Line folding tunnel construction method and formwork support structure thereof

Abstract

The invention relates to the technical field of tunnel construction, and discloses a stacked line tunnel construction method and a formwork support structure thereof.The stacked line tunnel construction method comprises the following steps that S1, a mining method is adopted for constructing a lower layer tunnel, the formwork support structure is set up for construction during secondary lining, and the formwork support structure is reserved after secondary lining is completed; s2, after secondary lining of the lower-layer tunnel is completed, an upper-layer interval tunnel is constructed, and a formwork support structure is used as a reinforcing support; and S3, a formwork support structure in the lower-layer tunnel is dismantled, and overall construction of the tunnel is completed. The construction efficiency of the stacked line tunnel can be improved, and the construction cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a stacked-line tunnel construction method and a template support structure thereof. Background Art

[0002] In the context of increasingly intensive development of urban underground space, small-clearance stacked tunnels are increasingly widely used in transportation infrastructure construction due to their high space utilization rate. At present, the construction of small-clearance stacked tunnels generally adopts the shield method, and follows the order of constructing the lower tunnel first and then the upper tunnel.

[0003] However, this construction technology has several limitations. First, the method requires that both the upper and lower tunnels be constructed using the shield method, which limits the diversity of construction methods and is not suitable for all geological conditions or engineering requirements. Second, the construction sequence has strict requirements. The construction of the lower tunnel must be completed before the construction of the upper tunnel can be carried out. This not only increases the construction period, but also leads to waste of resources and reduces construction efficiency. In addition, the organization and coordination of on-site construction has a significant impact on the progress of the project. The requirement to construct the lower tunnel first may lead to adjustments and delays in the construction plan, increasing project costs and risks.

[0004] Therefore, it is necessary to develop a more flexible and efficient small-clearance stacked tunnel construction method to overcome the limitations of the existing shield method, improve construction efficiency, reduce costs, and ensure the safety and reliability of the project. Summary of the invention

[0005] The purpose of the present invention is to design a stacked-line tunnel construction method and a formwork support thereof which can improve construction efficiency and reduce costs.

[0006] In order to achieve the above object, the present invention provides a stacked tunnel construction method, comprising the following steps:

[0007] S1 adopts the mining method to construct the lower tunnel, in which a formwork support structure is built for construction during the secondary lining, and the formwork support structure is retained after the secondary lining is completed;

[0008] S2 constructs the upper tunnel section after the secondary lining of the lower tunnel is completed, and uses the formwork support structure as a reinforcement support;

[0009] S3 dismantles the formwork support structure in the lower tunnel and completes the overall construction of the tunnel.

[0010] Furthermore, in S2, the upper interval tunnel is constructed using a shield machine.

[0011] The present invention also provides a formwork support structure for the above-mentioned stacked tunnel construction method, characterized in that it comprises: a main crossbeam, a bottom crossbeam, a supporting bottom column, a supporting top column, two upright columns, and a curved formwork body;

[0012] The main cross beam and the bottom cross beam are arranged in sequence at intervals up and down, and the left and right ends of the bottom cross beam are used to connect with the inner peripheral wall of the tunnel, the top end of the supporting bottom column is connected to the bottom side of the bottom cross beam, the bottom end of the supporting bottom column is used to connect with the bottom surface of the tunnel, and the bottom end of the supporting top column is connected to the middle of the main cross beam, the concave surface of the curved formwork body is defined as the inner wall, and the convex surface is defined as the outer wall, the outer wall of the formwork body is used to form the concrete shape, and the inner wall of the formwork body is connected to one end of the bottom cross beam, one end of the main cross beam, the top end of the supporting top column, the other end of the main cross beam and the other end of the bottom cross beam in sequence;

[0013] The two upright posts are spaced apart from each other, and the upper ends of the upright posts are connected to the main cross beam, and the lower ends thereof are connected to the bottom cross beam. The main cross beam, the bottom cross beam and the two upright posts define and form a passage for vehicles to pass through.

