A water passing culvert structure spanning a subway shield section and overlapping and sharing a slab with a tunnel and a construction method thereof

Abstract

The present invention relates to a water passing culvert structure that straddles a subway shield section and overlaps and shares a plate with a tunnel, and a construction method thereof. The subway shield section includes a left track and a right track; the water passing culvert includes a first culvert section, a second culvert section, and a third culvert section; the second culvert section is located above the tunnel; the bottom plate of the second culvert section is the top plate of the tunnel; the tunnel is located above the left track; the third culvert section is located above the right track; tunnel foundation pit support piles and tunnel foundation pit support secant piles are respectively arranged on both sides of the tunnel; the bottom plate of the first culvert section is arranged on the tunnel foundation pit support piles and structural piles; the bottom plate of the third culvert section is arranged on the tunnel foundation pit support secant piles and structural piles; a plurality of tunnel bottom plate structural pile foundations are arranged below the bottom plate of the tunnel. During construction, the culvert structures on both sides of the tunnel are constructed first, and then the structures of the section shared with the tunnel are constructed, which can save the project cost and reduce the safety risk.

Description

Technical Field

[0001] The present invention relates to a building structure and a construction method, in particular to a water-crossing box culvert structure and a construction method, specifically a water-crossing box culvert structure and a construction method that straddle a subway shield section and overlap and share a plate with a tunnel. Background Art

[0002] In the current situation of increasingly busy urban surface transportation, how to maximize the comprehensive utilization of underground space resources has become particularly important. How to improve the utilization rate of underground space and maximize the functions of underground structures has become an important part of municipal infrastructure construction. Urban tunnels and box culverts belong to two different types of underground structures. The combined design of overlapping and sharing construction between the two can efficiently and intensively utilize underground space resources, give full play to their comprehensive advantages. At the same time, the use of overlapping and sharing construction structures can save project costs and reduce material energy consumption, which is in line with the concept of sustainable development construction.

[0003] Currently, some construction projects require the overlapping and sharing construction of tunnels and box culverts, and also need to straddle a subway shield section. Therefore, the construction process is complex and difficult, and the absolute safety of the subway shield also needs to be ensured. However, it is difficult to meet the requirements using the current ordinary construction methods. Therefore, it is urgently necessary to improve. Summary of the Invention

[0004] The purpose of the present invention is to provide a water-crossing box culvert structure and a construction method that straddle a subway shield section and overlap and share a plate with a tunnel for the problems encountered in the overlapping and sharing construction of open-cut tunnels and box culverts at present, which can effectively save project costs, reduce construction safety risks, ensure the safety of the subway shield section, and fully meet the construction requirements.

[0005] The technical solution of the present invention is as follows:

[0006] A water-crossing box culvert structure that straddles a subway shield section and overlaps and shares a plate with a tunnel, the subway shield section includes a left track and a right track; the water-crossing box culvert includes a first box culvert area, a second box culvert area, and a third box culvert area; the second box culvert area is located above the tunnel; the bottom plate of the second box culvert area is the top plate of the tunnel; the tunnel is located above the left track; the third box culvert area is located above the right track; tunnel foundation pit support piles and tunnel foundation pit support secant piles are respectively arranged on both sides of the tunnel; several structural piles are respectively arranged outside the tunnel foundation pit support piles and the tunnel foundation pit support secant piles; the bottom plate of the first box culvert area is arranged on the tunnel foundation pit support piles and the structural piles; the bottom plate of the third box culvert area is arranged on the tunnel foundation pit support secant piles and the structural piles; a plurality of tunnel bottom plate structural pile foundations are arranged under the bottom plate of the tunnel.

[0007] Further, a pile cap beam is provided at the top of the supporting piles of the tunnel foundation pit; pile cap beams are respectively provided at the tops of the structural piles under the third area of the culvert and the tops of the overlapping retaining piles of the tunnel foundation pit.

[0008] Further, culvert side walls are provided in the second area of the culvert.

