CN116448755A - Slurry shield rock slag migration condition test device and method - Google Patents

Abstract

The invention relates to a slurry shield rock slag migration condition test device and a slurry shield rock slag migration condition test method, wherein a shield machine model is included, one side of a cutter disc of the shield machine model is provided with a slurry bin, the other side of the cutter disc of the shield machine model is provided with a cutting space, the slurry bin is connected with an air pressure source, the cutting space is connected with a rock slag injection mechanism, the slurry bin is communicated with a slurry injection pipe group, the slurry injection pipe group is connected with a slurry storage tank through a slurry conveying pipe, the slurry conveying pipe is provided with a first slurry pump, the slurry bin is communicated with one end of a slurry discharging pipe, the other end of the slurry discharging pipe is connected with a slurry discarding tank, the slurry discharging pipe is provided with a second slurry pump, a plurality of switching pipes are arranged between the slurry conveying pipe and the slurry discharging pipe, and switching valves are arranged on the switching pipes to simulate different conveying states of the slurry shield, and the test device provided by the invention realizes rock slag migration condition study of simulating different conveying states and conveying switching states.

Description

A test device and method for muddy water shield rock slag migration

technical field

The invention relates to the technical field of underground engineering tests, in particular to a test device and method for muddy water shield rock slag migration.

Background technique

The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

When the mud-water shield is excavating certain strata (the stratum contains gravel, pebbles, boulders, etc.), the muck cut by the cutter head will be accompanied by rock slag, which will reduce the slag-carrying ability of the mud, and even the rock slag will be deposited in the Sludge tank and slurry discharge pipe. This seriously affects the mud circulation of the mud-water shield, which makes the removal of muck difficult and reduces the efficiency of tunnel construction. In addition, the poor migration and deposition of rock slag will lead to abnormal pressure in the mud tank, which will seriously affect the stability of the excavation surface and cause damage to the shield machine, which brings great safety hazards to the project. Therefore, the research on the migration of slag in mud-water shield will provide reference for the deployment of formation-adaptive mud, which is a prerequisite for improving the slag-carrying capacity of mud and ensuring safe and efficient tunnel construction.

When the mud-water shield is excavating certain strata (the stratum contains gravel, pebbles, boulders, etc.), the rock slag in the cut muck will be deposited in the mud-water tank and the slurry discharge pipe, which will seriously affect the mud circulation of the mud-water shield, making Poor removal of slag reduces the efficiency of tunnel construction. In addition, during the excavation process of the mud-water shield, the strata are often complex and changeable, and the conveying state of the mud-water shield will also be switched and adjusted. The poor migration and sedimentation of rock slag under different conveying conditions of the slurry shield will lead to abnormal pressure in the slurry tank, which will seriously affect the stability of the excavation surface and cause damage to the shield machine, which will bring great safety hazards to the project . Therefore, the study of the different conveying states of the mud-water shield and the migration of rock slag when the conveying state is switched will provide a reference for the deployment of stratum-adaptive mud and the adjustment of the excavation state of the shield, which is a prerequisite for ensuring safe and efficient tunnel construction.

The patent application CN115219385A discloses a simulation test device for the mud flow state of the excavation face of the mud-water shield, and the penetration characteristics of the mud in the excavation face are studied by the particle tracer method, but the inventor finds that the technical scheme of the above-mentioned patent application cannot simulate the flow state of the rock. The migration of slag in the whole mud-water cycle, and the migration of rock slag when the mud-water shield is in different conveying states and when the conveying state is switched cannot be simulated.

