Large longitudinal slope water-rich sand mudstone interbed shield segment floating model test system

Abstract

The utility model discloses a large longitudinal slope water-rich sand mudstone interbedding shield segment floating model test system. The large longitudinal slope water-rich sand mudstone interbedding shield segment floating model test system comprises a main body box, a ground stress loading system, a power system, a shield system, a grouting system, a water injection system, a monitoring system and a gradient leveling system. A shield system and model soil are contained in the main body box; the ground stress loading system and the water injection system are used for simulating a water-rich sand shale interbed environment by applying stress and water pressure to the model soil in the main body box; the power system can carry out construction simulation of different gradients by adjusting the tunneling direction of the shield shell, and meanwhile, the grouting system carries out grouting on the gap between the shield shell and the duct piece. The large longitudinal slope water-rich sand mudstone interbed shield wall post-grouting visualization and duct piece floating integrated model test is realized, and a shield tunnel wall post-grouting filling project in a water-rich sand mudstone environment can be reduced in size; and the duct piece floating rule and the tunnel longitudinal deformation mechanism in the shield tunneling process are obtained by feeding back the large longitudinal slope water-rich sand mudstone interbed physical field in real time.

Description

Technical Field

[0001] The present invention relates to the technical fields of shield tunnel grouting and tunnel stability, and particularly relates to a large longitudinal slope water-rich sandstone and mudstone interbedded shield segment floating model test system. Background Technique

[0002] With the rapid development of urbanization and economy, the urban traffic pressure increases. Making full use of the underground space to build tunnels is an effective way to relieve urban traffic. The shield construction method is the mainstream tunnel construction method, and the shield method construction is widely used in the construction of urban subway tunnels due to its safety, high efficiency and strong applicability.

[0003] During the shield tunneling process, there will be a certain gap between the tail shield segment and the stratum. If no measures are taken in time, the segments will be misaligned, and at the same time, the stratum will also deform due to insufficient support. Among the corresponding treatment measures, the most crucial one is to carry out synchronous grouting at the tail shield to effectively fill the gap between the lining and the stratum.

[0004] In shield construction, the slurry is usually injected into the gap between the segment wall and the surrounding soil through the grouting holes reserved on the shield segment to reduce the stratum loss. However, during the grouting process, it is impossible to directly observe the grouting process, and it is difficult to quantitatively carry out grouting, so it is very difficult to evaluate whether the grouting is complete. Quality problems such as uneven grouting and poor grouting filling may cause serious geological disasters such as underground leakage, lining damage, reduction of the bearing capacity of the overlying stratum, uneven surface settlement, and ground collapse.

[0005] The existing shield tunnel segment floating model test devices only consider the construction simulation in the horizontal direction of the shield machine, and fail to consider the shield high-slope construction and segment floating simulation under the construction environment of a large longitudinal slope; the existing shield tunnel segment floating model test devices only simulate the shield tunneling in a horizontal stratum with a uniform stratum thickness, and fail to consider the simulation under the construction environment with uneven stratum thickness in a large longitudinal slope environment; currently, shield construction often encounters complex strata, such as water-rich sandstone and mudstone interbeds. There are few relevant indoor model tests, and most of them ignore the existence of the muddy water environment under the high water pressure of the soft stratum, especially lacking the grouting filling effect and segment floating model under the water-rich sandstone and mudstone interbeds. Utility Model Content

[0006] The purpose of the present utility model is to solve the above problems, and propose a large longitudinal slope water-rich sandstone and mudstone interbedded shield segment floating model test system, which can thus relatively realistically simulate the grouting and segment floating processes of the shield machine in the large longitudinal slope water-rich sandstone and mudstone interbeds, and can simulate and measure the floating conditions of multiple-ring segments, the grouting filling effect and mechanism under the influence of various different factors, and has the advantages of convenient operation, complete structure, and reusable.

