Floor heave treatment device for water-rich weak surrounding rock tunnel

Abstract

The utility model discloses a floor heave treatment device for a water-rich weak surrounding rock tunnel. The floor heave treatment device comprises a pre-stressed anchor cable and an inverted arch drainage device. The multiple pre-stressed anchor cables are arranged at the bottom of an inverted arch of the tunnel in the transverse direction of the tunnel, a one-way valve is arranged in the inverted arch drainage device, the water inlet end of the inverted arch drainage device is located in surrounding rock at the bottom of the inverted arch, and the water outlet end of the inverted arch drainage device is connected with a center drainage ditch of the tunnel. Outward prestress is applied to the bottom of the tunnel in advance through the pre-stressed anchor cable, so that the tunnel bears the surrounding rock pressure of the soft tunnel, and meanwhile, the pre-stressed anchor cable can effectively release the surrounding rock stress of the bottom of the tunnel to prevent the conditions of bottom upheaving and tunnel bottom heaving; the drainage method of the drainage device is simple, water at the bottom of the tunnel is drained to the center drainage ditch through the pressure intensity difference in the pipeline, the adverse effect of water on weak surrounding rock is weakened, drainage can be conducted spontaneously and efficiently, and accumulated water in the pipeline is reduced.

Description

Technical Field

[0001] The utility model relates to the field of tunnel construction, in particular to a device for treating floor heave in a water-rich soft surrounding rock tunnel. Background Art

[0002] In recent years, the construction of mountain highway tunnels in my country has not only greatly increased in number and length, but also an increasing number of mountain tunnels are being built under complex geological conditions, which has continuously brought new challenges to the design and construction of mountain tunnels in my country.

[0003] The water-rich soft surrounding rock tunnel is a type of tunnel built under complex geological conditions. The self-bearing capacity of the water-rich soft surrounding rock is often low, and it is easy to undergo large deformation under the action of external force. On the other hand, the water-rich soft surrounding rock often contains mineral components that swell when exposed to water, and the surrounding rock at the base of the tunnel has a high water content. The bottom surrounding rock absorbs water and expands, and the deformation of the surrounding rock increases, leading to cracks in the tunnel arch, uneven road surface, and instability of the tunnel structure, which worsens the driving environment and seriously affects driving safety.

[0004] At present, water-rich soft rock tunnels mostly use closed steel frames or flexible support solutions. The so-called flexible support means that the support structure is retractable. Under the pressure of the surrounding rock, a large pressure can cause the support to deform. By displacing the surrounding rock, the surrounding rock pressure is reduced and the stress is released. The support structure integrates the contraction function and the reserved deformation amount. However, this support structure does not solve the problem of tunnel bottom bulging caused by water absorption and expansion of the rock mass at the bottom of the tunnel, and its actual application cannot release the stress of the surrounding rock at the bottom of the tunnel, and cannot effectively avoid the bottom bulge, tunnel bottom bulging and other conditions. Utility Model Content

[0005] In view of the problems of existing tunnel floor heave and drainage at the tunnel invert, the utility model provides a device for treating the floor heave of a water-rich soft surrounding rock tunnel, which can effectively avoid the bottom heave and tunnel floor heave.

[0006] The utility model is realized by the following technical solutions:

[0007] A device for treating floor heave in a water-rich soft rock tunnel, comprising a prestressed anchor cable and an invert drainage device;

[0008] The plurality of prestressed anchor cables are arranged at the bottom of the inverted arch of the tunnel in the transverse direction of the tunnel, the upper ends of the prestressed anchor cables are connected to the inverted arch, and the lower ends of the prestressed anchor cables are located in the surrounding rock at the bottom of the inverted arch;

[0009] A one-way valve is provided in the inverted arch drainage device, the water inlet end of the inverted arch drainage device is located in the surrounding rock at the bottom of the inverted arch, and the water outlet end of the inverted arch drainage device is connected to the central drainage ditch of the tunnel. When the one-way valve is opened, the inverted arch drainage device is connected to the central drainage ditch.

[0010] Preferably, the plurality of prestressed anchor cables are arranged at the center of the inverted arch and at the arch foot of the inverted arch.

[0011] Preferably, the prestressed anchor cable includes a grouting pipe and a plurality of unbonded steel strands arranged circumferentially along the grouting pipe, the lower ends of the unbonded steel strands and the grouting pipe are located in the rock mass, and the upper ends of the unbonded steel strands and the grouting pipe are connected to the arc-shaped steel frame of the invert arch through anchors.

