Vertical Jacking Pipe Simulation Device and Method

Abstract

The present invention relates to a vertical pipe jacking simulation device and method. The purpose of the present invention is to provide a vertical pipe jacking simulation device and method with a simple structure and convenient operation, so as to better serve actual projects and provide data reference for actual projects. The technical solution of the present invention is: a vertical pipe jacking simulation device, characterized in that: it has a base and a model box placed on the base. A closable box opening is provided at the central position of the bottom of the model box. A horizontal tunnel model is arranged inside the model box and is fixed to the bottom of the model box along the axis of the bottom of the model box. A closable tunnel opening is provided on the horizontal tunnel model corresponding to the box opening below it. The model box is filled and tamped with sand and covers the horizontal tunnel model. A vertical pipe jacking mechanism is provided below the model box corresponding to the box opening and the tunnel opening. The present invention is applicable to the research on the key technologies of vertical pipe jacking in shield tunneling urban utility tunnels.

Description

Technical Field

[0001] The present invention relates to a vertical pipe jacking simulation device and method, which is applicable to the research on the key technologies of vertical pipe jacking in shield - method urban utility tunnels. Background Art

[0002] An underground utility tunnel is a tunnel space built underground in a city. This space integrates various engineering pipelines such as electricity, communication, gas, heating, water supply and drainage, and is equipped with special inspection openings, hoisting openings and corresponding monitoring systems, implementing unified planning, unified design, unified construction and unified management. It is an important infrastructure and "lifeline" for ensuring the operation of the city.

[0003] In the construction of urban utility tunnels, the construction of vertical shafts is often a key project. With the diversified development of current underground space construction technologies, the technology of tunneling from underground to the ground is becoming more and more popular, and the vertical pipe jacking method is a technology born in response to this era's demand.

[0004] Similar technologies include the vertical jacking method, the upward - tunneling shield method and the horizontal pipe jacking method. Among them, the vertical jacking method is mainly used in the intake and drainage pipeline projects along the coast and rivers, and has high requirements for soil properties. The upward - tunneling shield method has a large diameter and is not suitable for shaft construction. Most of the traditional shaft construction uses the open - cut method, but there are disadvantages such as disturbing the urban environment and difficult excavation in some areas.

[0005] In summary, the existing vertical pipe jacking technology is still in the research and exploration stage, and the construction technology is not yet mature. Existing similar technologies have problems such as difficult excavation, high requirements for soil properties, and not meeting the requirements of shaft construction, and there is an urgent need to solve these problems by improving the technology. Summary of the Invention

[0006] The technical problem to be solved by the present invention is: aiming at the above - mentioned problems, to provide a vertical pipe jacking simulation device and method with simple structure and convenient operation, so as to better serve the actual project and provide data reference for the actual project.

[0007] The technical solution adopted by the present invention is: a vertical pipe jacking simulation device, characterized in that: it has a base and a model box placed on the base. A closable box opening is provided at the central position of the bottom of the model box. A horizontal tunnel model is arranged in the model box and is fixed along the axis of the bottom of the model box. A closable tunnel opening is provided on the horizontal tunnel model corresponding to the box opening below it. The model box is filled with compacted sand and covers the horizontal tunnel model. A vertical pipe jacking mechanism is provided below the model box corresponding to the box opening and the tunnel opening.

[0008] On the compacted sand surface, there are several displacement gauges for measuring the settlement of the soil mass, and on the inner wall of the horizontal tunnel model, there are several strain gauges for measuring the deformation of the horizontal tunnel model.

[0009] The vertical pipe jacking mechanism has a vertically arranged jack. The upper end of the jack is connected with a tubular pipe jacking body arranged coaxially therewith. The upper end of the pipe jacking body is provided with a tunneling head adapted to the pipe jacking body. The tunneling head is driven by a micro motor, and the micro motor is fixed on the inner wall of the pipe jacking body through a motor bracket.

[0010] The lower end of the pipe jacking body is connected with a body bottom plate. Inside the pipe jacking body and on the body bottom plate, there is a liquid bag. The upper end of the liquid bag is provided with a baffle plate adapted to the inner diameter of the pipe jacking body and capable of moving up and down in the pipe jacking body. The liquid bag is communicated with a measuring cup through a liquid pipe, and a solenoid valve and a flowmeter are connected to the liquid pipe.

[0011] The baffle plate is provided with an earth pressure cell.

[0012] On the piston rod of the jack, marks are made every 0.05 m along its axial direction with fluorescent materials.

[0013] The upper end of the main body of the micro motor is connected with a protection plate.

[0014] The horizontal tunnel model is a semi-cylindrical tunnel and is composed of several segment models.