[0007] The present invention is achieved through the following technical solutions:

[0008] A shield segment floating model test system for a large longitudinal slope water-rich sandstone and mudstone interlayer includes a main box, a ground stress loading system, a power system, a shield system, a grouting system, a water injection system, a monitoring system, and a slope leveling device;

[0009] The main box is a box structure with an opening at one end. The lower body is welded by steel plates, and the upper body is made of visual materials. A shield shell hole is provided on the front end face of the main box;

[0010] The model soil filled in the main box includes sandy soil, muddy soil, and sandy mudstone soil to simulate the water-rich sandstone and mudstone interlayer;

[0011] The ground stress loading system includes weights and loading plates;

[0012] The power system is composed of four synchronous push rods and a traction frame with adjustable angle;

[0013] The shield system includes a shield shell, a segment lining, and a lining fixing device. The shield shell is located inside the main box and placed in the shield shell hole at the front end of the main box. It is composed of annular steel plates. The segment lining assembly includes multiple segment rings and joint structures connected between adjacent segment rings, and is placed in the shield shell in sequence. The lining fixing device is composed of a flange and a traction rope;

[0014] The grouting system is composed of an air compressor, an air delivery pipe, a pressure regulator, a water storage bucket, a pressure gauge, and a grout delivery pipe;

[0015] The water injection system provides dynamic water for the sandstone and mudstone interlayer in the model box and is composed of an air compressor, an air delivery pipe, a water storage bucket, a valve, and a water pressure gauge;

[0016] The monitoring system is used to monitor and collect relevant test parameters of the model soil in the main box and is composed of monitoring elements, signal lines, and a data acquisition processor;

[0017] The slope leveling system is used for leveling the large longitudinal slope and is composed of a slide rail, a telescopic wire, and a fixator.

[0018] The model box is determined by the diameter geometric similarity ratio of the prototype shield and the model shield. The overall structure of the model box is welded by steel plates, and PVC visual materials are used in some areas.

[0019] Furthermore, a circular opening for installing a synchronous grouting simulation sleeve is reserved at the front end of the model box for installing the shield system.

[0020] In the ground stress loading system, the weights are selected with different masses according to experimental requirements, and ground stress is applied to the soil through the loading plates placed on the ground surface.

[0021] The power system is embedded on both sides of the model box and is composed of a traction frame made of square steel. A push rod is used to synchronously advance the traction frame, so that the shield shell advances at a constant speed.

[0022] Furthermore, the traction frame can be adjusted according to construction requirements to change the tunneling angle, and it can relatively realistically simulate the process of the shield machine advancing and the segment exiting the shield tail.

[0023] The shield system uses a double-sleeve structure to simulate the shield tail gap. The shield shell is composed of annular steel plates, and the segment lining is made of transparent epoxy resin.

[0024] Furthermore, a high-definition camera is installed inside the sleeve to accurately observe and record the diffusion path of the slurry.

[0025] Furthermore, the shield shell is fixed by the reserved holes at the front end of the shield and the traction frame, and the segment lining is fixed by a flange, and the height of the flange can be adjusted according to construction requirements to adjust the tunneling angle.

[0026] Furthermore, the tunnel lining angle can be adjusted by adjusting the height of the flange, including 20‰ - 30‰, 30‰ - 40‰, 40‰ - 50‰

[0027] The grouting system can select the number, position, grouting volume and grouting pressure of the grouting holes according to the actual working conditions.

[0028] Furthermore, the grouting system can adjust the grouting pressure by controlling the air compressor, and an electromagnetic flowmeter is equipped on the slurry delivery pipe of each slurry storage barrel to monitor the slurry output at all times.

[0029] Furthermore, the grouting system is provided with an annular baffle plate behind the segment wall, and a plurality of grouting ports are provided along the circumferential direction of the baffle plate.

[0030] Furthermore, the grouting ports and the infusion pipes correspond one by one according to construction requirements, and the unused grouting ports are blocked with rubber plugs during the test process.

[0031] In the water injection system, the water storage barrel and the air compressor are connected through an air delivery pipe, and a pressure regulator is arranged on the air delivery pipe to control the water output of the water storage barrel by regulating the air delivery pressure.

[0032] Furthermore, the water outlet of the water storage barrel is communicated with a water delivery pipe, the water delivery pipe penetrates through the loading plate and then inserts into the model soil, and a valve and a water pressure gauge are installed on the water delivery pipe.

[0033] The monitoring elements include soil pressure sensors, displacement sensors and hydrodynamic pressure sensors.

[0034] Furthermore, the monitoring elements are arranged in the model soil, and the monitoring elements are connected to a data acquisition processor through signal lines.

[0035] The slope leveling system includes a transverse slide rail, a longitudinal slide rail, a telescopic wire, and a fixator.

