An experimental device and experimental system for simulating grouting plugging of leakage cavities

Abstract

The present invention discloses an experimental device and an experimental system for simulating the grouting plugging of leakage cavities, comprising a collection system, a water injection system, and a grouting system that are respectively connected to an overflow hole, a water injection hole, and grouting 1 of a box body; the water injection system includes: a water tank with a certain height connected through the water injection hole, one pipe orifice of the water tank is connected to a water storage tank through a water pump, and the other pipe orifice of the water tank is connected to a water inlet through an overflow pipe; the grouting system includes: a screw grouting pump connected through a grouting hole, and the screw grouting pump is connected to a grouting material storage tank; the collection system includes: a water outlet tank connected through the overflow hole. The present invention uses a triangular area to simulate the leakage cavity area, which is most fitting to the actual project, and realizes visual grouting while meeting the required strength.

Description

Technical Field

[0001] The present invention relates to the field of shield tunnel construction, and in particular to an experimental device and an experimental system for simulating the grouting plugging of leakage cavities. Background Art

[0002] In recent years, with the economic development of our country, rail transit has gradually become popular. In cities, the subway is the most common rail transit. When constructing subway tunnels, the shield method has the advantages of having little impact on the environment, not affecting surface traffic, having little impact on the residents near the construction, and relatively low cost, and is deeply favored by the engineering field. However, during the construction and use of shield tunnels, leakage phenomena may occur at the joints of the segments. Near the leakage points, groundwater will flow into the tunnel interior, and fine particles in the soil around the segments will be carried out. Gradually, the silt and fine sand strata outside the tunnel will be hollowed out, forming a large cavity area, which will cause changes in the stress of the segments, and disasters such as the segments opening and staggering will occur. In severe cases, continuous collapses and large-scale surface settlements will be caused. Therefore, when leakage occurs and cavities are formed, rapid emergency repair and plugging are particularly important.

[0003] However, since most of the cavity grouting plugging is carried out by injecting grouting pipes through the ground or post-grouting behind the segment wall, after the slurry flows out underground, it is impossible to directly observe the plugging mechanism when the slurry takes effect, and in some cases, when the slurry fails to plug the cavity, it is also impossible to directly observe the cause of failure. Therefore, there is an urgent need for an experimental device that can realize visual grouting plugging of leakage cavities and contribute to the research of grouting theory. Summary of the Invention

[0004] In order to solve the above problems in the prior art, the present invention provides an experimental device and an experimental system for simulating the grouting plugging of leakage cavities to solve the problem that the grouting process in actual grouting projects is visible and overcome the problem that the grouting plan mainly relies on experience and lacks theoretical guidance.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] An experimental device for simulating the grouting plugging of leakage cavities is composed of a box body. The box body includes a square upper top box 1 with a water overflow hole 3 provided on the side. The lower end of the upper top box 1 is connected to an inverted triangular chamber 5 with a fixed top plate 4 through horizontal bars 2 respectively provided on the left and right sides. A rectangular notch 7 for water flow is provided in the middle of the fixed top plate 4. On the lower end surface of the fixed top plate 4, two simulation top plates 6 for simulating the segment opening are provided. The gap between the openings of the simulation top plates 6 is 0.5 - 2 mm. The inverted triangular chamber 5 is fixed in the box body of a bottom box 9 containing a water injection hole 8 through the fixed top plate 4.

[0007] A water passing hole 10 is provided on the chamber wall of the triangular chamber 5.

[0008] The bottom box 9 is provided with a grouting hole 11 on the side wall communicating with the triangular chamber 5.

[0009] Another technical solution of the present invention is:

[0010] An experimental system including an experimental device for simulating grouting plugging of leakage cavities, comprising a collection system, a water injection system, and a grouting system that are interconnected with an overflow hole 3, a water injection hole 8, and a grouting hole 11 respectively provided on a box body; the water injection system includes: a water tank 12 with a certain height connected through the water injection hole 8, one pipe orifice of the water tank 12 is connected to a water storage tank 14 through a water pump 13, and the other pipe orifice of the water tank 12 is connected to a water inlet 16 through an overflow pipe 15; the grouting system includes: a screw grouting pump 17 connected through the grouting hole 11, and the screw grouting pump 17 is connected to a grouting material storage tank 18; the collection system includes: an outlet water tank 19 connected through the overflow hole 3.

[0011] A flow meter 20, a water meter 21, and a valve 22 are sequentially connected between the water injection hole 8 and the water tank 12.