Contents of the invention

In view of the deficiencies in the prior art, the object of the present invention is to provide a muddy water shield rock slag migration test device, which can simulate the rock slag migration in different conveying states of the muddy water shield and when the conveying state is switched.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

In the first aspect, the embodiment of the present invention provides a muddy water shield rock slag migration test device, including a shield machine model, one side of the shield machine model cutter head is a muddy water warehouse, and the other side is a cutting space, and the muddy water The chamber is connected with an air pressure source, the cutting space is connected with a slag injection mechanism, the mud water chamber is connected with the mud injection pipe group, the mud injection pipe group is connected with the slurry storage tank through the slurry delivery pipe, the slurry delivery pipe is installed with the first mud pump, and the mud water chamber It is connected to one end of the slurry discharge pipe, and the other end of the slurry discharge pipe is connected to the discarded slurry tank. The slurry discharge pipe is provided with a second mud pump. There are multiple switching pipes between the slurry delivery pipe and the slurry discharge pipe. The switching pipe is equipped with a switch valve to Simulate different conveying states of slurry shield.

Optionally, an image acquisition component is also included, which is used to collect images of rock slag migration in the slurry discharge pipe and the slurry tank. Correspondingly, the casing and the slurry discharge pipe of the shield machine model are made of transparent materials.

Optionally, the image acquisition element includes a first CCD camera and a second CCD camera, wherein the first CCD camera is used to be placed on the front of the shield machine model, and the second CCD camera is used to be placed on the side of the shield machine model , both the first CCD camera and the second CCD camera are connected with the control system.

Optionally, there are four switching pipes, which are respectively the first switching pipe, the second switching pipe, the third switching pipe and the fourth switching pipe. One end of the second switching tube, the third switching tube and the fourth switching tube are connected, and along the slurry discharge direction, the slurry discharging tube is connected with the fourth switching tube, the second switching tube, the third switching tube and the other end of the first switching tube in sequence .

Optionally, the four switching pipes are all provided with switching valves, the slurry delivery pipe section between the second switching pipe and the third switching pipe is provided with switching valves, and the slurry discharge pipe between the second switching pipe and the third switching pipe The pipe section is provided with an on-off valve.

Optionally, the slurry delivery pipe is provided with an on-off valve, and is located downstream of the connection position between the first switching pipe and the slurry delivery pipe, and the slurry discharge pipe is provided with a switch valve, and is located at the point where the slurry discharge pipe extends into the shield machine model. on the pipe section.

Optionally, both the slurry delivery pipe and the slurry discharge pipe are equipped with pressure detection elements.

Optionally, the rock slag injection mechanism includes a rock slag bin connected to the cutting space through a discharge pipe, the rock slag bin is also provided with a feeding port, and both the discharge pipe and the feeding port are provided with on-off valves.

In a second aspect, the embodiments of the present invention provide a method for a muddy water shield rock slag migration test device, comprising the following steps:

Pre-preparing mud materials and selecting rock slag particles, among the rock slag particles, making tracer particles according to the set ratio;

Add the prepared mud material into the mud storage tank;

Turn on the first mud pump and air pressure source, so that the mud enters the mud water tank through the slurry delivery pipe, the slurry fills the mud water tank, and uses the rock slag injection mechanism to add rock slag particles to the cutting space;

Start the shield machine model, control the second mud pump and the valve on the corresponding switching pipe according to the test target delivery state, and collect the migration images of the tracer particles in the rock slag particles after the mud forms a stable circulation.

Optionally, before adding mud materials into the mud storage tank, pre-inject water, then start the first mud pump, and control the second mud pump and the valves on the corresponding switching pipes according to the test target delivery state to form a stable water cycle. Check the test The airtightness of the device.

The beneficial effects of the present invention are as follows:

1. The test device of the present invention, by setting the rock slag injection mechanism, can make the mud carry rock slag to circulate, and through the switching pipe and the switch valve on the switching pipe, it can simulate the slurry circulation system of mud-water shield and different conveying states and conveying The movement of rock slag during state switching can intuitively and accurately express the law of rock slag migration. The test device can provide the migration characteristics of rock slag in mud under various construction conditions and reveal the interaction between mud and rock slag in mud circulation. It makes up for the gaps in research and test methods related to the migration of rock slag particles in the mud, and provides guidance and suggestions for the pressure control of the slurry tank of the mud-water shield, the deployment of the formation-compatible mud, and the adjustment of the mud transportation status of the shield machine. Ensure the efficiency and safety of construction.

