Soft soil grouting simulation test device

Abstract

The invention relates to the technical field of grouting simulation, and particularly discloses a soft soil grouting simulation test device which comprises a fixing frame, a test pipe arranged in the fixing frame and provided with an opening in the upper end, a sealing plug arranged at the opening of the test pipe in a sliding mode, a pressurizing device arranged above the sealing plug and a grouting device connected with the side wall of the test pipe. The water injection device is connected with the side wall of the test tube; the fixing frame comprises a bottom plate arranged on the lower side of the test tube, a cover plate arranged above the sealing plug, and a plurality of connecting rods for connecting the bottom plate and the cover plate; the pressurizing device comprises a jack arranged on the lower side of the cover plate and a plurality of buffer devices arranged on the lower side of the cover plate; the buffering device comprises buffering pipes vertically arranged on the lower side of the cover plate, buffering rods arranged in the buffering pipes in a sealed and sliding mode, and an air storage device connected with the multiple buffering pipes at the same time. The lower end of the buffer rod abuts against the sealing plug. The soft soil grouting simulation test device can effectively simulate the actual condition of a soft soil layer in the grouting process.

Description

Technical Field

[0001] The invention relates to the technical field of grouting simulation, in particular to a soft soil grouting simulation test device. Background Art

[0002] Grouting simulation devices are essential tools for studying the grouting process. Their core function is to investigate the diffusion patterns of grouting materials under different working conditions and to simulate and analyze the effects of water blocking, anti-seepage, and reinforcement. Currently, most commercially available simulated stratum grouting and reinforcement test devices focus on highly permeable geological structures such as sandstone and gravel formations. These devices allow researchers to effectively observe the diffusion path and penetration efficiency of slurry in permeable media, providing theoretical basis and data support for grouting projects in permeable formations.

[0003] However, the simulation research of grouting reinforcement for soft soil strata is still in a technological vacuum. Soft soil strata inherently possess low strength, strong thixotropy, and poor permeability. These characteristics can easily lead to soft soil disturbance during actual grouting operations. Specifically, the grouting pressure forces the soft soil to be compacted by the slurry. When the pressure exceeds the soil's tolerance limit, cracks can form in the soil. More directly, the injection of large amounts of slurry can cause ground uplift, seriously impacting both project quality and the safety of the surrounding environment.

[0004] In view of this, it is urgent to develop an experimental device that fits the characteristics of soft soil and can accurately simulate the actual state of soft soil during the grouting process. Summary of the Invention

[0005] The purpose of the present invention is to provide a soft soil grouting simulation test device, which can effectively simulate the actual situation of the soft soil layer during the grouting process.

[0006] The present invention is achieved through the following technical solutions: the soft soil grouting simulation test device of the present invention includes a fixing frame, a test tube with an upper end opened in the fixing frame, a sealing plug slidably arranged at the opening of the test tube, a pressurizing device arranged above the sealing plug, a grouting device connected to the side wall of the test tube, and a water injection device connected to the side wall of the test tube; the fixing frame includes a bottom plate arranged at the lower side of the test tube, a cover plate arranged above the sealing plug, and a plurality of connecting rods for connecting the bottom plate and the cover plate; the pressurizing device includes a jack arranged at the lower side of the cover plate, and a plurality of buffer devices arranged at the lower side of the cover plate; the movable end of the jack abuts against the upper side of the sealing plug; the buffer device includes a buffer tube vertically arranged at the lower side of the cover plate, a buffer rod sealingly and slidably arranged in the buffer tube, and an air storage device simultaneously connected to a plurality of buffer tubes; the lower end of the buffer rod abuts against the sealing plug.

[0007] Furthermore, the cylinder of the jack is fixedly connected to the lower side of the cover plate; a first pressure plate is fixedly provided on the movable end of the jack; and the lower side of the first pressure plate abuts against the upper side of the sealing plug.

[0008] Furthermore, the gas storage device includes an air tank arranged on the upper side of the cover plate, a plurality of air guide pipes for connecting the air tank and the buffer tube, an air relief valve arranged on the air tank, and an air inlet nozzle arranged on the air tank.

[0009] Furthermore, a connecting piece is provided at the upper end of the buffer tube, and a first air guide hole is opened on the connecting piece, and the connecting piece is sealed and fixedly connected to the cover plate; the cover plate is opened with a plurality of second air guide holes, and the air guide tube is connected to the upper end of the air guide hole; the first air guide hole and the second air guide hole correspond one to one, and the air guide tube is connected to the buffer tube through the first air guide hole and the second air guide hole.

