Device and method for studying flow law of grouting liquid on side of pipe pile following the drill

Abstract

The present invention relates to the technical field of pile foundation engineering tests, and specifically discloses a device and method for studying the flow law of grouting liquid on the side of the pipe-sinking pile while drilling. The device includes a model box system and a grouting system; the model box system includes a model box, a model pile, a grout stop plate, and a grouting pipe; the model box is filled with soil, and a simulated drilling hole is arranged in the soil. The diameter of the simulated drilling hole is larger than the diameter of the model pile, and the model pile is coaxially arranged in the simulated drilling hole; the grouting pipe is arranged in the model pile, and grouting holes are arranged on the model pile. The grouting holes are communicated with the gap between the model pile and the soil, and the grouting pipe is communicated with the grouting holes; the grout stop plate is provided with a through hole adapted to the model pile, and the grout stop plate is sleeved on the upper end of the model pile through the through hole to cover the gap; the slurry outlet of the grouting system is communicated with the grouting pipe. The device of the present invention can more realistically reproduce the environment of the grouting liquid flow, so that when studying and analyzing the flow law of the grouting liquid in the gap on the side of the pile, the results are closer to the reality.

Description

Technical Field

[0001] The present invention relates to the technical field of pile foundation engineering tests, and particularly to a device and method for studying the flow law of grouting liquid on the side of a pipe pile following drilling. Background Art

[0002] The pipe pile following drilling is an environment-friendly large-diameter (800 - 1400 mm) non-displacement pipe pile that drills, sinks the pile, and discharges soil simultaneously without mud discharge. The successful development of this pile type has solved the problem of pile sinking caused by a large pile diameter or hard soil layer. Its super strong formation adaptability enables large-diameter pipe piles to penetrate moderately weathered and slightly weathered rock layers, achieving full rock embedding at the pile tip, with high bearing capacity (the ultimate bearing capacity of a single pile with the same diameter has increased by 20.97% - 64.24%); it avoids damage to the pile body of the pipe pile by the hammering method and the static pressure method; the construction process does not require mud slurry to protect the wall, is relatively environmentally friendly, and has low noise; the diameter of the pipe pile is expanded to 800 - 1400 mm.

[0003] The unique construction technology of this pile type results in a gap of about 10 mm between the large-diameter pipe pile and the surrounding soil. It is necessary to fill this gap with cement slurry or cement mortar to increase the side friction resistance of the pile, and ultimately improve the bearing capacity of the pile foundation. Engineering practice shows that the flow characteristics of the slurry in the grouting gap greatly affect the ultimate skin friction and ultimate bearing capacity of the pipe pile following drilling. Therefore, the research on the flow and diffusion law of the grouting liquid in the side gap of the pile is of great significance for improving the ultimate skin friction and ultimate bearing capacity of the pipe pile following drilling. However, the current experimental devices and methods for studying the flow law of the grouting liquid on the side of the pile have problems such as non-standard and non-rigorous means, resulting in a large error between the experimental results and the actual situation.

[0004] Therefore, there is an urgent need for a new experimental device and experimental method to study the flow law of the grouting liquid. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a device for studying the flow law of grouting liquid on the side of a pipe pile following drilling. This device more realistically restores the formation environment, making the flow law of the grouting liquid obtained in the study in the side gap of the pile closer to the actual situation.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A device for studying the flow law of the grouting liquid on the side of the pipe - following pile while drilling, comprising a model box system and a grouting system; the model box system includes a model box, a model pile, a grout - stopping plate, and a grouting pipe; the model box is filled with soil, a simulated borehole is arranged in the soil, the diameter of the simulated borehole is larger than the diameter of the model pile, the model pile is coaxially arranged in the simulated borehole; the grouting pipe is arranged in the model pile, grouting holes are arranged on the model pile, the grouting holes are communicated with the gap between the model pile and the soil, and the grouting pipe is communicated with the grouting holes; the grout - stopping plate is provided with a through - hole adapted to the model pile, and the grout - stopping plate is sleeved on the upper end of the model pile through the through - hole to cover the gap; the slurry outlet of the grouting system is communicated with the grouting pipe.

[0008] Preferably, a support platform is arranged in the model box, several limiting members are arranged on the support platform, the model pile is arranged on the support platform and located in the space surrounded by the limiting members, and the model pile abuts against the limiting members.