2. In the test device of the present invention, the shell and the slurry discharge pipe of the shield machine model are made of transparent materials, and there are tracer particles in the slag particles, so that the slurry circulation system of the mud-water shield and the migration of the slag in the slurry Situation visualization can intuitively and accurately express the law of muck migration.

Description of drawings

The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention.

Fig. 1 is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of the mud conveying state under the simulated normal excavation state of Embodiment 2 of the present invention;

Fig. 3 is a schematic diagram of the mud conveying state under the simulated mud-water shield bypass mode of embodiment 2 of the present invention;

Fig. 4 is a schematic diagram of the mud conveying state under the simulated mud-water shield isolation mode of Embodiment 2 of the present invention;

Fig. 5 is a schematic diagram of the mud conveying state under the simulated mud-water shield backwashing mode of Embodiment 2 of the present invention;

Fig. 6 is a schematic diagram of the mud conveying state in the simulated mud-water shield stop mode of Embodiment 2 of the present invention;

Fig. 7 is a schematic diagram of rock slag migration at A in Fig. 1 of the present invention;

Fig. 8 is a schematic diagram of the migration of rock slag particles of different sizes at A in Fig. 1 of the present invention;

Fig. 9 is a schematic diagram of the average velocity of rock slag under different mud velocities at A in Fig. 1 of the present invention;

Fig. 10 is the average velocity curve of rock slag particles of Fig. 1 of the present invention;

Among them, 1. Mud storage tank, 2. Abandoned mud tank, 3. Air pressure source, 4. Rock slag injection mechanism, 5. Cutter, 6. Slurry discharge pipe, 7. Second mud pump, 8. First mud pump, 9. Cutterhead, 10. Support rod, 11. First CCD camera, 12. Second CCD camera, 13. Host computer, 14. Thirteenth switch valve, 15. Seventh switch valve, 16. Eleventh switch Valve, 17. first switch valve, 18. second switch valve, 19. third switch valve, 20. fourth switch valve, 21. fifth switch valve, 22. sixth switch valve, 23. eighth switch valve , 24. Ninth on-off valve, 25. Tenth on-off valve, 26. Twelfth on-off valve, 27. First pressure gauge, 28. Second pressure gauge, 29. Third pressure gauge, 30. Transmission shaft, 31 . Power mechanism, 32. Rock slag particles, 33. Tracer particles, 34. Slurry delivery pipe, 35. First switching pipe, 36. Second switching pipe, 37. Third switching pipe, 38. Fourth switching pipe.

Detailed ways

For the convenience of description, if the words "up" and "down" appear in the present invention, it only means that it is consistent with the up and down directions of the drawings themselves, and does not limit the structure. It is only for the convenience of describing the present invention and simplifying the description. It is not to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention.

Example 1

This embodiment provides a muddy water shield slag migration test device, as shown in Fig. Image acquisition components and control systems, etc.

The shield machine model can be an existing indoor test shield machine model, including a cylindrical shell. In this embodiment, the shell is made of transparent material, and a cutter head is arranged in the shell. The shell The inner space is divided into a cutting space and a mud tank by the interface of the cutter head. The cutting space can be filled with rock slag particles through the rock slag injection mechanism 4. The cutter head 9 is a circular cutter head, and the cutter head 9 is provided with a cutter 5 and an opening. Particles can enter the slurry tank through the opening. The diameter of the cutterhead 9 is slightly smaller than the inner diameter of the casing. The cutterhead is connected with a rotating drive mechanism, which can drive the cutterhead to rotate to simulate the shield excavation process.