[0010] Furthermore, a second pressing plate is provided at the lower end of the buffer rod, and the lower side of the second pressing plate abuts against the upper side of the sealing plug.

[0011] Furthermore, the fixing frame also includes a first connecting ring provided on the upper side of the base plate, and a second connecting ring provided on the lower side of the cover plate; the lower ends of multiple connecting rods are fixedly connected to the first connecting ring at the same time, and the upper ends of multiple connecting rods are fixedly connected to the second connecting ring at the same time; the first connecting ring is detachably connected to the base plate, and the second connecting ring is detachably connected to the cover plate.

[0012] Furthermore, the grouting device includes a slurry storage tank, a pump body arranged in the slurry storage tank, and a grouting pipe arranged at the outlet end of the pump body; the grouting pipe is connected to the middle part of the test tube.

[0013] Furthermore, the pressurizing device includes a water tank, a water pipe connected to the lower side wall of the water tank, a pressurizing pipe connected to the upper end of the water tank, and an air compressor connected to the pressurizing pipe; the water pipe is connected to the upper side wall of the test tube; the height of the connection between the water pipe and the test tube is lower than the height of the lower end surface of the sealing plug.

[0014] Furthermore, the projection of the sealing plug on the vertical plane is T-shaped, and the diameter of the upper end surface of the sealing plug is larger than the diameter of the test tube.

[0015] The technical solution of the present invention has at least the following advantages and beneficial effects: The soft soil grouting simulation test device of the present invention is pre-filled with soft soil into a test tube. Slurry is then injected into the test tube using a grouting device, and liquid is injected into the test tube using a water injection device. By adjusting the water injection distance of the water injection device, grouting conditions under different head pressures can be simulated. In the early stages of grouting, a jack in a pressure-applying device can be used to press the sealing plug downward, thereby quickly increasing the pressure in the test tube to a preset value. Grouting then continues, at which point the jack's pressure on the sealing plug is released (the jack's movable end moves upward a certain distance). The grouting slurry then compresses the piston plate upward (the piston plate's upward movement pushes a buffer rod into the buffer tube. By pre-injecting a rated air pressure into the air storage device, the buffer rod can withstand the upward thrust of the sealing plug and ensure a slow upward movement of the sealing plug under this thrust). This device can thus simulate the disturbance of soft soil during grouting, simulating conditions such as compaction and splitting of the soft soil by the slurry, and better simulating the actual conditions of the soft soil layer during upward grouting from the tunnel top. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of a soft soil grouting simulation test device provided in an embodiment of the present invention; Figure 2 A schematic structural diagram of a test tube portion provided in an embodiment of the present invention; Figure 3 for Figure 2 A cross-sectional view along the vertical direction; Figure 4 A schematic structural diagram of a fixing frame portion provided in an embodiment of the present invention; Figure 5 A schematic structural diagram of a pressure device according to an embodiment of the present invention from one perspective; Figure 6 A schematic structural diagram of a pressurizing device according to an embodiment of the present invention from two perspectives; Figure 7 for Figure 3 Enlarged view of part A.

[0017] Icons: 10-fixed frame, 11-base plate, 12-cover plate, 13-connecting rod, 14-first connecting ring, 15-second connecting ring, 20-test tube, 21-sealing plug, 30-pressurization device, 31-jack, 32-first pressure plate, 33-buffer device, 331-buffer tube, 332-buffer rod, 333-second pressure plate, 334-connecting plate, 335-first air guide hole, 336-second air guide hole, 34-air storage device, 341-air storage tank, 342-air guide pipe, 343-air relief valve, 344-air inlet nozzle, 40-grouting device, 41-slurry storage tank, 42-grouting pipe, 50-water injection device, 41-water storage tank, 52-water guide pipe, 53-air compressor, 54-pressurization pipe. DETAILED DESCRIPTION

