Construction method of double-deck traffic descending tunnel

Abstract

The application discloses a double-layer traffic descending tunnel construction method, wherein the double-layer traffic section comprises east-west direction traffic sections and north-south direction traffic sections from top to bottom, and comprises the following steps: S1, erecting a steel temporary bridge above the north-south direction traffic section, and the bridge deck of the steel temporary bridge is communicated with the east-west direction traffic section; S2, forming a box culvert below the east-west direction traffic section by using the open excavation method, and making the box culvert communicated with the north-south direction traffic section; S3, removing the east-west direction traffic section and the north-south direction traffic section above the descending tunnel to be constructed, and then constructing the descending tunnel by using the open excavation method, after the construction is completed, the east-west direction traffic section is recovered, then the steel temporary bridge is removed, and the north-south direction traffic section is recovered; and S4, laying pipelines in the box culvert, compared with the prior art, the safety risk of road surface settlement is eliminated, the construction period is shortened, the construction efficiency is improved, and the waterproof performance of the descending tunnel structure is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction, in particular, relates to a double-layer traffic descending tunnel construction method. BACKGROUND

[0002] The city descending tunnel refers to the tunnel located in the city, which is designed for vehicles to travel along a specific descending direction, and is designed for vehicles to quickly and safely pass from a higher area to a lower area. It can effectively alleviate the urban traffic pressure, improve the road traffic capacity, reduce the ground traffic congestion, and ensure the quick traffic of vehicles on the urban trunk road.

[0003] In the construction process of the city descending tunnel, the traffic of the upper road section is often ensured to be smooth. At present, when the upper traffic road section is divided into two layers, and the upper to lower traffic road sections are the east-west direction traffic road section and the north-south direction traffic road section, the east side is provided with a jacking box culvert to bury the pipeline, and the descending tunnel is constructed by the cover excavation method to ensure the smooth traffic of the upper road section.

[0004] However, the above construction has the following disadvantages: 1. The cover excavation top-down method construction will produce a horizontal structure joint, which will result in low waterproof performance of the descending tunnel structure, long construction period, and low construction efficiency; 2. The jacking of the box culvert may cause the safety risk of the road surface settlement of the upper east-west direction traffic road section. SUMMARY

[0005] The present application provides a double-layer traffic descending tunnel construction method to solve the technical problems of the existing descending tunnel construction under the double-layer traffic road section, which has the safety risk of road surface settlement, long construction period, low construction efficiency, and low waterproof performance of the descending tunnel structure.

[0006] According to one aspect of the present application, a double-layer traffic descending tunnel construction method is provided for the descending tunnel construction at the double-layer traffic road section, the double-layer traffic road section includes the east-west direction road section and the north-south direction traffic road section from top to bottom, comprising the following steps: S1, a steel temporary bridge is erected above the north-south direction traffic road section, and the bridge deck of the steel temporary bridge is communicated with the east-west direction traffic road section; S2, a box culvert is formed below the east-west direction traffic road section by the open excavation method, and the box culvert is communicated with the north-south direction traffic road section; S3, the east-west direction traffic road section and the north-south direction traffic road section above the descending tunnel to be constructed are removed, and the descending tunnel is constructed by the open excavation method, after the construction is completed, the east-west direction traffic road section is restored to traffic, then the steel temporary bridge is removed, and the north-south direction traffic road section is restored to traffic; S4, pipeline laying is carried out in the box culvert.

[0007] As a further improvement of the above technical solution:

[0008] Further, in step S2, the box culvert is divided into two north-south sections and is excavated in sequence.

[0009] Further, in step S2, the width, height and length of the box culvert are 15.3m x 6.9m x 36m.

[0010] Further, in step S2, after the box culvert is formed, the concrete pavement between the box culvert and the north-south traffic section is built.