The rotary driving mechanism includes a power mechanism 31, the power mechanism 31 is connected with the transmission shaft 30, the transmission shaft 30 extends into the cutting space and is detachably and fixedly connected with the center position of the cutterhead 9, and the power mechanism 31 adopts a motor, a reducer Etc., also can adopt the equipment that can output rotational movement such as hydraulic motor.

The mud water bin is used to simulate the movement of rock slag under cutting by the cutter head. There is a partition in the mud bin, and the partition is fixed to the inner surface of the shell. The second partition is connected to the support rod 10, and the function of the support rod is to fix the The nozzle of the mud pipe connected to the cutting space, the bottom end of the second partition does not extend to the shell, so the two spaces separated by the second partition of the mud tank communicate with each other.

Among the two spaces of the mud tank, the space away from the cutting space is an air pressure tank, which is connected to the air pressure source 3, and the air pressure source can inject gas into the air pressure tank to keep the air pressure in the mud tank stable.

In this embodiment, the air pressure source 3 may be an air compressor or an air pressure chamber, which can output gas at a set pressure.

The inside of the shield machine model is a sealed space, which can carry out circulating transportation of mud.

A slag injection mechanism 4 is connected to the top of the cutting space for injecting slag particles into the cutting space.

The rock slag injection mechanism 4 includes a rock slag bin, the rock slag bin is used to hold rock slag particles, the bottom end of the rock slag bin is connected to one end of the discharge pipe, and the other end of the discharge pipe is connected to the cutting space. The rock slag particles in the rock slag bin can be sent into the cutting space through the discharge pipe, and the discharge switch valve is arranged on the discharge pipe for controlling the opening and closing of the discharge pipe.

The top of the rock slag bin is provided with a feed port, and a feed switch valve is provided at the feed port for controlling the opening and closing of the feed port.

The shield machine model is connected with a mud injection pipe group, and the mud injection pipe group includes multiple groups of mud injection pipes distributed up and down.

The slurry outlet ends of the upper two groups of slurry injection pipes pass through the partition and communicate with the space of the slurry tank near the cutting space for injecting slurry into the space. The upper two groups of mud injection pipes are respectively equipped with a first on-off valve 17 and a second on-off valve 18 .

A group of mud injection pipes located in the middle are divided into two branch pipes after passing through the partition, and the two branch pipes are connected with the cutting space, and are used to spray mud to the cutter head to flush the cutter head and prevent the cutter head from being blocked. The mud injection pipe located in the middle is equipped with a third on-off valve 19 .

The slurry outlet ends of the two sets of slurry injection pipes located below are provided with a 90° downward bend for injecting slurry into the space of the air pressure chamber. The two sets of mud injection pipes located below are respectively equipped with a fourth on-off valve 20 and a fifth on-off valve 21 .

The liquid inlet ends of the five groups of mud injection pipes are connected to one end of the slurry delivery pipe after they are collected, and the other end of the slurry delivery pipe is connected to the slurry storage tank 1 .

The first mud pump 8 is installed on the slurry delivery pipe, which is used to drive the mud in the slurry storage tank 1 to enter the shield machine model through the slurry delivery pipe.

The bottom of the air chamber is also communicated with one end of the slurry discharge pipe 6, and the other end of the slurry discharge pipe 6 is connected to the slurry disposal tank 2, and the second mud pump 7 is installed on the slurry discharge pipe 6 for driving the slurry tank The mud in the mud enters the slurry tank 2.

Under the action of the first mud pump and the second mud pump, the mud can form a circulation flow among the mud storage tank, the shield machine model and the discarded mud tank.

A sixth on-off valve 22 is installed on the pipe section where the slurry discharge pipe extends into the model of the shield machine, and is used to control the conduction and closure of the slurry discharge pipe.

A plurality of switching pipes are also arranged between the slurry feeding pipe and the slurry discharging pipe 6, and switching valves are arranged on the switching pipes to simulate different conveying states of the mud-water shield.

