A synchronous grouting test system and method for a shield

Abstract

The present application relates to the technical field of shield engineering, and particularly relates to a synchronous grouting test system and test method for shield, which comprises a soil box, a synchronous grouting ring and a pipe joint are sequentially embedded in the soil box; a pipe joint bearing table is arranged at a position close to a front tunnel door, a counterforce frame is arranged outside the pipe joint bearing table, a jacking oil cylinder is arranged on the counterforce frame, and a flow divider is arranged at one end of the synchronous grouting ring; a pushing oil cylinder is arranged at the front tunnel door, the pushing oil cylinder drives the synchronous grouting ring to move forward, and a building gap is formed between the pipe joint and the transparent soil; the flow divider can distribute grouting liquid to each grouting point on the synchronous grouting ring, and further inject the grouting liquid into the building gap, so that the synchronous grouting process of the shield is simulated. By using the test device, the synchronous grouting parameter optimization control method, the flow trajectories of different types of grouting liquid in the grouting process, the setting time, the influence of grouting points and grouting parameters on the flow trajectories and the setting time of the grouting liquid, and the mechanism and control measures of the pipe piece floating can be studied.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel engineering, in particular to a shield synchronous grouting test system and a test method. BACKGROUND

[0002] The shield tail synchronous grouting is performed simultaneously with the shield tunneling, and is used for filling the gap between the outer wall of the segment and the excavated soil body. The grouting pressure and the grouting amount are two important control parameters of the synchronous grouting. For the construction of the super-large diameter slurry shield, after the segment is separated from the tail of the shield machine, the ringed segment is wrapped in the grouting slurry, and under the combined action of the grouting slurry buoyancy, the shield thrust and the like, the segment structure is prone to floating. The segment floating will lead to the misalignment between the segments and even damage the segment connection structure, thereby affecting the tunnel construction quality. At present, the parameters of the synchronous grouting and the mechanism of the segment floating are mainly researched by using the theoretical calculation or numerical simulation, and it is difficult to comprehensively consider the actual environment of the segment and the influence of the complex acting force. SUMMARY

[0003] In order to solve the above technical problems, the present application specifically adopts the following technical solutions.

[0004] A shield synchronous grouting test system is designed, which comprises a soil box, a circular front portal and a rear portal are respectively arranged at the front and rear ends of the soil box, a synchronous grouting ring is arranged in the soil box, one end of the synchronous grouting ring is fixed at the front portal, and the other end of the synchronous grouting ring extends out of the rear portal and is provided with a flow divider;

[0005] A fixing ring is arranged outside the front portal, a pipe joint is embedded in the synchronous grouting ring, one end of the pipe joint is arranged on the front portal through the fixing ring, and the other end of the pipe joint is inserted into the synchronous grouting ring;

[0006] A support plate is arranged on the fixing ring, a pushing oil cylinder is arranged on the support plate, one end of the pushing oil cylinder penetrates into the synchronous grouting ring, and the telescopic end of the pushing oil cylinder is connected with one end of the synchronous grouting ring where the flow divider is arranged;

[0007] A pipe joint bearing table is arranged near the front portal, a counterforce frame is arranged outside the pipe joint bearing table, a jacking oil cylinder is arranged on the counterforce frame, and a top plate is connected with the telescopic end of the jacking oil cylinder.

[0008] Preferably, an arc-shaped plate is arranged at the bottom of the soil box near the front portal, guide rails are respectively arranged below the two sides of the rear portal, one end of the synchronous grouting ring is slidingly supported on the arc-shaped plate, and the other end of the synchronous grouting ring is slidingly arranged in the guide rails through a support frame.

[0009] Preferably, the flow divider comprises a housing arranged at one end of the synchronous grouting ring, a grouting inlet arranged on the housing, a plurality of three-way valves distributed along the circumference of the synchronous grouting ring, a plurality of grouting points arranged on the synchronous grouting ring, the grouting points being in communication with the inside of the pipe section, one inlet of the three-way valve being connected to the housing through a grouting pipe, and two outlets being communicated to the grouting points on the synchronous grouting ring through grouting pipes.

[0010] Preferably, the pipe section comprises a plurality of pipe segments connected end to end, an elastic pad being arranged between adjacent two pipe segments and being connected and fixed by a connecting bolt, and a plurality of pressure sensors being uniformly distributed along the circumferential direction of the inner wall of each pipe segment.

[0011] Preferably, transparent observation windows are arranged on the top and side walls of the soil tank, respectively.

[0012] Preferably, a sampling port is arranged on the top of the soil tank.

