Anti-floating structure for shallow-buried subway station and construction method of anti-floating structure

Abstract

The invention relates to the technical field of subway safety protection construction, and discloses an anti-floating structure for a shallow-buried subway station and a construction method of the anti-floating structure, the anti-floating structure comprises a pipe roof jacking pipe, the pipe roof jacking pipe is horizontally arranged in a stratum, and the two ends of the pipe roof jacking pipe are rigidly connected with two enclosure structures respectively. The construction of the anti-floating structure does not need to excavate shallow covering soil above the subway station, so that further aggravation of upheaval deformation of the subway station can be avoided, and the construction safety is improved; the pipe-roofing jacking pipe is rigidly connected with the enclosure structure, anti-floating load is transmitted to the pipe-roofing jacking pipe from the subway station, then transmitted to the enclosure structure through the pipe-roofing jacking pipe and further transmitted to the stratum, and the upheaval deformation resisting effect of the subway station can be improved; in addition, a safe distance is reserved between the pipe-roofing jacking pipe and the top plate of the subway station, the anti-floating load does not directly act on the top plate but is buffered through the stratum between the pipe-roofing jacking pipe and the top plate, the top plate can be effectively protected, and safety is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of subway safety protection construction, in particular to an anti-floating structure for a shallow-buried subway station and a construction method thereof. BACKGROUND

[0002] In recent years, in order to optimize the allocation of water resources and alleviate the shortage of water resources in northern regions, the state has implemented a series of inter-basin water transfer projects. These projects have brought significant social and economic benefits, but also have a profound impact on the hydrogeological environment along the line. Through various ways such as river water replenishment, reduction of groundwater exploitation, and canal system leakage, the groundwater level has risen universally and continuously. However, this regional groundwater level rise under human intervention has changed the long-term mechanical balance environment of the subway station structure, and the groundwater level has risen year by year and is close to or exceeds the highest water level line of the shallow-buried subway station in the design stage. The groundwater exerts a large upward force on the shallow-buried subway station, which is likely to cause irreversible damage to the subway station structure and the track.

[0003] At present, the anti-floating measures for the subway station structure are mostly to set anti-pulling piles, anti-floating anchor rods at the bottom or to set pressure top beams at the top. However, anti-pulling piles and anti-floating anchor rods need to be constructed during the construction of the subway station, and cannot be implemented for the subway stations that are already in operation. Although the pressure top beam can be implemented for the subway stations that are already in operation, the soil above the side wall of the subway station needs to be excavated during the implementation process, which may further aggravate the uplift deformation of the subway station and pose a safety problem. In addition, the pressure top beam needs to be applied to the top of the intersection of the side wall and the top plate of the subway station, and the anti-floating load will act directly on the top plate of the subway station, which also poses a safety problem.

[0004] Therefore, how to provide an anti-floating structure construction method suitable for shallow-buried subway stations and ensuring safety is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0005] The purpose of the present application is to provide an anti-floating structure for a shallow-buried subway station and a construction method thereof to solve the problems existing in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides an anti-floating structure for a shallow-buried subway station, comprising:

[0007] A pipe roof jacking pipe is horizontally arranged in the stratum, and the two ends of the pipe roof jacking pipe are rigidly connected with the two enclosing structures, respectively.

[0008] Further, a safety distance is left between the pipe roof jacking pipe and the top plate.

[0009] This invention also provides a construction method for an anti-buoyancy structure for shallow-buried subway stations, comprising:

[0010] S1: The top of the subway station is equipped with a roof slab, and the ground is above the roof slab. The subway station is equipped with a retaining structure on both sides along its length. The upper end of the retaining structure extends into the ground. The foundation pit is formed by excavating from top to bottom on the outside of the retaining structure.

[0011] S2: Install a pipe jacking machine and a reaction wall adapted to the pipe jacking machine in the foundation pit;

[0012] S3: The enclosure structure is broken through from the outside to the inside to form the installation hole for the pipe curtain top pipe, and the installation hole is connected to the stratum.