[0012] A flow meter 20 is connected between the overflow hole 3 and the outlet water tank.

[0013] The grouting hole 2 is connected to two screw grouting pumps 17 respectively through a tee joint.

[0014] The beneficial effects of the present invention are:

[0015] When conducting experiments with the present invention, the water pressure can be conveniently adjusted by adjusting the water tank with a certain height; by replacing the top plate with different simulated segment slits, the slit size can be changed to simulate grouting plugging under different working conditions; during the experiment, water is added to the water tank through a water pump, and the overflow pipe can prevent water from overflowing after the water tank is filled; after the water addition is completed, water is injected into the box body through the water injection hole, and the water passes through the triangular chamber, the bottom plate, and the top plate and enters the top box, and then overflows from the overflow hole into the outlet water tank. The water in the outlet water tank in the collection system can also flow back to the water storage tank through the water inlet; after the water flow is stable, the grouting experiment can be started, and the water flow rate and the grouting rate can be accurately recorded through the flow meter during water injection and grouting. According to actual engineering experience, the experimental device uses a triangular area to simulate the leakage cavity area, which is most fitted to the actual project. Most of the entire device is made of plexiglass, which can achieve visual grouting while meeting the required strength, and the entire process of the slurry solidifying and plugging the leakage cavity can be clearly observed. Description of the Drawings

[0016] Figure 1 is a schematic diagram of the overall structure of the experimental system of the present invention;

[0017] Figure 2It is a schematic diagram of the box structure of the present invention;

[0018] Figure 3 is Figure 2 a schematic diagram of the upper top box structure in the middle;

[0019] Figure 4 is Figure 2 a three-dimensional structure schematic diagram of the inverted triangular chamber in the middle;

[0020] Figure 5 is Figure 4 a side view structure schematic diagram of the inverted triangular chamber in the middle;

[0021] Figure 6 is Figure 2 a schematic diagram of the bottom box structure in the middle.

[0022] Reference numerals in the drawings: upper top box 1; cross bar 2; overflow hole 3; fixed top plate 4; inverted triangular chamber 5; simulation top plate 6; rectangular notch 7; water injection hole 8; bottom box 9; water passing hole 10; grouting hole 11; water tank 12; water pump 13; water storage tank 14; overflow pipe 15; water inlet 16; screw grouting pump 17; grouting material storage tank 18; water outlet tank 19; flow meter 20; water meter 21; valve 22. Specific embodiments

[0023] The following will further describe the present invention in conjunction with the accompanying drawings:

[0024] As Figure 1-6 shown, an experimental device for simulating the grouting plugging of leakage cavities is composed of a box body. The main materials of this box body are made of plexiglass and angle iron. The box body includes a square upper top box 1 with an overflow hole 3 on the side. The lower end of the upper top box 1 is connected to an inverted triangular chamber 5 with a fixed top plate 4 through cross bars 2 respectively arranged on the left and right sides. According to the actual situation of the project, the shape of the cavity left after water and sand leakage in the shield tunnel fits the triangle most closely. Therefore, the present invention simplifies the leakage cavity into an inverted triangular chamber for simulation experiments. Water passing holes 10 are distributed on the cavity wall of the inverted triangular chamber 5 for water penetration; a rectangular notch 7 for water flow is arranged in the middle of the fixed top plate 4. On the lower end face of the fixed top plate 4, two simulation top plates 6 for simulating the opening of the segment are arranged. The two simulation top plates 6 can be replaced to simulate the size of the segment opening under different working conditions. The distance between the openings is between 0.5 - 2 mm. In this embodiment, the distances that can be replaced are 0.5 mm, 1 mm, 1.5 mm, and 2 mm, which can be arbitrarily selected; the inverted triangular chamber 5 of the present invention is fixed in the box body of the bottom box 9 containing a water injection hole 8 through the fixed top plate 4. The bottom box 9 is also provided with a grouting hole 11 on the side wall communicating with the triangular chamber 5. Since the bottom box 9 of the present invention is composed of plexiglass and angle iron, in order to prevent the device from being damaged due to high water head or expansion of the grouting material during the experiment, supports are added to its glass.

