A large-section tunnel portal temporary support structure system

Abstract

The utility model discloses a large section of cut tunnel portal temporary support structure system, including a plurality of linear arrangement's steel pipe support system and a plurality of linear arrangement's section steel support system, every steel pipe support system and every section steel support system are inclined to be installed between steel encloses the purlin and main body structure to form the triangular support structure. The utility model has solved the problem that the existing temporary support structure adopts the form of easy existence of face deformation control limited, secondary disturbance deformation aggravation and tunnel excavation needs secondary demolition of face spray mix + anchor rod, based on existing steel encloses the purlin and main body structure, has reduced the safety hidden danger of subway large section of cut tunnel portal construction. In the subsequent cut tunnel construction process, the section steel support system and steel pipe support system in the portal can be removed flexibly according to the tunnel excavation step sequence, which ensures the safety of the face operation and minimizes the engineering waste.

Description

Technical Field

[0001] This utility model relates to the field of subway construction technology, specifically to a temporary support structure system for the portal of a large-section cut-and-cover tunnel. Background Technology

[0002] Due to the complex procedures involved in subway construction, coupled with the constraints of the ever-changing surrounding environment, the temporary large-section tunnel face cannot be excavated on time. The long-term exposed tunnel face is prone to deformation and instability under the pressure of water and soil, which affects the safety of subsequent tunnel excavation operations. Currently, the common approach to addressing this type of problem is to use a combination of shotcrete and anchor bolts at the exposed tunnel face. However, this approach often leads to the following issues: 1) For large-section cut-and-cover tunnels, the temporary support structure of shotcrete and anchor bolts is an integrated structure with limited deformation control capabilities, especially for exposed tunnel faces that have already experienced localized deformation. 2) During the shotcrete and anchor bolt installation process, this temporary support structure is prone to causing secondary disturbances to the tunnel face, affecting its self-stabilizing ability and exacerbating deformation and instability. 3) The temporary support structure requires secondary removal of the shotcrete and anchor bolts during subsequent excavation, resulting in significant engineering waste and hindering subsequent cut-and-cover tunnel construction.

[0003] Steel walers are the core components of deep foundation pit support systems. They are welded and fixed to the corbels or triangular supports of the main structure (such as steel sheet piles or SMW method piles), forming a connecting link between the steel support and the retaining structure.

[0004] Based on this, this utility model proposes a structure that provides effective temporary support for the face of a large-section underground subway tunnel, based on existing steel walers and a pre-formed main structure, without secondary ground disturbance. Utility Model Content

[0005] The technical problem to be solved by this utility model is that the existing temporary support structure using the form of sprayed concrete + anchor bolts at the tunnel face is prone to problems such as limited control of tunnel face deformation, aggravated deformation due to secondary disturbance, and the need for secondary demolition during tunnel excavation. The purpose is to provide a temporary support structure system for the portal of a large-section cut-and-cover tunnel, which utilizes existing structural steel walers and the already formed main structure to provide an effective temporary support structure for the tunnel face of a large-section cut-and-cover subway tunnel.

[0006] This utility model is achieved through the following technical solution: A temporary support structure system for the portal of a large-section cut-and-cover tunnel includes several linearly arranged steel pipe support systems and several linearly arranged profile steel support systems. Each of the steel pipe support systems and each of the profile steel support systems is installed at an incline between the steel waler and the main structure to form a triangular support structure.

[0007] As one of the preferred technical solutions, one end of the steel pipe support system is welded to the steel waler, and the other end is welded to the main structure.

[0008] As one of the preferred technical solutions, the steel pipe support system includes steel pipes and square steel plates. Two square steel plates are provided. One square steel plate is welded to the steel waler and the steel pipe on both sides, and the other square steel plate is pre-embedded in the main structure and welded to the steel pipe.

[0009] As one of the preferred technical solutions, the square steel plate is connected to the main structure by a plurality of evenly arranged chemical expansion bolts.

[0010] As one of the preferred technical solutions, one end of the steel support system is welded to the steel waler, and the other end is welded to the main structure.

[0011] As one of the preferred technical solutions, the steel support system includes spliced ​​steel components and rectangular steel plates. Two rectangular steel plates are provided. One rectangular steel plate is welded to one end of the steel waler and the spliced ​​steel component on both sides, and the other rectangular steel plate is pre-embedded in the main structure and welded to the other end of the spliced ​​steel component.