[0013] The application further relates to an experimental method of the shield synchronous grouting test system, and specifically comprises the following steps:

[0014] S1: filling the soil tank with transparent soil and sealing the tank;

[0015] S2: connecting a grouting pump to the grouting inlet, and adjusting the outlets of the three-way valves to select the grouting points according to the experimental requirements;

[0016] S3: controlling the advancing oil cylinder to extend at a set speed to drive the synchronous grouting ring to move forward, and injecting the grout at a given pressure and flow rate, the grouting amount and grouting pressure being cooperatively controlled by the control system according to the displacement amount of the advancing oil cylinder;

[0017] S4: continuously collecting the data of the pressure sensors, and observing and recording the grout diffusion;

[0018] S5: stopping the grouting after the synchronous grouting ring is advanced to a limited position, and taking samples through the sampling port to verify the grouting effect.

[0019] The application has the following beneficial effects:

[0020] 1. The transparent observation windows arranged on the top and rear sides of the soil tank, the filling of the transparent soil and the loading of the transparent soil can facilitate the observation of the grout diffusion.

[0021] 2. The advancing oil cylinder drives the synchronous grouting ring to move forward and backward, forming a building gap between the pipe section and the transparent soil, so that the synchronous grouting process of the shield is simulated; meanwhile, the advancing speed, the grouting pressure and the grouting amount are controlled, the grouting effect is observed, the relationship between the grouting parameters is studied, and the optimal grouting parameters are obtained.

[0022] 3. The application is characterized in that the elastic pad is arranged between two adjacent pipe sections, and the adjacent pipe sections are connected by connecting bolts, so that the elastic pad is compressed, thereby making the assembled pipe section flexible and capable of floating under the action of slurry buoyancy, and realizing the simulation of the pipe section floating process; and the pipe section adopts a detachable segmented structure, and the number of pipe sections can be increased or decreased according to specific requirements, so as to adjust the total length of the flexible pipe section and improve the use flexibility.

[0023] 4. The application is characterized in that the slurry is distributed to each grouting point on the synchronous grouting ring through the flow divider and the three-way valve, and the grouting point is switched and adjusted through the independently controllable three-way valve, so that the slurry is injected into the building gap, and the influence of the grouting point on the slurry flow trajectory and diffusion process can be studied. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic diagram of the overall structure of the application structure;

[0025] Figure 2 is a schematic diagram of the structure of the soil box in the application;

[0026] Figure 3 is a schematic diagram of the structure of the pipe section in the application;

[0027] Figure 4 is a schematic diagram of the structure of the flow divider in the application;

[0028] The figure is marked: 1 soil box, 1-1 front door, 1-2 rear door, 1-3 observation window, 1-4 sampling port, 1-5 arc plate, 2 pipe section, 2-1 pipe section, 2-2 elastic pad, 2-3 connecting bolt, 2-4 pressure sensor, 3 synchronous grouting ring, 4 flow divider, 4-1 grouting inlet, 4-2 shell, 4-3 grouting pipe, 4-4 three-way valve, 4-5 grouting outlet, 5 fixed ring, 6 support plate, 7 propelling oil cylinder, 8 pipe section bearing table, 9 counterforce frame, 10 jacking oil cylinder, 11 top plate, 12 guide rail. DETAILED DESCRIPTION

[0029] The preferred embodiments of the application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the application, and are not used to limit the application.

[0030] Example 1

[0031] A shield synchronous grouting test system, such as Figures 1 to 4As shown, including the soil tank 1, the front and rear ends of the soil tank 1 are respectively provided with circular front door 1-1 and rear door 1-2, and a synchronous grouting ring 3 is arranged in the soil tank 1, which is used to simulate the forward movement of the shield tail and the injection of the slurry during the synchronous grouting process. One end of the synchronous grouting ring 3 is fixed at the front door 1-1, and the other end extends out of the rear door 1-2 and is provided with a flow divider 4. The flow divider 4 includes a housing 4-2 arranged at one end of the synchronous grouting ring 3, a grout inlet 4-1 arranged on the housing 4-2, and a plurality of three-way valves 4-4 distributed along the circumference of the synchronous grouting ring 3. Each three-way valve 4-4 can be independently controlled to switch the grouting point position and realize the combination of different grouting point positions. A plurality of grouting points are arranged on the synchronous grouting ring 3 and are in communication with the inside of the pipe joint 2. One inlet of the three-way valve 4-4 is connected to the housing 4-2 through a grouting pipe 4-3, and two outlets are connected to the grouting points on the synchronous grouting ring 3 through a grout outlet pipe 4-5. After the slurry is injected into the housing 4-2 through the grout inlet 4-1, it is distributed to each grouting point on the synchronous grouting ring 3 through the grouting pipe 4-3 and the two outlets of the three-way valve 4-4, and then the delivered slurry is injected into the building gap.