[0009] Further, tunnel side walls are provided on both sides of the tunnel, and a tunnel middle wall is provided in the middle thereof.

[0010] Further, the number of the structural piles is determined according to the length of the water passing culvert.

[0011] Further, the number of the pile foundations of the tunnel floor structure is determined according to the width of the tunnel.

[0012] A construction method for a water passing culvert structure that straddles a subway shield section and overlaps and shares a slab with a tunnel includes the following steps:

[0013] 1) Construct the structural piles in the first area of the culvert and the structural piles in the third area of the culvert, as well as the supporting piles of the tunnel foundation pit, the overlapping retaining piles of the tunnel foundation pit, and the pile foundations of the tunnel floor structure;

[0014] 2) Construct pile cap beams at the tops of the supporting piles of the tunnel foundation pit, the overlapping retaining piles of the tunnel foundation pit, and some of the structural piles, and then construct the culvert floor slab, culvert side walls, and culvert roof slab structures on the pile cap beams;

[0015] 3) Excavate the soil in the tunnel foundation pit, and construct the tunnel floor slab, tunnel side walls, tunnel middle wall, and tunnel roof slab; the tunnel roof slab is the floor slab of the second area of the culvert;

[0016] 4) Construct the side walls and roof slab of the second area of the culvert to penetrate the entire water passing culvert.

[0017] Further, in step 2), a pile cap beam is constructed at the top of the structural piles in the third area of the culvert.

[0018] Further, in step 3), horizontal steel supports are arranged between the supporting piles of the tunnel foundation pit and the overlapping retaining piles of the tunnel foundation pit, and the steel supports are removed after the concrete strength of the tunnel floor slab reaches the design strength.

[0019] The beneficial effects of the present invention:

[0020] 1. By constructing pile cap beams at the pile tops, the supporting piles are connected into a whole, the overall stability of the tunnel foundation pit support is increased, and at the same time, the anti-buoyancy of the culvert floor slab is increased, so that the distance between the pile foundations of the culvert floor slab structure and the subway shield section meets the requirements of the protection clearance distance of the subway shield section, fully ensuring the safety of the subway shield section.

[0021] 2. During the excavation of the deep foundation pit of the tunnel, since the box culvert structures on both sides of the tunnel are constructed first, the earth pressure in the area within the height range of the box culverts on both sides of the tunnel has been unloaded in advance. The first concrete support at the top of the foundation pit in the co - construction section can be omitted, which greatly reduces the construction cost, reduces the risk of foundation pit collapse, speeds up the construction progress, and improves construction efficiency.

[0022] 3. In the co - construction section of the tunnel and the box culvert, a co - plate structure of the box culvert bottom slab and the tunnel top slab is adopted. Compared with the design where the box culvert bottom slab and the tunnel top slab are both independent and not co - plated, it can save the consumption of main materials such as structural steel bars and concrete for the construction of the bottom slab.

[0023] 4. The construction method of the present invention can be applied to the orthogonal and skew - intersection sections of the tunnel and the box culvert. The box culvert structure above the tunnel can be a single - chamber or multi - chamber structure. The construction method is simple and has high construction efficiency, with great promotion value and is worthy of promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The plan view of the present invention.

[0025] Figure 2 Figure 1 Sectional view A - A in the middle.

[0026] Figure 3 Figure 1 Sectional view B - B in the middle.

[0027] Among them, 1 - the first area of the box culvert; 2 - the second area of the box culvert; 3 - the third area of the box culvert; 4 - the box culvert top slab; 5 - the tunnel foundation pit support pile; 6 - the box culvert bottom slab; 7 - the tunnel top slab; 8 - the box culvert side wall; 9 - the steel support; 10 - the structural pile; 11 - the tunnel middle wall; 12 - the tunnel side wall; 13 - the tunnel bottom slab; 14 - the pile cap beam; 15 - the left track; 16 - the right track; 17 - the tunnel foundation pit support secant pile; 18 - the tunnel bottom slab structural pile foundation. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention will be further described below in conjunction with the drawings and embodiments.