Specifically, four switching pipes are arranged between the pulp feeding pipe and the pulp discharging pipe, which are respectively a first switching pipe 35 , a second switching pipe 36 , a third switching pipe 37 and a fourth switching pipe 38 .

Among them, the seventh switching valve 15 is installed on the first switching tube 35, the eighth switching valve 23 is installed on the second switching tube 36, the ninth switching valve 24 is installed on the third switching tube 37, and the fourth switching tube 38 is installed. A tenth switching valve 25 is installed.

Along the pulp feeding direction of the pulp feeding pipe 34 , the pulp feeding pipe 34 is sequentially connected with one end of the first switching pipe 35 , the second switching pipe 36 , the third switching pipe 37 and the fourth switching pipe 38 .

Along the slurry discharge direction of the slurry discharge pipe 6 , the slurry discharge pipe 6 is sequentially connected with the fourth switching pipe 38 , the second switching pipe 36 , the third switching pipe 37 and the other end of the first switching pipe 35 .

On the slurry delivery pipe 34, the eleventh on-off valve 16 is arranged on the pipe section between the second switching pipe 36, the third switching pipe 37 and their connection positions, and on the slurry discharge pipe 6, it is located on the second switching pipe 36, the third A twelfth switching valve 26 is arranged on the pipe section between the switching pipe 37 and its connection position.

The thirteenth on-off valve 14 is arranged on the slurry delivery pipe 34, which is used to control the conduction and closure of the slurry delivery tube 34. The thirteenth on-off valve 14 is located downstream of the first switching tube 35 and its connection position, and the second switching tube 36 and upstream of its connection.

In this embodiment, the first mud pump 8 is installed on the slurry delivery pipe section between the first switching pipe 35 and the slurry storage tank 1, and the second mud pump 7 is installed on the first switching pipe 35 and the third switching pipe. On the 6 pipe sections of the slurry discharge pipe between 37.

Both the slurry delivery pipe 34 and the slurry discharge pipe 6 are equipped with pressure detection elements for detecting the mud pressure and for simulating and studying the pressure characteristics of the mud pipeline.

The pressure detection element can be an existing pressure gauge. In this embodiment, the first pressure gauge 27 is set on the slurry delivery pipe section between the fourth switching pipe 38 and the mud injection pipe group, and the fourth switching pipe 38 A second pressure gauge 28 is provided on the section of the slurry discharge pipe 6 between the second switching pipe 36 and a third pressure gauge 29 is provided on the section of the slurry discharge pipe 6 between the second mud pump 7 and the first switching pipe 35 .

The image acquisition element includes a first CCD camera 11 and a second CCD camera 12, the first CCD camera 11 is placed on the front of the shield machine model, can carry out continuous image acquisition, and records the shield machine mud circulation from the front and rock slag migration, the second CCD camera 12 is used to place on the side of the shield machine model, which can carry out continuous image acquisition, and record the mud circulation and rock slag migration of the shield machine from the side. The first CCD camera 11 and the second CCD camera 12 are all connected to the control system, correspondingly, the shell of the shield machine model, the mud injection pipe group, the slurry feeding pipe and the slurry discharge pipe are all made of transparent materials, which can be collected by two CCD cameras The flow image of mud and rock cinder is transmitted to the control system.

By adjusting the positions of the two CCD cameras, the movement of rock slag in the mud in the cutting space, mud tank and slurry discharge pipe can be collected

The control system can use the host computer 13, which will not be described in detail here.

In this embodiment, the slurry storage tank 1, the slurry disposal tank 2, the slurry delivery pipe, the slurry discharge pipe 6, the switching pipe, the air pressure source of the shield machine model, the cutter head 9, the cutter 5, the transmission shaft 30, and the power mechanism 31 all adopt the mode of detachable connection to assemble. All pipes used for slurry delivery have a radius of 5 cm.