[0013] S4: The pipe jacking machine is used to horizontally push the pipe curtain jacking pipe into the stratum from the installation hole, leaving a safe distance between the pipe curtain jacking pipe and the roof slab;

[0014] S5: Connect the top pipe of the pipe curtain to the vertical steel bars of the enclosure structure;

[0015] S6: Pressurize and fill the pipe with cement mortar, and rigidly connect both ends of the pipe to the installation hole by pouring concrete.

[0016] S7: Dismantle the pipe jacking machine and reaction wall, and backfill the foundation pit.

[0017] Furthermore, in step S1, there are two foundation pits located on the outside of the two retaining structures, and the two foundation pits are excavated symmetrically.

[0018] Furthermore, in step S1, the portion of the foundation pit near the retaining structure is excavated manually.

[0019] Furthermore, in step S3, a static cutting method is used to penetrate and break through the enclosure structure.

[0020] Furthermore, in step S4, during the process of horizontally pushing the pipe curtain jacking pipe into the formation from the installation hole using a pipe jacking machine, slag is removed by an auger drill placed inside the pipe curtain jacking pipe.

[0021] Furthermore, a continuous grouting pipe is welded to the outside of the arch foot of the pipe curtain jacking pipe. Grouting holes are opened on the continuous grouting pipe. In step S4, during the process of the pipe curtain jacking pipe being horizontally pushed into the stratum from the installation hole by the pipe jacking machine, grout is injected into the stratum through the continuous grouting pipe to reinforce it.

[0022] Furthermore, the grouting holes are shaped like plum blossoms.

[0023] Furthermore, the top pipe of the tube curtain is provided with connection holes near both ends, and the connection holes penetrate the top pipe of the tube curtain from top to bottom; in step S3, the vertical steel bars of the enclosure structure corresponding to the installation holes are cut off; in step S5, the connecting steel bars are passed through the connection holes, and the two ends of the connecting steel bars are welded to the vertical steel bars of the enclosure structure.

[0024] The present invention discloses the following technical effects:

[0025] This invention involves arranging a pipe curtain jacking pipe above the roof slab of a subway station and rigidly connecting it to the existing retaining structure to form an anti-buoyancy structure for the subway station. Compared with existing technologies, the construction of this anti-buoyancy structure does not require excavation of the shallow overburden above the subway station, thus avoiding further exacerbation of the station's uplift deformation and improving construction safety. The rigid connection between the pipe curtain jacking pipe and the retaining structure allows the anti-buoyancy load to be transferred from the subway station to the pipe curtain jacking pipe, then through the pipe curtain jacking pipe to the retaining structure, and finally to the ground, improving the subway station's resistance to uplift deformation. Furthermore, a safe distance is maintained between the pipe curtain jacking pipe and the subway station's roof slab, meaning the anti-buoyancy load is not directly applied to the roof slab but is buffered by the ground layer between the pipe curtain jacking pipe and the roof slab, effectively protecting the roof slab and improving safety. This invention has promising application prospects and a wide range of applicability. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the foundation pit excavation.

[0028] Figure 2 This is a schematic diagram of the demolition of the enclosure structure;

[0029] Figure 3 This is a schematic diagram of the horizontal insertion of the pipe curtain into the strata.

[0030] Figure 4 This is a schematic diagram of the installation of connecting steel bars;

[0031] Figure 5 This is a schematic diagram of the pipe jacking after backfilling the foundation pit;

[0032] Figure 6 A top view showing the installation of multiple pipe curtain jacking pipes;

[0033] Among them, 1. subway station; 2. retaining structure; 3. pipe curtain jacking pipe; 4. foundation pit; 5. vertical reinforcement; 6. connecting reinforcement; 7. connecting hole. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figures 1-6 As shown, an embodiment of the present invention provides an anti-buoyancy structure for shallow-buried subway stations, comprising:

[0037] The tube curtain jacking pipe 3 is installed on the top of the subway station 1, and the ground is above the top of the top plate. The two sides of the subway station 1 are equipped with enclosure structures 2 along their length. The upper end of the enclosure structure 2 extends into the ground. The tube curtain jacking pipe 3 is horizontally installed in the ground, and its two ends are rigidly connected to the two enclosure structures 2 respectively.

[0038] In this embodiment, a safe distance is maintained between the pipe curtain top pipe 3 and the top plate.