[0012] Preferably, a section of the non-bonded steel strand close to the arc-shaped steel frame is an anchoring section, a section close to the rock mass is a free end, and a protective layer is sleeved on the free end of the non-bonded steel strand.

[0013] Preferably, the upper end of the inverted arch drainage device is connected to the transverse drainage pipe of the tunnel, and the transverse drainage pipe is connected to the central drainage ditch.

[0014] Preferably, the inverted arch drainage device includes a plurality of drainage devices, and the plurality of drainage devices are symmetrically arranged along the longitudinal center of the tunnel, and the upper ends of the drainage devices are connected to the transverse drainage pipes.

[0015] Preferably, the drainage device comprises a pressure reducing pipe, the lower end of which extends into the rock mass, a one-way valve is fixed in the pressure reducing pipe, and the upper end of the pressure reducing pipe is connected to the transverse drainage pipe.

[0016] Preferably, the pressure reducing valve comprises a valve plate, a waterproof rubber gasket and a support frame;

[0017] The support frame is arranged in the pressure reducing pipe, the waterproof rubber gasket is located on the top of the support frame and is close to the pipe wall of the pressure reducing pipe, the center of the valve plate is connected to the support frame, and the edge of the valve plate covers the waterproof rubber gasket.

[0018] Preferably, the valve plate is a rubber valve plate, the thickness of which gradually decreases from the center to the edge, the center of the valve plate is connected to the center of the support frame, and the edge of the valve plate is covered on a waterproof rubber gasket.

[0019] Preferably, the one-way valve comprises a valve plate, a pressure ball and a spring;

[0020] The valve plate includes two semicircular paddles, the straight edges of the two paddles are rotatably connected, the center of the valve plate is connected to the center of the support frame, the support frame is fixed in the pressure reducing tube, the pressure ball is arranged at the center of the valve plate, a fixing frame is arranged on the top of the pressure ball, the fixing frame is connected to the tube wall of the pressure reducing tube, a spring is arranged between the fixing frame and the pressure ball, the upper end of the spring is connected to the fixing frame, the lower end of the spring is connected to the pressure ball, and a hollow area is arranged on the fixing frame.

[0021] Compared with the prior art, the utility model has the following beneficial technical effects:

[0022] The utility model provides a device for treating the bottom bulge of a water-rich soft surrounding rock tunnel. A prestressed anchor cable and a one-way drainage device are arranged at the bottom of the tunnel invert arch. The prestressed anchor cable is used to apply outward prestress to the bottom of the tunnel in advance, so that it bears the surrounding rock pressure of the soft tunnel. At the same time, the prestressed anchor cable can effectively release the surrounding rock stress at the bottom of the tunnel to prevent the bottom from bulging and the bottom bulge of the tunnel. The lower end of the drainage device extends into the surrounding rock, and the upper end of the drainage device is connected to the drainage ditch. The drainage device at the invert arch discharges the water at the bottom of the invert arch through the transverse drainage pipe through the pressure difference and finally into the central drainage ditch, thereby preventing the surrounding rock at the bottom of the tunnel from absorbing water and expanding, thereby avoiding the occurrence of tunnel bottom bulge. The drainage method of the drainage device is simple. The pressure difference in the pipeline is used to drain the water at the bottom of the tunnel to the central drainage ditch, which reduces the adverse effect of water on the soft surrounding rock, can drain water spontaneously and efficiently, and reduces the accumulation of water in the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is an overall schematic diagram of the utility model.

[0024] Figure 2 It is a schematic diagram of the prestressed anchor cable in the utility model.

[0025] Figure 3 It is a comparison diagram of the drainage device in the utility model when it is in working state and when it is not in working state.

[0026] Figure 4 for Figure 2 aa section view in .

[0027] Figure 5 for Figure 3 bb cross-section diagram in.

[0028] In the figure: transverse drainage pipe 1, prestressed anchor cable 2, arch drainage device 3, central drainage ditch 4, filter screen 5, waterproof rubber gasket 6, pressure reducing pipe 7, valve plate 8, support frame 9, spring 11, pressure ball 12, arc steel frame 13, pressure plate 14, anchor 15, sealing anchor 16, non-bonded steel strand 17, grouting pipe 18, cement slurry 19. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings, which are intended to explain the present invention rather than to limit it.

[0030] See also Figure 1-5 A device for treating floor heave in a water-rich soft rock tunnel comprises a prestressed anchor cable 2 and an invert drainage device 3.