Example 2

This embodiment provides a method for the muddy water shield slag migration test device described in Embodiment 1, comprising the following steps:

The mud material is prepared in advance and the rock slag particles are selected. Among the rock slag particles, tracer particles are made according to the set ratio.

The mud is prepared in a certain proportion using 15# white oil, n-dodecane and transparent clay. Preferably, the mass ratio of 15# white oil to n-dodecane in the mud is 6.4:1, and the content of transparent clay can be adjusted so that the viscosity and weight of the mud are similar to the actual mud. In this embodiment, the mud density reaches 1.1g/cm ³ .

The rock slag particles are made of transparent soil material, preferably of two types. The first one is composed of amorphous silica powder as aggregate and transparent clay, through which monomers can form large porous media with different particle sizes, and its properties are similar to natural clay. The second consists of fused silica sand as the aggregate, similar to natural sand. The transparent soil material can be used to configure the rock residue according to the similarity theory.

In this embodiment, the rock slag particles are spherical fused silica sand with a particle diameter of 0.25 cm, wherein the rock slag particles are colored as tracer particles according to a set ratio, and the set ratio is 0-100%, preferably 5 %.

Step 2: Test the mud circulation system formed by the shield machine model, slurry storage tank 1, discarded slurry tank 2 and corresponding mud pipelines, switch valves, shield machine model and image acquisition components.

Before adding the mud material into the mud storage tank 1, pre-inject water, then start the first mud pump 8, and control the second mud pump and the valve on the corresponding switching pipe according to the test target delivery state, and set different cutterhead speeds according to the project. Form a circulation path similar to the construction project, form a stable water circulation, and check the airtightness of the test device.

Step 3: After the airtightness of the entire test device is qualified, add the pre-prepared mud material into the mud storage tank.

Step 4: Turn on the first mud pump 8 and the air pressure source 3, so that the mud enters the mud water bin and the cutting space through the slurry delivery pipe, and the slurry fills the mud water bin and the cutting space; the air pressure source makes the air pressure in the mud water bin and the cutting space stable. After the muddy water tank and the cutting space are filled, the slag particles 32 with tracer particles 33 are sent into the cutting space by the slag injection mechanism 4 .

Specifically, first close the discharge pipe switch valve of the discharge pipe of the rock slag bin, then open the feeding switch valve, add rock slag particles into the rock slag bin, and open the discharge pipe switch after the mud slurry fills the mud water bin and cutting space valve to inject rock slag particles into the cutting space.

Step 5: Start the shield machine model, control the second mud pump and the valve on the corresponding switching pipe according to the test target delivery state, and collect the migration images of the tracer particles in the rock slag particles after the mud forms a stable circulation.

The power mechanism 31 drives the transmission shaft 30 to rotate, and the transmission shaft 30 drives the cutter head 9 to rotate, simulating the excavation process of the shield machine. The rotation speed of the cutter head 9 is 1.2 RPM, and the rock slag particles 32 and the tracer particles 33 pass through the cutter head 9 and the first The holes on the clapboard enter the mud tank, and then are discharged through the slurry discharge pipe 6, and the rock slag particles and tracer particle migration are captured by the CCD camera. During this period, different muddy water shield conveying states can be switched through the switch of the control valve, specifically:

Close the seventh on-off valve 15, the eighth on-off valve 23, the ninth on-off valve 24, the tenth on-off valve 25, the third on-off valve 19, the fourth on-off valve 20 and the fifth on-off valve 21, and open the thirteenth on-off valve 14 , the eleventh on-off valve 16, the first on-off valve 17, the second on-off valve 18, the sixth on-off valve 22, and the twelfth on-off valve 26 form a conveying state as shown in Figure 2, which can simulate muddy water shield excavation Rock residue migration in normal excavation mode.

