Shield tunnel synchronous grouting model test device and model test method

Abstract

The invention relates to the technical field of shield tunnels, and discloses a shield tunnel synchronous grouting model test device which comprises a model box, a shield system, a propelling system, a grouting system and a monitoring system. A fault fracture zone is arranged in the model box, and the model box is filled with model soil; the shield system comprises a simulation duct piece fixed in the model box and a simulation shield movably arranged on the outer side of the simulation duct piece in a sleeving mode. The propelling system is connected to the simulation shield and used for pulling the simulation shield out of the model box; the grouting system is used for conveying grout into the model box; the monitoring system is used for monitoring and collecting related test parameters in the synchronous grouting process. According to the shield tunnel synchronous grouting model test device provided by the invention, the technical problem that a model test device in related technologies cannot simulate a terrain structure of a fault fracture zone is solved. The invention further provides a shield tunnel synchronous grouting model test method.

Description

Technical Field

[0001] The present application relates to the technical field of shield tunnels, and in particular to a shield tunnel synchronous grouting model test device and a model test method. Background Art

[0002] The synchronous grouting model test device for shield tunnel is a test equipment used to simulate and study the synchronous grouting process in shield tunnel construction. This type of equipment allows researchers to conduct model tests in a laboratory environment to verify the effectiveness of grouting materials, grouting equipment and grouting processes, and find the optimal grouting solution.

[0003] The existing synchronous grouting model test device for shield tunnels has certain limitations and is unable to simulate complex geological conditions, such as topographic structures such as fault fracture zones, which limits the accurate analysis of the grouting effect under special geological conditions. Summary of the invention

[0004] The purpose of the present application is to provide a shield tunnel synchronous grouting model test device and a model test method, which are used to solve the technical problem that the model test device in the related art cannot simulate the terrain structure of the fault fracture zone.

[0005] In the first aspect, the present application provides a shield tunnel synchronous grouting model test device, comprising: a model box, in which a fault fracture zone is arranged and filled with model soil; a shield system, comprising a simulated segment fixed in the model box and a simulated shield movably mounted on the outside of the simulated segment, the simulated shield and the simulated segment pass through the fault fracture zone; a propulsion system, connected to the simulated shield, the propulsion system is used to pull the simulated shield out of the model box; a grouting system, comprising a slurry storage tank and a first grouting pipe, the first grouting pipe is connected between the slurry storage tank and the model box, the first grouting pipe is used to transport the slurry in the slurry storage tank to the model box; a monitoring system, comprising a sensor, the sensor is used to collect and monitor test parameters during the synchronous grouting process.

[0006] In some embodiments, the simulated shield includes a plurality of shield parts connected in sequence, and every two adjacent shield parts are detachably connected.

[0007] In some embodiments, a grouting channel is provided in the side wall of the simulated shield, and the first grouting pipe is connected to the grouting channel; or, a second grouting pipe is provided on the inner wall of the simulated shield, and the first grouting pipe is connected to the second grouting pipe.

[0008] In some embodiments, lubricating oil is coated on the outer wall of the simulated shield and / or the inner wall of the simulated shield.

[0009] In some embodiments, a hole is provided on the side wall of the model box, and the hole is used to expose the simulated shield and the simulated pipe segment; the end of the simulated pipe segment away from the hole also has a fixing plate, and the fixing plate is fixed to the side wall of the model box by fasteners; and / or, the shield tunnel synchronous grouting model test device also includes a reaction frame and a first jack, the reaction frame is installed on the outer wall of the model box and arranged opposite to the hole, one end of the first jack is fixed on the reaction frame, and the other end is against the simulated pipe segment.

[0010] In some embodiments, in the horizontal direction perpendicular to the extension direction of the simulated shield, the width of the fault fracture zone is 1.2 to 1.8 times the outer diameter of the simulated shield.

[0011] In some embodiments, the shield tunnel synchronous grouting model test device also includes a water supply system, which includes a water tank and an air compressor. The water tank is arranged above the fault fracture zone, and a drainage hole is arranged at the bottom of the water tank. The air compressor is connected to the water tank and is used to adjust the pressure in the water tank.

[0012] In some embodiments, the shield tunnel synchronous grouting model test device also includes a vertical loading device, which is arranged above the model soil and is used to apply pressure to the model soil.

[0013] In some embodiments, a reaction top plate is provided on the model box, an isolation layer is laid on the model soil, and the vertical loading device includes a second jack, one end of the second jack is fixed to the reaction top plate, and the other end abuts against the isolation layer.

[0014] The shield tunnel synchronous grouting model test device provided in the above embodiment arranges a fault fracture zone in the model box, so that the model test device can simulate the geological environment with a fault fracture zone. At the same time, by designing the shield system, the propulsion system, and the grouting system, the model test device can simulate the grouting test in the geological environment with a fault fracture zone. At the same time, by designing the monitoring system, the model test device can obtain various test parameters of the grouting test conducted in the geological environment with a fault fracture zone.