[0031] The multiple prestressed anchor cables 2 are arranged at the bottom of the tunnel invert and the arch foot along the transverse direction of the tunnel. The prestressed anchor cables 2 apply outward prestress to the bottom of the tunnel in advance, so that it can bear the surrounding rock pressure of the weak tunnel, which can effectively prevent the occurrence of tunnel bottom bulge.

[0032] The inverted arch drainage device 3 is arranged at the bottom of the tunnel inverted arch, the lower end of the drainage device extends into the surrounding rock, and the upper end of the drainage device is connected with the drainage ditch. The drainage device at the inverted arch discharges the water at the bottom of the inverted arch through the transverse drainage pipe 1 through the pressure difference and finally into the central drainage ditch 4, thereby preventing the surrounding rock at the bottom of the tunnel from absorbing water and expanding, thereby avoiding the occurrence of tunnel bottom bulge.

[0033] like Figure 1 As shown, the number of the plurality of prestressed anchor cables 2 is 6-10, preferably 6, and appropriate prestress is provided for the bottom of the tunnel invert arch and the arch foot through the plurality of prestressed anchor cables. At the same time, the prestressed anchor cables 2 can fix the broken surrounding rock with the surrounding rock with good structure, increase the bonding friction between the anchor body and the soil layer, increase the bearing pressure of the anchor body to improve the bearing capacity of the tunnel base surrounding rock;

[0034] like Figure 2 As shown, the prestressed anchor cable includes four unbonded steel strands 17; a grouting pipe 18 is arranged in the middle of the four unbonded steel strands 17; the position of the four unbonded steel strands 17 close to the arc steel frame 13 is the free section, and the position away from the arc steel frame 13 is the anchoring section; in the free section, a steel strand protective layer is sheathed on the outside of each unbonded steel strand 17, and the steel strand protective layer is a plastic tube; after the anchor cable is placed in the anchor cable hole, cement slurry 19 is filled through the grouting pipe 18; for the free section, the unbonded steel strand 17 can be tensioned relative to the steel strand protective layer; in the anchoring section, the unbonded steel strand 17 is fixed with the cement slurry 19 and the rock mass around the anchor cable hole. The sealing anchor 16 is used to seal the end of the prestressed anchor 15 to prevent the interior of the anchor 15 from being corroded by moisture, corrosive substances, etc. in the environment, and to protect the long-term stability and reliability of the anchor 15.

[0035] When the prestressed anchor cable 2 is installed, the two ends of the arc-shaped steel frame 13 are welded to two adjacent I-beam wing plates, and the free section of the anchor cable passes through the gap of the steel mesh.

[0036] Working principle of prestressed anchor cable 2: by applying prestress to the anchor cable, the prestressed anchor cable 2 transmits the tension to the arc-shaped steel frame 13 through the pressure-bearing plate 14, and then the arc-shaped steel frame 13 bears the surrounding rock pressure. The utility model can not only effectively control the deformation of the tunnel surrounding rock, but also effectively prevent the tunnel base from bearing the load from the surrounding rock pressure, thereby avoiding the occurrence of tunnel bottom bulge.

[0037] The inverted arch drainage device 3 includes multiple drainage structures, which are symmetrically distributed along the center line of the tunnel. Four groups are arranged on each side of the tunnel, totaling eight groups. The pressure difference in the pipeline is used to drain the water at the bottom of the tunnel to the central drainage ditch 4, thereby reducing the adverse effect of water on the soft surrounding rock and reducing the water accumulation at the bottom of the tunnel surrounding rock.

[0038] The lower end of the drainage structure is connected to the surrounding rock at the bottom of the tunnel, and the upper end of the drainage structure is connected to the transverse drainage pipe 1 of the tunnel. The drainage structure includes a pressure reducing pipe 7 and a one-way valve. The one-way valve fixes the upper end of the pressure reducing pipe, and the upper end of the pressure reducing pipe 7 is connected to the transverse drainage pipe. The one-way valve is used to prevent water in the transverse drainage pipe from entering the pressure reducing pipe, so that the water flow in the pressure reducing pipe enters the transverse drainage pipe and is discharged under the action of the pressure difference.

[0039] The one-way valve includes a valve plate 8, a waterproof rubber gasket 6 and a support frame 9; the support frame is arranged in the middle and upper part of the pressure reducing pipe, the waterproof rubber gasket 6 is located on the top of the support frame and is close to the pipe wall of the pressure reducing pipe, the center of the valve plate is connected to the support frame, and the edge of the valve plate covers the waterproof rubber gasket 6.