[0014] Furthermore, it also includes two side cross beams and two side diagonal braces, the side cross beams are arranged between the main cross beam and the bottom cross beam, the first ends of the two side cross beams are respectively connected to the two columns one by one, the second ends of the two side cross beams are connected to the inner wall of the template body, one end of the side diagonal brace is correspondingly connected to the first end of one of the side cross beams, and the other end is connected to the main cross beam, and the angle formed between the side diagonal brace and the corresponding side beam is an acute angle.

[0015] Furthermore, it also includes a top support assembly, which includes two top diagonal supports, the top ends of the two top diagonal supports are connected to the template body, the bottom ends of the two top diagonal supports are connected to the top surface of the main beam, and the bottom ends of the two top diagonal supports intersect and form an acute angle.

[0016] Furthermore, it comprises at least two top support assemblies, and the two top support assemblies and the two columns are arranged on the upper and lower sides of the main beam in a one-to-one correspondence.

[0017] Furthermore, a triangular support plate is provided at the connection between the column and the bottom cross beam.

[0018] Furthermore, it also includes a bottom support plate, two adjacent edges of the bottom support plate are respectively connected to the supporting bottom column and the bottom cross beam, and the other edge of the bottom support plate is used to connect with the bottom surface of the tunnel.

[0019] Furthermore, the template support structure is symmetrically arranged left and right along the extension direction of the supporting top column.

[0020] Furthermore, the main crossbeam includes a first sub-beam and a second sub-beam connected in sequence, the first sub-beam and the second sub-beam are respectively arranged on the left and right sides of the supporting top column, and the first sub-beam and the second sub-beam are respectively connected to the two columns one by one, and the end of the first sub-beam away from the second sub-beam and the end of the second sub-beam away from the first sub-beam are respectively connected to the template body.

[0021] Compared with the prior art, the template support structure of the embodiment of the present invention has the following beneficial effects:

[0022] The formwork support structure of the embodiment of the present invention adopts the mining method to construct the lower tunnel, and uses the second lining formwork support during the construction process as a reinforced steel support to meet the force requirements of the upper tunnel construction. This design allows the construction unit to flexibly arrange the construction procedures of the upper and lower tunnels according to the actual progress on site, without having to wait for the lower tunnel to be fully built before starting the construction of the upper tunnel. This not only improves the construction efficiency, but also helps to reduce the overall construction cost, while ensuring the safety of the construction and the stability of the structure. At the same time, when the lower tunnel is under construction, the passage can also be used for continuous excavation construction. The passage in the middle of the support has a space of 1.8m in width and 2.9m in height, which can be used for slag truck transportation, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a structural schematic diagram of a template support structure according to an embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of the section of the interval when the present invention is applied to the construction of the upper and lower tunnels.

[0025] In the figure, 1, main crossbeam; 11, first sub-beam; 12, second sub-beam; 2, bottom crossbeam; 3, supporting bottom column; 4, supporting top column; 5, column; 6, formwork body; 71, side crossbeam; 72, side diagonal brace; 73, bottom support plate; 74, triangular support plate; 8, top support assembly; 81, top diagonal brace; 9, passage. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0027] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" used in the present invention to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] In the description of the present invention, it should be understood that the terms "connected", "connected", "fixed" and the like used in the present invention should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a welding connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] The present invention uses the terms "first", "second", etc. to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0030] Reference Figure 1 A stacked tunnel construction method according to an embodiment of the present invention comprises the following steps:

[0031] S1 adopts the mining method to construct the lower tunnel, in which a formwork support structure is built for construction during the secondary lining, and the formwork support structure is retained after the secondary lining is completed;

[0032] S2 constructs the upper tunnel section after the secondary lining of the lower tunnel is completed, and uses the formwork support structure as a reinforcement support;

[0033] S3 dismantles the formwork support structure in the lower tunnel and completes the overall construction of the tunnel.