[0015] In the second aspect, the present application provides a shield tunnel synchronous grouting model test method, comprising: assembling a simulated shield and a simulated segment, and arranging the simulated shield and the simulated segment in a model box, wherein the simulated shield can be movably mounted on the outside of the simulated segment; arranging a fault fracture zone in the model box and filling it with model soil, and burying a sensor in the model box; starting a propulsion system to pull the simulated shield out of the model box; starting a grouting system to synchronously grout the gap formed between the simulated segment and the simulated soil or the fault fracture zone; and collecting test parameters.

[0016] The shield tunnel synchronous grouting model test method provided in the above embodiment simulates a geological environment with a fault fracture zone by arranging a fault fracture zone in the model box. By setting up a shield system, a propulsion system, a grouting system, and sensors and using the above components to conduct simulation tests, various test parameters of the grouting test conducted in a geological environment with a fault fracture zone can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of the structure of a synchronous grouting model test device for a shield tunnel provided in an embodiment of the present application;

[0019] Figure 2 for Figure 1 A side view of the model test apparatus shown;

[0020] Figure 3 A schematic diagram of the structure of a shield system provided in an embodiment of the present application;

[0021] Figure 4 A schematic diagram of the structure of another shield system provided in an embodiment of the present application;

[0022] Figure 5 for Figure 4 The schematic diagram of the structure of the simulated shield in the shield system shown;

[0023] Figure 6 A flow chart of a shield tunnel synchronous grouting model test method provided in an embodiment of the present application.

[0024] Description of main component symbols:

[0025] 100. Model test device; 200. Slurry;

[0026] 1. Model box; 11. Fault fracture zone; 111. Fault core; 112. Fracture zone; 12. Model soil; 2. Shield system; 21. Simulated segment; 211. Fastener; 22. Simulated shield; 221. Shield section; 222. Grouting channel; 223. Mounting slot; 23. Slurry blocking ring; 24. Shield tail brush; 3. Propulsion system; 31. Motor; 32. Screw rod; 4. Grouting system; 41. Slurry storage tank; 411. Agitator; 42. First grouting pipe; 43. Second grouting pipe; 44. Grouting pump; 45. Grouting control valve; 46. Flow meter; 5. Monitoring system; 51. Sensor; 511. Micro soil pressure sensor; 512. Pore water pressure sensor; 52. Data acquisition processor; 61. Reaction frame; 62. First jack; 7. Water supply system; 71. Water tank; 72. Air compressor; 73. Pressure gauge; 74. Pressure stabilizing control valve; 75. Permeable layer; 8. Vertical loading device; 81. Reaction top plate; 82. Second jack; 83. Isolation layer. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly or indirectly disposed on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the patent. The terms "first" and "second" are only used for the convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0029] References to "one embodiment", "some embodiments" or "an embodiment" described in the specification of this application mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some other embodiments", "in some other embodiments", etc., which appear at different places in this specification, do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. In addition, in one or more embodiments, particular features, structures or characteristics may be combined in any suitable manner.

[0030] In a first aspect, the present application provides a shield tunnel synchronous grouting model test device, which can perform a shield tunnel synchronous grouting model test in a laboratory environment.

[0031] See also Figure 1 and Figure 2 The shield tunnel synchronous grouting model test device 100 provided in the embodiment of the present application includes a model box 1, a shield system 2, a propulsion system 3, a grouting system 4 and a monitoring system 5. A fault fracture zone 11 is arranged in the model box 1 and filled with a model soil 12. The shield system 2 includes a simulated segment 21 fixed in the model box 1 and a simulated shield 22 movably sleeved on the outside of the simulated segment 21, and the simulated shield 22 and the simulated segment 21 pass through the fault fracture zone 11. The propulsion system 3 is connected to the simulated shield 22, and the propulsion system 3 is used to pull the simulated shield 22 out of the model box 1. The grouting system 4 includes a slurry storage tank 41 and a first grouting pipe 42, the first grouting pipe 42 is connected between the slurry storage tank 41 and the model box 1, and the first grouting pipe 42 is used to transport the slurry 200 in the slurry storage tank 41 to the model box 1. The monitoring system 5 includes a sensor 51, and the sensor 51 is used to collect and monitor the test parameters during the synchronous grouting process.

[0032] The model box 1 is used to simulate the actual geological environment during the shield tunnel construction process, including the different geological layers around the tunnel and the interaction between the tunnel and the surrounding strata. The model box 1 is generally made of visual materials, specifically, it can be made of transparent or translucent materials. Optionally, in some embodiments, the model box 1 is made of a high-strength transparent protective plate, and angle steel and steel plates are arranged on the outside of the box to improve the overall strength of the model box 1. Scale marks are also arranged on the side walls of the model box 1, wherein the scale marks facilitate the compaction of the model soil 12 layers.

[0033] The fault fracture zone 11 includes a fault core 111 and a fracture zone 112 surrounding the fault core 111. The fault fracture zone 11 can be composed of crushed stone, gravel, cement ash, pulverized mud ash, kerosene, clay, mortar and other materials in a certain ratio. In some cases, appropriate foam fragments, lightweight aggregates, glass beads, expanded perlite and other materials can be added as needed. The model soil 12 can be composed of fine sand, coarse sand, clay, gypsum and other materials in a certain ratio to reproduce different strata such as soft soil, sandy soil, and hard rock.