[0032] A fixing ring 5 is arranged outside the front door 1-1, and a pipe joint 2 is embedded in the synchronous grouting ring 3 and is sealed therebetween. Specifically, an embedding groove can be formed on the inner wall of the tail of the synchronous grouting ring 3, and a sealing ring is embedded in the embedding groove to achieve a sealing effect, thereby preventing slurry leakage. One end of the pipe joint 2 is arranged on the front door 1-1 through the fixing ring 5, and the other end is inserted into the inside of the synchronous grouting ring 3 to simulate the assembled pipe segment ring.

[0033] The pipe joint 2 includes a plurality of pipe segments 2-1 connected end to end, and an elastic pad 2-2 is arranged between adjacent two pipe segments 2-1 and is connected and fixed by a connecting bolt 2-3. This combination can make the pipe joint 2 as a whole flexible, realize the simulation of the tunnel pipe segment floating, and can increase or decrease the length of the pipe joint 2 according to the experimental requirements. A plurality of pressure sensors 2-4 are uniformly distributed on the inner wall of each pipe segment 2-1 along the circumferential direction thereof, which are used to detect the change of the slurry pressure after grouting. An ultrasonic sensor can also be installed to detect the state of the slurry.

[0034] A pipe joint bearing table 8 is arranged near the front door 1-1, a counterforce frame 9 is arranged outside the pipe joint bearing table 8, a jacking oil cylinder 10 is arranged on the counterforce frame 9, and a top plate 11 is connected to the telescopic end of the jacking oil cylinder 10. After the pipe segments 2-1 are assembled and placed on the pipe joint bearing table 8, the pipe joint 2 is jacked into the inside of the synchronous grouting ring 3 by the jacking oil cylinder 10. The jacking oil cylinder 10 can be used to jack the pipe joint 2 into the synchronous grouting ring 3 once for each added pipe segment 2-1, and the pipe segments 2-1 can be jacked into the synchronous grouting ring 3 one by one according to the above method according to specific requirements.

[0035] The synchronous grouting ring 3 is coaxially arranged with the front tunnel door 1-1 and the rear tunnel door 1-2, an arc-shaped plate 1-5 is arranged at the bottom of the soil box 1 near the front tunnel door 1-1, guide rails 12 are arranged at the lower sides of the rear tunnel door 1-2, one end of the synchronous grouting ring 3 is slidingly supported on the arc-shaped plate 1-5, and the other end is slidingly arranged in the guide rail 12 through a support frame.

[0036] A support plate 6 is arranged on the fixing ring 5, a pushing oil cylinder 7 is arranged on the support plate 6, one end of the pushing oil cylinder 7 is arranged in the synchronous grouting ring 3, and the telescopic end of the pushing oil cylinder 7 is connected with one end of the synchronous grouting ring 3 in which the shunt 4 is arranged; when the telescopic end of the pushing oil cylinder 7 is extended, the synchronous grouting ring 3 is driven to move forward along the guide rail 12, and a building gap is formed between the pipe section 2 and the transparent soil.

[0037] Transparent observation windows 1-3 are arranged on the top and the side wall of the soil box 1.

[0038] A sampling port 1-4 is arranged on the top of the soil box 1, which can be used to extract patterns after the experiment.

[0039] The working mode of the present application is as follows: firstly, the synchronous grouting ring 3 is inserted into the soil box 1, and one end is supported on the arc-shaped plate 1-5, and the bottom of the other end is slidingly supported on the guide rail 12 through a support frame, then the pipe section 2 is assembled and placed on the pipe section bearing table 8, the telescopic end of the jacking oil cylinder 10 is controlled to be extended, the top plate 11 is driven to push the pipe section 2, the pipe section 2 is jacked into the inside of the synchronous grouting ring 3, and the above mode is used to jack the pipe section 2 into the inside of the synchronous grouting ring 3 in sequence, after the pipe section 2 is jacked in, the one end of the pipe section 2 is fixed at the front tunnel door 1-1 by the joint fixing ring 5, then the one end of the pushing oil cylinder 7 is fixed on the support plate 6, the other end is arranged in the synchronous grouting ring 3, and the telescopic end is connected with one end in the synchronous grouting ring 3, for driving the synchronous grouting ring 3 to move forward along the guide rail 12, and forming a building gap between the pipe section 2 and the transparent soil, finally, the transparent soil is densely filled in the soil box 1 and the box body is sealed, and the transparent soil can facilitate the observation of the diffusion of the slurry.