[0015] The displacement gauge is fixed on the model box through a displacement gauge bracket, and the end of the displacement gauge is connected with the surface of the compacted sand through adhesive tape.

[0016] The model box is made of plexiglass.

[0017] A method for simulation using the vertical pipe jacking simulation device is characterized in that:

[0018] Tunneling simulation: Open the hole of the box body of the simulation box and the tunnel hole on the horizontal tunnel model, start the vertical pipe jacking mechanism, and jack the vertical pipe jacking mechanism into the soil mass at a certain speed. Stop jacking after jacking a certain depth.

[0019] Soil discharging simulation: After jacking a certain distance, open the solenoid valve connecting the liquid bag in the vertical pipe jacking mechanism, and release liquid to the same volume through the flowmeter to simulate the process of soil discharging.

[0020] Monitoring and observation: Observe and record the readings of the displacement gauges, strain gauges and earth pressure cells on the vertical pipe jacking mechanism during each jacking process, and observe the deformation of the soil mass during the tunneling process.

[0021] The beneficial effects of the present invention are:

[0022] 1) Relying on indoor model experiments, it can better simulate actual projects

[0023] In the present invention, the compacted sand in the model box simulates natural soil, the horizontal tunnel model simulates the shield method urban utility tunnel, and the vertical pipe jacking mechanism uses a micro-motor to drive the tunneling head to work, which can simulate the cutting of soil by a tunneling machine in actual projects. The cut soil can fall onto the baffle after passing through the tunneling head and the motor support. The baffle can move up and down in the fuselage. By opening the solenoid valve to release the calcium chloride solution in the liquid bladder, the process of soil discharge in actual projects can be simulated. When the device is installed and the jack is lifted, the vertical pipe jacking mechanism will move upward into the soil, thus realizing the simulation of the whole process of vertical pipe jacking tunneling.

[0024] 2) Install various measuring devices, with strong practicability

[0025] In the present invention, displacement gauges are connected to the soil surface to measure the soil settlement during the operation of vertical pipe jacking; strain gauges are pasted inside the horizontal tunnel model to measure the deformation of the horizontal tunnel during the operation of vertical pipe jacking; earth pressure cells are installed at the baffle to measure the earth pressure during the operation of vertical pipe jacking. At the same time, the jack can measure the jacking force, and the frictional force between the pipe jacking fuselage and the soil can be calculated.

[0026] 3) High economic benefits

[0027] The construction operation of the present invention is simple, without the need for large-scale mechanical equipment, the construction speed is fast, the construction period is greatly reduced, and the project cost can be reduced. Brief Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the overall structure of the embodiment.

[0029] Figure 2 It is a schematic diagram of the structure of the model box in the embodiment.

[0030] Figure 3 It is a schematic diagram of the structure of the horizontal tunnel model in the embodiment.

[0031] Figure 4 It is a schematic diagram of the structure of the vertical pipe jacking mechanism in the embodiment;

[0032] Figure 5 It is a schematic diagram of the structure of the tunneling head in the embodiment.

[0033] Figure 6 It is a schematic diagram of the structure of the micro-motor in the embodiment.

[0034] Figure 7 It is a schematic diagram of the structure of the motor support in the embodiment.

[0035] Figure 8 It is a top view of the displacement gauge support in the embodiment.

[0036] 1. Displacement gauge; 2. Displacement gauge support; 3. Model box; 4. Box opening; 5. Rammed sand; 6. Horizontal tunnel model; 601. Segment model; 7. Tunnel opening; 8. Boring head; 9. Micro motor; 10. Protection plate; 11. Motor support; 12. Baffle; 13. Earth pressure cell; 14. Liquid sac; 15. Jacking pipe body; 16. Body bottom plate; 17. Solenoid valve; 18. Flowmeter; 19. Liquid pipe; 20. Measuring cup; 21. Jack; 22. Base; 23. Strain gauge. Specific implementation manner

[0037] As Figure 1 shown, this embodiment is a vertical pipe jacking simulation device having a base 22 and a model box 3 placed on the base 22. The model box 3 is open at the upper end, and a closable box opening 4 is provided at the central position of the bottom. The model box is made of plexiglass (see Figure 2 ). In this example, a horizontal tunnel model 6 is arranged inside the model box 3, and the horizontal tunnel model 6 arranged along the central axis in the width direction of the model box 3 is fixedly arranged at the bottom of the model box 3. The horizontal tunnel model 6 is a semi-cylindrical tunnel and is composed of a number of segment models 601 (see Figure 3 ). Among them, a tunnel opening 7 corresponding to the box opening 4 in the segment model is opened, which is vertically corresponding and of the same size as the box opening 4. The model box 3 is filled with rammed sand 5 and covers the surface of the horizontal tunnel model 6, and the height of the covering layer is the same as the outer diameter of the horizontal tunnel model 6. In this example, a vertical pipe jacking mechanism is provided below the model box 3 corresponding to the box opening 4 of the model box 3, and tunneling simulation is carried out through the vertical pipe jacking mechanism.