[0040] The valve plate is a rubber valve plate, and the thickness of the valve plate gradually decreases from the center to the edge. The center of the valve plate is connected to the center of the support frame, and the edge of the valve plate is covered on the waterproof rubber gasket 6; when the water pressure in the surrounding rock increases, the water flows through the pressure reducing pipe and surges up to impact the valve plate under the action of the pressure difference, and the edge of the valve plate is separated from the waterproof rubber gasket 6 to form a water flow channel, so that the pressure reducing pipe and the horizontal drainage pipe are connected; under normal conditions, the edge of the valve plate fits on the waterproof rubber gasket 6 and is sealed, and the water at the horizontal drainage pipe 1 can flow smoothly to the central drainage ditch 4 without flowing to the bottom of the tunnel through the invert drainage device 3. At the same time, the water flow in the horizontal drainage pipe 1 will generate pressure caused by gravity on the valve plate, so that the valve plate and the waterproof rubber gasket 6 will form a sealed state.

[0041] The support frame includes a fixing ring and a cross-shaped support rod arranged inside the fixing ring, the end of the support rod is connected to the inner wall of the fixing ring, the fixing ring is fixedly connected to the inside of the pressure reducing tube, and a waterproof rubber gasket 6 is arranged on the top of the fixing ring, and the center of the waterproof rubber gasket 6 is connected to the center of the support rod.

[0042] like Figure 3 and Figure 5In another embodiment, the one-way valve includes a valve plate, a pressure ball and a spring. The valve plate includes two semicircular paddles, the straight edges of the two paddles are connected by rotation, and the center of the valve plate is connected to the center of the support frame 9. For example, the straight edges of the two paddles are connected by hinges, the hinge is arranged at the center of the paddles, the hinge is arranged at the center of the support frame, the pressure ball is arranged at the center of the valve plate, a fixing frame is arranged on the top of the pressure ball, a spring is arranged between the fixing frame and the pressure ball, the upper end of the spring is connected to the fixing frame, and the lower end of the spring is connected to the pressure ball. A plurality of hollow areas are arranged on the fixing frame, so that the gushing water can enter the transverse drainage pipe. When the pressure relief pipe gushes, the water flow impacts the valve plate to make the two paddles rotate upward along the center relative to each other, and at the same time, the spring compresses the pressure ball to move upward, and the edge of the paddle is separated from the waterproof rubber gasket 6 to form a water flow channel, so that the water flow in the pressure relief pipe enters the transverse drainage pipe. Under normal conditions, the spring applies pressure to the pressure ball and acts on the paddle, so that the valve plate and the waterproof rubber gasket 6 are sealed, so as to prevent the water flow in the transverse drainage pipe from entering the pressure relief pipe.

[0043] The lower end of the decompression pipe is provided with a filter 5 for filtering the gushing water entering the decompression pipe to prevent debris from clogging the decompression pipe. The filter 5 is a microporous filter with a very small pore size, which can isolate soil particles and only allow water molecules to pass through, so as to prevent soil particles from entering the inverted arch drainage device 3 and clogging it.

[0044] The working principle of the inverted arch drainage device 3 is explained below.

[0045] Under normal conditions, there is no water gushing out of the pressure reducing pipe, the one-way valve is in a closed state, and the water in the transverse drainage pipe 1 can flow smoothly to the central drainage ditch 4 without flowing to the bottom of the tunnel through the invert drainage device 3.

[0046] In the working state, when the water pressure from the bottom surrounding rock is large enough, the gushing water enters the pressure reducing pipe, and the pressure reducing valve opens under the action of pressure. The gushing water from the bottom of the tunnel enters the horizontal drainage pipe 1 through the one-way valve and then flows to the central drainage ditch 4 for discharge.

[0047] The present application arranges a prestressed anchor cable 2 and a one-way flow arch drainage device 3 at the bottom of the tunnel invert. The prestressed anchor cable 2 can effectively control the deformation of the tunnel surrounding rock, and can effectively prevent the tunnel base from bearing the load from the surrounding rock pressure, and effectively release the surrounding rock stress at the bottom of the tunnel to prevent the bottom from bulging and the tunnel bottom from bulging. The drainage method of the drainage device is simple, and the pressure difference in the pipeline is used to drain the water at the bottom of the tunnel to the central drainage ditch 4, which reduces the adverse effect of water on the weak surrounding rock, can drain water spontaneously and efficiently, and reduces the accumulation of water in the surrounding rock at the bottom of the tunnel.