[0009] Preferably, a sleeve is further included. When filling soil in the model box, the sleeve is arranged in the model box so that a simulated borehole is formed in the soil when the sleeve is withdrawn.

[0010] Preferably, the inner side surface of the sleeve abuts against the limiting members.

[0011] Preferably, a breathable layer is arranged between the grout - stopping plate and the model pile.

[0012] Preferably, a first notch is arranged on the bottom - end pile wall of the model pile, the first notch is the grouting hole, a second notch is arranged on the bottom - end pipe wall of the grouting pipe corresponding to the first notch, and the first notch is communicated with the second notch.

[0013] Preferably, a bottom - sealing member for sealing the bottom end of the model pile is arranged in the model pile, and the first notch and the second notch are buried in the bottom - sealing member.

[0014] Preferably, the model box includes a first semi - cylinder and a second semi - cylinder, and the first semi - cylinder and the second semi - cylinder are detachably connected and fixed by fixing members.

[0015] Preferably, the grouting system includes a mixing pool, a grouting machine for injecting the slurry in the mixing pool into the grouting pipe, and a slurry - conveying pipe for connecting the mixing pool with the grouting machine and the grouting machine with the grouting pipe.

[0016] On the other hand, the present invention also discloses a method for studying the flow law of the grouting liquid on the side of the pipe - following pile while drilling, comprising the following steps:

[0017] Construct the device as described above, and start the grouting system to grout into the gap after the construction of the device is completed;

[0018] Take out the model pile solidified with the slurry, and use three-dimensional scanning technology to obtain the three-dimensional view of the model pile solidified with the slurry. The three-dimensional view includes three-dimensional point cloud coordinate data and spatial point position information;

[0019] Use panoramic flattening image technology to flatten the three-dimensional view to obtain the three-dimensional space distribution form, geometric dimensions of the solidified slurry, and the area covering the model pile;

[0020] Adjust the grouting parameters and repeat the above steps to obtain the three-dimensional space distribution form, geometric dimensions of the solidified slurry, and the area covering the model pile under different grouting parameters;

[0021] Compare the changes in the three-dimensional space distribution form, geometric dimensions of the solidified slurry, and the area covering the model pile under different grouting parameters to obtain the flow law of the grouting liquid on the side of the pipe - following pile while drilling.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] The device and method for studying the flow law of the grouting liquid on the side of the pipe - following pile while drilling of the present invention can more realistically reproduce the environment of the grouting liquid flowing inside the side of the pipe - following pile while drilling, making the results closer to the reality when studying and analyzing the flow law of the grouting liquid in the gap on the side of the pile. The structure of the device for studying the flow law of the grouting liquid on the side of the pipe - following pile while drilling of the present invention is simple, the processing technology is not complicated, the processing cost is low, the quality is light, the transportation is convenient, the operation process is simple, easy to learn and use, and the safety is good; the method for studying the flow law of the grouting liquid on the side of the pipe - following pile while drilling of the present invention can accurately characterize the flow law of the grouting liquid on the side of the pipe - following pile while drilling, has a wide application range, can be applied to various soils and various soil layers, the operation process is simple, and it is safe and easy to implement. Brief Description of the Drawings

[0024] Now, the present invention will be further described in conjunction with the accompanying drawings and specific embodiments:

[0025] Figure 1 is the schematic structural diagram of the device of the present invention;

[0026] Figure 2 is the schematic structural diagram of the model pile of the present invention;

[0027] Figure 3 is the schematic structural diagram of the grouting pipe of the present invention;

[0028] Figure 4 is the schematic structural diagram of the grout - stopping plate of the present invention;

[0029] Figure 5 is a flowchart of the method of the present invention.

[0030] In the figure:

[0031] 1. Stirring pool, 2. Pouring slurry port, 3. Slurry pumping valve, 4. First pressure gauge, 5. Slurry pumping pipe, 6. Grouting machine, 7. Second pressure gauge, 8. Grout outlet valve, 9. Grout outlet pipe, 10. Grouting pipe, 11. Model pile, 12. Sleeve, 13. Model box, 14. Grout stop plate, 141. Long screw, 142. Threaded hole, 143. Semi-circular arc, 15. Limiting part, 16. Bottom sealing part, 17. Second incision, 18. Support platform, 19. Soil body, 20. Gap, 21. Fixing part, 22. First incision. Specific embodiments

[0032] The following is a description of the preferred embodiments of the present invention with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not intended to limit the present invention.