[0034] The simulated shield 22 and the simulated segment 21 are generally cylindrical pipes, which are sleeved together to form a sleeve structure, wherein the simulated shield 22 can move relatively along the simulated segment 21. The simulated shield 22 needs to provide sufficient support force and can be made of steel, but is not limited thereto. The simulated segment 21 can be made of lightweight materials and needs to bear the contact force when the simulated shield 22 is pushed forward.

[0035] The propulsion system 3 is used to simulate the power transmission mechanism of an actual shield machine. The propulsion system 3 can drive the simulated shield 22 to move relative to the simulated segment 21 to simulate the propulsion process of the actual shield in the tunnel.

[0036] The slurry storage tank 41 is used to store the slurry 200, wherein the slurry 200 can be composed of cement, fly ash, bentonite, sand, water, additives and other materials in a certain ratio. A stirrer 411 for stirring the slurry 200 is also provided in the slurry storage tank 41.

[0037] The sensor 51 includes but is not limited to a pressure sensor, a displacement sensor, and a flow sensor, and the test parameters include but are not limited to stress changes of the model soil 12, displacement of the simulated shield 22, grouting speed, and grouting volume.

[0038] The specific use of the above-mentioned shield tunnel synchronous grouting model test device 100 is as follows: using the propulsion system 3 to drive the simulated shield 22 to perform horizontal excavation movement outside the model box 1, so that the simulated shield 22 moves relative to the simulated segment 21, and a shield tail gap is formed at the tail end of the simulated shield 22, and the grouting system 4 and the monitoring system 5 are started at the same time, and the grouting system 4 is used to transport slurry 200 to the shield tail gap, so that the slurry 200 fills the shield tail gap, and the monitoring system 5 is used to collect and monitor necessary test parameters. Among them, the shield tail gap can refer to the gap formed between the model soil 12 or the fault fracture zone 11 and the simulated segment 21 at the original position after the simulated shield 22 is moved out. Filling the shield tail gap with slurry 200 can prevent the model soil 12 or the fault fracture zone 11 from collapsing.

[0039] The shield tunnel synchronous grouting model test device 100 provided in the above embodiment arranges a fault fracture zone 11 in the model box 1, so that the model test device 100 can simulate the geological environment with a fault fracture zone 11. At the same time, by designing the shield system 2, the propulsion system 3, and the grouting system 4, the model test device 100 can simulate the grouting test in the geological environment with a fault fracture zone 11. At the same time, by designing the monitoring system 5, the model test device 100 can obtain various test parameters of the grouting test conducted in the geological environment with a fault fracture zone 11.

[0040] In the embodiments provided in this application, Figure 1 As shown, the simulated shield 22 includes a plurality of shield parts 221 connected in sequence, and every two adjacent shield parts 221 are detachably connected.

[0041] The simulated shield 22 adopts a segmented assembled circular ring design. For example, multiple shield parts 221 extend along the extension direction of the simulated segment 21 (such as Figure 1 The shield parts 221 are sequentially sleeved on the outside of the simulated segments 21 in the direction indicated by X in the figure. At the splicing position of the shield parts 221, a gasket is arranged on the inner wall of one shield part 221, and a mounting hole is opened on the other shield part 221. Fasteners such as screws and bolts are arranged on the mounting hole and the gasket to connect two adjacent shield parts 221. It can be understood that a structure such as a buckle can also be designed to connect multiple shield parts 221.

[0042] With such a design, part of the shield part 221 pulled out of the model box 1 can be removed during the test, thereby avoiding the dragging process and affecting the normal advancement of the simulated shield.

[0043] It can be understood that in some embodiments, the simulated shield 22 can also be designed as an integral pipe, and during the test, a cutting machine or other tool is used to cut off part of the simulated shield 22 that is moved outside the model box 1.

[0044] In the embodiment provided in the present application, the simulated shield 22 includes a plurality of shield parts 221 connected in sequence. To further reduce the difficulty of removing the shield parts 221 , the shield parts 221 may be assembled from two semicircular rings.

[0045] In the embodiments provided in this application, Figure 1 and Figure 3 As shown, a grouting channel 222 is provided in the side wall of the simulated shield 22 , and the first grouting pipe 42 is connected to the grouting channel 222 .

[0046] The simulated shield 22 is a cylindrical pipe, and its wall has a certain thickness. A grouting channel 222 arranged along the extension direction of the simulated segment 21 can be opened on the wall of the simulated shield 22. The number of grouting channels 222 can be one or more, and the first grouting pipe 42 is correspondingly connected to one or more grouting channels 222. Optionally, in a specific embodiment, two first grouting pipes 42 are provided, and six grouting channels 222 are provided, and one first grouting pipe 42 is connected to three grouting channels 222.