Close the seventh on-off valve 15, the first on-off valve 17, the second on-off valve 18, the third on-off valve 19, the fourth on-off valve 20, the fifth on-off valve 21, the sixth on-off valve 22, the eighth on-off valve 23, the Nine on-off valves 24, open the thirteenth on-off valve 14, the eleventh on-off valve 16, the tenth on-off valve 25 and the twelfth on-off valve 26 to form the conveying state as shown in Figure 3, which can simulate the muddy water shield bypass Rock debris migration in standby mode (for example, when installing segments).

Only the seventh on-off valve 15 is opened, and the other on-off valves are all closed to form the conveying state as shown in Figure 4, which can simulate rock slag migration in the mud-water shield isolation mode (for example, when the mud pipeline is extended and the mud pool adjusts the mud quality). Condition.

Close the seventh on-off valve 15, the eleventh on-off valve 16, the tenth on-off valve 25, and the twelfth on-off valve 26, and open other on-off valves to form the mud conveying state as shown in Figure 5, which can simulate backwashing of mud-water shield The rock slag migration in the mode (used to clear the blockage of the slurry discharge pipe).

Only open the thirteenth on-off valve 14, the eleventh on-off valve 16, and the first on-off valve 17, and close the other on-off valves to form the mud conveying state as shown in Figure 6, which can simulate rock slag migration in the muddy water shield shutdown mode Condition.

Use the first CCD camera 11 and the second CCD camera 12 to collect the moving images of rock slag particles, set the frame rate of the first CCD camera 11 and the second CCD camera 12 to 25, the first CCD camera 11 can capture the row from the front Clag migration information in slurry pipes and slurry tanks. The second CCD camera 12 can capture the rock slag migration information in the slurry discharge pipe and mud water bin from the side. The CCD camera transmits the information to the control system, and after data processing, the migration data of rock slag under different working conditions can be obtained. Fig. 7 is a schematic diagram of the migration of slag in the slurry discharge pipe, and Fig. 8 is a schematic diagram of the migration of slag particles of different sizes in the slurry discharge pipe. (The proportion of rock slag particles with different radii for the rock slag materials used is 0.15cm:0.3cm:0.5cm=3:2:1). Fig. 9 is a schematic diagram of the average velocity of rock slag under different mud velocities; Fig. 10 is a velocity curve of rock slag in the slurry discharge pipe.

At present, there are few studies on mud carrying slag discharge and rock slag migration in slurry shield tunneling. The evaluation of the existing mud slag-carrying capacity mainly relies on mud specific gravity, viscosity and other indicators for evaluation. Indoor tests are generally carried out by mixing and transporting mud and rock slag samples. The test device is simple and it is difficult to simulate the mud-water shield circulation system. This embodiment The test device, by setting the rock slag injection mechanism, can make the mud carry the rock slag to circulate, and through the switching pipe and the switching valve on the switching pipe, it can simulate the mud circulation system of the mud-water shield and different conveying states and when the rock is switched. The movement of slag can intuitively and accurately show the law of slag migration. The test device can provide the migration characteristics of slag in mud under various construction conditions, reveal the interaction law between mud and slag in mud circulation, and make up for the There is a gap in research and test methods related to the migration law of rock slag particles in the mud. It provides guidance and suggestions for the pressure control of the mud water shield mud tank, the deployment of formation-adaptive mud, and the adjustment of the mud transportation status of the shield machine to ensure efficient construction. It is safe and safe, and the shell and slurry discharge pipe of the shield machine model are made of transparent materials, and there are tracer particles in the rock slag particles, so that the mud circulation system of the mud-water shield and the movement of slag in the mud can be visualized, which can Intuitively and accurately express the law of muck migration.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims (10)