[0012] As one of the preferred technical solutions, the splicing steel component includes two steel sections, which are symmetrically arranged and formed into a whole by splicing steel plates.

[0013] As one of the preferred technical solutions, multiple splicing steel plates are provided, and the multiple splicing steel plates are arranged along the length direction of the steel section.

[0014] As one of the preferred technical solutions, the rectangular steel plate is connected to the main structure through multiple evenly arranged anchor bars.

[0015] As one of the preferred technical solutions, the anchor reinforcement bar is in the shape of a hook.

[0016] Compared with the prior art, this utility model has the following advantages and beneficial effects: 1. Based on the existing steel walers and the already formed main structure, a temporary support system is provided to effectively provide temporary support for the tunnel face of large-section underground subway tunnels without secondary ground disturbance, thereby reducing the safety hazards of tunnel portal construction for large-section underground subway tunnels.

[0017] 2. The temporary support structure system of this application is actually distributed in the tunnel portal and at the same time forms a support system. During the subsequent construction of the tunnel, the steel support system and steel pipe support system in the tunnel portal can be flexibly dismantled in stages according to the tunnel excavation sequence, so as to ensure the safety of the working face and minimize the waste of the project. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a transverse cross-sectional view of the temporary support structure system for the portal of a large-section mined tunnel according to this utility model; Figure 2 for Figure 1 Sectional view at point AA; Figure 3 This is a schematic diagram of the end connection structure of the steel pipe support system of this utility model; Figure 4 This is a schematic diagram of the connection structure at the other end of the steel pipe support system of this utility model; Figure 5 This is a structural schematic diagram of the splicing steel component of this utility model; Figure 6 for Figure 5 Sectional view at point BB; Figure 7 This is a schematic diagram of the end connection structure of the steel support system of this utility model; Figure 8 This is a schematic diagram of the structure of the anchored steel bar of this utility model.

[0019] The attached diagram shows the markings and corresponding component names: 1-Steel pipe support system, 2-Steel section support system, 3-Chemical expansion bolt, 4-Square steel plate, 5-Steel pipe, 6-Steel section, 7-Spliced ​​steel plate, 8-Rectangular steel plate, 9-Anchored steel bar, 10-Steel waler, 11-Main structure, 12-Large cross-section mined tunnel. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0021] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] In the description of this invention, the terms "front," "rear," "left," "right," "up," "down," "vertical," "horizontal," "high," "low," "inner," and "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 invention 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 limiting the scope of protection of this invention.

[0023] This embodiment 1 provides a temporary support structure system for the portal of a large-section cut-and-cover tunnel, such as... Figures 1-2 As shown, it includes several linearly arranged steel pipe support systems 1 and several linearly arranged steel profile support systems 2. Each of the steel pipe support systems 1 and each of the steel profile support systems 2 is installed obliquely between the steel waler 10 and the main structure 11 to form a triangular support structure.

[0024] The temporary support structure system for the portal of the large-section cut-and-cover tunnel in this embodiment is based on the existing steel waler 10 and main structure 11, and is used to stably support the working face of the large-section cut-and-cover tunnel 12. Specifically, the steel pipe support system 1 is located below the steel section support system 2. It can be seen that the number of steel pipe support systems and steel section support systems can be set according to the actual working conditions at the tunnel portal.

[0025] Engineering practice has proven that this support system combination can be applied to the temporary support of the 12 working faces of large-section underground subway tunnels, especially for the working faces that have undergone local deformation, where the support effect is significant.

[0026] like Figure 3 and Figure 4As shown, the steel pipe support system 1 includes a steel pipe 5 and a square steel plate 4. In this embodiment, a ∅609 steel pipe 5 and a square steel plate 4 with dimensions of 950×950×20 mm are selected. Two square steel plates 4 are provided. One square steel plate 4 is welded to the steel waler 10 and the steel pipe 5 on both sides, respectively. The other square steel plate 4 is pre-embedded in the main structure 11 and welded to the steel pipe 5. Specifically, the square steel plate 4 is pre-embedded in the main structure 11 using multiple M24 chemical expansion bolts 3, which are arranged neatly.