[0033] Embodiment 1

[0034] As Figure 1 shown, this embodiment discloses a device for studying the flow law of the grouting liquid on the side of the pipe-sinking pipe pile while drilling, including a model box 13 system and a grouting system; the model box 13 system includes a model box 13, a model pile 11, a grout stop plate 14, and a grouting pipe 10; the model box 13 is filled with a soil body 19, a simulated drill hole is arranged in the soil body 19, the diameter of the simulated drill hole is larger than the diameter of the model pile 11, and the model pile 11 is coaxially arranged in the simulated drill hole; the grouting pipe 10 is arranged in the model pile 11, a grouting hole is arranged on the model pile 11, the grouting hole is communicated with the gap 20 between the model pile 11 and the soil body 19, and the grouting pipe 10 is communicated with the grouting hole; the grout stop plate 14 is provided with a through hole adapted to the model pile 11, and the grout stop plate 14 is sleeved on the upper end of the model pile 11 through the through hole to cover the gap 20; the grout outlet of the grouting system is communicated with the grouting pipe 10.

[0035] Compared with the prior art, the device and method for studying the flow law of the grouting liquid on the side of the pipe-sinking pipe pile while drilling of the present invention can more truly reproduce the environment of the grouting liquid flowing inside the side of the pipe-sinking pipe pile while drilling, so that when studying and analyzing the flow law of the grouting liquid in the side gap of the pile, the results are closer to the truth. The device for studying the flow law of the grouting liquid on the side of the pipe-sinking pipe pile while drilling of the present invention has a simple structure, is not complicated in processing technology, has a low processing cost, is light in weight, is convenient for transportation, has a simple operation process, is easy to learn and use, and has good safety.

[0036] As Figures 2 - 3As shown, in this embodiment, a first incision 22 is provided on the bottom pile wall of the model pile 11. The first incision 22 is the grouting hole. A second incision 17 is provided on the bottom pipe wall of the grouting pipe 10 corresponding to the first incision 22, and the first incision 22 communicates with the second incision 17. A bottom sealing member 16 for sealing the bottom end of the model pile 11 is arranged inside the model pile 11, and the first incision 22 and the second incision 17 are buried in the bottom sealing member 16. Among them, the bottom sealing member 16 is a concrete solidification member. The height of the bottom sealing member 16 should not be too high. The purpose of bottom sealing is to prevent groundwater or slurry from flowing out of the inner cavity of the model pile 11, resulting in the failure of the test. Preferably, the height of the bottom sealing member 16 is controlled within 10 - 15 cm;

[0037] In this embodiment, a support platform 18 is arranged inside the model box 13. A number of limiting members 15 are arranged on the support platform 18. The model pile 11 is arranged on the support platform 18 and is located within the space surrounded by the limiting members 15, and the model pile 11 abuts against the limiting members 15. Further, a number of nuts are arranged on the bottom of the model box 13. The limiting members 15 are bolts fixed on the nuts. The support platform 18 is located at the center of the model box 13, and the support platform 18 is a circular soil filling layer, and the support platform 18 is bounded by the circumscribed circle formed by the bolts.

[0038] In this embodiment, a sleeve 12 is further included. When filling soil in the model box 13, the sleeve 12 is arranged inside the model box 13 so that a simulated drilling hole is formed in the soil body 19 when the sleeve 12 is withdrawn. The inner side surface of the sleeve 12 abuts against the limiting members 15.

[0039] In this embodiment, there are several sleeves 12 in this embodiment. The outer diameter of each sleeve 12 is different, so that the size of the gap is also different. The position of the nuts at the bottom of the model box 13 is adjustable, so that the size of the circumscribed circle formed by the bolts is adjustable. In this embodiment, the diameter of the bolts should be selected according to the grouting gap 20 and the thickness of the cylindrical sleeve 12. Its length, diameter and quantity should ultimately ensure that the cylindrical sleeve 12 and the model pile 11 can be fixed and difficult to shake.

[0040] In this embodiment, the model box 13 is cylindrical. Specifically, the model box 13 includes a first semi - cylinder and a second semi - cylinder, and the first semi - cylinder and the second semi - cylinder are detachably connected and fixed by a fixing member 21. In this embodiment, the fixing member 21 is a snap switch.