[0047] With such a design, the slurry 200 in the slurry storage tank 41 can be transported to the shield tail gap via the first grouting pipe 42 and the grouting channel 222 .

[0048] In the embodiments provided in this application, Figure 1 , Figure 4 and Figure 5 As shown, a second grouting pipe 43 is provided on the inner wall of the simulated shield 22 , and the first grouting pipe 42 is connected to the second grouting pipe 43 .

[0049] The simulated shield 22 is a hollow cylindrical pipe. After the simulated shield 22 is sleeved on the simulated shield, there is still a gap between the two, and the second grouting pipe 43 can be arranged in the gap. The second grouting pipe 43 can be a thin-walled hose, and the number of the second grouting pipes 43 can be one or more, and the first grouting pipe 42 is connected to one or more second grouting pipes 43. Optionally, in a specific embodiment, two first grouting pipes 42 are provided, and six second grouting pipes 43 are provided, and one first grouting pipe 42 is connected to three second grouting pipes 43. The second grouting pipe 43 can be a thin-walled hose.

[0050] In some cases, when the gap between the simulated shield 22 and the simulated segment 21 is small, a mounting groove 223 may be provided on the inner wall of the simulated shield 22 along the extension of the simulated segment 21, and the second grouting pipe 43 may be entirely or partially provided in the mounting groove 223. The mounting groove 223 may be designed as an outward convex structure.

[0051] With such a design, the slurry 200 in the slurry storage tank 41 can be transported to the shield tail gap via the first grouting pipe 42 and the second grouting pipe 43 .

[0052] It can be understood that in some embodiments, the first grouting pipe 42 can also be directly extended and arranged in the model soil 12 or the fault fracture zone 11. The first grouting pipe 42 is arranged to fit the outer surface of the simulated shield 22. As the simulated shield 22 is continuously moved out, the slurry 200 is directly filled into the shield tail gap through the first grouting pipe 42.

[0053] In the embodiment provided in the present application, a slurry blocking ring 23 and a shield tail brush 24 are further provided at the tail end of the simulated shield 22 , and the slurry blocking ring 23 and the shield tail brush 24 are used to prevent the slurry 200 from entering the gap between the simulated shield 22 and the simulated pipe segment 21 .

[0054] In the embodiment provided in the present application, lubricating oil is coated on the outer wall of the simulated shield 22 and / or the inner wall of the simulated shield 22 .

[0055] Optionally, in some embodiments, lubricating oil is coated on both the outer wall of the simulated shield 22 and the inner wall of the simulated shield 22 .

[0056] Such a design can reduce the sliding resistance between the simulated shield 22 and the model soil 12 , the fault fracture zone 11 , and the simulated segment 21 , thereby reducing the difficulty of removing the simulated shield 22 .

[0057] In the embodiment provided in the present application, a hole (not shown) is provided on the side wall of the model box 1, and the hole is used to expose the simulated shield 22 and the simulated pipe segment 21. The simulated pipe segment 21 also has a fixing plate at one end away from the hole, and the fixing plate is fixed to the side wall of the model box 1 by fasteners; and / or, the shield tunnel synchronous grouting model test device 100 also includes a reaction frame 61 and a first jack 62, the reaction frame 61 is installed on the outer wall of the model box 1 and is arranged opposite to the hole, one end of the first jack 62 is fixed to the reaction frame 61, and the other end is against the simulated pipe segment 21.

[0058] In some embodiments, the end of the simulated segment 21 away from the hole has a fixing plate, and the fixing plate is fixed to the side wall of the model box 1 by fasteners. Optionally, in a specific embodiment, a plurality of positioning holes are respectively provided at relative positions of the fixing plate and the model box 1, and fasteners such as screws and bolts are installed in the positioning holes to connect the simulated segment 21 and the box body of the model box 1.

[0059] In some embodiments, a reaction frame 61 is provided on the outer wall of the model box 1, and a first jack 62 is provided on the reaction frame 61. The first jack 62 is located between the reaction frame 61 and the hole, and one end of the first jack 62 is fixed on the reaction frame 61, and the other end is connected to the simulated pipe segment 21. The first jack 62 is in a loaded state and can resist and support the simulated pipe segment 21.

[0060] In some embodiments, one end of the simulated segment 21 is fixed to the body of the model box 1 by a fastener, and the other end is abutted against the first jack 62 .

[0061] The propulsion system 3 is connected to one end of the simulated shield 22 near the hole, and the simulated shield 22 passes through the hole and moves out of the model box 1 under the action of the propulsion system 3. During the test, it is only necessary to pull out the simulated shield 22, and fix the simulated segment 21 in the model box 1 through the fixing plate or the first jack 62, so as to avoid displacement of the simulated segment 21, thereby improving the reliability of the test.

[0062] It can be understood that since the simulated shield 22 and the simulated segment 21 can be movably mounted together, the risk of displacement of the simulated segment 21 can also be reduced by reducing the friction between the two.

[0063] In the embodiment provided in the present application, the simulated segment 21 is an integral round tube. The material modulus of the simulated segment 21 is reduced according to the segment modulus ratio, and a slot may be provided on the outer surface of the simulated segment 21 to simulate the segment 21 joint.