[0036] Furthermore, for the fixators on the movable slide rail, a telescopic wire is linked between the fixators to form planes with different slopes for filling model soil.

[0037] Furthermore, by moving the fixators on the transverse slide rail and the longitudinal slide rail, the slopes of the model soil in the model box in different directions can be adjusted.

[0038] A model test system for shield segment floating in a large longitudinal slope water-rich sandstone and mudstone interlayer. Using the model test system for shield segment floating in a large longitudinal slope water-rich sandstone and mudstone interlayer of the present invention, the following steps are included:

[0039] Step 1: Install the main box;

[0040] Step 2: Fill the model soil required for the test according to the test requirements;

[0041] Step 3: Adjust the positions of the slide rails and fixators according to the required longitudinal and transverse slopes for the test, and level the slopes;

[0042] Step 4: Adjust the angle of the power system and fix it;

[0043] Step 5: Install the shield system. Embed the shield shell at the shield shell hole of the main box. Link and inlay multiple segments at the rear flange of the model box, and connect them with bolts. Connect the power system to the front end of the shield shell;

[0044] Step 6: Install the grouting system;

[0045] Step 7: Install the water injection system;

[0046] Step 8: Bury displacement sensors, soil layer pressure sensors, and dynamic water pressure sensors in the model soil. Install a loading plate on the upper part of the model soil, and configure counterweights on the loading plate;

[0047] Step 9: Apply water pressure. The water injection system injects water into the model soil through a water delivery pipe;

[0048] Step 10: Add counterweights to make the ground stress load evenly transmitted to the model soil through the loading plate. After reaching the ground stress of the required environment, stop loading;

[0049] Step 11: Start the power system to make the shield shell move outward for tunneling. While the shield shell is moving, the grouting system injects grout into the gap formed between the segments and the model soil through a grout delivery pipe;

[0050] Step Twelve: After the grouting is completed, collect data through the monitoring system, summarize the law of segment floating and the grouting diffusion reinforcement mode of segments in different rings, and evaluate the effect of synchronous grouting behind the shield tunneling segment.

[0051] Step Thirteen: Repeat Steps One to Eleven, set different parameters of ground stress pressure, water pressure, grout type, grouting volume, grouting pressure, gap between the shield shell and the segment, and shield shell tunneling speed, and complete the synchronous grouting test behind the shield tunneling segment under different conditions and different types of model soil.

[0052] The utility model has the following beneficial effects:

[0053] 1. For the large longitudinal slope water-rich sandstone and mudstone interbedded strata, the utility model determines the size by using the diameter geometric similarity ratio between the actual large-diameter shield and the model shield, restores the operation state and construction environment of the large-diameter shield in the large longitudinal slope water-rich sandstone and mudstone interbedded strata, and realizes the floating state and law of the segment during the shield tunneling process through real-time feedback of the multi-physical field of the strata.

[0054] 2. Compared with the existing shield tunneling segment floating model test device that only considers the construction simulation of the shield machine in the horizontal strata, the utility model can simulate the shield tunneling in large slopes by adjusting the angle of the power device and the angle of the segment lining.

[0055] 3. Compared with the existing shield tunneling segment floating model test device that only simulates the shield tunneling construction in uniform strata with uniform ground stress on the segment, the utility model adjusts the horizontal and longitudinal slopes of the model soil through the slope leveling device, realizing the simulation of the construction of a large-diameter shield in different slopes and different strata depth environments.

[0056] 4. The present invention can set a variety of key influencing factors (such as the speed of shield tunneling, grouting pressure, grouting volume, tunneling slope, etc.) through the system, deeply study the variation laws of grouting filling and segment floating, and can present the visualization of the grouting filling process behind the shield and the dynamic effect of segment floating in the water-rich sandstone and mudstone interbedded strata. After adding the monitoring system, the present invention can better and more accurately measure the key parameters such as the stress, seepage pressure and deformation of the model soil, and can effectively obtain the law of shield segment floating and the longitudinal deformation of tunnel tunneling. Brief Description of the Drawings

[0057] Figure 1 It is a schematic plan view of the main structure provided by the embodiment of the present invention;

[0058] Figure 2 It is a schematic plan view of the test device after grouting provided by the embodiment of the present invention;

[0059] Figure 3 It is a plan view of the side of the main box and the power system provided by the embodiment of the present invention;