[0038] As Figure 4 shown, in this embodiment, the vertical pipe jacking mechanism has a vertically arranged jack 21. The upper end of the jack 21 is connected with a tubular jacking pipe body 15. The sizes of the jacking pipe body 15 and the jack 21 are slightly smaller than the sizes of the box opening 4 and the tunnel opening 7. The lower end of the jacking pipe body 15 is blocked by the body bottom plate 16 and coaxially connected to the upper end of the jack 21 through the body bottom plate 16. The upper end of the jacking pipe body 15 is provided with a boring head 8 adapted to the jacking pipe body 15 (see Figure 5 ). The boring head 8 is driven by a micro motor 9. As Figure 6 shown, the upper end of the body of the micro motor 9 is connected with a protection plate 10. The protection plate 10 plays a role in protecting the body of the micro motor 9. The micro motor is fixed on the inner wall of the upper part of the jacking pipe body 15 through a motor support 11 (see Figure 7 ).

[0039] In this embodiment, a liquid bag 14 and a baffle 12 are arranged inside the pipe jacking body 15. The liquid bag 14 is located between the body bottom plate 16 and the motor support 11 and placed on the body bottom plate 16; the baffle 12 is placed at the upper end of the liquid bag 14. The shape and size of the baffle 12 are adapted to the inner diameter of the pipe jacking body 15 and can move up and down inside the pipe jacking body 15. In this example, the liquid bag 14 is processed according to the pipe jacking inner diameter and is filled with an aqueous solution inside. The liquid bag 14 is connected to a measuring cup 20 located below the pipe jacking body 15 through a liquid pipe 19. A solenoid valve 17 and a flowmeter 18 are connected to the liquid pipe 19.

[0040] In this embodiment, a displacement gauge support 2 is provided at the upper end of the model box 3. The displacement gauge support 2 is placed horizontally on the model box 3 and arranged along the central axis in the length direction of the model box 3. Both ends of the displacement gauge support 2 are fixedly connected to the model box 3. Seven fixing holes are evenly opened along the axial direction of the displacement gauge support 2, and a displacement gauge 1 is fixed corresponding to each fixing hole. The lower end of the displacement gauge 1 is connected to the surface of the tamped sand 5 through adhesive tape for measuring the soil settlement during the vertical pipe jacking process. In this embodiment, a number of strain gauges 23 are symmetrically pasted on the inner walls of the segment model with a tunnel opening 7 and its adjacent segment model 601 for measuring the horizontal tunnel deformation during the vertical pipe jacking process. In this embodiment, an earth pressure cell 13 is placed on the baffle 12 inside the pipe jacking body 15 to measure the earth pressure during the vertical pipe jacking process. At the same time, the jack 21 can measure the jacking force, and the frictional force between the pipe jacking body 15 and the soil can be calculated.

[0041] The installation method of this embodiment is as follows:

[0042] Place the model box 3 on the base 22, fix the horizontal tunnel model 6 at the bottom of the model box 3, and place the vertical pipe jacking mechanism directly below the box opening 4 of the model box 3;

[0043] Simulate the actual project, lay the tamped sand 5, and convey the sieved sand to the sand sprinkling device above the model box 3 through the conveying device. The sand is evenly poured into the model box 3 through the sand sprinkling device, and tamping is carried out every 5 cm, layer by layer until the specified height;

[0044] Apply lubricating oil inside the pipe jacking body 15 to reduce the frictional force between the inner pipe wall and the soil. The piston rod of the jack 21 is marked with fluorescent material every 0.05 m along its axial direction before working;

[0045] Paste the strain gauges 23 on the inner wall of the horizontal tunnel model 6; fix the displacement gauge support 2 on the top surface of the model box 3, and the displacement gauge 1 passes through the corresponding fixing hole on the displacement gauge support 2 and is fixed on the soil surface, and the end of the displacement gauge 1 is connected to the soil surface through adhesive tape; place the earth pressure cell 13 on the baffle 12 inside the pipe jacking body 15.

[0046] Disassembly and recycling of the vertical pipe jacking simulation device in this embodiment: After the jacking work is completed, the vertical pipe jacking mechanism, displacement meter 1, displacement meter bracket 2, compacted sand 5, horizontal tunnel model 6 and other components are promptly sorted and recycled. At the same time, the opening of the horizontal tunnel model 6 and the model box 3 are closed for use in the next project.