[0064] Designing the simulated segment 21 as an integral structure can reduce the difficulty of assembling the simulated segment 21 and the simulated shield 22. By providing slots on the simulated segment 21, the elastic modulus of the simulated tunnel structure can be reduced.

[0065] In the embodiment provided in the present application, the dimensions of the simulated shield 22 and the simulated segment 21 are designed according to the actual proportion. Optionally, in a specific embodiment, the dimensions of the model box 1 are designed according to the geometric similarity ratio of 1:30, with a length of 1.2 m, a width of 0.9 m, and a height of 1.2 m, an inner diameter of the simulated shield 22 of 34.6 cm, and an outer diameter of the simulated segment 21 of 33.2 cm.

[0066] It can be understood that the above data are only examples and are not used to limit the sizes of the model box 1, the simulated shield 22, and the simulated segment 21. The specific sizes can be adjusted according to the test requirements.

[0067] In the embodiment provided in the present application, in the horizontal direction perpendicular to the extension direction of the simulated shield 22 (such as Figure 2 In the direction indicated by Y in the figure, the width of the fault fracture zone 11 is 1.2 to 1.8 times the outer diameter of the simulated shield 22.

[0068] Optionally, in some embodiments, the width of the fault fracture zone 11 is 1.5 times the outer diameter of the simulated shield 22 .

[0069] Such a design can reduce the risk of the shield system 2 escaping from the fault fracture zone 11 and improve the reliability of the model test device 100.

[0070] In the embodiments provided in the present application, the arrangement of the fault fracture zone 11 can be adjusted according to the test requirements. Optionally, in some embodiments, the top of the fault fracture zone 11 is exposed to the surrounding model soil 12, and the bottom contacts the bottom plate of the model box 1. The fault fracture zone 11 is inclined, and along the extension direction of the simulated segment 21, the fault fracture zone 11 is arranged in a parallelogram shape.

[0071] In the embodiments provided in this application, Figure 1 As shown, the shield tunnel synchronous grouting model test device 100 also includes a water supply system 7. The water supply system 7 includes a water tank 71 and an air compressor 72. The water tank 71 is arranged above the fault fracture zone 11. A drainage hole (not shown) is arranged at the bottom of the water tank 71. The air compressor 72 is connected to the water tank 71 and is used to adjust the pressure in the water tank 71.

[0072] The water tank 71 is of sealed design and stores a certain amount of tap water therein. The water tank 71 is made of transparent material, and a scale mark is provided on the surface of the tank.

[0073] like Figure 1 As shown, the water supply system 7 further includes a pressure gauge 73 and a pressure regulating control valve 74, wherein the pressure gauge 73 is installed on the top of the water tank 71 and connected to the water tank 71, and is used to monitor the air pressure inside the water tank 71, and the pressure regulating control valve 74 is arranged on the connecting pipeline between the water tank 71 and the air compressor 72, and is used to work with the air compressor 72 to adjust the air pressure in the water tank 71. It can be understood that the water pressure in the water tank 71 affects the water supply speed.

[0074] The water supply system 7 is used to supply water to the fault fracture zone 11 , thereby simulating the geological environment of the water-rich fault fracture zone 11 .

[0075] In some embodiments, holes for the simulated shield 22 to pass through are provided on the side walls of the model box 1. To prevent water leakage from the holes, sealing rings may be provided at the edges of the holes.

[0076] In the embodiments provided in this application, Figure 1 As shown, a permeable layer 75 is also provided between the water tank 71 and the fault fracture zone 11. The size of the permeable layer 75 is consistent with the size of the bottom plate of the water tank 71, and the permeable layer 75 has drainage pores.

[0077] The water-permeable layer 75 is made of a material with a certain hardness and has a certain thickness. Optionally, in some embodiments, the water-permeable layer 75 can be a multi-layer metal filter.

[0078] The permeable layer 75 has the functions of isolation and filtering, and can bear the pressure of the water tank 71 so that the pressure of the water tank 71 is evenly transmitted to the fault fracture zone 11.

[0079] In the embodiments provided in this application, Figure 1 As shown, the shield tunnel synchronous grouting model test device 100 also includes a vertical loading device 8, which is arranged above the model soil 12 and is used to apply pressure to the model soil 12.

[0080] On the one hand, the vertical loading device 8 can apply corresponding equivalent vertical stress according to different burial depths, so that the model test is closer to the actual engineering conditions and the reliability of the model test device 100 is improved; on the other hand, by applying pressure to the model soil 12, it is also beneficial to maintain the shape of the model soil 12 and the fault fracture zone 11 and improve the structural stability of the fault fracture zone 11.

[0081] In the embodiments provided in this application, Figure 1 As shown, the model box 1 is covered with a reaction top plate 81 , the model soil 12 is covered with an isolation layer 83 , and the vertical loading device 8 includes a second jack 82 , one end of the second jack 82 is fixed on the reaction top plate 81 , and the other end abuts against the isolation layer 83 .