[0029] As Figures 1 to 3 shown.

[0030] A water - passing box culvert that straddles the subway shield section and overlaps and shares a plate with the tunnel. The water - passing box culvert includes the first area 1 of the box culvert, the second area 2 of the box culvert, and the third area 3 of the box culvert. The total length of the water - passing box culvert is 76m. Among them, the first area of the box culvert is 23.45m long, the second area of the box culvert is 32.59m long, and the third area of the box culvert is 19.96m long. The clear width of each hole is 6.1m. The clear heights of the first area and the third area of the box culvert are both 2.6m. The clear height of the second area of the box culvert is 2.0m - 2.6m. The ground elevation is 7.7m, and the bottom elevation of the box culvert bottom slab is 3.3m. At the same time, the subway shield section includes the left track 15 and the right track 16.

[0031] There is a tunnel below the second box culvert area 2, and it has a common slab structure with the tunnel, that is, the bottom slab of the second box culvert area is the top slab of the tunnel. The tunnel is located above the left track 15 of the subway shield section, and the third box culvert area 3 is located above the right track 16, achieving the crossing of the subway shield section. There are multiple tunnel bottom slab structure pile foundations 18 below the bottom slab of the tunnel to support the tunnel.

[0032] On both sides of the tunnel, there are tunnel foundation pit support piles 5 and tunnel foundation pit support secant piles 17, which also serve as the bottom slab structure piles of the first box culvert area 1 and the third box culvert area 3. At the same time, in order to improve the support strength of the tunnel foundation pit support, pile cap beams 14 are respectively provided at the pile tops of the tunnel foundation pit support piles 5 and the tunnel foundation pit support secant piles 17 to connect the piles into a whole. The bottom slabs of the first box culvert area 1 and the third box culvert area 3 are respectively arranged on the structural piles. Since the third box culvert area 3 straddles the right track 16 of the subway shield section, the setting of the box culvert bottom slab structure pile foundation is restricted by the protection clearance of the subway. At the same time, in order to improve the anti-buoyancy of the bottom slab of the third box culvert area 3, a pile cap beam is provided at the pile top of the structural pile of the third box culvert area 3, so that the distance between the box culvert bottom slab structure pile foundation and the subway shield section meets the requirements of the protection clearance of the subway shield section, greatly protecting the safety of the subway shield and eliminating potential safety hazards.

[0033] Box culvert side walls 8 are provided at both ends of the second box culvert area 2 to improve the stability of the box culvert.

[0034] Tunnel side walls 12 are provided on both sides of the tunnel, and a tunnel middle wall 11 is provided in the middle.

[0035] A construction method of a water-crossing box culvert that straddles the subway shield section and overlaps and shares a common slab with the tunnel of the present invention adopts an open-cut process, and the specific construction steps are as follows:

[0036] 1) Construction of the first box culvert area and the third box culvert area:

[0037] First, construct earthbag cofferdams on the outer sides of the structures of the first box culvert area and the third box culvert area in the river channel, then pump out water, dredge silt, and backfill soil inside the cofferdams; then, construct the structural piles 10 of the first box culvert area 1 and the third box culvert area 3 on both sides of the tunnel, as well as the tunnel foundation pit support piles 5, the tunnel foundation pit support secant piles 17, and the tunnel bottom slab structure pile foundations 18. Among them, the effective pile length of the structural piles 10 in the first box culvert area is 32 m, the pile diameter is 1 m, and there are 12 in total. The effective pile length of the structural piles 10 in the third box culvert area is 32 m, the pile diameter is 1 m, and there are 14 in total. The pile top elevations are all the bottom elevations of the box culvert bottom slab. The bottom elevations of the tunnel foundation pit support piles 5 and the tunnel foundation pit support secant piles 17 are the same as those of the structural piles 10, the pile top elevations are the bottom elevations of the pile cap beam 14, the pile diameter is 1.2 m, and the pile spacing of the tunnel foundation pit support piles 5 is 20 cm;

