6. The adjustable prefabricated temporary support structure in the tunnel according to claim 1, characterized in that: The bottom wall panel (75) of the prefabricated wall panel (71) is provided with an adjustable support assembly, and the top wall panel (78) of the prefabricated wall panel (71) is provided with an arch frame fixing assembly.

7. The adjustable prefabricated temporary support structure in a tunnel according to claim 6, characterized in that: The adjustable support assembly includes an adjustable base (76) and an adjustable sleeve (77). The adjustable base (76) and the adjustable sleeve (77) are threaded together. The adjustable base (76) is supported on the ground of the excavation area, and the adjustable sleeve (77) is installed on the bottom wall panel (75).

8. The adjustable prefabricated temporary support structure in the tunnel according to claim 7, characterized in that: The bottom wall panel (75) is provided with several adjustable sleeves (77).

9. The adjustable prefabricated temporary support structure in a tunnel according to claim 6, characterized in that: The arch frame fixing assembly includes a wall panel fixing plate (79) and an arch frame fixing plate (51). The wall panel fixing plate (79) is connected to the arch frame fixing plate (51) by high-strength bolts (74). The wall panel fixing plate (79) is located on the top wall panel (78), and the arch frame fixing plate (51) is located on the initial support steel arch frame (5).

10. The adjustable prefabricated temporary support structure in a tunnel according to claim 9, characterized in that: The wall panel fixing plate (79) is arranged horizontally or at an angle.

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