[0060] Figure 4 Layout diagram of the monitoring system for the cross-section of the main box provided by the embodiment of the present invention;

[0061] Figure 5 Schematic structural diagram of the slope leveling system provided by the embodiment of the present invention;

[0062] Figure 6 Top view of the structural diagram of the slope leveling system provided by the embodiment of the present invention;

[0063] Figure 7 Schematic structural diagram of the rear main board of the main box provided by the embodiment of the present invention;

[0064] Figure 8 Schematic structural diagram of the segment provided by the embodiment of the present invention;

[0065] Figure 9 Schematic cross-sectional diagram of the segment structure provided by the embodiment of the present invention;

[0066] In the figure: 1. Main box; 2. Shield shell; 3. Tractor frame; 4. Segment; 5. Grouting pipe; 6. Grouting port; 7. Baffle; 8. Loading plate; 9. Counterweight; 10. First flow recorder; 11. Slurry mixer; 12. Valve I; 13. Valve II; 14. First air compressor; 15. Air delivery pipe I; 16. Valve III; 17. Valve IV; 18. Slurry storage tank I; 19. Slurry storage tank II; 20. Pressure gauge I; 21. Pressure gauge II; 22. Second flow recorder; 23. Data acquisition and processor; 24. Signal line; 25. Second air compressor; 26. Air delivery pipe II; 27. Valve V; 28. Water storage tank; 29. Water pressure gauge; 30. Displacement sensor; 31. Soil pressure sensor; 32. Dynamic water pressure sensor; 33. Shield shell hole; 34. Power system fixer; 35. PVC board; 36. Front slide rail; 37. Rear slide rail; 38. Fixer; 39. Telescopic line; 40. Flange; 41. Towing line; 42. Segment buckle; 43. Push rod. Detailed implementation manners

[0067] The present invention will be further described below in conjunction with the accompanying drawings and embodiments

[0068] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanations for the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0069] It should be noted that the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0070] In the present invention, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only relational terms determined for the convenience of describing the structural relationship of each component or element of the present invention and do not specifically refer to any part or element in the present invention. It should not be construed as a limitation to the present invention.

[0071] In the present invention, terms such as "fixed", "connected", "joined", etc. should be understood in a broad sense and may mean a fixed connection, an integral connection or a detachable connection; it may be directly connected or indirectly connected through an intermediate medium. For those skilled in the relevant scientific research or technology in this field, the specific meanings of the above terms in the present invention can be determined according to specific circumstances and should not be construed as a limitation to the present invention.

[0072] The present utility model designs a large longitudinal slope water-rich sandstone and mudstone interlayer shield segment floating model test system, as Figures 1-9 shown, which mainly includes a main box, a ground stress loading system, a power system, a shield system, a grouting system, a water injection system, a monitoring system, and a slope leveling system.

[0073] As Figures 1-9 shown, the model box 1 is integrally composed of steel plates. A shield shell hole 33 is left on the front side of the model box, and PVC plates 35 are laid around the model box to visually observe the grouting process.

[0074] As Figures 1-9 shown, the ground stress loading system consists of a loading plate 8 and a counterweight 9. The loading plate 8 is placed on the large longitudinal slope model soil, and the counterweight 9 is placed on the loading plate 8 to simulate the uniformly loaded ground stress.

[0075] As Figures 1-9 shown, the power system consists of a traction frame 3, a push rod 43, and a power system fixer 34. After the traction frame 3 is fixed by the power system fixer 34, it is driven by the push rod 43 to drive the traction frame 3 forward to drive the shield shell to make a uniform tunneling motion outward.

[0076] As Figures 1-9As shown in the figure, the shield system is composed of a shield shell 2, segments 4, segment fasteners 42, traction lines 41, and flange plates 40. The segments 4 are connected pairwise by the segment fasteners 42. The assembled segments are clamped on the flange plates 40, and the height is adjusted through the traction lines 41. The shield shell 2 is sleeved outside the segments 4 to form a double-sleeve structure to simulate the shield tail gap.

