CN107100653A - A kind of flat top wall pipe curtain structure builds the construction method of super Shallow Covered Metro Station - Google Patents

Abstract

The invention provides a new construction method for construction of urban ultra-shallow underground excavation subway stations. Large-diameter steel pipes are densely jacked into the horizontal and vertical positions respectively, and high-strength bolts and flange plates are used to connect adjacent steel pipes. Concrete is poured inside the steel pipe and between the rigid pipes, and then in the lower pilot hole under the side steel pipe, the pre-cast reinforced concrete wall is connected with the side steel pipe, so that the reinforced concrete wall serves as the base of the overall pipe curtain structure. Before the construction of the main body of the station, a support system with high rigidity has been formed. Compared with the traditional pipe curtain construction method, due to the increase in the lateral bearing capacity and rigidity of the overall pipe curtain structure, large-section excavation can be realized, and the excavation There is no need to erect too many temporary support systems during the process, which shortens the construction period and saves costs; the support system proposed by the present invention has a flat roof and straight wall structure, which increases the space utilization rate.

Description

A construction method for constructing an ultra-shallow underground excavation subway station with a flat-top and straight-wall pipe-curtain structure

technical field

The invention relates to a flat-roofed straight-wall pipe-curtain support system formed after pouring concrete with large-diameter dense steel pipes, and a construction method for constructing urban ultra-shallow underground excavation subway stations under the new pipe-curtain support system, belonging to the field of tunnels and underground engineering .

Background technique

The pipe curtain construction method was first used in Japan to build a passageway project across the railway. The first use of the pipe curtain construction method in China was in the construction of an underground passage in a city in Hong Kong. After many years of domestic research and successful implementation in engineering, the pipe curtain construction method has matured. However, since the adjacent steel pipes in the traditional pipe curtain structure are only connected by locks, the lateral stiffness and bearing capacity of the overall pipe curtain are relatively weak. Stability, resulting in slower construction progress. In addition, most of the transverse sections are arch structures, and the space utilization rate is low.

Contents of the invention

The invention provides a construction method for building an ultra-shallow underground excavation subway station with a flat roof and straight wall tube curtain structure. When the main body of the station is not under construction, a support system with high rigidity can be formed to improve construction efficiency.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A construction method for constructing an ultra-shallow underground excavation subway station with a flat-top and straight-wall tube-curtain structure, comprising the following steps:

1) Construct enclosure piles around the working well. After the enclosure piles reach strength, excavate the working well and build a pipe jacking construction platform;

2) Weld the flange plates on both sides of the steel pipe for construction, and set up reserved bolt holes and reserved grooves on both sides;

3) Use the jacking method to construct all the top steel pipes and the uppermost side steel pipes on both sides of the underground excavation section, remove the soil inside the steel pipes while excavating, and remove the soil between the steel pipes through the reserved grooves on the side of the steel pipes; After the entry and excavation work is completed, the connecting bolts are installed in the adjacent steel pipes through the reserved bolt holes. After the installation of the horizontal connection of the adjacent steel pipes is completed, the sealing plates are welded at both ends of the steel pipes and poured into the interior of the steel pipes and between adjacent steel pipes. concrete;

4) After the uppermost side steel pipes on both sides are firmly connected to the top steel pipes, the jacking of the remaining side steel pipes, the connection between the steel pipes, and the grouting operations in and between the steel pipes are performed sequentially from top to bottom;

5) Advanced pre-grouting is used to strengthen the ground, and the lower pilot tunnels on both sides are excavated by step method and the initial support is applied. Reinforced concrete side walls and lower wall strip foundations are built in the lower pilot tunnels to connect the lowermost ends of both sides. side steel pipes;

6) Use the excavation method of side pilot tunnels to excavate the first bottom pilot tunnel, and implement initial support;

7) After the first bottom pilot tunnel is penetrated, the step method is used to excavate the first upper pilot tunnel, and the first upper pilot tunnel is supported by grids;

8) Waterproofing of the first upper pilot tunnel and the first bottom pilot tunnel, as well as the bottom longitudinal beam and part of the bottom plate shall be applied respectively, and the steel pipe column shall be built with manual excavation piles, and then the top longitudinal beam and part of the roof shall be poured;

9) Use the method from step 6) to step 8) to excavate the second bottom pilot tunnel and the second upper pilot tunnel vertically and step by step, and perform grouting reinforcement on the soil between the adjacent pilot tunnels during the excavation of the pilot tunnels , and construct waterproof boards, bottom longitudinal beams, part of the bottom plate and top longitudinal beams, part of the roof, and steel pipe columns in the pilot tunnel respectively;