[0038] Carry out the foundation pit earth excavation for the first section 1 of the culvert box and the third section 3 of the culvert box;

[0039] Construct the steel bar skeletons of the pile cap beams 14 and the culvert box bottom plates 6 for the first section 1 of the culvert box and the third section 3 of the culvert box; the size of the pile cap beam is 1.4m x 1.5m; then, pour the concrete for the pile cap beams 14 and the bottom plates 6; after the concrete pouring and curing of the bottom plates of the first section and the third section of the culvert box reach the design strength, erect the full hall formwork support with disc couplers;

[0040] Construct the steel bar skeletons of the culvert box side walls 8 and the culvert box top plates 4, and finally pour the concrete for the culvert box side walls 8 and the culvert box top plates 4 to complete the construction of the first section and the third section of the culvert box;

[0041] 2) Construction of the co - built section of the tunnel and the culvert box:

[0042] Carry out the foundation pit earth excavation for the co - built section of the tunnel and the culvert box. When the foundation pit is excavated to the elevation of 2.8m, erect the steel support 9 between the tunnel foundation pit retaining piles 5 and the tunnel foundation pit overlapping retaining piles 17; since the construction of the first section and the third section of the culvert box on both sides of the tunnel foundation pit is completed and the earthwork in the areas of the first section and the third section of the culvert box has been completely unloaded, there is no lateral earth pressure on the tunnel foundation pit retaining piles, and only one steel support 9 needs to be erected; this steel support uses double - spliced φ609mm steel pipes, and its two ends are supported on the steel wales of the tunnel foundation pit retaining piles 5 and the tunnel foundation pit overlapping retaining piles 17; the center elevation of the steel support is 2.8m, and finally excavate to the bottom elevation of the tunnel floor - 3.0m;

[0043] Carry out the construction of the steel bar skeleton of the tunnel floor 13 and pour the tunnel floor concrete; after the concrete strength of the tunnel floor reaches the design strength, remove the steel support 9;

[0044] Erect the formwork support for the tunnel top plate 7, and construct the steel bar skeletons and formworks of the tunnel side walls 12 and the tunnel middle wall 11; then pour the concrete for the tunnel side walls 12 and the tunnel middle wall 11, and finally carry out the pouring construction of the tunnel top plate;

[0045] 3) Construction of the second section of the culvert box above the tunnel top:

[0046] When constructing the co - plate of the tunnel and the culvert box in the co - built section area, reserve the installation of the steel bars of the side walls 8 of the second section of the co - built culvert box in the steel bar skeleton of the tunnel top plate 7. Then, after the tunnel top plate 7 is poured and cured to reach the design strength, erect the formwork support for the culvert box top plate 4 of the second section 2 of the co - built culvert box, and construct the steel bar skeleton of the culvert box side wall 8 of the second section of the co - built culvert box, as well as the formwork of the culvert box side wall 8 and the steel bar skeleton of the culvert box top plate 4. Finally, pour the culvert box side wall and the culvert box top plate of the second section of the culvert box together to penetrate the entire water - passing culvert box; then, remove the earth - bag cofferdams on both sides of the culvert box structure to complete the river water system connection.

[0047] After construction is completed, the structure of the present invention has the following characteristics:

[0048] The second box culvert area is located above the tunnel, and its bottom slab is the top slab of the tunnel, realizing the common slab of the tunnel and the box culvert.

[0049] The tunnel is located above the left track of the subway shield, and the third box culvert area is located above the right track of the subway shield, realizing the crossing of the subway shield section.

[0050] The tunnel foundation pit support piles and the tunnel foundation pit support secant piles are respectively located on both sides of the tunnel, and pile cap beams are arranged on the tops of the tunnel foundation pit support piles and the tunnel foundation pit support secant piles, and then the bottom slabs of the first box culvert area and the third box culvert area are installed on the pile cap beams, effectively improving the support strength.