[0048] The above content is only for explaining the technical idea of ​​the utility model and cannot be used to limit the protection scope of the utility model. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the utility model shall fall within the protection scope of the claims of the utility model.

Claims

1. A device for treating floor heave in water-rich soft surrounding rock tunnels, characterized in that: Includes prestressed anchor cables and invert drainage devices; The plurality of prestressed anchor cables are arranged at the bottom of the inverted arch of the tunnel in the transverse direction of the tunnel, the upper ends of the prestressed anchor cables are connected to the inverted arch, and the lower ends of the prestressed anchor cables are located in the surrounding rock at the bottom of the inverted arch; A one-way valve is provided in the inverted arch drainage device, the water inlet end of the inverted arch drainage device is located in the surrounding rock at the bottom of the inverted arch, and the water outlet end of the inverted arch drainage device is connected to the central drainage ditch of the tunnel. When the one-way valve is opened, the inverted arch drainage device is connected to the central drainage ditch.

2. The device for treating floor heave in water-rich soft surrounding rock tunnel according to claim 1 is characterized in that: The plurality of prestressed anchor cables are arranged at the center of the inverted arch and at the arch foot of the inverted arch.

3. The device for treating floor heave in water-rich soft surrounding rock tunnel according to claim 1 is characterized in that: The prestressed anchor cable comprises a grouting pipe and a plurality of unbonded steel strands arranged circumferentially along the grouting pipe. The lower ends of the unbonded steel strands and the grouting pipe are located in the rock mass, and the upper ends of the unbonded steel strands and the grouting pipe are connected to the arc-shaped steel frame of the invert arch through anchors.

4. The device for treating floor heave in water-rich soft surrounding rock tunnel according to claim 3 is characterized in that: A section of the non-bonded steel strand close to the arc-shaped steel frame is an anchoring section, and a section close to the rock mass is a free end. A protective layer is sleeved on the free end of the non-bonded steel strand.

5. The device for treating floor heave in water-rich soft surrounding rock tunnel according to claim 1 is characterized in that: The upper end of the inverted arch drainage device is connected to the transverse drainage pipe of the tunnel, and the transverse drainage pipe is communicated with the central drainage ditch.

6. The device for treating floor heave in water-rich soft surrounding rock tunnel according to claim 5 is characterized in that: The inverted arch drainage device comprises a plurality of drainage devices, which are symmetrically arranged along the longitudinal center of the tunnel, and the upper ends of the drainage devices are connected to the transverse drainage pipes.

7. The device for treating floor heave in water-rich soft surrounding rock tunnel according to claim 6 is characterized in that: The drainage device comprises a pressure reducing pipe, the lower end of which extends into the rock mass, a one-way valve is fixed in the pressure reducing pipe, and the upper end of the pressure reducing pipe is communicated with the horizontal drainage pipe.

8. A device for treating floor heave in a water-rich soft surrounding rock tunnel according to any one of claims 1 to 7, characterized in that: The one-way valve comprises a valve plate, a waterproof rubber gasket and a support frame; The support frame is arranged in the pressure reducing pipe, the waterproof rubber gasket is located on the top of the support frame and is close to the pipe wall of the pressure reducing pipe, the center of the valve plate is connected to the support frame, and the edge of the valve plate covers the waterproof rubber gasket.

9. The device for treating floor heave in water-rich soft surrounding rock tunnel according to claim 8 is characterized in that: The valve plate is a rubber valve plate, the thickness of which decreases gradually from the center to the edge. The center of the valve plate is connected to the center of the support frame, and the edge of the valve plate is covered on a waterproof rubber gasket.

10. A device for treating floor heave in a water-rich soft surrounding rock tunnel according to any one of claims 1 to 7, characterized in that: The one-way valve comprises a valve plate, a pressure ball and a spring; The valve plate includes two semicircular paddles, the straight edges of the two paddles are rotatably connected, the center of the valve plate is connected to the center of the support frame, the support frame is fixed in the pressure reducing tube, the pressure ball is arranged at the center of the valve plate, a fixing frame is arranged on the top of the pressure ball, the fixing frame is connected to the tube wall of the pressure reducing tube, a spring is arranged between the fixing frame and the pressure ball, the upper end of the spring is connected to the fixing frame, the lower end of the spring is connected to the pressure ball, and a hollow area is arranged on the fixing frame.

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