Tunnel bottom pressurized water automatic overflow device and installation method thereof

Abstract

The present invention relates to an automatic overflow device for pressurized water at the bottom of a tunnel and a method for installing the device. The device is installed on a primary support steel frame of an inverted arch at the bottom of the tunnel and includes a drainage well, a plurality of blind drainage pipes at the bottom of the inverted arch, a central ditch, and a drainage pipe. The drainage wells are located at both ends of the primary support steel frame of the tunnel bottom inverted arch and are connected to the blind drainage pipes at the bottom of the inverted arch. The blind drainage pipes at the bottom of the inverted arch are radially distributed, and the pipe openings at the radial center positions thereof are connected to the central ditch via a bracket. The central ditch is connected to the drainage pipe. The present invention can effectively drain the pressurized water at the bottom of a water-rich tunnel or a tunnel with a large burial depth and at the bottom of a lining inverted arch, reduce the risk of water seepage and water gushing from an inverted arch of a long high-speed railway tunnel passing through a water-rich section, and reduce the frequency of inspection and replacement of one-way valves in drainage pipes at the bottom of the inverted arch during operation of a long high-speed railway tunnel.

Description

Technical Field

[0001] The present invention relates to the field of tunnel engineering, and in particular to an automatic overflow device for pressurized water at the bottom of a tunnel and an installation method thereof. Background Art

[0002] The geological conditions of tunnels passing through mountains are complex and changeable. For example, when a tunnel passes through a water-rich area in the mountain, after the tunnel lining construction is completed, the lining drainage system and the bottom of the invert tunnel are closed into a ring due to the lining drainage system, and pressurized water is easily formed on the outside of the lining drainage system and the bottom of the tunnel; if the pressurized water cannot be drained away in a timely and effective manner, the invert settlement joints and deformation joints of the tunnel will be frequently disturbed during the operation of the high-speed railway due to the high-speed and high-frequency passage of trains, and pressurized water overflow will easily occur at the construction joints and deformation joints. During the operation of the electrified railway, strict requirements are placed on water seepage and gushing in the tunnel. The invert lining is difficult to inspect and maintain during operation, which affects the service life of the railway tunnel invert and invert filling.

[0003] At present, there is no effective way to drain the pressurized water at the bottom of railway tunnels during construction. This can easily lead to the inability to effectively drain the pressurized water at the bottom of water-rich tunnels or tunnels with large burial depths and at the bottom of the lining invert. As a result, during the operation of high-speed railways, pressurized water overflows from the deformation joints and construction joints of water-rich sections of tunnels or causes the bottom plate to bulge, affecting the safety of high-speed railway operations.

[0004] In the prior art, a drainage pipe with a one-way valve is generally installed 5m from the central rectangular trench of the tunnel to connect to the tunnel bottom to drain the pressurized water. Figure 1 As shown, the central ditch collects the confined water from the entire tunnel drainage system. The water quality is unstable, and suspended particles are easily present in the water. Since the ditch flows year-round, suspended matter can settle through the one-way valve orifice onto the valve disc, potentially blocking it and preventing smooth drainage of the confined water at the inverted arch, shortening the service life of the one-way valve. Furthermore, the one-way valve is difficult to replace during operation. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides an automatic overflow device for tunnel bottom pressurized water, which can timely drain the tunnel bottom pressurized water and prevent the tunnel bottom invert arch from shortening its service life due to the pressurized water.

[0006] The technical solution of the present invention provides, on one hand, a tunnel bottom pressurized water automatic overflow device, which is installed on the primary support steel frame of the tunnel bottom invert arch, and comprises:

[0007] Drainage wells, several arch bottom drainage blind pipes, a central ditch and a drainage pipe. The drainage wells are located at both ends of the primary support steel frame of the tunnel bottom invert and are connected to the arch bottom drainage blind pipes. The arch bottom drainage blind pipes are radially distributed, and the pipe openings at the radial center are connected to the central ditch through a bracket. The central ditch is connected to the drainage pipe.

[0008] Furthermore, the arch bottom drainage blind pipe is installed at the bottom of the inverted arch primary support steel frame, and the pipe mouth near the central ditch is bent upward and flush with the primary support surface of the inverted arch primary support steel frame.

[0009] Furthermore, a waterproof plate is provided at the opening of one end of the arch bottom drainage blind pipe away from the central ditch.

[0010] Furthermore, the arch bottom drainage blind pipe is a single-wall perforated corrugated pipe, and the openings at both ends and the outer surface are wrapped with non-woven fabric.

[0011] Furthermore, the drainage well is 80 cm long, 80 cm wide and 50 cm deep.