[0051] The bottom slab of the tunnel is supported by multiple tunnel bottom slab structural pile foundations, making the tunnel fully stable.

[0052] The bottom slab of the first box culvert area is arranged on multiple structural piles, being stable and safe.

[0053] Parts not involved in the present invention are the same as or can be implemented by using the prior art.

Claims

1. A water box culvert structure spanning across a subway shield tunnel section and overlapping with the tunnel on the same slab, wherein the subway shield tunnel section includes a left track and a right track; Characterized in that, The water box culvert includes a first box culvert area, a second box culvert area and a third box culvert area; the second box culvert area is located above the tunnel; the bottom slab of the second box culvert area is the top slab of the tunnel; the tunnel is located above the left track; the third box culvert area is located above the right track; on both sides of the tunnel, there are respectively tunnel foundation pit support piles and tunnel foundation pit support secant piles; several structural piles are arranged outside the tunnel foundation pit support piles and the tunnel foundation pit support secant piles; the bottom slab of the first box culvert area is arranged on the tunnel foundation pit support piles and the structural piles; the bottom slab of the third box culvert area is arranged on the tunnel foundation pit support secant piles and the structural piles; there are multiple tunnel bottom slab structural pile foundations under the bottom slab of the tunnel.

2. The water box culvert structure spanning across a subway shield tunnel section and overlapping with the tunnel on the same slab according to claim 1, Characterized in that, A pile cap beam is provided at the top of the tunnel foundation pit support piles; pile cap beams are respectively provided at the top of the structural piles under the third box culvert area and at the top of the tunnel foundation pit support secant piles.

3. The water box culvert structure spanning across a subway shield tunnel section and overlapping with the tunnel on the same slab according to claim 1, Characterized in that, There are box culvert side walls in the second box culvert area.

4. The water box culvert structure spanning across a subway shield tunnel section and overlapping with the tunnel on the same slab according to claim 1, Characterized in that, There are tunnel side walls on both sides of the tunnel, and a tunnel middle wall is provided in the middle.

5. The water box culvert structure spanning across a subway shield tunnel section and overlapping with the tunnel on the same slab according to claim 1, Characterized in that, The number of the structural piles is determined according to the length of the water box culvert.

6. The water box culvert structure spanning across a subway shield tunnel section and overlapping with the tunnel on the same slab according to claim 1, Characterized in that, The number of the tunnel bottom slab structural pile foundations is determined according to the width of the tunnel.

7. A construction method for the water box culvert structure spanning across a subway shield tunnel section and overlapping with the tunnel on the same slab according to claim 1, Characterized in that, It includes the following steps: 1) Construct the structural piles of the first box culvert area and the third box culvert area, as well as the tunnel foundation pit support piles, the tunnel foundation pit support secant piles and the tunnel bottom slab structural pile foundations; 2) Construct pile cap beams at the top of the tunnel foundation pit support piles, the tunnel foundation pit support secant piles and some of the structural piles, and then construct the box culvert bottom slab, box culvert side walls and box culvert top slab structures on the pile cap beams; 3) Excavate the tunnel foundation pit soil, and construct the tunnel bottom slab, tunnel side walls, tunnel middle wall and tunnel top slab; the tunnel top slab is the bottom slab of the second box culvert area; 4) Construct the side walls and top slab of the second box culvert area to penetrate the entire water box culvert.

8. The construction method for the water box culvert structure spanning across a subway shield tunnel section and overlapping with the tunnel on the same slab according to claim 7, Characterized in that, In step 2), a pile cap beam is constructed at the top of the structural piles in the third box culvert area.

9. The construction method for the water box culvert structure spanning across a subway shield tunnel section and overlapping with the tunnel on the same slab according to claim 7, Characterized in that, In step 3), a horizontal steel support is arranged between the tunnel foundation pit retaining piles and the tunnel foundation pit secant piles, and the steel support is removed after the concrete strength of the tunnel floor reaches the design strength.

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