[0025] The experimental system of an experimental device for simulating grouting plugging of leakage cavities in the present invention includes a collection system, a water injection system, and a grouting system that are interconnected with an overflow hole 3, a water injection hole 8, and a grouting hole 11 respectively provided on a box body; the water injection system includes: a water tank 12 with a certain height connected through the water injection hole 8. During the experiment, the water pressure can be adjusted by adjusting the height of the water tank 12. In this embodiment, a flow meter 20, a water meter 21, and a valve 22 are sequentially connected between the water injection hole 8 and the water tank 12; one pipe orifice of the water tank 12 is connected to a water storage tank 14 through a water pump 13, and the other pipe orifice of the water tank 12 is connected to a water inlet 16 through an overflow pipe 15. The overflow pipe 15 can prevent water from overflowing after the water tank is filled with water; the grouting system includes: a screw grouting pump 17 connected through the grouting hole 11. In the present invention, the grouting hole 11 is connected to two screw grouting pumps 17 respectively through a tee joint, and the screw grouting pump 17 is connected to a grouting material storage tank 18; the collection system includes: an out water tank 19 connected through the overflow hole 3, and a flow meter 20 is connected between the overflow hole 3 and the out water tank.

[0026] The experimental steps of the present invention are as follows:

[0027] Connect the water injection hole of the box body to the water tank in the water injection system, connect the grouting hole to two grouting pumps in the grouting system through a tee joint, and connect the overflow hole to the out water tank in the collection system. The grouting system consists of two screw grouting pumps, and the water injection system consists of a water storage tank, a water tank lifted by a crane, a water pump, and an overflow pipe. During the experiment, the water pressure can be adjusted by adjusting the height of the lifted water tank, and different working conditions of grouting and plugging can be simulated by replacing the top plates with different slit sizes. During the experiment, water is added to the lifted water tank through the water pump, and the overflow pipe can prevent water from overflowing after the water tank is filled with water. After the water addition is completed, water is injected into the box body through the water injection hole. The water passes through the inverted triangular chamber, the simulated top plate, and the fixed top plate and enters the upper top box, and then overflows through the overflow hole into the out water tank. The water in the out water tank in the collection system can also flow back to the water storage tank through the water inlet. After the water flow is stable, the grouting experiment can be started. The water flow rate and the grouting rate are recorded by a flow meter during water injection and grouting.

Claims

1. An experimental device for simulating the grouting plugging of leakage cavities, characterized in that: It is composed of a box body, and the box body includes a square upper top box (1) with an overflow hole (3) provided on the side. The lower end of the upper top box (1) is connected to an inverted triangular chamber (5) with a fixed top plate (4) through cross bars (2) respectively provided on the left and right sides. A rectangular notch (7) for water flow to pass through is provided in the middle of the fixed top plate (4). On the lower end face of the fixed top plate (4), two simulation top plates (6) for simulating the slits of the segment are provided. The slit spacing of the simulation top plates (6) is 0.5 - 2 mm. The inverted triangular chamber (5) is fixed in the box body of a bottom box (9) containing a water injection hole (8) through the fixed top plate (4); water passing holes (10) are provided on the chamber wall of the inverted triangular chamber (5); a grouting hole (11) is provided on the side wall of the bottom box (9) communicating with the inverted triangular chamber (5).

2. An experimental system comprising the experimental device for simulating grouting plugging of leakage cavities as described in claim 1, characterized in that: It includes a collection system, a water injection system, and a grouting system that are respectively connected to the overflow hole (3), the water injection hole (8), and the grouting hole (11) provided separately from the box body; the water injection system includes: a water tank (12) with a certain height connected through the water injection hole (8). One pipe orifice of the water tank (12) is connected to a water storage tank (14) through a water pump (13), and the other pipe orifice of the water tank (12) is connected to an inlet (16) through an overflow pipe (15); the grouting system includes: a screw grouting pump (17) connected through the grouting hole (11), and the screw grouting pump (17) is connected to a grouting material storage tank (18); the collection system includes: a water outlet tank (19) connected through the overflow hole (3).

3. An experimental system comprising the experimental device for simulating grouting plugging of leakage cavities according to claim 1 as claimed in claim 2, characterized in that: A flow meter (20), a water meter (21), and a valve (22) are sequentially connected between the water injection hole (8) and the water tank (12).

4. An experimental system comprising the experimental device for simulating grouting plugging of leakage cavities according to claim 1 as claimed in claim 2, characterized in that: A flow meter (20) is connected between the overflow hole (3) and the water outlet tank (19).

5. An experimental system comprising the experimental device for simulating grouting plugging of leakage cavities according to claim 1 as claimed in claim 2, characterized in that: The grouting hole (11) is connected to two screw grouting pumps (17) respectively through a tee joint.

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