[0039] This invention also provides a construction method for an anti-buoyancy structure for shallow-buried subway stations, comprising:

[0040] S1: The top of the subway station 1 is equipped with a roof slab, and the ground is above the roof slab. The two sides of the subway station 1 are equipped with retaining structures 2 along their length. The upper end of the retaining structure 2 extends into the ground. The foundation pit 4 is excavated from top to bottom on the outside of the retaining structure 2. Before excavation, the size of the pipe jacking machine, the installation position and length of the pipe curtain jacking pipe 3 and the impact on the surrounding pipelines should be fully considered. After comprehensive analysis, the excavation length, width and depth of the foundation pit 4 should be determined.

[0041] S2: Install a pipe jacking machine and a reaction wall adapted to the pipe jacking machine in the foundation pit 4;

[0042] S3: The enclosure structure 2 is broken through from the outside to the inside to form the installation hole of the pipe curtain top pipe 3, and the installation hole is connected to the stratum.

[0043] S4: The pipe jacking pipe 3 is horizontally pushed into the stratum from the installation hole using a pipe jacking machine, with a safe distance left between the pipe jacking pipe 3 and the top plate;

[0044] S5: Connect the top pipe 3 of the pipe curtain to the vertical steel bars 5 of the enclosure structure 2;

[0045] S6: Pressurize and fill the pipe 3 with cement mortar, and rigidly connect both ends of the pipe 3 to the installation hole by pouring concrete. During the pouring process, the grouting pressure should be controlled to avoid affecting the subway station 1.

[0046] S7: Remove the pipe jacking machine and reaction wall, and backfill the foundation pit 4. At this time, the pipe jacking pipe 3 and the retaining structure 2 form a "bench"-shaped integrated structure. When the groundwater level rises, it can suppress the uplift deformation of the subway station 1 and transfer the anti-buoyancy load from the subway station 1 to the pipe jacking pipe 3, the retaining structure 2 and the ground layer in sequence, so as to ensure the safe operation of the subway station 1.

[0047] In this embodiment, in step S1, there are two foundation pits 4 located on the outside of the two retaining structures 2 respectively, and the two foundation pits 4 are excavated symmetrically to reduce the impact on the subway station 1.

[0048] In this embodiment, in step S1, the portion of the foundation pit 4 near the retaining structure 2 is excavated manually to avoid damage to the retaining structure 2.

[0049] In this embodiment, in step S3, static cutting is used to penetrate and demolish the retaining structure 2. Static cutting is an advanced construction technology that uses tools such as diamond wire saws or hydraulic shears to precisely cut and demolish hard materials such as concrete and vertical reinforcing bars 5 under conditions of no impact, low vibration, and low noise. The core of static cutting lies in the word "static," that is, the continuous and controllable thrust or pull force provided by the hydraulic system allows the diamond wire saw or saw blade to cut the material by high-speed grinding, rather than by traditional blasting or impact crushing methods. Diamond wire saw: composed of steel wire rope and diamond beads, it rotates at high speed driven by a hydraulic motor, grinding the concrete and vertical reinforcing bars 5, while cooling water simultaneously removes heat and debris. Hydraulic shears / saw: apply pressure through the hydraulic system to slowly and steadily cut the components without generating shock waves.

[0050] Before demolishing the retaining structure 2, the scope of demolition should be determined based on factors such as the installation location of the pipe curtain jacking pipe 3. The demolition area should be slightly larger than the construction area of ​​the pipe curtain jacking pipe 3.

[0051] In this embodiment, during step S4, when the pipe jacking machine horizontally pushes the pipe curtain jacking pipe 3 into the formation from the installation hole, the slag is discharged by the auger drill placed inside the pipe curtain jacking pipe 3.

[0052] In this embodiment, a continuous grouting pipe is welded to the outer side of the arch foot of the pipe curtain jacking pipe 3. Grouting holes are opened on the continuous grouting pipe. In step S4, during the process of the pipe curtain jacking pipe 3 being horizontally pushed into the stratum from the installation hole by the pipe jacking machine, grout is injected into the stratum through the continuous grouting pipe to reinforce it.

[0053] In this embodiment, the grouting holes are shaped like plum blossoms.