10) Remove the grid support between the upper pilot tunnels, lay a waterproof layer, and construct the mid-span roof;

11) After the mid-span roof reaches 80% of the design strength, excavate the soil above the bottom of the mid-slab in the station hall layer longitudinally and segmentally, and use section steel support at the connection between the horizontal steel pipe and the vertical steel pipe to make the side span of the station structure at the station hall The waterproof layer of the side wall of the first floor, the welded corbel support at the end of the middle plate is connected with the vertical steel pipe, and the middle longitudinal beam and the middle plate of the station hall floor are respectively constructed;

12) After the middle slab of the station hall floor reaches 80% of the design strength, excavate the mid-span soil and side-span soil to the bottom slab respectively, and construct the bottom slab;

13) Remove the remaining grid support, implement the remaining waterproof facilities, pour the remaining main structure, and complete the construction.

In step 4), during the construction of the side steel pipe, it is necessary to wait until the previous side steel pipe is firmly connected to the constructed steel pipe and the soil inside and between the steel pipes and the concrete have been excavated before jacking the next side steel pipe. Steel Pipe. A steel bar bracket connected to the reinforced concrete side wall inside the lower pilot tunnel is reserved in the lowermost side steel pipe.

In step 11), the upper and lower side walls at the end of the middle plate of the station hall layer are provided with a joint structure.

In step 12), the specific method of applying the bottom plate is as follows:

Excavate the mid-span soil to the bottom of the bottom slab, apply the back-sealing structure and remove part of the pilot tunnel structure, apply the mid-span bottom slab waterproof layer and pour the mid-span bottom slab;

After the mid-span bottom slab concrete reaches 80% of the design strength, excavate the side-span soil to the bottom of the bottom slab, construct the back-sealing structure and remove part of the pilot tunnel structure, apply the waterproof layer of the bottom slab and pour the remaining structure of the bottom slab.

It can be seen from the above technical solutions that the present invention proposes a new construction form, in which large-diameter steel pipes are intensively jacked in the horizontal and vertical positions respectively, and high-strength bolts and flange plates are used to connect adjacent steel pipes, and then inside the steel pipes and rigid Concrete is poured between the pipes, and then in the lower pilot hole under the side steel pipes, the pre-cast reinforced concrete wall is connected with the side steel pipes, so that the reinforced concrete wall serves as the base of the overall pipe curtain structure. When the main body of the station is not under construction, a support system with high rigidity has been formed. Compared with the traditional pipe curtain construction method, due to the increase in the lateral bearing capacity and rigidity of the overall pipe curtain structure, large-section excavation can be realized, and in the excavation There is no need to erect too many temporary support systems during the process, which shortens the construction period and saves costs; the support system proposed by the present invention has a flat roof and straight wall structure, which increases the space utilization rate.

Description of drawings

Figure 1 is a schematic diagram of a pipe jacking construction platform;

Fig. 2 is a structural schematic diagram of a steel pipe with a flange plate;

Fig. 3 is a schematic diagram of the connection state of adjacent steel pipes;

Fig. 4 is a schematic diagram of station excavation process;

Fig. 5 is a schematic diagram of station excavation process two;

Fig. 6 is a schematic diagram of station excavation process two;

Fig. 7 is a schematic diagram of station excavation process three;

Fig. 8 is a schematic diagram of station excavation process four;

Fig. 9 is a schematic diagram of station excavation process five;

Fig. 10 is a schematic diagram of station excavation process six;

Fig. 11 is a schematic diagram of station excavation process seven;

Fig. 12 is a schematic diagram of station excavation process eight;

Fig. 13 is a nine schematic diagram of station excavation process;

Fig. 14 is a ten schematic diagram of station excavation process;

Fig. 15 is a schematic diagram of the station excavation process eleven.

In the figure: 1. Working well, 2. Surrounding pile, 3. Steel pipe, 4. Flange plate, 6. Reserved groove, 7. Connecting bolt, 8. Nut, 9. Concrete, 11. Steel support, 12 . Reinforced concrete side wall, 13. Initial support, 131. Grid support, 14. Strip foundation under the wall, 15. Bottom longitudinal beam, 16. Bottom plate, 17. Artificial hole-digging pile, 18. Steel pipe column, 19, Top longitudinal beam, 20. Roof above the top longitudinal beam, 21. Soil reinforcement, 22. Mid-span roof, 23. Middle plate of station hall floor, 24. Diagonal bracing, 25. Corbel support, 26. Middle longitudinal beam, 27 , side wall joint, 28, bottom plate, 29, slope.

detailed description

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

The invention provides a construction method for constructing an ultra-shallow underground excavation subway station, which adopts a flat roof and straight wall pipe curtain structure, and specifically includes the following construction steps:

Step 1: Construct enclosure piles 2 around the working well 1. After the enclosure piles reach strength, excavate the working well and build a pipe jacking construction platform, see Figure 1.