[0018] Example The following is further described in conjunction with specific embodiments. Figure 1 -Attached Figure 7As shown, the soft soil grouting simulation test device of this embodiment includes a fixing frame 10, a test tube 20 with an upper end opened and disposed in the fixing frame 10, a sealing plug 21 slidably disposed at the opening of the test tube 20, a pressurizing device 30 disposed above the sealing plug 21, a grouting device 40 connected to the side wall of the test tube 20, and a water injection device 50 connected to the side wall of the test tube 20; the fixing frame 10 includes a bottom plate 11 disposed on the lower side of the test tube 20, a cover plate 12 disposed above the sealing plug 21, and a plurality of The connecting rod 13 between the bottom plate 11 and the cover plate 12; the pressurizing device 30 includes a jack 31 provided on the underside of the cover plate 12, and multiple buffer devices 33 provided on the underside of the cover plate 12; the movable end of the jack 31 abuts against the upper side of the sealing plug 21; the buffer device 33 includes a buffer tube 331 vertically provided on the underside of the cover plate 12, a buffer rod 332 sealingly slidingly provided in the buffer tube 331, and an air storage device 34 simultaneously connected to the multiple buffer tubes 331; the lower end of the buffer rod 332 abuts against the sealing plug 21. Specifically, during use, soft soil is pre-filled into the test tube 20, and then slurry is injected into the test tube 20 using the grouting device 40. Liquid is then injected into the test tube 20 using the water injection device 50. By adjusting the water injection distance of the water injection device 50, grouting conditions under different head pressures can be simulated. In the early stages of grouting, the jack 31 in the pressure-applying device 30 can be used to press the sealing plug 21 downward, thereby quickly raising the pressure in the test tube 20 to a preset value. Grouting then continues, and the pressure from the jack 31 on the sealing plug 21 is removed (the movable end of the jack 31 moves upward a certain distance). The grouting slurry compresses the piston plate upward (this upward movement pushes the buffer rod 332 into the buffer tube 331. By pre-injecting a rated air pressure into the air storage device 34, the buffer rod 332 can withstand the upward thrust of the sealing plug 21 and ensure that the sealing plug 21 rises slowly under this thrust). This simulates the disturbance of soft soil during grouting, simulating the compaction and splitting of the soft soil by the slurry, and better simulating the actual conditions of the soft soil layer during upward grouting from the tunnel top. It should be noted that in the early stages of grouting and water injection, the gas in the test tube 20 is discharged through an exhaust pipe (not shown).

[0019] In this embodiment, the cylinder of the jack 31 is fixedly connected to the underside of the cover plate 12; a first pressure plate 32 is fixedly mounted on the movable end of the jack 31; and the underside of the first pressure plate 32 abuts against the upper side of the sealing plug 21. Specifically, the larger first pressure plate 32 provided at the movable end of the jack 31 effectively increases the contact area between the jack 31 and the sealing plug 21, preventing deformation of the sealing plug 21. Furthermore, during the initial rise of the sealing plug 21, the first pressure plate 32 moves upward a certain distance, which determines the upper limit of the movable height of the sealing plug 21, effectively preventing the sealing plug 21 from falling out of the test tube 20. Furthermore, the range of motion of the buffer rod 332 is also limited. Therefore, the dual action of the jack 31 and the buffer rod 332 effectively prevents the sealing plug 21 from falling out of the test tube 20.

[0020] The gas storage device 34 in this embodiment includes a gas tank 341 disposed on the upper side of the cover plate 12, a plurality of gas guide tubes 342 for connecting the gas tank 341 and the buffer tubes 331, a gas relief valve 343 disposed on the gas tank 341, and an air inlet nozzle 344 disposed on the gas tank 341. Specifically, by connecting an air compressor to the gas inlet nozzle 344, the gas tank 341 can be inflated, thereby simultaneously adjusting the pressure that the multiple buffer rods 332 can withstand. After the test is completed, the high-pressure gas in the gas tank 341, gas guide tubes 342, and buffer tubes 331 can be discharged through the gas relief valve 343. Before releasing the force from the jack 31, the air tank 341 can be inflated using an air compressor. A pressure sensor can be installed on the underside of the first pressure plate 32. When the pressure value of the pressure sensor gradually decreases to near 0, it can be determined that the jack 31 has lost its force on the sealing plug 21. At this point, the force of the sealing plug 21 is fully applied to the multiple buffer rods 332. The first pressure plate 32 is then lifted a certain distance and fixed. Grouting can then be continued, and during the grouting process, air can be slowly released through the air release valve 343. This release reduces the air pressure in the air tank 341 and the buffer tube 331, allowing the sealing plug 21 to push the buffer rods 332 and slowly move upward until it reaches the upper limit (i.e., the buffer rods 332 contact the cover plate 12, or the sealing plug 21 contacts the first pressure plate 32).