[0011] Further, step S3 specifically comprises the following steps: S31, setting a partition pile in the middle of the descending tunnel foundation pit, and dividing the east-west traffic section above the descending tunnel to be constructed and the north-south traffic section into a south end section and a north end section according to the partition pile; S32, removing the south end section to perform open cut construction of the descending tunnel below the south end section; S33, after the descending tunnel below the south end section is constructed, restoring the traffic of the east-west traffic section in the south end section, removing the north end section and the partition pile to perform open cut construction of the descending tunnel below the north end section; S34, after the descending tunnel below the north end section is constructed, restoring the traffic of the east-west traffic section in the north end section, removing the steel temporary bridge, and then restoring the traffic of the north-south traffic section.

[0012] Further, in step S32, a string saw is used for cutting when the south end section is removed.

[0013] Further, in step S32, when the descending tunnel below the south end section is constructed by open cut, the side structure of the descending tunnel close to the partition pile is a tongue and groove structure.

[0014] Further, in step S33, a string saw is used for cutting when the north end section is removed.

[0015] Further, in step S33, a string saw is used for segmented cutting when the partition pile is removed, and each segment has a height of 1m-2m.

[0016] Further, in steps S33-S34, the traffic of the traffic section needs to be restored when the concrete strength of the roof reaches 100% of the design strength, and the pavement paving and maintenance reach the opening conditions.

[0017] The present application has the following beneficial effects:

[0018] The double-layer traffic downlink tunnel construction method of the application, by erecting a steel temporary bridge above the north-south direction traffic section, and the bridge deck of the steel temporary bridge is communicated with the east-west direction traffic section, so that when the downlink tunnel is constructed, the east-west direction vehicles are diverted to pass through the steel temporary bridge, thereby ensuring the smooth traffic of the east-west direction road; on the other hand, since the steel temporary bridge ensures the smooth traffic of the east-west direction road, the open cut method can be used to form a box culvert under the east-west direction traffic section, thereby fundamentally eliminating the safety risk of road surface settlement caused by jacking the box culvert, and the box culvert is communicated with the north-south direction traffic section, when the downlink tunnel is constructed, the north-south direction vehicles are diverted to pass through the box culvert, thereby ensuring the smooth traffic of the north-south direction road; the east-west direction traffic section and the north-south direction traffic section above the downlink tunnel to be constructed are removed to provide construction conditions for the open cut method, so that the downlink tunnel is constructed by using the open cut method, thereby greatly shortening the construction progress and improving the construction efficiency, and ensuring the waterproof performance of the downlink tunnel; after the construction is completed, the east-west direction traffic section is restored for traffic, then the steel temporary bridge is removed, and the north-south direction traffic section is restored for traffic; finally, pipeline laying is carried out in the box culvert; compared with the prior art, the steel temporary bridge and the box culvert cooperate to ensure the smooth traffic of the double-layer traffic section, thereby reducing the influence of the downlink tunnel open cut construction, the box culvert is formed by open cut, thereby eliminating the safety risk of road surface settlement, shortening the construction period, improving the construction efficiency, ensuring the waterproof performance of the downlink tunnel structure, and having strong practicability, and is suitable for being widely promoted and applied.

[0019] In addition to the objects, features, and advantages described above, the present application has other objects, features, and advantages. The present application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, illustrate the preferred embodiments of the application, and assist in the explanation of the application. In the drawings:

[0021] Fig. 1 is a step schematic diagram of the double-layer traffic downlink tunnel construction method of the preferred embodiment of the present application;

[0022] Fig. 2 is a structure schematic diagram of the double-layer traffic downlink tunnel construction method of the preferred embodiment of the present application during construction;

[0023] Fig. 3 is a partial structure schematic diagram of the double-layer traffic downlink tunnel construction method of the preferred embodiment of the present application during construction. DETAILED DESCRIPTION

[0024] The embodiments of the present application will be described in detail below with reference to the drawings, but the present application can be implemented in various different ways as defined and covered below.