Step 2: Process the construction steel pipe 3 in the processing plant, weld the flange plate 4 at the design position on both sides of the steel pipe, and open reserved bolt holes and reserved grooves 6 at the design position, see FIG. 2 .

Step 3: Use the jacking method to construct the No. 1 to No. 24 top steel pipes and No. 25 and No. 34 side steel pipes in the underground excavation section. Remove the soil inside the steel pipes while excavating, and remove the steel pipes through the reserved grooves on the side of the steel pipes. For soil, see Figure 4. When the steel pipe jacking construction, the direction should be controlled well, and the deflection should not be allowed. After the jacking and excavation work is completed, the connecting bolt 7 is installed in the adjacent steel pipe 3, and the nuts 8 are placed at both ends of the bolt to increase the distance between the bolt and the concrete 9. anchoring force. After the installation of the horizontal connection of the adjacent steel pipes 3 is completed, weld the sealing plates at both ends of the steel pipes, reserve grouting holes through the sealing plates, pour concrete into the steel pipes, and pour concrete between the steel pipes at the same time, see Figures 2 and 3.

Step 4: After the uppermost side steel pipes on both sides are firmly connected to the top steel pipes, carry out the jacking of No. 26-32 side steel pipes, No. 35-41 side steel pipes, the connection between the steel pipes and the inside of the steel pipes from top to bottom. And grouting between steel pipes. During the construction of the side steel pipe, the next steel pipe needs to be pushed in after the previous steel pipe is firmly connected to the constructed steel pipe, the soil inside and between the steel pipes has been excavated, and concrete has been poured. In No. 33 and No. 42 of the side steel pipes of the lowest section, a steel bar bracket 11 connected with the reinforced concrete side wall 12 inside the pilot tunnel is reserved, as shown in FIG. 5 .

Step 5: Use advanced pre-grouting to strengthen the ground, excavate the lower pilot tunnels Z5 and Z6 by step method, and implement initial support 13 . Build the reinforced concrete side wall 12 and the lower strip foundation 14 in the lower pilot tunnel, and make the lowermost part 33, 42 of the side steel pipes firmly connected with the reinforced concrete side wall in the pilot tunnel, see Fig. 6 and 7 .

Step 6: Use the excavation method of the lower pilot tunnel to excavate the first bottom pilot tunnel Z2, and implement initial support 13, see FIG. 8 .

Step 7: After the first bottom pilot tunnel Z2 is penetrated, the first upper pilot tunnel Z1 is excavated using the step method, and the pilot tunnel is supported by a grid 131 , see FIG. 9 .

Step 8: Waterproofing and bottom longitudinal beams 15 and part of the bottom plate 16 in the first upper pilot tunnel Z1 and the first bottom pilot tunnel Z2 are constructed respectively, and steel pipe columns 18 are built with manual excavation piles 17, and then the top longitudinal beams 19 and Part of the top plate 20, see FIG. 10 .

Step 9: Excavate the second bottom pilot tunnel Z4 and the second upper pilot tunnel Z3 vertically and step-by-step using the above method and steps. During the excavation of the pilot tunnel, the soil between the adjacent pilot tunnels is grouted and reinforced to form Soil reinforcement 21, injection of cement and water glass double slurry, and construction of waterproof boards, bottom longitudinal beams, part of the bottom plate and top longitudinal beams, part of the roof, and steel pipe columns in the pilot tunnel, see Figure 11.

Step 10: Remove the grid support between the upper pilot tunnels, lay a waterproof layer, and make the mid-span roof 22, see Figure 12.

Step 11: After the mid-span roof reaches 80% of the design strength, excavate the soil above the bottom of the mid-slab 23 of the station hall layer in longitudinal sections, and use section steel supports 24 at the connection between the top steel pipe and the side steel pipes to be used as the side span of the station structure The waterproof layer of the side wall of the station hall floor, the welded corbel support 25 at the end of the middle plate of the station hall floor is connected with the side steel pipes, and the middle longitudinal beam 26, the middle plate 23 of the station hall floor, and the upper and lower floors at the end of the middle plate are constructed sequentially side wall joint 27, see Figure 13.

Step 12: After the mid-slab 23 of the station hall floor reaches 80% of the design strength, excavate the mid-span soil to the bottom slab, construct the bottom slab 28 and remove the grid support, reserve a certain slope 29 for the soil, see Figure 4- 11. After the mid-span bottom slab concrete reaches 80% of the design strength, excavate the side-span soil to the bottom of the bottom slab, construct the back-sealing structure and remove part of the pilot tunnel structure, apply the waterproof layer of the bottom slab and pour the remaining structure of the bottom slab, see Figure 14.