[0041] In this embodiment, a breathable layer is arranged between the grout - stopping plate 14 and the model pile 11. The breathable layer is preferably a cotton layer. As Figure 4As shown, the grout stop plate 14 includes a first sub-plate and a second sub-plate. The first sub-plate is provided with a first semi-circular arc, and first threaded holes are arranged on both sides of the first semi-circular arc on the first sub-plate. Corresponding to the first semi-circular arc and the first threaded holes on the second sub-plate, there are respectively a second semi-circular arc and second threaded holes. The first sub-plate and the second sub-plate are fixed on the model pile 11 by long screws 141 or bolts. In other words, the first sub-plate and the second sub-plate are respectively provided with corresponding semi-circular arcs 143, threaded holes 142 are arranged on the first sub-plate, the second sub-plate and on both sides of the semi-circular arc 143, and the first sub-plate and the second sub-plate are fixed on the model pile 11 by long screws 141 or bolts.

[0042] In this embodiment, the grouting system includes a mixing tank 1, a grouting machine 6 for injecting the slurry in the mixing tank 1 into the grouting pipe 10, and slurry pipes connecting the mixing tank 1 with the grouting machine 6 and the grouting machine 6 with the grouting pipe 10; the slurry pipes include a suction pipe 5 and a discharge pipe 9. The suction pipe 5 is used to connect the mixing tank 1 and the grouting machine 6, and the discharge pipe 9 is used to connect the grouting machine 6 and the grouting pipe 10; a suction valve 3 and a first pressure gauge 4 are arranged on the suction pipe 5, a discharge valve 8 and a second pressure gauge 7 are arranged on the discharge pipe 9, and a slurry pouring port 2 is arranged on the top end of the mixing tank 1.

[0043] In this embodiment, the pile diameter of the model pile 11 can be selected according to the actual project, and the optional range is between 100 mm and 1500 mm. The material of the model pile 11 is not limited to acrylic pipes, prestressed pipe piles, and high-strength PPR pipes; the sleeve 12 is cylindrical, and the diameter of the cylindrical sleeve 12 can be selected according to the diameter of the model pile 11 and the size of the grouting gap 20. The final effect should ensure that the formed pile-soil gap 20, that is, the grouting gap 20, ranges from 0 to 5 cm. The material of the cylindrical sleeve 12 is not limited to acrylic pipes, prestressed pipe piles, and high-strength PPR pipes; the diameter of the model box 13 should be greater than the diameter of the cylindrical sleeve 12, and the diameter difference between the two should be more than 500 mm to ensure that the slurry has sufficient space for penetration and compaction.

[0044] In this embodiment, the grouting pressure / grouting rate of the grouting machine 6 is adjustable, and the adjustable range is 0 - 5 MPa to meet the actual project requirements; the suction valve 3, the first pressure gauge 4, the suction pipe 5, the second pressure gauge 7, the discharge valve 8, the discharge pipe 9, the grouting pipe 10, etc. all have the ability to withstand high pressure, and the rated pressure resistance value is not less than 6 MPa;

[0045] In this embodiment, the soil body 19 used in the test is not limited to silty soil, sandy soil, cohesive soil, backfill soil, sandy soil, silt soil, etc., and can also be a mixture of multiple soil bodies 19.

[0046] Embodiment Two

[0047] As Figure 5 shown, this embodiment discloses a method for studying the flow law of the grouting liquid on the side of the pipe - following pile while drilling, including the following steps:

[0048] S1: Set up the device as described in Embodiment 1, and after the device is set up, start the grouting system to grout into the gap 20;

[0049] S2: Take out the model pile 11 solidified with the slurry, and use three - dimensional scanning technology to obtain the three - dimensional image of the model pile 11 solidified with the slurry. The three - dimensional image includes three - dimensional point cloud coordinate data and spatial point position information;

[0050] S3: Use panoramic flattening image technology to flatten the three - dimensional image to obtain the three - dimensional space distribution form, geometric size of the solidified slurry, and the area covering the model pile 11;

[0051] S4: Adjust the grouting parameters and repeat the above steps to obtain the three - dimensional space distribution form, geometric size of the solidified slurry, and the area covering the model pile 11 under different grouting parameters;

[0052] S5: Compare the changes in the three - dimensional space distribution form, geometric size of the solidified slurry, and the area covering the model pile 11 under different grouting parameters to obtain the flow law of the grouting liquid on the side of the pipe - following pile while drilling.