[0077] As Figures 1-9 shown in the figure, the grouting system is composed of a grouting pipe 5, a grouting port 6, a baffle 7, a first flow recorder 10, a slurry mixer 11, valve I 12, valve II 13, a first air compressor 14, an air delivery pipe I 15, valve III 16, valve IV 17, a slurry storage tank I 18, a slurry storage tank II 19, a pressure gauge I 20, a pressure gauge II 21, and a second flow recorder 22. The slurry storage tanks I 18 and II 19 are connected to the first air compressor 14 through the air delivery pipe I 15 to provide pressure for the slurry for synchronous grouting. Valve III 16 and valve IV 17 are provided on the air delivery pipe I 15 to be opened or closed for single-fluid grouting or double-fluid grouting according to the actual situation. Pressure gauges I 20 and II 21 are provided on the slurry storage tanks I 18 and II 19 to monitor the pressure in the slurry storage tanks at all times. The slurry is output from the slurry storage tank through the grouting pipe 5. Valve I 12 and valve II 13 are provided in front of the slurry mixer 11 to control the output volume of the slurry from each slurry storage tank. The slurry is mixed in the slurry mixer 11 and then input into the pores behind the shield wall for grouting. A baffle 7 is provided around the grouting port 6 to prevent the slurry from leaking out. Flow recorders are provided on each grouting pipe to record the slurry flow rate in each pipeline at all times. In this embodiment, the water injection pressure in the water injection system should be ensured to be 0.5 MPa - 1.0 MPa. A high water pressure is applied to the soft stratum to form a water-rich sandy mudstone environment, simulating the shield grouting process in the interbedded water-rich sandy mudstone with a large longitudinal slope.

[0078] As Figures 1-9 shown in the figure, the water injection system is composed of a second air compressor 25, an air delivery pipe II 26, valve V 27, a water storage tank 28, and a water pressure gauge 29. The second air compressor 25 is connected to the water storage tank 28 through the air delivery pipe II 26. Valve V 27 is provided on the air delivery pipe II 26 to control the air delivery volume of the second air compressor 25. A water pressure gauge 29 is provided on the water storage tank 28 to detect the water pressure in the water storage tank.

[0079] As Figures 1-9As shown in the figure, the monitoring system consists of a data acquisition processor 23, a signal line 24, a displacement sensor 30, a soil layer pressure sensor 31, and a hydrodynamic pressure sensor 32. The displacement sensor 30, the soil layer pressure sensor 31, and the hydrodynamic pressure sensor 32 are laid in the model soil according to requirements. The soil layer pressure sensor 31 and the hydrodynamic pressure sensor 32 are respectively used to detect the changes in the internal stress and seepage pressure of the model soil during the test, and the displacement sensor 30 is used to detect the floating condition of the segment during the test. The sensors are connected to the data acquisition processor 23 by the signal line 24 to monitor the data changes in real time. In this embodiment, there are two distribution forms of the monitoring elements, as Figure 4 shown, one is that the monitoring elements are distributed in the model soil at the middle position of each ring of segments. As Figure 1 shown, the other is that the measuring elements are distributed in the model soil at the position between adjacent segments. In other embodiments, the positions and quantities of the monitoring elements should be selected according to the actual simulation requirements.

[0080] As Figures 1-9 shown, the slope leveling system consists of a front slide rail 36, a rear slide rail 37, a fixator 38, and a telescopic line 39. The front slide rail 36 is fixed on the front side of the model box 1, and the rear slide rail 37 is fixed on the rear side of the model box 1. The height of the fixator 38 can be moved to adjust the slope required for the experiment, and leveling is performed through the telescopic line 39.

[0081] In this embodiment, the model soil used can simulate mudstone intercalated with sandstone type, upper mud and lower sand type, lower mud and upper sand type, sand and mud interbedded type, sandstone intercalated with mudstone type of large longitudinal slope and water-rich sand and mudstone interbedding according to the test requirements, and fill with silty sand, fine sand, medium-fine sand, gravel sand, etc.