Step 13: Remove the remaining grid support 13, implement the remaining waterproof facilities, pour the remaining main structure, and complete the construction, see Figure 15.

The above-mentioned embodiments are only descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, those skilled in the art may make various modifications to the technical solutions of the present invention. and improvements, all should fall within the scope of protection determined by the claims of the present invention.

Claims (5)

1. a kind of flat top wall pipe curtain structure builds the construction method of super Shallow Covered Metro Station, it is characterised in that including such as Lower step：

1）In active well surrounding construction fender post, after fender post reaches intensity, the excavation of well is operated, jacking construction is built Platform；

2）Flange plate is welded in the both sides of construction steel pipe, and prepared screw-bolt hole and preformed groove are opened up in both sides；

3）Using all top steel pipes and the side steel pipe of both sides the top of pipe jacking method tunneling section, steel is removed when excavating The soil body between the soil body inside pipe, and each steel pipe of preformed groove removing for passing through steel pipe side；After the completion of jacking and digger make, in phase Connecting bolt is installed by prepared screw-bolt hole in adjacent steel pipe, after adjacent steel pipe lateral connection is installed, in the weldering of steel pipe two ends Plugging plate is connect, to concrete perfusion between steel duct and adjacent steel pipe；

4）After the side steel pipe and top fastener for connection of both sides the top are firm, remaining side steel pipe is carried out successively from top to bottom Jacking, the slip casting operation in the connection between steel pipe, and steel pipe and between steel pipe；

5）Using front pre-grouting strengthening stratum, benching tunnelling method excavates the following pilot tunnel in both sides and applies preliminary bracing, in following pilot tunnel Armored concrete abutment wall and strip foundation under wall are inside applied, the side steel pipe for connecting both sides bottom；

6）First bottom heading excavation is carried out using the excavation method of side pilot tunnel, and applies preliminary bracing；

7）After first bottom heading insertion, the excavation of the first top pilot tunnel is carried out again using benching tunnelling method, the first top pilot tunnel is used Grid supporting；

8）The first top pilot tunnel, the waterproof in the first bottom heading, and bottom girder and part backplane are applied respectively, using artificial Caisson builds steel pipe column, then pours top longeron and partial panels；

9）Using step 6）To step 8）The longitudinal bottom heading of step excavation second of method and the second top pilot tunnel, pilot drive During carry out grouting and reinforcing processing to the soil body between pilot tunnel adjacent thereto, and respectively constructing pilot tunnel inner waterproofing plate, bottom girder, Part backplane and top longeron, partial panels, steel pipe column；

10）Top pilot tunnel layout grid supporting is abolished, waterproof layer is laid, across top plate in performing；

11）In after top plate reaches design strength 80%, longitudinal divisionses excavate the bottom above soil body of plate in station hall layer, level Steel pipe and vertical steel pipe junction use type steel support, perform station hall layer side wall waterproof layer at station structure end bay, middle plate termination Place's welding corbels support is connected with vertical steel pipe, respectively plate in longeron and station hall layer in construction；

12）After plate in station hall layer reaches design strength 80%, applied in excavating respectively across the soil body and the end bay soil body to bottom plate position Do bottom plate；

13）Remaining grid supporting is abolished, remaining Lock gate is performed, remaining agent structure is poured, construction is completed.

2. construction method according to claim 1, it is characterised in that step 4）In, in the steel pipe work progress of side, it need to treat A upper side steel pipe and construction steel pipe are connected firmly and excavated in steel pipe and between steel pipe after the soil body and concrete perfusion, then Next side steel pipe of jacking.

3. construction method according to claim 2, it is characterised in that reserved in undermost side steel pipe with leading below The Steel bar rack that armored concrete abutment wall is connected inside hole.

4. construction method according to claim 1, it is characterised in that step 11）In, plate end in the station hall layer Upper and lower layer side wall sets joint design.

5. construction method according to claim 1, it is characterised in that step 12）In, perform the specific method of bottom plate such as Under：

Across the bottom of the soil body to bottom plate position in excavation, apply back cover structure and remove part pilot tunnel structure, across bottom plate in performing Waterproof layer and in pouring across bottom plate；

In after underplate concrete reaches design strength 80%, the end bay soil body is excavated to the bottom of bottom plate position, back cover knot is applied Structure simultaneously removes part pilot tunnel structure, performs base plate waterproofing and pours bottom plate remaining structure.