[0053] Compared with the prior art, the method for studying the flow law of the grouting liquid on the side of the pipe - following pile while drilling of the present invention can accurately characterize the flow law of the grouting liquid on the side of the pipe - following pile while drilling, has a wide application range, can be applied to a variety of soils 19 and a variety of soil layers, has a simple operation process, and is safe and easy to implement.

[0054] More specifically:

[0055] (1) As Figure 3 shown, select a "three - rubber - two - wire" high - pressure rubber hose as the grouting pipe 10. The inner diameter of this grouting pipe 10 is 19 mm, the outer diameter is 25 mm, the working pressure is as high as 2 MPa, and the bursting pressure is as high as 5 MPa, which is much greater than the maximum rated grouting pressure 1.2 MPa of the grouting machine 6. After selecting the grouting pipe 10, cut a "T" - shaped incision at the bottom of the grouting pipe 10, that is, the second incision 17. The second incision 17 serves as the slurry outlet of the grouting pipe 10. The depth of the second incision 17 is 1 / 4 of the diameter of the grouting pipe 10, and the height is 5 cm;

[0056] (2) As Figure 2As shown in the figure, an acrylic plexiglass tube with an outer diameter of 500 mm and a thickness of 10 mm is selected as the model pile 11. A rectangular incision with a length and width of 6 cm and 1.5 cm respectively is cut at the bottom of the model pile 11, that is, the first incision 22, and the first incision 22 penetrates the pile wall of the model pile 11. Immediately afterwards, the grouting pipe 10 is inserted into the inner cavity of the model pile 11. After inserting to the bottom of the model pile 11, the second incision 17 on the grouting pipe 10 is adhered to and bonded with the first incision 22 at the bottom of the model pile 11 in the direction of the pile wall of the model pile 11 with 502 glue with high bond strength and quick drying to form a side grouting channel of the pile.

[0057] (3) After the 502 glue reaches a certain strength, the model pile 11 together with the grouting pipe 10 is erected and placed on a flat ground. Mortar with water, cement, and sand ratios of 0.5, 1, and 2 respectively is poured into the inner cavity of the model pile 11. The pouring height stops at 10 cm from the bottom of the model pile 11. After the slurry solidifies, the bottom sealing work of the model pile 11 is completed. At this time, the grouting becomes the bottom sealing member 16. The solidified bottom sealing member 16 can fix the grouting pipe 10 and can further fix the connection between the first incision 22 and the second incision 17 on the basis of the 502 glue. In addition, the bottom sealing member 16 can also prevent the slurry flowing out from the second incision 17 from flowing out through the inner cavity of the model pile 11, resulting in grouting failure, ensuring that the slurry can only flow out from the second incision 17 and then enter the grouting gap 20. In addition, in order to prevent slurry leakage at the bottom of the pile and block the second incision 17 during the cement slurry bottom sealing, the following measures are taken: Before the model pile 11 is erected and placed on a flat ground, a plastic foam board with a thickness of 1 cm is laid on the ground in advance. Under the action of the self-weight of the model pile 11, the bottom of the model pile 11 can be seamlessly docked with the foam board. At the same time, the second incision 17 is blocked with soft cotton, and the cotton is taken out after the bottom sealing member 16 solidifies.

[0058] (4) Subsequently, the test soil body 19 used in the test is selected according to the experimental plan (not limited to clay, sand, backfill soil, mixed soil, etc.), and the physical and mechanical parameters such as the density, particle size distribution, and specific gravity of the soil body 19 are measured. Subsequently, the limiting member 15 (i.e., the bolt) is connected and tightened with the nut on the bottom of the model box 13. The diameter of the limiting member 15 is 7 cm. A soil layer with a thickness of 10 cm is laid along the outer tangent circle boundary of the limiting member 15 and compacted to form a support platform 18. The model pile 11 with the grouting pipe 10 after the cement slurry bottom sealing is placed vertically on the support platform 18, and the model pile 11 is just stuck by the inner side of the limiting member 15, playing a role in fixing the model pile 11.

[0059] (5) Select an acrylic plexiglass tube with an outer diameter of 520 mm and a thickness of 6 mm as the cylindrical sleeve 12. Place the cylindrical sleeve 12 from the top of the model pile 11 to cover the model pile 11. At this time, the cylindrical sleeve 12 is just stuck by the outside of the limiting member 15, playing a role in fixing the sleeve 12.