[0034] In some embodiments of the present application, in S2, the upper interval tunnel is constructed by a shield machine. In other embodiments, the upper interval tunnel may also be constructed by other construction methods such as the jacking method. Since there is a formwork support structure as support, the construction requirements for the upper tunnel are relatively low, allowing the use of more diverse construction methods.

[0035] The present invention also provides a formwork support structure for the above-mentioned stacked tunnel construction method, comprising: a main crossbeam 1, a bottom crossbeam 2, a supporting bottom column 3, a supporting top column 4, two upright columns 5, and a curved formwork body 6;

[0036] The main crossbeam 1 and the bottom crossbeam 2 are arranged in sequence at intervals up and down, and the left and right ends of the bottom crossbeam 2 are used to connect with the inner wall of the tunnel, the top end of the supporting bottom column 3 is connected to the bottom side of the bottom crossbeam 2, the bottom end of the supporting bottom column 3 is used to connect with the bottom surface of the tunnel, the bottom end of the supporting top column 4 is connected to the middle of the main crossbeam 1, the concave surface of the curved formwork body 6 is defined as the inner wall, and the convex surface is defined as the outer wall, the outer wall of the formwork body 6 is used to form the concrete shape, the inner wall of the formwork body 6 is connected to one end of the bottom crossbeam 2, one end of the main crossbeam 1, the top end of the supporting top column 4, the other end of the main crossbeam 1 and the other end of the bottom crossbeam 2 in sequence; the two columns 5 are arranged at intervals left and right, and the upper end of the column 5 is connected to the main crossbeam 1, and the lower end thereof is connected to the bottom crossbeam 2, the main crossbeam 1, the bottom crossbeam 2 and the two columns 5 enclose and define a passage 9 for vehicles to pass through. The passage 9 serves as a transportation channel for the subsequent construction of the lower tunnel to prevent the template support structure from affecting the subsequent construction of the lower tunnel when reinforcing the upper tunnel. The curved template body 6 can be adjusted according to the actual situation of the tunnel. In the specific embodiment of the present application, the template body 6 is curved in a horseshoe shape.

[0037] Specifically, the bottom cross beam 2 and the main cross beam 1 are both 20a I-beams, the column 5 is a 22a I-beam, the supporting top column 4 is formed by two 20a channel steels connected by bolts, the column 5 is connected to the main cross beam 1 and the bottom cross beam 2 by M16 high-strength bolts, and the template body 6 is welded with corner seams to the main cross beam 1 and the supporting top column 4.

[0038] In some embodiments of the present application, two side cross beams 71 and two side diagonal braces 72 are also included. The side cross beams 71 are arranged between the main cross beam 1 and the bottom cross beam 2 at intervals. The first ends of the two side cross beams 71 are connected to the two columns 5 one by one respectively. The second ends of the two side cross beams 71 are connected to the inner wall of the template body 6. One end of the side diagonal brace 72 is connected to the first end of one side cross beam 71, and the other end is connected to the main cross beam 1. The angle formed between the side diagonal brace 72 and the corresponding side cross beam 71 is an acute angle. The side cross beam 71 can be connected to the middle position of the column 5, so that the column 5 can withstand greater pressure and is not easy to deform during the construction process; the side diagonal brace 72, the column 5 and the main cross beam 1 form a stable triangular structure, which can effectively transmit the external force to the main cross beam 1, thereby enhancing the rigidity and stability of the overall structure. Specifically, the side cross beam 71 and the side diagonal brace 72 are both 18a I-beams, the side cross beam 71 and the template body 6 are welded by fillet seams, and the side diagonal brace 72 and the side cross beam 71 are connected by M16 high-strength bolts.

[0039] In some embodiments of the present application, a top support assembly 8 is also included, and the top support assembly 8 includes two top diagonal supports 81, the top ends of the two top diagonal supports 81 are connected to the template body 6, the bottom ends of the two top diagonal supports 81 are connected to the top surface of the main beam 1, and the bottom ends of the two top diagonal supports 81 intersect and form an acute angle. The connection positions between each top support and the template body 6 can be evenly distributed, so as to effectively disperse the load applied to the template, reduce the risk of template deformation, and further improve its support stability for the upper tunnel. Specifically, the top diagonal support 81 is an 18a I-beam, and the top diagonal support 81 is welded to the main beam 1 and the template body 6 by corner seams.