[0021] In this embodiment, a connecting piece 334 is provided at the upper end of the buffer tube 331. This connecting piece 334 defines a first air guide hole 335 and is sealed and fixedly connected to the cover plate 12. The cover plate 12 defines a plurality of second air guide holes 336, and an air guide tube 342 communicates with the upper ends of these air guide holes. The first air guide holes 335 correspond to the second air guide holes 336, and the air guide tube 342 communicates with the buffer tube 331 through the first and second air guide holes 335, 336. Specifically, the air guide tube 342 communicates with the interior of the buffer tube 331 through the first and second air guide holes 335, 336. This avoids opening holes in the sidewall of the buffer tube 331, allowing the buffer rod 332 to move to the end of the buffer tube 331, thus providing a longer travel range.

[0022] In this embodiment, the lower end of the buffer rod 332 is provided with a second pressing plate 333, and the lower side of the second pressing plate 333 abuts the upper side of the sealing plug 21. Specifically, the second pressing plate 333 provided at the lower end of the buffer rod 332 can increase the contact area between the buffer rod 332 and the sealing plug 21.

[0023] The fixing frame 10 in this embodiment also includes a first connecting ring 14 disposed on the upper side of the base plate 11 and a second connecting ring 15 disposed on the lower side of the cover plate 12. The lower ends of multiple connecting rods 13 are simultaneously fixedly connected to the first connecting ring 14, and the upper ends of multiple connecting rods 13 are simultaneously fixedly connected to the second connecting ring 15. The first connecting ring 14 is detachably connected to the base plate 11, and the second connecting ring 15 is detachably connected to the cover plate 12. Specifically, the base plate 11, first connecting ring 14, connecting rods 13, second connecting ring 15, and cover plate 12 form a structure similar to a reaction frame. The test tube 20 can be removed by removing the bolts connecting the base plate 11 and the first connecting ring 14, or by removing the bolts connecting the cover plate 12 and the second connecting ring 15.

[0024] The grouting device 40 in this embodiment includes a slurry storage tank 41, a pump body disposed in the slurry storage tank 41, and a grouting pipe 42 disposed at the outlet end of the pump body; the grouting pipe 42 is connected to the middle of the test tube 20. Specifically, the pump body injects the slurry in the slurry storage tank 41 into the test tube 20 through the grouting pipe 42.

[0025] The pressurizing device 30 in this embodiment includes a water tank, a water conduit 52 connected to the lower sidewall of the water tank, a pressurizing pipe 54 communicating with the upper end of the water tank, and an air compressor 53 connected to the pressurizing pipe 54. The water conduit 52 is connected to the upper sidewall of the test tube 20. The height of the connection between the water conduit 52 and the test tube 20 is lower than the height of the lower end surface of the sealing plug 21. Specifically, the air compressor 53 pressurizes the water tank through the pressurizing pipe 54, thereby forcing the water in the water tank into the end of the test tube 20 near the sealing plug 21, effectively simulating the pressure at the water head.

[0026] The projection of the sealing plug 21 on the vertical plane in this embodiment is T-shaped, and the diameter of the upper end surface of the sealing plug 21 is larger than the diameter of the test tube 20. Specifically, the upper end surface of the sealing plug 21 has a larger area, which can better contact the first pressing plate 32 and the second pressing plate 333.

[0027] In summary, the soft soil grouting simulation test device of this embodiment is used by pre-filling the test tube 20 with soft soil. Grouting device 40 then injects slurry into the test tube 20. Liquid is then injected into the test tube 20 via water injection device 50. By adjusting the distance of water injection device 50, grouting conditions under different head pressures can be simulated. In the early stages of grouting, the sealing plug 21 can be pressed downward by jack 31 in pressurizing device 30, thereby quickly increasing the pressure in the test tube 20 to a preset value. Then continue grouting, at this time, the pressure of the jack 31 on the sealing plug 21 is released (the movable end of the jack 31 moves upward a certain distance), and the piston plate will be pushed up under the squeezing of the grouting slurry (when the piston plate moves up, the buffer rod 332 will be pushed into the buffer tube 331, and by injecting the rated air pressure into the air storage device 34 in advance, the buffer rod 332 can withstand the upward thrust of the sealing plug 21 and ensure that the sealing plug 21 rises slowly under this thrust), thereby simulating the situation where the soft soil is disturbed during grouting, simulating the situation where the soft soil is compacted and split by the slurry, etc., and can better simulate the actual situation of the soft soil layer during the upward grouting process from the top of the tunnel.