[0082] The isolation layer 83 has a certain hardness and thickness. After the isolation layer 83 is provided, the loading force of the second jack 82 can be evenly transmitted to the model soil 12 .

[0083] In practical applications, the second jack 82 can be adjusted according to test requirements to accurately control the magnitude of the applied pressure, thereby improving the accuracy of the test.

[0084] It can be understood that in some embodiments, a load-bearing platform can be set above the model soil 12, and a weight block can be set on the load-bearing platform to change the loading force; or, in some embodiments, the model soil 12 can be loaded by using structures such as elastic elements and pneumatic loading systems.

[0085] In the embodiments provided in this application, Figure 1 As shown, the propulsion system 3 includes a motor 31 and a screw rod 32, wherein a nut is sleeved on the screw rod 32. One end of the screw rod 32 is connected to the simulated shield 22, and the other end is freely arranged. The motor 31 is connected to the nut and is used to drive the nut to rotate, so as to drive the screw rod 32 to reciprocate along the extension direction of the simulated shield 22, wherein the movement of the screw rod 32 can drive the simulated shield 22 to move.

[0086] It can be understood that in some embodiments, the simulated shield 22 includes multiple shield parts 221. When the shield part 221 connected to the screw rod 32 is completely moved out of the model box 1, the shield part 221 and the screw rod 32 can be removed, and the screw rod 32 can be connected to the next shield part 221.

[0087] In the embodiments provided in this application, Figure 1 As shown, the grouting system 4 also includes a grouting pump 44 , a grouting control valve 45 and a flow meter 46 .

[0088] The grouting pump 44 is used to extract and pressurize the slurry 200 from the slurry storage tank 41, and then transport it to the model box 1. According to design requirements, one or more grouting pumps 44 can be provided. Optionally, in a specific embodiment, the grouting system 4 includes two grouting pumps 44, each of which is connected to a first grouting pipe 42.

[0089] The grouting control valve 45 is disposed on the first grouting pipe 42, and is used to control the opening or closing of the slurry 200 delivery path, and to switch between different grouting modes. Optionally, in a specific embodiment, two first grouting pipes 42 are provided, and a grouting control valve 45 is disposed on each of the two first grouting pipes 42, and the grouting control valves 45 on different first grouting pipes 42 can be opened or closed separately.

[0090] The flow meter 46 is disposed at the outlet of the slurry storage tank 41 or in the first grouting pipe 42 to measure the flow velocity and flow rate of the slurry 200 .

[0091] In the embodiments provided in this application, Figure 1 As shown, the monitoring system 5 includes a micro soil pressure sensor 511, a pore water pressure sensor 512, and a displacement sensor (not shown).

[0092] The micro soil pressure sensor 511 is set in the model soil 12, and the pore water pressure sensor 512 is set in the fault fracture zone 11. The micro soil pressure sensor 511 and the pore water pressure sensor 512 are set around the simulated shield 22, and are mainly used to monitor the stress changes of the geological layer around the simulated shield 22 during the grouting process.

[0093] The displacement sensor is arranged on the surface of the propulsion system 3 or the simulated shield 22 . Optionally, the displacement sensor can be arranged on a connecting piece of the propulsion system 3 . The displacement sensor is used to monitor the propulsion distance of the simulated shield 22 .

[0094] It can be understood that the monitoring system 5 may also include other types of sensors 51 , and the number of sensors 51 of any type is not unique.

[0095] In the embodiments provided in this application, Figure 1 As shown, the monitoring system 5 further includes a data acquisition processor 52 , and the data acquisition processor 52 is electrically connected to the plurality of sensors 51 .

[0096] In a second aspect, the present application provides a shield tunnel synchronous grouting model test method.

[0097] See also Figure 1 and Figure 6 , the model test method provided in this embodiment includes:

[0098] S1, assembling the simulated shield 22 and the simulated segment 21, and placing the simulated shield 22 and the simulated segment 21 in the model box 1, wherein the simulated shield 22 can be movably sleeved on the outer side of the simulated segment 21.

[0099] The simulated shield 22 includes a plurality of shield sections 221 connected in sequence, and each two adjacent shield sections 221 are detachably connected. The simulated pipe segment 21 is an integral round tube. The simulated shield 22 and the simulated pipe segment 21 are sleeved together to form a sleeve structure, wherein the simulated shield 22 can move relatively along the simulated pipe segment 21.

[0100] The dimensions of the simulated shield 22 and the simulated segment 21 are designed based on actual proportions.

[0101] S2. Arrange the fault fracture zone 11 in the model box 1 and fill it with model soil 12, and bury the sensor 51 in the model box 1.

[0102] The fault fracture zone 11 includes a fault core 111 and a fracture zone 112 surrounding the fault core 111. The fault fracture zone 11 can be composed of crushed stone, gravel, cement ash, pulverized mud ash, kerosene, clay, mortar and other materials in a certain ratio. In some cases, appropriate foam fragments, lightweight aggregates, glass beads, expanded perlite and other materials can also be added as needed.