[0040] In some embodiments of the present application, at least two of the top support assemblies 8 are included, and the two top support assemblies 8 and the two columns 5 are arranged on the upper and lower sides of the main beam 1 in a one-to-one correspondence, that is, the two top diagonal supports 81 in one of the top support assemblies 8 are correspondingly connected to the top of the column 5 through the main beam 1, thereby effectively dispersing and transmitting the load from the template body 6 and the main beam 1, reducing local stress concentration, and thus improving the stability of the overall structure.

[0041] In some embodiments of the present application, a triangular support plate 74 is provided at the connection between the column 5 and the bottom beam 2, which can effectively disperse and transfer the load from the column 5 and the bottom beam 2, and enhance the stability of the structure and the ability to resist lateral forces.

[0042] In some embodiments of the present application, a bottom support plate 73 is further included, wherein two adjacent edges of the bottom support plate 73 are respectively connected to the supporting bottom column 3 and the bottom cross beam 2, and the other edge of the bottom support plate 73 is used to connect to the bottom surface of the tunnel. The bottom support plate 73 can fill the remaining space at the bottom, further enhancing the stability and bearing capacity of the overall structure.

[0043] In some embodiments of the present application, the formwork support structure is symmetrically arranged on the left and right along the extension direction of the supporting top column 4. The left-right symmetrical layout can evenly distribute the pressure applied to the supporting top column 4, reduce local stress concentration, and thus reduce the risk of structural deformation and damage.

[0044] In some embodiments of the present application, the main cross beam 1 includes a first sub-beam 11 and a second sub-beam 12 connected in sequence, the first sub-beam 11 and the second sub-beam 12 are respectively arranged on the left and right sides of the supporting top column 4, and the first sub-beam 11 and the second sub-beam 12 are respectively connected to the two columns 5 in a one-to-one correspondence, and the end of the first sub-beam 11 away from the second sub-beam 12 and the end of the second sub-beam 12 away from the first sub-beam 11 are respectively connected to the formwork body 6. Specifically, the first sub-beam 11 and the second sub-beam 12 can be connected by bolts through a pad to form the main cross beam 1. The two sub-beam design facilitates the installation and transportation of the present formwork support structure.

[0045] The formwork support structure of the present application reduces unnecessary support and reinforcement measures through reasonable structural design and material use, thereby reducing the overall construction cost.

[0046] refer to Figure 2 , which is a schematic diagram of the section section of the specific embodiment of the present invention applied to the construction of the upper and lower tunnels, wherein the right side is the station location, where the minimum clear distance L between the upper and lower tunnels is about 0.98m, the lower section tunnel is constructed by the mining method, and the upper section tunnel is constructed by the shield method.

[0047] In summary, the embodiment of the present invention provides a stacked tunnel construction method and its formwork support structure, which adopts the mining method to construct the lower tunnel, and innovatively utilizes the formwork support structure of the secondary lining as a reinforced steel support to meet the mechanical requirements during the construction of the upper tunnel. This design allows the construction of the upper tunnel to be independent of the construction progress of the lower tunnel, thereby improving construction efficiency. While the lower tunnel is being constructed, the formwork support structure of the present invention serves as a secondary lining formwork to help pour and form concrete, and also serves as a reinforced steel support to meet the mechanical requirements of the upper tunnel construction. After the secondary lining is completed, the formwork support structure does not need to be dismantled immediately, and its passage 9 can be used as a transportation channel for the lower tunnel, avoiding obstruction to subsequent construction, thereby continuing to provide support for the construction of the upper tunnel.