[0060] (6) The cylindrical model box 13 is composed of two semi-cylindrical bodies and is connected by a snap switch. The diameter of the cylindrical model box 13 is 1.5 m. Open the snap switch and move the two semi-cylindrical bodies until the cylindrical sleeve 12 and the model pile 11 reach the center position of the model box 13, and then close the snap switch.

[0061] (7) At this time, a filling gap 20 will be formed between the cylindrical sleeve 12 and the model box 13. Starting from the bottom of the model box 13, fill the gap 20 with soil layer by layer and perform saturation and compaction treatment. Each layer is 5 - 10 cm thick. After compaction, measure the density of the soil sample. After the density meets the test requirements, fill the next layer of soil until the top of the model box 13 is filled. At this time, the gap 20 is filled with dense soil mass 19, and the thickness of the soil mass 19 in the horizontal direction is 490 mm.

[0062] (8) After the filling is completed, pull out the sleeve 12. Since the outer diameter of the model pile 11 is 500 and the outer diameter of the sleeve 12 is 520 mm, the gap 20 between the model pile 11 and the surrounding soil mass 19 is 10 mm at this time, that is, the width of the grouting gap 20 is 10 mm.

[0063] (9) After completing the above steps, connect each component according to the Figure 1 method. Close the slurry outlet valve 8 and judge the airtightness of the grouting system by the reading of the second pressure gauge 7. After the airtightness of the grouting system is okay, the pile side grouting test of the follow - up - drilling pipe - following pile can be carried out. Specifically: configure the grouting liquid according to the test design plan and place it in the mixing tank 1 for mixing. After mixing evenly, the slurry is pumped into the grouting machine 6 through the slurry suction pipe 5. The grouting machine 6 injects the slurry into the grouting pipe 10 through the slurry outlet pipe 9. The slurry in the grouting pipe 10 flows into the grouting gap 20 through the second cut 17 under the action of pressure, and the slurry flows in the grouting gap 20.

[0064] (10) In order to prevent slurry spraying caused by excessive pressure and form a pressure - holding effect to achieve the required grouting pressure, a grout - stopping plate 1414 needs to be set at the top of the gap 20, as Figure 5As shown in the figure, the main part of the grout stop plate 14 is made of steel, that is, mainly composed of a steel plate provided with two semi-circular holes. It also includes long screws 141, screw holes provided on the steel plate, and semi-circular arcs 143. The diameter of the semi-circular arc 143 is 2 mm larger than the diameter of the model pile 11. The model pile 11 is sleeved by two semi-circular arcs 143. The 1-mm gap 20 between the model pile 11 and the semi-circular arcs 143 is sealed with cotton with good air permeability. In this way, air leakage can be prevented while the grouting liquid is not leaked, so that air can be discharged during grouting and the cement slurry can be pressured to simulate the action of different grouting pressures. In order to prevent excessive pressure, if the pressure-holding effect formed by the self-weight of the grout stop plate 14 is not good, heavy objects such as steel plates, sandbags, and stones can be stacked on the upper part of the grout stop plate 14 to ensure the success of pressure-holding;

[0065] (11) After the grouting is completed, clean the mixing tank 1, the slurry suction pipe 5, the grouting machine 6, the slurry outlet pipe 9, etc. At the same time, cure the grouting liquid on the side of the model pile 11 for more than 7 days. After the slurry solidifies and reaches a certain strength, excavate the soil body 19. Specifically, open the buckle switch, move the two semi-cylindrical model boxes 13 away. After the soil body 19 scatters under its own weight, remove the remaining soil body 19 and dig out the model pile 11. At this time, the surface of the model pile 11 is successively the solidified body of the grouting liquid and the residual soil body 19. After removing the residual soil body 19 on the surface of the model pile 11 with clean water and a soft brush, place the model pile 11 aside to dry naturally, which takes about 2 hours;

[0066] (12) After the surface treatment of the model pile 11 is completed, use three-dimensional scanning technology to obtain a three-dimensional view of the model pile 11 with the solidified slurry. Among them, this three-dimensional view includes the three-dimensional point cloud coordinates and spatial position information of the contact interface between the slurry and the soil body 19; combined with panoramic flattening image processing technology, flatten the three-dimensional view to quantitatively characterize the three-dimensional spatial distribution form, geometric size, and the area covering the model pile 11 of the solidified slurry; adjust the grouting parameters (such as grouting pressure, slurry ratio, slurry type, grouting frequency, etc.) to obtain the three-dimensional spatial distribution form, geometric size, and the area covering the model pile 11 of the solidified slurry quantitatively characterized under different grouting parameters; analyze the influence of grouting parameters on the diffusion range (or the area covering the model pile 11) of the solidified slurry, the three-dimensional spatial distribution form and geometric size of the grout veins, so as to reveal the flow and diffusion mechanism of the grouting liquid around the follow-up pipe pile during drilling;

[0067] (13) After the test is completed, seal the model pile 11 with plastic wrap and attach a label on the outside of the plastic wrap for storage in the warehouse for later use.