[0027] It is known that M24 chemical expansion bolts 3 can provide extremely high load-bearing capacity through the dual effects of chemical bonding (resin reacting with the substrate) and mechanical expansion (expansion tubes expanding outwards). Compared with ordinary expansion bolts, M24 chemical expansion bolts 3 do not generate expansion stress during the curing process, avoiding cracking of the substrate (such as concrete) due to stress concentration, and are especially suitable for installation near thin walls or edges.

[0028] like Figure 7 As shown, the steel support system 2 includes spliced ​​steel components and rectangular steel plates 8. In this embodiment, a rectangular steel plate 8 with dimensions of 400×450×20 mm is selected. Two rectangular steel plates 8 are provided; one rectangular steel plate 8 is welded to the steel waler 10 and the spliced ​​steel components on both sides, while the other rectangular steel plate 8 is embedded in the main structure 11. It can be seen that the rectangular steel plate 8 is connected to the main structure 11 by multiple anchor steel bars 9. Figure 8 As shown, the anchor reinforcement 9 is in the shape of a hook. In beam-column joints or shear walls, the hooked reinforcement is arranged diagonally or laterally to enhance the shear resistance of the member and prevent the expansion of diagonal cracks from causing the reinforcement to slip.

[0029] like Figure 5 and Figure 6 As shown, the spliced ​​steel section assembly includes two steel sections 6, which are symmetrically arranged and formed into a whole by splicing steel plates 7. It can be seen that multiple splicing steel plates 7 are provided, arranged along the length of the steel sections 6. Specifically, the two steel sections 6 form an "integrated frame" through the splicing steel plates 7, rather than being independent load-bearing entities.

[0030] The spliced ​​steel plate 7 can quickly transfer the local pressure borne by a single steel section 6 to another steel section 6, allowing the two steel sections 6 to share the load. This is equivalent to forming a composite support structure of "double ribs + rigid connection," with an overall stiffness far greater than the sum of the stiffness of the two steel sections 6 supported independently. Even if one steel section 6 experiences minor deformation due to local geological issues, the other steel section 6 and the spliced ​​steel plate 7 can limit its further deformation through "cooperative constraints," forming "redundant support" and preventing overall collapse caused by single-point failure.

[0031] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A temporary support structure system for the portal of a large-section cut-and-cover tunnel, characterized in that, It includes several linearly arranged steel pipe support systems and several linearly arranged steel profile support systems, each of which is installed at an angle between the steel waler and the main structure to form a triangular support structure.

2. The temporary support structure system for the portal of a large-section mined tunnel according to claim 1, characterized in that, The steel pipe support system is welded to the steel waler at one end and to the main structure at the other end.

3. The temporary support structure system for the portal of a large-section cut-and-cover tunnel according to claim 2, characterized in that, The steel pipe support system includes steel pipes and square steel plates. Two square steel plates are provided. One square steel plate is welded to the steel waler and the steel pipe on both sides, and the other square steel plate is pre-embedded in the main structure and welded to the steel pipe.

4. The temporary support structure system for the portal of a large-section mined tunnel according to claim 3, characterized in that, The square steel plate is connected to the main structure by a number of evenly arranged chemical expansion bolts.

5. The temporary support structure system for the portal of a large-section cut-and-cover tunnel according to claim 1, characterized in that, The steel support system is welded to the steel waler at one end and to the main structure at the other end.

6. The temporary support structure system for the portal of a large-section cut-and-cover tunnel according to claim 5, characterized in that, The steel support system includes spliced ​​steel components and rectangular steel plates. Two rectangular steel plates are provided. One rectangular steel plate is welded to one end of the steel waler and the spliced ​​steel component on both sides, and the other rectangular steel plate is pre-embedded in the main structure and welded to the other end of the spliced ​​steel component.

7. The temporary support structure system for the portal of a large-section cut-and-cover tunnel according to claim 6, characterized in that, The spliced ​​steel component includes two steel sections, which are symmetrically arranged and formed into a whole by splicing steel plates.

8. The temporary support structure system for the portal of a large-section cut-and-cover tunnel according to claim 7, characterized in that, Multiple splicing steel plates are provided, and the multiple splicing steel plates are arranged along the length direction of the steel section.

9. The temporary support structure system for the portal of a large-section cut-and-cover tunnel according to claim 6, characterized in that, The rectangular steel plate is connected to the main structure by multiple evenly arranged anchor bars.

10. The temporary support structure system for the portal of a large-section mined tunnel according to claim 9, characterized in that, The anchor reinforcement bars are in the shape of hooks.

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