[0103] In the horizontal direction perpendicular to the extension direction of the simulated shield 22, the width of the fault fracture zone 11 is 1.2 to 1.8 times the outer diameter of the simulated shield 22. Optionally, in some embodiments, the width of the fault fracture zone 11 is 1.5 times the outer diameter of the simulated shield 22. The arrangement of the fault fracture zone 11 can be adjusted according to the test requirements. Optionally, in some embodiments, the top of the fault fracture zone 11 is exposed to the surrounding model soil 12, and the bottom contacts the bottom plate of the model box 1. The fault fracture zone 11 is inclined, and along the extension direction of the simulated segment 21, the fault fracture zone 11 is arranged in a parallelogram.

[0104] The model soil 12 can be composed of materials such as fine sand, coarse sand, clay, gypsum, etc. according to a certain ratio to reproduce different strata such as soft soil, sandy soil, hard rock, etc.

[0105] S3, start the propulsion system 3 to pull the simulated shield 22 out of the model box 1.

[0106] It can be understood that in some embodiments, before starting the propulsion system 3, a step of installing the propulsion system 3 is also included.

[0107] The propulsion system 3 drives the simulated shield 22 to perform horizontal excavation movement outside the model box 1, so that the simulated shield 22 moves relative to the simulated segment 21 and forms a shield tail gap at the tail end of the simulated shield 22.

[0108] The propulsion system 3 includes a motor 31 and a screw rod 32, wherein a nut is sleeved on the screw rod 32. One end of the screw rod 32 is connected to the simulated shield 22, and the other end is freely set. The motor 31 is connected to the nut and is used to drive the nut to rotate, so as to drive the screw rod 32 to move back and forth along the extension direction of the simulated shield 22, wherein the movement of the screw rod 32 can drive the simulated shield 22 to move. It can be understood that in some embodiments, the simulated shield 22 includes a plurality of shield parts 221, and when the shield part 221 connected to the screw rod 32 is completely moved out of the model box 1, the shield part 221 and the screw rod 32 can be removed, and the screw rod 32 can be connected to the next shield part 221.

[0109] S4, starting the grouting system 4 to synchronously inject grout into the gap formed between the simulated pipe segment 21 and the simulated soil or fault fracture zone 11.

[0110] It can be understood that in some embodiments, before starting the grouting system 4, a step of installing the grouting system 4 is also included.

[0111] The grouting system 4 is used to deliver slurry 200 to the gap at the shield tail, so that the slurry 200 fills the gap at the shield tail. The grouting speed should match the pulling speed of the simulated shield 22.

[0112] The grouting system 4 includes a slurry storage tank 41, a first grouting pipe 42, a grouting pump 44, a grouting control valve 45 and a flow meter 46. The slurry storage tank 41 is used to store the slurry 200. The first grouting pipe 42 is connected between the slurry storage tank 41 and the model box 1, and is used to transport the slurry 200 in the slurry storage tank 41 to the model box 1. The grouting pump 44 is used to extract and pressurize the slurry 200 from the slurry storage tank 41, and then transport it to the model box 1. The grouting control valve 45 is arranged on the first grouting pipe 42, and is used to control the opening or closing of the slurry 200 transportation path. The flow meter 46 is arranged at the outlet of the slurry storage tank 41 or in the first grouting pipe 42, and is used to measure the flow rate and flow of the slurry 200.

[0113] S5. Collect test parameters.

[0114] The test parameters include, but are not limited to, stress changes of the model soil 12, displacement of the simulated shield 22, grouting speed, and grouting volume. The test parameters can be used to evaluate the grouting effect.

[0115] It can be understood that after step S9, the model test method also includes post-test processing, which includes but is not limited to cleaning the grouting system 4, letting the slurry 200 in the slurry storage tank 41 stand and solidify, taking out the grouting body in the model box 1, and measuring and recording processing data.

[0116] The shield tunnel synchronous grouting model test method provided in the above embodiment simulates a geological environment with a fault fracture zone 11 by arranging a fault fracture zone 11 in a model box 1. By setting up a shield system 2, a propulsion system 3, a grouting system 4, and a sensor 51 and using the above components to perform simulation tests, various test parameters of the grouting test conducted in a geological environment with a fault fracture zone 11 can be obtained.

[0117] In the embodiment provided in the present application, before step S1 , the method further includes: coating lubricating oil on the outer wall and the inner wall of the simulated shield 22 .

[0118] Applying lubricating oil on the outer wall of the simulated shield 22 can reduce the sliding resistance between the simulated shield 22 and the model soil 12 and the fault fracture zone 11. Applying lubricating oil on the inner wall of the simulated shield 22 can reduce the sliding resistance between the simulated shield 22 and the simulated pipe segment 21, thereby reducing the difficulty of removing the simulated shield 22.

[0119] In the embodiment provided in the present application, in step S2, burying the sensor 51 in the model box 1 includes: burying a micro soil pressure sensor 511 in the model soil 12, and burying a pore water pressure sensor 512 in the fault fracture zone 11.