[0068] The present invention is not limited to the above embodiments. If various modifications or variations of the present invention do not depart from the spirit and scope of the present invention, and if these modifications and variations fall within the scope of the claims of the present invention and equivalent technical scope, then the present invention also intends to include these modifications and changes.

Claims

1. A device for studying the flow law of grouting liquid on the side of the pipe - following pile while drilling, characterized in that It includes a model box system and a grouting system; The model box system includes a model box, model piles, a grout stop plate, and grouting pipes; The model box includes a first semi-cylindrical body and a second semi-cylindrical body, and the first semi-cylindrical body and the second semi-cylindrical body are detachably connected and fixed by fixing members; the model box is filled with soil, and a simulated borehole is provided in the soil, the diameter of the simulated borehole is larger than the diameter of the model pile, and the model pile is coaxially arranged in the simulated borehole; a support platform is provided in the model box, and a number of limiting members are provided on the support platform, the model pile is arranged on the support platform and located in the space surrounded by the limiting members, and the model pile abuts against the limiting members; The model pile is provided with grouting holes, the grouting holes communicate with the gap between the model pile and the soil, the grouting pipe is arranged in the model pile, a first cut is provided on the bottom end pile wall of the model pile, the first cut is the grouting hole, and a second cut is provided on the bottom end pipe wall of the grouting pipe corresponding to the first cut, and the first cut communicates with the second cut; a bottom sealing member for sealing the bottom end of the model pile is arranged in the model pile, and the first cut and the second cut are buried in the bottom sealing member; The grout stop plate is provided with through holes adapted to the model pile, and the grout stop plate is sleeved on the upper end of the model pile through the through holes to cover the gap, and a breathable layer is arranged between the grout stop plate and the model pile; the grout stop plate includes a first sub-plate and a second sub-plate, the first sub-plate is provided with a first semi-circular arc, and first threaded holes are provided on both sides of the first semi-circular arc on the first sub-plate, and a second semi-circular arc and second threaded holes are respectively provided on the second sub-plate corresponding to the first semi-circular arc and the first threaded holes, and the first sub-plate and the second sub-plate are fixed to the model pile by long screws or bolts; The slurry outlet of the grouting system is communicated with the grouting pipe, the grouting system includes a mixing tank, a grouting machine for injecting the slurry in the mixing tank into the grouting pipe, and also includes a slurry conveying pipe for connecting the mixing tank with the grouting machine and the grouting machine with the grouting pipe.

2. The device according to claim 1, characterized in that It also includes a sleeve, and when filling soil in the model box, the sleeve is arranged in the model box so that when the sleeve is withdrawn, the simulated borehole is formed in the soil.

3. The device according to claim 2, characterized in that, The inner side surface of the sleeve abuts against the limiting members.

4. A method for studying the flow law of the grouting liquid on the side of the pipe-supported pile while drilling, characterized in that, It includes the following steps: Build the device according to any one of claims 1 to 3, and start the grouting system to grout into the gap after the device is built; Take out the model pile solidified with the slurry, and use three-dimensional scanning technology to obtain a three-dimensional view of the model pile solidified with the slurry, and the three-dimensional view includes three-dimensional point cloud coordinate data and spatial point position information; Use panoramic flattening image technology to flatten the three-dimensional view to obtain the three-dimensional space distribution form, geometric size of the solidified slurry, and the area covering the model pile; Adjust the grouting parameters and repeat the above steps to obtain the three-dimensional space distribution form, geometric size of the solidified slurry, and the area covering the model pile under different grouting parameters; Compare the three-dimensional spatial distribution pattern, geometric dimensions, and the change in the area covering the model pile of the solidified grout under different grouting parameters to obtain the flow law of the side grouting fluid of the pipe - following pile while drilling.

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