[0012] Furthermore, a one-way valve is provided on the drainage pipe, and a filter is provided at the outlet of the drainage pipe in the flow direction of the one-way valve, and the filter has a built-in filter sponge.

[0013] Furthermore, the diameter of the drainage pipe and the arch bottom drainage blind pipe is 50 mm.

[0014] Another aspect of the present invention further provides a method for installing the above-mentioned tunnel bottom pressurized water automatic overflow device, the installation method comprising the following steps:

[0015] S1. Lay the primary arch support and set up a water collection well at the end of the primary arch support to drain the water accumulated at the bottom of the tunnel during the construction of the primary arch support; cut radial drainage blind pipe installation grooves on the primary arch support;

[0016] S2. Install drainage blind pipes according to the radial drainage blind pipe installation grooves. The blind pipes are connected to the central ditch by fixing the pipe openings with brackets near the radial center, and ensure that the pipe openings of the blind pipes extend at least 5 cm beyond the initial support surface of the inverted arch.

[0017] S3. During the construction of shotcrete at the tunnel bottom, the pressurized water at the tunnel bottom will flow out from the blind pipe opening;

[0018] S4. Before the construction of the lining inverted arch, remove the slag on the inner surface of the primary support of the inverted arch, cut the opening of the tunnel bottom drainage blind pipe and the primary support surface flat, and cover the blind pipe opening with a waterproof sheet;

[0019] S5, installing an inverted arch bottom drain pipe and a one-way valve on the central ditch, wherein the one-way valve is connected to the inverted arch bottom drain pipe;

[0020] S6. Customize the stainless steel mesh and filter according to the size of the drainage pipe, and cover the filter with each drainage pipe at the bottom of the inverted arch after installation.

[0021] Furthermore, the step S6 also includes the following steps: S61, inserting a filter sponge into the filter net.

[0022] Furthermore, steps S1 to S6 are repeated at intervals of 8 to 12 meters at the tunnel bottom, and the tunnel bottom pressurized water automatic overflow device is installed at the tunnel bottom.

[0023] The technical solution of the present invention utilizes radially distributed drainage blind pipes for ease of operation. The tunnel excavation surface is large, and the dispersed pressure at the inrush points of the pressurized water is low, allowing centralized drainage during construction. Furthermore, during tunnel invert lining construction, the pressurized water drawn from the blind pipes at the outer edge of the primary support at the tunnel bottom has low pressure due to the unsealed ends of the primary support. This allows centralized drainage, facilitating tunnel invert lining construction.

[0024] Moreover, a filter device is installed at the outlet of the drainage pipe at the bottom of the inverted arch. It is easy to install and replace. It can filter suspended matter in the water to extend the service life of the one-way valve and ensure the smooth discharge of pressurized water at the bottom of the inverted arch.

[0025] Based on the above technical solution, the frequency of inspection and replacement of the one-way valve at the bottom of the drainage pipe of the invert arch during the operation of long and large high-speed railway tunnels can be reduced. At the same time, the risk of water seepage and water gushing in the invert arch of long and large high-speed railway tunnels passing through water-rich sections can be reduced, and the service life of the invert arch lining of long and large high-speed railway tunnels passing through water-rich sections can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the arrangement structure of the drainage pipe at the bottom of the inverted arch in the prior art;

[0027] Figure 2 Schematic diagram of the installation plan structure of the arch bottom drainage blind pipe in the present invention;

[0028] Figure 3 Schematic diagram of the installation cross-sectional structure of the arch bottom drainage blind pipe in the present invention;

[0029] Figure 4 Schematic diagram of the structure of the drainage pipe in the present invention;

[0030] Figure 5 It is a structural schematic diagram of the drainage pipe filter in the present invention.

[0031] Figure 6 It is a flow chart of the installation method of the automatic overflow device for pressurized water at the bottom of the tunnel in the present invention. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. However, it should be noted that many of the details listed in the specification are merely intended to help the reader have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be practiced even without these specific details.

[0033] First, according to Figure 6 The tunnel bottom pressure water automatic overflow device installation method is to install the tunnel bottom pressure water automatic overflow device. Step S1 is as follows Figure 2 As shown in the figure, after the arch primary support steel frame is laid, a water collection well is set at the end of the arch primary support. The size of the water collection well is 80cm*80cm*50cm. The water collection well is used to pump out the water accumulated at the bottom of the tunnel during the construction of the arch primary support. After the accumulated water is pumped out, radial drainage blind pipe installation grooves are chiseled on the arch primary support. The specific location of the chiseling groove is as shown in the figure. Figure 2 As shown in the radial shape in the figure, the number of grooves can be appropriately increased or decreased according to the groundwater conditions in the construction area at the bottom of the tunnel.