1. A muddy water shield rock slag migration test device, comprising a shield machine model, one side of the shield machine model cutter head is a muddy water bin, and the other side is a cutting space, and the muddy water bin is connected with an air pressure source, and it is characterized in that , the cutting space is connected with a slag injection mechanism, the mud water tank is connected with the mud injection pipe group, the mud injection pipe group is connected with the slurry storage tank through the slurry delivery pipe, the first mud pump is installed on the slurry delivery pipe, and one end of the mud water warehouse is connected with the slurry discharge pipe The other end of the slurry discharge pipe is connected to the discarded slurry tank. The slurry discharge pipe is equipped with a second mud pump. There are multiple switching pipes between the slurry delivery pipe and the slurry discharge pipe. Different delivery status. 2. a kind of muddy water shield rock slag migration situation test device as claimed in claim 1, is characterized in that, also comprises image acquisition element, is used for collecting the rock slag migration image in the slurry discharge pipe and the muddy water bin, corresponding Yes, the casing and slurry discharge pipe of the shield machine model are made of transparent materials. 3. a kind of muddy water shield slag migration test device as claimed in claim 2, is characterized in that, described image acquisition element comprises the first CCD camera and the second CCD camera, and wherein the first CCD camera is used for placing On the front of the shield machine model, the second CCD camera is used to place on the side of the shield machine model, and both the first CCD camera and the second CCD camera are connected with the control system. 4. A kind of muddy water shield rock slag migration test device as claimed in claim 1, is characterized in that, described switching tube has four, is respectively the first switching tube, the second switching tube, the third switching tube and the fourth switching pipe, along the pulp feeding direction, the pulp feeding pipe is connected with one end of the first switching pipe, the second switching pipe, the third switching pipe and the fourth switching pipe in turn, along the pulp discharging direction, the pulp discharging pipe is connected with the first switching pipe in turn The other ends of the four switch tubes, the second switch tube, the third switch tube and the first switch tube are connected. 5. a kind of muddy water shield slag migration test device as claimed in claim 4, is characterized in that, four switching pipes are all provided with on-off valves, the slurry feeding between the second switching pipe and the third switching pipe The pipe section is provided with a switching valve, and the slurry discharge pipe section between the second switching pipe and the third switching pipe is provided with a switching valve. 6. A muddy water shield rock slag migration test device as claimed in claim 4, characterized in that the slurry delivery pipe is provided with an on-off valve, and is located downstream of the connection position between the first switching pipe and the slurry delivery pipe , the slurry discharge pipe is provided with a switch valve and is located on the pipe section where the slurry discharge pipe extends into the shield machine model. 7 . The muddy water shield rock slag migration test device according to claim 1 , characterized in that, both the slurry feeding pipe and the slurry discharging pipe are equipped with pressure detection elements. 7 . 8. A muddy water shield rock slag migration test device as claimed in claim 1, wherein the rock slag injection mechanism comprises a rock slag bin, and the rock slag bin is connected with the cutting space through a discharge pipe, and the rock slag injection mechanism The slag bin is also provided with a feeding port, and both the discharge pipe and the feeding port are provided with on-off valves. 9. a method for the muddy water shield slag migration situation test device described in any one of claims 1-8, is characterized in that, comprises the following steps: Pre-preparing mud materials and selecting rock slag particles, among the rock slag particles, making tracer particles according to the set ratio; Add the prepared mud material into the mud storage tank; Turn on the first mud pump and air pressure source, so that the mud enters the mud water tank through the slurry delivery pipe, the slurry fills the mud water tank, and uses the rock slag injection mechanism to add rock slag particles to the excavation space; Start the shield machine model, control the second mud pump and the valve on the corresponding switching pipe according to the test target delivery state, and collect the migration images of the tracer particles in the rock slag particles after the mud forms a stable circulation. 10. The method of a muddy water shield slag migration test device as claimed in claim 9, characterized in that, before the mud storage tank is added to the mud material, water is injected in advance, then the first mud pump is started, and according to the test The target delivery state controls the operation of the valves on the second mud pump and the corresponding switching pipe to form a stable water cycle and check the airtightness of the test device.