[0054] In this embodiment, the top pipe of the pipe curtain 3 is provided with connecting holes 7 near both ends, and the connecting holes 7 penetrate the top pipe of the pipe curtain 3 from top to bottom; in step S3, the vertical steel bars 5 corresponding to the installation holes of the enclosure structure 2 are cut off; in step S5, the connecting steel bars 6 are passed through the connecting holes 7, and the two ends of the connecting steel bars 6 are welded to the vertical steel bars 5 of the enclosure structure 2; the connecting steel bars 6 are selected with the same specifications as the original vertical steel bars 5 of the enclosure structure 2.

[0055] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0056] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An anti-floating structure for a shallow-buried subway station, characterized by, include: The top of the subway station (1) is provided with a roof slab, and the ground is above the roof slab. The subway station (1) is provided with enclosure structures (2) along its length on both sides. The upper end of the enclosure structure (2) extends into the ground. The top of the tube curtain (3) is horizontally installed in the ground, and its two ends are rigidly connected to the two enclosure structures (2) respectively.

2. The anti-floating structure for a shallow-buried subway station according to claim 1, wherein A safe distance is maintained between the pipe curtain top pipe (3) and the top plate.

3. A method for constructing an anti-floating structure for a shallow-buried subway station, characterized by, include: S1: The top of the subway station (1) is provided with a roof slab, and the ground is above the roof slab. The subway station (1) is provided with a retaining structure (2) along its length on both sides. The upper end of the retaining structure (2) extends into the ground. The foundation pit (4) is excavated from top to bottom on the outside of the retaining structure (2). S2: Arrange a pipe jacking machine and a reaction wall adapted to the pipe jacking machine in the foundation pit (4); S3: The enclosure structure (2) is broken through from the outside to the inside to form the installation hole of the pipe curtain top pipe (3), and the installation hole is connected to the stratum; S4: The pipe jacking pipe (3) is horizontally pushed into the stratum from the installation hole by the pipe jacking machine, and a safe distance is left between the pipe jacking pipe (3) and the top plate; S5: Connect the top pipe (3) of the pipe curtain to the vertical steel bars (5) of the enclosure structure (2); S6: Pressurize and fill the pipe top tube (3) with cement mortar, and rigidly connect the two ends of the pipe top tube (3) with the installation hole by pouring concrete. S7: Remove the pipe jacking machine and reaction wall, and backfill the foundation pit (4).

4. The anti-floating structure construction method for a shallow-buried subway station according to claim 3, characterized in that, In step S1, there are two foundation pits (4) located on the outside of the two retaining structures (2), and the two foundation pits (4) are excavated symmetrically.

5. The anti-floating construction method for a shallow-buried subway station according to claim 3, wherein In step S1, the portion of the foundation pit (4) near the retaining structure (2) is excavated manually.

6. The anti-floating construction method for a shallow-buried subway station according to claim 3, wherein In step S3, the static cutting method is used to penetrate and break through the enclosure structure (2).

7. The anti-floating construction method for a shallow-buried subway station according to claim 3, wherein In step S4, during the process of the pipe jacking machine horizontally pushing the pipe curtain jacking pipe (3) into the formation from the installation hole, the slag is discharged by the auger drill placed inside the pipe curtain jacking pipe (3).

8. The anti-floating construction method for a shallow-buried subway station according to claim 3, wherein A continuous grouting pipe is welded to the outside of the arch foot of the pipe curtain jacking pipe (3). Grouting holes are opened on the continuous grouting pipe. In step S4, during the process of the pipe curtain jacking pipe (3) being horizontally pushed into the stratum from the installation hole by the pipe jacking machine, grouting is injected into the stratum through the continuous grouting pipe to reinforce it.

9. The anti-floating construction method for a shallow-buried subway station according to claim 8, wherein, The grouting holes are shaped like plum blossoms.

10. The anti-floating construction method for a shallow-buried subway station according to claim 3, wherein The pipe curtain top pipe (3) is provided with connection holes (7) near both ends, and the connection holes (7) penetrate the pipe curtain top pipe (3) from top to bottom; in step S3, the vertical steel bars (5) of the enclosure structure (2) corresponding to the installation holes are cut off; in step S5, the connecting steel bars (6) are passed through the connection holes (7), and the two ends of the connecting steel bars (6) are welded to the vertical steel bars (5) of the enclosure structure (2).

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