[0025] As Figs. 1-3 shown, the double-layer traffic downlink tunnel construction method of the embodiment is used for downlink tunnel construction at a double-layer traffic section, the double-layer traffic section sequentially includes an east-west direction traffic section and a south-north direction traffic section from top to bottom, and includes the following steps: S1, erecting a steel temporary bridge above the south-north direction traffic section, and the bridge deck of the steel temporary bridge is communicated with the east-west direction traffic section; S2, forming a box culvert below the east-west direction traffic section by using the open excavation method, and making the box culvert communicated with the south-north direction traffic section; S3, removing the east-west direction traffic section and the south-north direction traffic section above the downlink tunnel to be constructed, and then performing downlink tunnel construction by using the open excavation method, after the construction is completed, the east-west direction traffic section is restored to traffic, then the steel temporary bridge is removed, and the south-north direction traffic section is restored to traffic; and S4, performing pipeline laying in the box culvert.

[0026] As Figs. 1-3 shown, specifically, the double-layer traffic downlink tunnel construction method of the embodiment, by erecting a steel temporary bridge above the south-north direction traffic section, and the bridge deck of the steel temporary bridge is communicated with the east-west direction traffic section, to ensure smooth east-west direction road traffic when the downlink tunnel is constructed, on the other hand, since the steel temporary bridge ensures smooth east-west direction road traffic, a box culvert can be formed below the east-west direction traffic section by using the open excavation method, to fundamentally eliminate the safety risk of road surface settlement caused by jacking the box culvert, and make the box culvert communicated with the south-north direction traffic section, when the downlink tunnel is constructed, the south-north direction vehicles are diverted to pass through the box culvert, to ensure smooth south-north direction road traffic; removing the east-west direction traffic section and the south-north direction traffic section above the downlink tunnel to be constructed, to provide construction conditions for the open excavation method, to perform downlink tunnel construction by using the open excavation method, to greatly shorten the construction progress and improve the construction efficiency, and ensure the waterproof performance of the downlink tunnel, after the construction is completed, the east-west direction traffic section is restored to traffic, then the steel temporary bridge is removed, and the south-north direction traffic section is restored to traffic; finally, pipeline laying is performed in the box culvert; compared with the prior art, the steel temporary bridge and the box culvert cooperate to ensure smooth traffic of the double-layer traffic section, to reduce the influence of the downlink tunnel open excavation construction, the box culvert is formed by open excavation, to eliminate the safety risk of road surface settlement, shorten the construction period, improve the construction efficiency, ensure the waterproof performance of the downlink tunnel structure, has strong practicability, and is suitable for wide promotion and application.

[0027] Optionally, the east-west two ends of the steel temporary bridge include cast-in-place piles, pile caps, bent caps and columns, and a design pier column is avoided in the downlink tunnel foundation pit, to avoid affecting the open excavation construction of the foundation pit.

[0028] In the embodiment, in step S2, the box culvert is divided into two parts in the south and north directions for construction by open excavation in sequence. Specifically, the box culvert is divided into two parts in the south and north directions for construction by open excavation in sequence, so that when the box culvert in the south is constructed by open excavation, the south side of the road of the east-west direction road section is occupied, and the vehicles in the east-west direction can pass through the steel temporary bridge and the north side of the road of the east-west direction road section; when the box culvert in the north is constructed by open excavation, the north side of the road of the east-west direction road section is occupied, and the vehicles in the east-west direction can pass through the steel temporary bridge and the south side of the road of the east-west direction road section; that is, the box culvert is divided into two parts in the south and north directions for construction by open excavation in sequence, which can greatly reduce the influence of the construction of the box culvert by open excavation on the road traffic.

[0029] In the embodiment, in step S2, the size of the box culvert is 15.3m x 6.9m x 36m in width, height and length. It should be understood that in the prior art, the jacking box culvert is used for laying pipelines, and the width, height and length thereof are 7.2m x 6.6m x 50.82m, which cannot meet the requirements of the vehicles passing in the south and north directions, while the size of the box culvert in the embodiment is 15.3m x 6.9m x 36m in width, height and length, and the width of 15.3m of the box culvert can meet the requirements of the vehicles passing in the south and north directions.