[0034] S2. Next, install the drainage blind pipe according to the radial drainage blind pipe installation groove. The blind pipe is connected to the central ditch by fixing the pipe mouth with a bracket near the radial center. The central ditch is located on the center line of the tunnel bottom, and ensure that the blind pipe mouth extends out of the initial support surface of the inverted arch by no less than 5 cm. The blind pipe in the installation groove is fixed once every 50 cm with rivets and pressure strips. During the fixing process, fix the pipe mouth first and then fix the blind pipe in the groove to avoid pulling the blind pipe in the groove during the fixing process of the pipe mouth and blind pipe; after the drainage blind pipe is fixed, wrap the pipe mouth at both ends with non-woven fabric to prevent foreign matter from entering the pipe and affecting the drainage effect of the blind pipe. The effect of the completed installation is as follows: Figure 3 shown.

[0035] S3. During the tunnel bottom shotcrete construction, the tunnel bottom pressurized water will flow out from the blind pipe opening. During the construction process, it is necessary to pay attention to protecting the tunnel bottom drainage blind pipe. After the initial shotcrete construction is completed, the tunnel bottom pressurized water will flow out from the blind pipe opening.

[0036] S4. Before the construction of the lining invert, remove the loose slag on the inner surface of the primary support of the invert, cut the radial drainage blind pipe openings and the primary support surface of the tunnel bottom flat, and cover the blind pipe openings with waterproof sheets. The edges of the waterproof sheets are firmly fixed with nails + hot-melt washers, with a spacing of no more than 30 cm. The waterproof sheets should be covered with appropriate tightness to allow the pressurized water at the bottom of the tunnel to be effectively discharged without invading the invert lining. The overflowed pressurized water should be pumped out from the water collection well set at the front end of the invert to avoid water accumulation on the primary support surface of the invert, which would affect the construction quality of the invert lining concrete.

[0037] S5. After the lining inverted arch is constructed, a drainage pipe and a one-way valve at the bottom of the inverted arch are installed on the central ditch. Figure 4 As shown, the one-way valve is connected to the drainage pipe at the bottom of the inverted arch. Pay attention to controlling the tee during the installation of the drainage pipe. The drainage pipe is also a single-wall perforated corrugated pipe. It is necessary to ensure that the joints are firm and leak-proof. After the one-way valve is installed, the quality of the one-way valve is checked according to the requirements to ensure that the quality of each one-way valve is qualified. The one-way valve is connected to the drainage pipe at the bottom of the inverted arch by hot welding. Check the installation quality of each one-way valve to ensure that the installation quality of the one-way valve meets the design requirements.

[0038] S6. After the drainage pipes are installed, a stainless steel mesh and filter are made on each drainage pipe according to the size of the drainage pipe, and the filter is covered after the installation of each drainage pipe at the bottom of the inverted arch. Figure 5 As shown, the filter mesh has a hole diameter of 5 mm and is uniformly manufactured according to the diameter of the drainage pipe. A filter sponge is built into the filter mesh and is located above the filter mesh.

[0039] During the tunnel bottom construction process, the above steps are repeated every 8-12m to ensure that the entire tunnel bottom can ensure the smooth discharge of pressurized water.

[0040] When tunnel construction enters a water-rich area, "radial" drainage blind pipes are added at the bottom of the tunnel to allow the pressurized water at the bottom of the tunnel to overflow automatically. At the same time, the number of drainage blind pipes can be controlled, and the pressure at the bottom of the tunnel can be discharged to the central ditch through the drainage pipe at the bottom of the invert, thereby extending the service life of the tunnel invert.

[0041] After installation, each inverted arch drainage pipe must be covered with a filter to prevent foreign matter from entering the pipe opening and to ensure the function of the one-way valve. This protects the inverted arch drainage pipe and the one-way valve, extends the service life of the one-way valve, and reduces the frequency of one-way valve maintenance and replacement in railway tunnels, especially long and large ones, making it economical and easy to operate.

[0042] It should be noted that the installation method described in the present invention is also applicable to the treatment of pressurized water at the base of other structures, such as the treatment of pressurized water at the bottom of a deep foundation pit pedestal and the treatment of pressurized water at the foundation of a culvert.

[0043] For example, the bottom of a deep foundation pit is difficult to control the quality of the bottom concrete construction during the cofferdam construction process. After the foundation pit is excavated, there are pressurized water seepage and gushing points at the bottom of the foundation pit. The same method can be used to drain the pressurized water at the bottom of the pit before the construction of the deep foundation pit pedestal. The water can be concentratedly pumped out at the collection well. After the pedestal concrete pouring is completed and the strength meets the design requirements, the pumping of pressurized water can be stopped. This can effectively prevent the loose structure, seepage points and quality defects caused by the pressurized water at the base during the pedestal pouring process.