[0082] The specific sand and mudstone combination types are as follows

[0083]

[0084] The present invention also provides a method for a large longitudinal slope and water-rich sand and mudstone interbedded shield segment floating model test system, and the specific steps are as follows:

[0085] Step 1: Install the main box 1;

[0086] Step 2: Fill the model soil required for the test according to the test requirements;

[0087] Step 3: Adjust the positions of the front slide rail 36, the rear slide rail 37 and the fixator 38 according to the longitudinal and transverse slopes required for the test, and perform leveling through the telescopic line 39;

[0088] Step 4: Adjust the angle of the push rod 43, and use the power system fixator 34 to fix it, and place the traction frame 3 at the front end of the push rod;

[0089] Step 5: Install the shield system. Embed the shield shell into the shield hole of the main box. Connect the segments 4 in pairs by segment fasteners 42 and inlay them on the rear part of the model box on the flange 40, and adjust the height through the towing wire 41. Connect the power system to the front end of the shield shell;

[0090] Step 6: Install the grouting system. Connect the slurry storage barrel I 18, the slurry storage barrel II 19 and the first air compressor 14 through the air delivery pipe I 15. The air delivery pipe I 15 is equipped with valves III 16 and valves IV 17, which can be opened and closed for single-fluid grouting or double-fluid grouting according to the actual situation. The slurry storage barrel I 18 and the slurry storage barrel II 19 are equipped with pressure gauges I 20 and pressure gauges II 21 to monitor the pressure in the slurry storage barrels at all times. Install the grouting pipes 5 on the slurry storage barrel I 18 and the slurry storage barrel II 19, and install the slurry mixer 11 behind the two grouting pipes and insert it into the grouting port 6 in the shield pore. Valves I 12 and valves II 13 are provided in front of the slurry mixer 11 to control the output of the slurry from each slurry storage barrel, and a baffle 7 is provided around the grouting port 6. Flow recorders are provided on each grouting pipe to record the slurry flow of each pipeline at all times;

[0091] Step 7: Install the water injection system. Connect the second air compressor 25 and the water storage bucket 28 through the air delivery pipe II 26. The air delivery pipe II 26 is equipped with a valve V 27 to control the air output of the second air compressor 25. The water storage bucket 28 is equipped with a water pressure gauge 29 to detect the water pressure in the water storage bucket;

[0092] Step 8: Bury displacement sensors, soil layer pressure sensors and hydrodynamic pressure sensors in the model soil according to the experimental requirements. Install a loading plate 8 on the upper part of the model soil, and configure counterweights 9 on the loading plate;

[0093] Step 9: Apply water pressure. The water injection system starts the second air compressor 25 to pressurize the water storage bucket 28, so that the water in the water storage bucket 28 enters the soil through the pipeline. The water pressure gauge 29 records the water pressure in the water storage bucket 28 at all times.

[0094] Step 10: Place the loading plate 8 on the model soil, add counterweights 9 to evenly transfer the load into the model soil, and stop loading after reaching the in-situ stress of the required environment;

[0095] Step 11: Start the power system to make the shield shell move outward for tunneling. While the shield shell is moving, the grouting system injects grout into the gap formed between the segments and the model soil through the grout delivery pipe;

[0096] Step 12: After the grouting is completed, collect data through the data acquisition processor 23, summarize the law of segment floating and the grouting diffusion reinforcement mode of segments in different rings, and evaluate the effect of synchronous grouting behind the shield wall;

[0097] Step Thirteen: Repeat Steps One to Eleven, set different parameters of in-situ stress pressure, water pressure, grout type, grouting volume, grouting pressure, gap between shield and segment, and shield tunneling speed, and complete the synchronous grouting test behind the shield under different conditions and different types of model soil.