[0030] In the embodiment, in step S2, after the box culvert is formed, a concrete pavement is built between the box culvert and the traffic road section in the south and north directions. Specifically, the concrete pavement is built between the box culvert and the traffic road section in the south and north directions, so as to ensure that when the downward tunnel is constructed by open excavation, the vehicles in the south and north directions can pass through the box culvert.

[0031] In the embodiment, step S3 specifically includes the following steps: S31, an isolation pile is arranged in the middle of the downward tunnel pit, and the east-west direction traffic road section and the traffic road section in the south and north directions above the downward tunnel to be constructed are divided into a south end road section and a north end road section according to the isolation pile; S32, the south end road section is removed to construct the downward tunnel below the south end road section by open excavation; S33, after the construction of the downward tunnel below the south end road section is completed, the traffic of the east-west direction traffic road section in the south end road section is restored, and then the north end road section and the isolation pile are removed to construct the downward tunnel below the north end road section by open excavation; S34, after the construction of the downward tunnel below the north end road section is completed, the traffic of the east-west direction traffic road section in the north end road section is restored, the steel temporary bridge is removed, and then the traffic of the traffic road section in the south and north directions is restored. Specifically, the isolation pile is used to provide adjustment for the downward tunnel constructed by open excavation in sections, and then the downward tunnel below the south end road section and the north end road section is constructed by open excavation in sequence, so as to reduce the influence of the construction by open excavation on the road traffic, and after the construction is completed, the steel temporary bridge can be removed, so that the road returns to the original state.

[0032] In this embodiment, in step S32, a wire saw is used to cut the southern section of the road during demolition. Specifically, using a wire saw to cut and demolish the southern section reduces the impact on surrounding roads. It should be understood that wire saw cutting has the following characteristics: 1. Wire saw cutting does not require mechanical vibration, thus avoiding vibration impact on surrounding roads; 2. Wire saw cutting is electrostatically driven, resulting in low noise and reducing interference with the surrounding environment and personnel; 3. Wire saw cutting does not generate dust, avoiding dust pollution to the surrounding environment and roads; 4. Wire saw cutting uses a precise cutting line and a high-speed rotating steel wire rope, which can control the damage range of the road to a small area, which is beneficial to protecting the structure and facilities of surrounding roads.

[0033] In this embodiment, during the open-cut construction of the downhill tunnel below the southern section in step S32, the side structure of the downhill tunnel near the isolation piles is tongue-and-groove. Specifically, by making the side structure of the downhill tunnel near the isolation piles tongue-and-groove during the open-cut construction of the downhill tunnel below the southern section, it is easier to connect with the downhill tunnel structure below the northern section. Optionally, the downhill tunnel structure includes a bottom slab, side walls, and a top slab.

[0034] In this embodiment, in step S33, a wire saw is used to cut the northern section of the road during demolition. Specifically, using a wire saw to cut and demolish the northern section of the road can reduce the impact on surrounding roads.

[0035] In this embodiment, in step S33, the bollards are removed by cutting them into sections using a wire saw, with each section being 1m-2m high. Specifically, using a wire saw to cut the bollards into sections reduces the impact on surrounding roads.

[0036] In this embodiment, in steps S33-S34, restoring traffic flow requires the top slab concrete to reach 100% of its design strength, and the road surface paving and maintenance to meet the conditions for reopening, in order to ensure the safety of traffic flow on the road section.

[0037] like Figs. 1-3 As shown, in one embodiment, the construction steps of the double-layer down-traffic tunnel are as follows:

[0038] A four-lane steel temporary bridge will be built above the north-south traffic section and on the north side of the east-west traffic section.

[0039] The box culvert will be divided into two sections, north and south, for open-cut construction below the east-west traffic section. The box culvert is 15.3m wide, 6.9m high and 36m long. Within the area of ​​the steel temporary bridge widening the road, a concrete pavement will be built between the box culvert and the north and south roads, and north and south vehicles will be diverted to pass through the box culvert.

[0040] A reinforced concrete isolation pile with diameters of Φ1000@1300 is designed in the middle of the downlink tunnel foundation pit. Before construction, the borehole area should be cut off using a wire saw.