[0047] The simulation method of this embodiment is as follows:

[0048] Tunneling simulation: open the box opening 4 at the bottom of the simulation box and the tunnel opening 7 on the horizontal tunnel model 6, start the micro motor 9, make the tunneling machine head 8 perform cutting work, lift the jack 21, push the vertical jacking mechanism into the soil at a certain speed, and stop pushing at each fluorescent mark;

[0049] Soil discharge simulation: after each jacking distance, the electromagnetic valve 17 connected to the liquid bag 14 is opened, and the liquid is released to the same volume through the flow meter 18 (the jacking speed of the jacking pipe is provided by the jack, and the jacking speed of the jack can be controlled. At the same time, it is assumed that all the cut soil enters the inside of the jacking pipe. Since the inner diameter of the jacking pipe is known, the soil volume can be calculated after a certain distance of jacking. During the liquid discharge process, the electromagnetic flow meter can be used with an electromagnetic liquid valve to ensure it) to simulate the soil discharge process;

[0050] Monitoring and observation: Observe and record the readings of the displacement meter 1, strain gauge 23 and soil pressure box 13 during each jacking process, and observe the soil deformation during the excavation process.

Claims

1. A vertical pipe jacking simulation device, characterized in that: it has a base (22) and a model box (3) placed on the base (22). At the central position of the bottom of the model box (3), there is an openable and closable box opening (4). Inside the model box (3), there is a horizontal tunnel model (6). The horizontal tunnel model (6) is fixed to the bottom of the model box (3) along the axis of the bottom of the model box (3). An openable and closable tunnel opening (7) is provided on the horizontal tunnel model corresponding to the box opening (4) below it. The model box (3) is filled with compacted sand (5) and covered on the horizontal tunnel model (6). Below the model box (3), a vertical pipe jacking mechanism is provided corresponding to the box opening (4) and the tunnel opening (7); on the surface of the compacted sand (5), there are several displacement gauges (1) for measuring the settlement of the soil body, and on the inner wall of the horizontal tunnel model (6), there are several strain gauges (23) for measuring the deformation of the horizontal tunnel model (6); the vertical pipe jacking mechanism has a vertically arranged jack (21). The upper end of the jack (21) is connected with a tubular pipe jacking body (15) arranged coaxially with it. At the upper end of the pipe jacking body (15), there is a tunneling head (8) adapted to the pipe jacking body (15). The tunneling head (8) is driven by a micro motor (9), and the micro motor is fixed to the inner wall of the pipe jacking body (15) through a motor bracket (11); the lower end of the pipe jacking body (15) is connected with a body bottom plate (16). Inside the pipe jacking body (15) and on the body bottom plate (16), there is a liquid bag (14). At the upper end of the liquid bag (14), there is a baffle (12) adapted to the inner diameter of the pipe jacking body (15) and capable of moving up and down in the pipe jacking body (15). The liquid bag (14) is connected to a measuring cup (20) through a liquid pipe (19), and an electromagnetic valve (17) and a flowmeter (18) are connected to the liquid pipe (19); a soil pressure cell (13) is provided on the baffle (12); the horizontal tunnel model (6) is a semi-cylindrical tunnel and is composed of several segment models (601).

2. The vertical pipe jacking simulation device according to claim 1, characterized in that: on the piston rod of the jack (21), marks are made every 0.05 m along its axial direction with fluorescent material.

3. The vertical pipe jacking simulation device according to claim 1, characterized in that: a protection plate (10) is connected to the upper end of the main body of the micro motor (9).

4. The vertical pipe jacking simulation device according to claim 1, characterized in that: the displacement gauge (1) is fixed to the model box (3) through a displacement gauge bracket (2), and the end of the displacement gauge is connected to the surface of the compacted sand (5) through adhesive tape.

5. The vertical pipe jacking simulation device according to claim 1, characterized in that: the model box (3) is made of plexiglass.

6. A method for simulation using the vertical pipe jacking simulation device according to any one of claims 1 to 5, characterized in that: Driving simulation: Open the box opening (4) of the simulation box and the tunnel opening (7) on the horizontal tunnel model (6), start the vertical pipe jacking mechanism, and jack the vertical pipe jacking mechanism into the soil at a certain speed. Stop jacking after jacking a certain depth each time; Soil discharge simulation: Open the solenoid valve (17) connecting the liquid bladder (14) inside the vertical pipe jacking mechanism every time a certain distance is jacked, and release liquid through the flowmeter (18) to the same volume to simulate the soil discharge process; Monitoring and observation: Observe and record the readings of the displacement meter (1), strain gauge (23), and soil pressure cell (13) on the vertical pipe jacking mechanism during each jacking process, and observe the soil deformation during the driving process.

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