[0048] The construction method of the present invention enables the construction unit to flexibly arrange the construction procedures of the upper and lower tunnels according to the actual progress on site, without having to wait for the lower tunnel to be fully built before starting the construction of the upper tunnel. This not only improves the construction efficiency and reduces the overall construction cost, but also ensures the safety of the construction and the stability of the structure.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A stacked tunnel construction method, characterized in that: The following steps are involved: S1 adopts the mining method to construct the lower tunnel, in which a formwork support structure is built for construction during the secondary lining, and the formwork support structure is retained after the secondary lining is completed; S2 constructs the upper tunnel section after the secondary lining of the lower tunnel is completed, and uses the formwork support structure as a reinforcement support; S3 dismantles the formwork support structure in the lower tunnel and completes the overall construction of the tunnel.

2. The overlapping tunnel construction method according to claim 1, characterized in that: In S2, the upper interval tunnel is constructed using a shield machine.

3. A formwork support structure, used in the overlapping tunnel construction method according to claims 1 to 2, characterized in that: include: Main cross beam, bottom cross beam, supporting bottom column, supporting top column, two upright columns, and curved formwork body; The main cross beam and the bottom cross beam are arranged in sequence at intervals up and down, and the left and right ends of the bottom cross beam are used to connect with the inner peripheral wall of the tunnel, the top end of the supporting bottom column is connected to the bottom side of the bottom cross beam, the bottom end of the supporting bottom column is used to connect with the bottom surface of the tunnel, and the bottom end of the supporting top column is connected to the middle of the main cross beam, the concave surface of the curved formwork body is defined as the inner wall, and the convex surface is defined as the outer wall, the outer wall of the formwork body is used to form the concrete shape, and the inner wall of the formwork body is connected to one end of the bottom cross beam, one end of the main cross beam, the top end of the supporting top column, the other end of the main cross beam and the other end of the bottom cross beam in sequence; The two upright posts are spaced apart from each other, and the upper ends of the upright posts are connected to the main cross beam, and the lower ends thereof are connected to the bottom cross beam. The main cross beam, the bottom cross beam and the two upright posts define and form a passage for vehicles to pass through.

4. The formwork support structure according to claim 3, characterized in that: It also includes two side cross beams and two side diagonal braces, the side cross beams are arranged between the main cross beam and the bottom cross beam, the first ends of the two side cross beams are respectively connected to the two columns one by one, the second ends of the two side cross beams are connected to the inner wall of the template body, one end of the side diagonal brace is correspondingly connected to the first end of one of the side cross beams, and the other end is connected to the main cross beam, and the angle formed between the side diagonal brace and the corresponding side beam is an acute angle.

5. The formwork support structure according to claim 3, characterized in that: It also includes a top support assembly, which includes two top diagonal supports, the top ends of the two top diagonal supports are connected to the template body, the bottom ends of the two top diagonal supports are connected to the top surface of the main beam, and the bottom ends of the two top diagonal supports intersect and form an acute angle.

6. The formwork support structure according to claim 5, characterized in that: It comprises at least two top support assemblies, and the two top support assemblies and the two upright posts are arranged on the upper and lower sides of the main cross beam in a one-to-one correspondence.

7. The formwork support structure according to claim 3, characterized in that: A triangular support plate is provided at the connection between the upright column and the bottom cross beam.

8. The formwork support structure according to claim 3, characterized in that: It also includes a bottom support plate, two adjacent edges of which are respectively connected to the supporting bottom column and the bottom cross beam, and the other edge of the bottom support plate is used to connect with the bottom surface of the tunnel.

9. The formwork support structure according to claim 3, characterized in that: The template support structure is symmetrically arranged on the left and right along the extension direction of the supporting top column.

10. The formwork support structure according to claim 3, characterized in that: The main crossbeam includes a first sub-beam and a second sub-beam connected in sequence, the first sub-beam and the second sub-beam are respectively arranged on the left and right sides of the supporting top column, and the first sub-beam and the second sub-beam are respectively connected to the two columns one by one, and the end of the first sub-beam away from the second sub-beam and the end of the second sub-beam away from the first sub-beam are respectively connected to the template body.

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