[0041] The south end section is cut by a rope saw for open excavation construction of the descending tunnel under the south end section, and the side structure of the descending tunnel close to the isolation pile is a tongue and groove structure;

[0042] After the descending tunnel under the south end section is constructed, the east-west direction traffic section in the south end section is restored, the north end section is cut by a rope saw, and the isolation pile is cut by a rope saw for open excavation construction of the descending tunnel under the north end section;

[0043] After the descending tunnel under the north end section is constructed, the east-west direction traffic section in the north end section is restored, the steel temporary bridge is removed, and then the north-south direction traffic section is restored;

[0044] Pipeline laying is performed in the box culvert.

[0045] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Various modifications and changes can be made by those skilled in the art based on the principles and spirit of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for constructing a downhill tunnel in a double-layer traffic section, used for constructing downhill tunnels in a double-layer traffic section, wherein the double-layer traffic section comprises, from top to bottom, an east-west traffic section and a north-south traffic section, characterized in that, Includes the following steps: S1, a temporary steel bridge is built above the north-south traffic section, and the bridge deck of the temporary steel bridge connects with the east-west traffic section. S2, a box culvert is formed under the east-west traffic section using the open-cut method, and the box culvert is connected to the north-south traffic section. S3, demolish the east-west and north-south traffic sections above the downhill tunnel to be constructed, then use the open-cut method to construct the downhill tunnel. After the construction is completed, restore traffic on the east-west traffic section, then demolish the temporary steel bridge and restore traffic on the north-south traffic section. S4, Pipeline laying is carried out inside the box culvert.

2. The construction method for a double-layer downhill traffic tunnel according to claim 1, characterized in that, In step S2, the box culvert is constructed by open excavation in two sections, north and south.

3. The construction method for a double-layer downhill traffic tunnel according to claim 1, characterized in that, In step S2, the dimensions of the box culvert are 15.3m in width, 6.9m in height, and 36m in length.

4. The construction method for a double-layer downhill traffic tunnel according to claim 1, characterized in that, In step S2, after the box culvert is formed, a concrete pavement is constructed between the box culvert and the north-south traffic section.

5. The construction method for a double-layer downhill traffic tunnel according to any one of claims 1-4, characterized in that, Step S3 specifically includes the following steps: S31, isolation piles are set in the middle of the down-going tunnel foundation pit, and the east-west traffic section and the north-south traffic section above the down-going tunnel to be constructed are divided into the south end section and the north end section according to the isolation piles; S32, demolish the southern section of the road to allow for open-cut construction of the downhill tunnel beneath the southern section; After the construction of the downhill tunnel under the southern section of S33 is completed, traffic in the east-west direction of the southern section will be restored. Then, the northern section and the guardrails will be removed in order to carry out the open-cut construction of the downhill tunnel under the northern section. After the construction of the downhill tunnel under the northern section of S34 is completed, east-west traffic in the northern section will be restored, the temporary steel bridge will be demolished, and then north-south traffic will be restored.

6. The construction method for a double-layer downhill traffic tunnel according to claim 5, characterized in that, In step S32, a wire saw is used to cut the southern section of the road during demolition.

7. The construction method for a double-layer downhill traffic tunnel according to claim 5, characterized in that, In step S32, during the open-cut construction of the downhill tunnel below the southern section, the side structure of the downhill tunnel near the isolation pile is tongue and groove joint.

8. The construction method for a double-layer downhill traffic tunnel according to claim 5, characterized in that, In step S33, a wire saw is used to cut the northern section of the road during demolition.

9. The construction method for a double-layer downhill traffic tunnel according to claim 5, characterized in that, In step S33, the isolation piles are removed by cutting them into sections using a wire saw, with each section being 1m-2m high.

10. The construction method for a double-layer downhill traffic tunnel according to claim 5, characterized in that, In steps S33-S34, restoring traffic flow to the road section requires the top slab concrete strength to reach 100% of the design strength, and the road surface paving and maintenance to meet the conditions for reopening.

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