[0028] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A soft soil grouting simulation test device, characterized by: The invention comprises a fixing frame (10), a test tube (20) arranged in the fixing frame (10) and having an upper end open, a sealing plug (21) slidably arranged at the opening of the test tube (20), a pressurizing device (30) arranged above the sealing plug (21), a grouting device (40) connected to the side wall of the test tube (20), and a water injection device (5) connected to the side wall of the test tube (20); The fixing frame (10) comprises a bottom plate (11) provided on the lower side of the test tube (20), a cover plate (12) provided above the sealing plug (21), and a plurality of connecting rods (13) for connecting the bottom plate (11) and the cover plate (12); The pressurizing device (30) includes a jack (31) provided on the lower side of the cover plate (12), and a plurality of buffer devices (33) provided on the lower side of the cover plate (12); the movable end of the jack (31) abuts against the upper side of the sealing plug (21); The buffer device (33) includes a buffer tube (331) vertically arranged on the lower side of the cover plate (12), a buffer rod (332) sealingly and slidingly arranged in the buffer tube (331), and an air storage device (34) simultaneously connected to multiple buffer tubes (331); the lower end of the buffer rod (332) abuts against the sealing plug (21).

2. The soft soil grouting simulation test device according to claim 1, characterized in that: The cylinder of the jack (31) is fixedly connected to the lower side of the cover plate (12); a first pressing plate (32) is fixedly provided at the movable end of the jack (31); the lower side of the first pressing plate (32) abuts against the upper side of the sealing plug (21).

3. The soft soil grouting simulation test device according to claim 1, characterized in that: The gas storage device (34) includes a gas storage tank (341) provided on the upper side of the cover plate (12), a plurality of air guide pipes (342) for connecting the gas storage tank (341) and the buffer tube (331), a gas relief valve (343) provided on the gas storage tank (341), and an air inlet nozzle (344) provided on the gas storage tank (341).

4. The soft soil grouting simulation test device according to claim 3, characterized in that: A connecting piece (334) is provided at the upper end of the buffer tube (331), the connecting piece (334) is provided with a first air guide hole (335), and the connecting piece (334) is sealed and fixedly connected to the cover plate (12); The cover plate (12) is provided with a plurality of second air guide holes (336), and the air guide pipe (342) is connected to the upper ends of the air guide holes; the first air guide holes (335) and the second air guide holes (336) correspond one to one, and the air guide pipe (342) is connected to the buffer tube (331) through the first air guide holes (335) and the second air guide holes (336).

5. The soft soil grouting simulation test device according to claim 1, characterized in that: A second pressing plate (333) is provided at the lower end of the buffer rod (332), and the lower side of the second pressing plate (333) abuts against the upper side of the sealing plug (21).

6. The soft soil grouting simulation test device according to claim 1, characterized in that: The fixing frame (10) further comprises a first connecting ring (14) provided on the upper side of the base plate (11), and a second connecting ring (15) provided on the lower side of the cover plate (12); The lower ends of the plurality of connecting rods (13) are simultaneously fixedly connected to the first connecting ring (14), and the upper ends of the plurality of connecting rods (13) are simultaneously fixedly connected to the second connecting ring (15); The first connecting ring (14) is detachably connected to the bottom plate (11), and the second connecting ring (15) is detachably connected to the cover plate (12).

7. The soft soil grouting simulation test device according to claim 1, characterized in that: The grouting device (40) comprises a slurry storage tank (41), a pump body arranged in the slurry storage tank (41), and a grouting pipe (42) arranged at the outlet end of the pump body; the grouting pipe (42) is connected to the middle part of the test tube (20).

8. The soft soil grouting simulation test device according to claim 1, characterized in that: The pressurizing device (30) includes a water tank, a water guide pipe (52) connected to the side wall of the lower end of the water tank, a pressurizing pipe (54) communicating with the upper end of the water tank, and an air compressor (53) connected to the pressurizing pipe (54); The water conduit (52) is connected to the upper side wall of the test tube (20); the height of the connection between the water conduit (52) and the test tube (20) is lower than the height of the lower end surface of the sealing plug (21).

9. The soft soil grouting simulation test device according to claim 1, characterized in that: The projection of the sealing plug (21) on the vertical plane is T-shaped, and the diameter of the upper end surface of the sealing plug (21) is larger than the diameter of the test tube (20).

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