[0098] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and transformations can be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A shield segment floating model test system for interbedded rich water sandy mudstone with large longitudinal slope, characterized in that, It includes a main box, a ground stress loading system, a power system, a shield system, a grouting system, a water injection system, a monitoring system, and a slope leveling system; The main box is a box structure with an opening at one end. The lower body is welded by steel plates, and the upper body is made of visual materials. There is a shield shell hole on the front end face of the main box; The model soil filled in the main box includes sandy soil, muddy soil, and sandy mudstone soil to simulate the water-rich sandy mudstone interlayer; The ground stress loading system includes counterweights and loading plates; The power system is composed of four synchronous push rods and a traction frame with adjustable angle; The shield system includes a shield shell, a segment lining, and a lining fixing device. The shield shell is located inside the main box and placed in the shield shell hole at the front end of the main box. It is composed of annular steel plates. The segment lining assembly includes multiple segment rings and joint structures connected between adjacent segment rings, and they are placed in the shield shell in sequence. The lining fixing device is composed of a flange and a traction rope; The grouting system is composed of an air compressor, an air delivery pipe, a pressure regulator, a slurry storage tank, a pressure gauge, and a slurry delivery pipe; The water injection system provides dynamic water for the sandy mudstone interlayer in the model box and is composed of an air compressor, an air delivery pipe, a water storage tank, a valve, and a water pressure gauge; The monitoring system is used to monitor and collect relevant test parameters of the model soil in the main box and is composed of monitoring elements, signal lines, and a data acquisition processor; The slope leveling system is used for slope leveling of large longitudinal slopes and is composed of a slide rail, a telescopic wire, and a fixator; 2. The floating model test system for shield segments in the interbedded strata of water-rich sandy mudstone with a large longitudinal slope according to claim 1, characterized in that, The size of the model box is determined by the geometric similarity ratio of the diameters of the prototype shield and the model shield. The overall structure of the model box is welded by steel plates, and PVC visual materials are used in some areas. A circular opening for installing a synchronous grouting simulation sleeve is reserved at the front end of the model box; 3. The floating model test system for shield segments in the interbedded sandstone and mudstone with a large longitudinal slope and rich water according to claim 1, characterized in that, In the ground stress loading system, the counterweights of different masses are selected according to experimental requirements, and ground stress is applied to the soil through the loading plates placed on the ground surface; 4. A large longitudinal slope water-rich sandstone-mudstone interbed shield segment floating model test system according to claim 1, characterized in that, The power system is embedded on both sides of the model box and is composed of a traction frame made of square steel. The push rods are used to synchronously push the traction frame to make the shield shell move forward at a constant speed. The tunneling angle can be adjusted according to construction requirements (20‰ - 30‰, 30 - 40‰, 40 - 50‰), and it can relatively realistically simulate the process of the shield machine advancing and the segments emerging from the shield tail; 5. The floating model test system for shield segments in the interbedded strata of water-rich sandy mudstone with a large longitudinal slope according to claim 1, characterized in that, The shield system uses a double-sleeve structure to simulate the shield tail voids. The shield shell is composed of annular steel plates. The segment lining is made of transparent epoxy resin. A high-definition camera is installed inside the sleeve to accurately observe and record the diffusion path of the slurry. The shield shell is fixed by the reserved hole at the front end of the shield and the traction frame. The segment lining is fixed by a flange, and the height of the flange can be adjusted according to construction requirements to adjust the tunneling angle, and the angles include 20‰ - 30‰, 30 - 40‰, 40 - 50‰.

6. The floating model test system for shield segments in the interbedded sandstone and mudstone with large longitudinal slope and rich water according to claim 1, characterized in that, The grouting system can select the number, position, grouting volume and grouting pressure of the grouting holes according to the actual working conditions. The grouting system can adjust the grouting pressure by controlling the first air compressor. The slurry delivery pipe of each slurry storage barrel is equipped with an electromagnetic flowmeter to monitor the slurry output at all times. The grouting system is provided with an annular baffle plate behind the segment wall. The baffle plate is provided with a plurality of grouting ports along the circumferential direction. The grouting ports correspond to the slurry delivery pipes one by one according to the construction requirements. The unused grouting ports are blocked with rubber plugs during the test.

7. A large longitudinal slope water-rich sandstone-mudstone interbedded shield segment floating model test system according to claim 1, characterized in that, In the water injection system, the water storage barrel and the air compressor are connected through an air delivery pipe. The air pressure regulator is arranged on the air delivery pipe to control the water output of the water storage barrel by regulating the air delivery pressure. The water outlet of the water storage barrel is communicated with the water delivery pipe. The water delivery pipe penetrates through the loading plate and then inserts into the model soil. A valve and a water pressure gauge are installed on the water delivery pipe.

8. A large longitudinal slope water-rich sandstone and mudstone interbedded shield segment floating model test system according to claim 1, characterized in that, The monitoring elements include soil layer pressure sensors, displacement sensors and hydrodynamic pressure sensors. The monitoring elements are arranged in the model soil and are connected to the data acquisition processor through signal lines.

9. The shield segment floating model test system for large longitudinal slope water-rich interbedded sandstone and mudstone according to claim 1, characterized in that The slope leveling system includes a longitudinal slide rail, a transverse slide rail, a telescopic wire and a fixator. The fixators on the movable slide rail are linked with the telescopic wire between them to form planes with different slopes for filling the model soil.

Images