[0120] The micro soil pressure sensor 511 and the pore water pressure sensor 512 are arranged around the simulated shield 22 and are mainly used to monitor the stress changes of the geological layer around the simulated shield 22 during the grouting process.

[0121] In some embodiments provided in the present application, after step S2 and before step S3, the method further includes: installing a water supply system 7 above the fault fracture zone 11 , and installing a vertical loading device 8 above the model soil 12 .

[0122] The water supply system 7 is used to supply water to the fault fracture zone 11 , thereby simulating the geological environment of the water-rich fault fracture zone 11 .

[0123] The water supply system 7 includes a water tank 71, a barometer 73, an air compressor 72 and a pressure-stabilizing control valve 74. The water tank 71 is arranged above the fault fracture zone 11, and a certain amount of tap water is stored therein, and a drainage hole is arranged at the bottom. The water tank 71 is made of a transparent material, and a scale mark is arranged on the surface of the tank. The barometer 73 is installed on the top of the water tank 71 and connected to the water tank 71, and is used to monitor the air pressure inside the water tank 71. The pressure-stabilizing control valve 74 is arranged on the connecting pipeline between the water tank 71 and the air compressor 72, and is used to work with the air compressor 72 to adjust the air pressure in the water tank 71.

[0124] The vertical loading device 8 is disposed above the model soil 12 , and is used to apply pressure to the model soil 12 .

[0125] The vertical loading device 8 includes but is not limited to a jack, an elastic element, and a pneumatic loading system.

[0126] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A shield tunnel synchronous grouting model test device, characterized in that: include: A model box, wherein a fault fracture zone is arranged in the model box and the model soil is filled; A shield system, comprising a simulated segment fixed in the model box and a simulated shield movably sleeved on the outside of the simulated segment, wherein the simulated shield and the simulated segment pass through the fault fracture zone; A propulsion system connected to the simulated shield, wherein the propulsion system is used to pull the simulated shield out of the model box; The grouting system comprises a slurry storage tank and a first grouting pipe, wherein the first grouting pipe is connected between the slurry storage tank and the model box, and the first grouting pipe is used to transport the slurry in the slurry storage tank to the model box; The monitoring system comprises sensors, wherein the sensors are used to collect and monitor test parameters during the synchronous grouting process.

2. The shield tunnel synchronous grouting model test device according to claim 1, characterized in that: The simulated shield includes a plurality of shield parts connected in sequence, and every two adjacent shield parts are detachably connected.

3. The shield tunnel synchronous grouting model test device according to claim 1, characterized in that: A grouting channel is provided in the side wall of the simulated shield, and the first grouting pipe is connected to the grouting channel; or, A second grouting pipe is arranged on the inner wall of the simulated shield, and the first grouting pipe is connected to the second grouting pipe.

4. The shield tunnel synchronous grouting model test device according to claim 1, characterized in that: Lubricating oil is coated on the outer wall of the simulated shield and / or the inner wall of the simulated shield.

5. The shield tunnel synchronous grouting model test device according to claim 1, characterized in that: The side wall of the model box is provided with holes, and the holes are used to expose the simulated shield and the simulated segments; The simulated pipe segment also has a fixing plate at one end away from the hole, and the fixing plate is fixed to the side wall of the model box by fasteners; and / or, the shield tunnel synchronous grouting model test device also includes a reaction frame and a first jack, the reaction frame is installed on the outer wall of the model box and arranged opposite to the hole, one end of the first jack is fixed to the reaction frame, and the other end is against the simulated pipe segment.

6. The shield tunnel synchronous grouting model test device according to any one of claims 1 to 5, characterized in that: In the horizontal direction perpendicular to the extension direction of the simulated shield, the width of the fault fracture zone is 1.2 to 1.8 times the outer diameter of the simulated shield.

7. The shield tunnel synchronous grouting model test device according to any one of claims 1 to 5, characterized in that: It also includes a water supply system, which includes a water tank and an air compressor. The water tank is arranged above the fault fracture zone, and a drainage hole is arranged at the bottom of the water tank. The air compressor is connected to the water tank and is used to adjust the pressure in the water tank.

8. The shield tunnel synchronous grouting model test device according to any one of claims 1 to 5, characterized in that: It also includes a vertical loading device, which is arranged above the model soil and is used to apply pressure to the model soil.

9. The shield tunnel synchronous grouting model test device according to claim 8, characterized in that: The model box is covered with a reaction top plate, the model soil is covered with an isolation layer, and the vertical loading device includes a second jack, one end of the second jack is fixed on the reaction top plate, and the other end abuts against the isolation layer.

10. A shield tunnel synchronous grouting model test method, characterized in that: include: Assembling a simulated shield and a simulated segment, and placing the simulated shield and the simulated segment in a model box, wherein the simulated shield can be movably sleeved on the outer side of the simulated segment; Arranging the fault fracture zone in the model box and filling the model soil, and burying the sensor in the model box; Starting a propulsion system to pull the simulated shield out of the model box; Starting a grouting system to synchronously inject grout into a gap formed between the simulated pipe segment and the simulated soil or the fault fracture zone; Collect test parameters.

Images