Claims

1. An automatic overflow device for pressurized water at the bottom of a tunnel, which is installed on the primary support steel frame of the tunnel invert arch, and is characterized by: The automatic overflow device for pressurized water at the tunnel bottom includes a water collection well, a plurality of blind drainage pipes at the bottom of the inverted arch, a central ditch, and a drainage pipe at the bottom of the inverted arch. The water collection well is located at both ends of the primary support steel frame of the tunnel bottom inverted arch and is connected to the blind drainage pipes at the bottom of the inverted arch. The blind drainage pipes at the bottom of the inverted arch are radially distributed, and the pipe openings at the radial center are connected to the central ditch through a bracket. The central ditch is connected to the drainage pipe at the bottom of the inverted arch. Radial arch bottom drainage blind pipe installation grooves are chiseled on the primary support of the inverted arch for installing the arch bottom drainage blind pipes.

2. The automatic overflow device for pressurized water at the bottom of a tunnel according to claim 1, characterized in that: The inverted arch bottom drainage blind pipe is installed at the bottom of the inverted arch primary support steel frame, and the pipe mouth near the central ditch is bent upward and flush with the primary support surface of the inverted arch primary support steel frame.

3. The automatic overflow device for pressurized water at the bottom of a tunnel according to claim 2, characterized in that: A waterproof plate is provided at the opening of one end of the inverted arch bottom drainage blind pipe away from the central ditch.

4. The automatic overflow device for pressurized water at the bottom of a tunnel according to claim 3, characterized in that: The drainage blind pipe at the bottom of the inverted arch is a single-wall perforated corrugated pipe, and the openings at both ends and the outer surface thereof are wrapped with non-woven fabric.

5. The automatic overflow device for pressurized water at the bottom of a tunnel according to claim 4, characterized in that: The water collection well has a length of 80 cm, a width of 80 cm and a depth of 50 cm.

6. The automatic overflow device for pressurized water at the bottom of a tunnel according to claim 1, characterized in that: A one-way valve is provided on the inverted arch bottom drainage pipe, and a filter is provided at the pipe opening of the inverted arch bottom drainage pipe in the flow direction of the one-way valve, wherein a filter sponge is built in the filter.

7. The automatic overflow device for pressurized water at the bottom of a tunnel according to claim 6, characterized in that: The diameter of the drainage pipe at the bottom of the inverted arch and the blind drainage pipe at the bottom of the inverted arch is 50 mm.

8. A method for installing the automatic overflow device for tunnel bottom pressure water according to claim 6, characterized in that: The method comprises the following steps: S1. Lay the primary support of the inverted arch and set up a water collection well at the end of the primary support to pump out the water accumulated at the bottom of the tunnel during the construction of the primary support. Carve out radial grooves for the drainage blind pipes at the bottom of the inverted arch on the primary support. S2. Install the drainage blind pipe at the bottom of the inverted arch according to the radial drainage blind pipe installation groove. The drainage blind pipe at the bottom of the inverted arch is connected to the central ditch by fixing the pipe mouth with a bracket near the radial center, and ensure that the pipe mouth of the drainage blind pipe at the bottom of the inverted arch extends not less than 5 cm from the initial support surface of the inverted arch; S3. During the construction of shotcrete at the tunnel bottom, the pressurized water at the tunnel bottom will flow out from the drainage blind pipe at the bottom of the inverted arch; S4. Before the lining inverted arch is constructed, the inner surface of the primary support of the inverted arch is cleaned of the slag, the opening of the drainage blind pipe at the bottom of the inverted arch is cut flat with the primary support surface, and the opening of the drainage blind pipe at the bottom of the inverted arch is covered with a waterproof sheet; S5. Installing an inverted arch bottom drainage pipe and a one-way valve on the central ditch, wherein the one-way valve is connected to the inverted arch bottom drainage pipe; S6. Customize the stainless steel mesh and filter according to the size of the inverted arch drainage pipe, and cover each inverted arch drainage pipe with the filter after installation.

9. A method for installing an automatic overflow device for pressurized water at the bottom of a tunnel according to claim 8, characterized in that: The step S6 further includes the following steps: S61, placing a filter sponge inside the filter.

10. The method for installing an automatic overflow device for pressurized water at the bottom of a tunnel according to claim 9, characterized in that: Repeat steps S1 to S6 at the tunnel bottom every 8 to 12 meters, and install the tunnel bottom pressurized water automatic overflow device at the tunnel bottom.

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