[0040] Example 2:

[0041] An experimental method of a shield synchronous grouting test system, comprising the following steps:

[0042] S1: connecting the grouting pump at the grouting inlet 4-1, adjusting the outlet of the three-way valve 4-4 to select the grouting point according to the experimental requirements;

[0043] S2: controlling the pushing oil cylinder 7 to extend at a set speed, driving the synchronous grouting ring 3 to move forward, and injecting the slurry at a given pressure and flow rate, the grouting amount and the grouting pressure being cooperatively controlled by the control system according to the displacement amount of the pushing oil cylinder 7;

[0044] S3: continuously collecting the data of the pressure sensor 2-4, observing and recording the diffusion of the slurry;

[0045] S4: After pushing the synchronous grouting ring 3 to the defined position, stop grouting and take samples through the sampling ports 1-4 to check the grouting effect.

[0046] Finally, it should be noted that the above only for the preferred embodiments of the present application, and is not intended to limit the application, although the foregoing embodiments of the application were described in detail, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement of the technical solutions described in the foregoing embodiments; any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application, should be included within the scope of the present application.

Claims

1. A shield tunneling synchronous grouting test system, comprising a soil box (1), wherein circular front openings (1-1) and rear openings (1-2) are respectively provided at the front and rear ends of the soil box (1), characterized in that, A synchronous grouting ring (3) is provided inside the soil box (1). One end of the synchronous grouting ring (3) is fixed at the front portal (1-1), and the other end extends out of the rear portal (1-2) and is provided with a diverter (4). A fixing ring (5) is provided on the outside of the front portal (1-1), and a pipe section (2) is embedded in the synchronous grouting ring (3). One end of the pipe section (2) is set on the front portal (1-1) through the fixing ring (5), and the other end is inserted into the synchronous grouting ring (3). A support plate (6) is provided on the fixed ring (5), and a propulsion cylinder (7) is provided on the support plate (6). One end of the propulsion cylinder (7) is inserted into the synchronous grouting ring (3), and its telescopic end is connected to one end of the synchronous grouting ring (3) on which the diverter (4) is installed. A pipe section support platform (8) is provided near the front opening (1-1). A reaction frame (9) is provided on the outside of the pipe section support platform (8). A jacking cylinder (10) is provided on the reaction frame (9). A top plate (11) is connected to the telescopic end of the jacking cylinder (10). An arc-shaped plate (1-5) is provided at the bottom of the soil box (1) near the front door (1-1), and guide rails (12) are provided on both sides below the rear door (1-2). One end of the synchronous grouting ring (3) is slidably supported on the arc-shaped plate (1-5), and the other end is slidably set in the guide rail (12) through the support frame. The diverter (4) includes a housing (4-2) at one end of the synchronous grouting ring (3), a grout inlet (4-1) on the housing (4-2), and multiple three-way valves (4-4) distributed around the circumference of the synchronous grouting ring (3). Multiple grouting points are provided on the synchronous grouting ring (3). The grouting points are connected to the interior of the pipe section (2). One inlet of the three-way valve (4-4) is connected to the housing (4-2) through the grouting pipe (4-3), and the two outlets are connected to the grouting points on the synchronous grouting ring (3) through the grouting pipe (4-5).

2. The shield tunneling synchronous grouting test system as described in claim 1, characterized in that: The pipe section (2) includes multiple pipe segments (2-1) connected end to end. An elastic pad (2-2) is provided between two adjacent pipe segments (2-1) and they are connected and fixed by connecting bolts (2-3). Multiple pressure sensors (2-4) are evenly distributed along the circumference on the inner wall of each pipe segment (2-1).

3. The shield tunneling synchronous grouting test system as described in claim 1 or 2, characterized in that: Transparent observation windows (1-3) are provided on the top and side walls of the soil box (1).

4. The shield tunneling synchronous grouting test system as described in claim 3, characterized in that: Sampling ports (1-4) are provided on the top of the soil box (1).

5. The test method using the shield tunneling synchronous grouting test system according to claim 4, characterized in that: Includes the following steps: S1: Connect the grouting pump at the grout inlet (4-1), and adjust the outlet of the three-way valve (4-4) according to the test requirements to select the grouting point; S2: Control the propulsion cylinder (7) to extend at a set speed, drive the synchronous grouting ring (3) to move forward, and inject grout at a given pressure and flow rate. The grouting volume and grouting pressure are controlled by the control system according to the displacement of the propulsion cylinder (7). S3: Continuously collect data from pressure sensors (2-4), observe and record the slurry diffusion; S4: After advancing the synchronous grouting ring (3) to the specified position, stop grouting and take samples through the sampling port (1-4) to check the grouting effect.

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