Experimental device and method for simulating soil grouting based on improved grouting pipe

Abstract

The present disclosure relates to a test device and method for simulating soil grouting based on an improved grouting pipe. The test device includes: a pressure source; a slurry delivery assembly coupled to the pressure source and including an outer slurry delivery pipe, the slurry delivery assembly being configured to deliver slurry via the outer slurry delivery pipe based on the pressure provided by the pressure source; and a grouting pipe, fluidically coupled to the outer slurry delivery pipe and including a first slurry stopper, a slurry stopper plate, a second slurry stopper and a flower pipe, the flower pipe being at least partially inserted into the test soil during the test, the first slurry stopper extending and enlarging in a first direction and fitting the slurry stopper plate, the second slurry stopper extending and enlarging in a second direction and fitting the slurry stopper plate, the first direction including the direction of slurry delivery and being opposite to the second direction. In this way, the composition structure of the grouting pipe combines the fluid characteristics of slurry overflow, and when it is sensed that the slurry is about to leak out, it can timely perform external pressure intervention, thereby avoiding slurry leakage and grouting pipe rising during the grouting process, and ensuring smooth slurry injection.

Description

Technical Field

[0001] The present disclosure generally relates to the technical field of rock and soil grouting simulation, and in particular to a test device and method for simulating soil grouting based on an improved grouting pipe. Background Art

[0002] Grouting technology utilizes supporting mechanical equipment and a rational grouting process to inject appropriate grouting materials into the project object to achieve purposes such as filling, reinforcement, water blocking, elevation, and deviation correction. This technology is widely used in underground projects with complex engineering geology and hydrogeology, across multiple industries including civil engineering, municipal engineering, road and railway construction, and water conservancy and hydropower. Its primary applications include soft foundation treatment, settlement control, deformation control, grouting water blocking, dam anti-seepage, landslide prevention, and emergency rescue.

[0003] In sharp contrast to the rapid development of grouting materials, processes and equipment, the research on grouting theory lags significantly behind engineering practice. The main reason is that grouting theories are mostly based on idealized models and have many assumed conditions. In engineering practice, the diffusion of slurry is extremely complex. Different geological conditions, different grouting processes, different grouting materials and even different grouting equipment have an important impact on the grouting effect, the flow and diffusion of slurry, resulting in the distribution of slurry in rock and soil being highly uneven and random, which increases the difficulty of theoretical analysis.

[0004] In engineering practice, the selection of grouting materials, grouting equipment and grouting parameters is mainly determined through field tests or similar engineering experience. However, grouting technology involves multiple professional fields and a lot of professional knowledge, and the grouting process is vague, hidden, complex and highly random. Therefore, it is difficult to accurately control the grouting process, predict and evaluate the grouting effect, etc.

[0005] At present, due to the large scale of on-site grouting tests, complex test processes, high test costs, and the fact that the rock and soil composition and geological conditions are fixed and there are no conditions for repeated comparative tests with multivariable control, most of the existing literature uses indoor physical model tests to carry out research on grouting technology.

[0006] Chinese patent application CN111006951A discloses an indoor grouting test apparatus and simulated grouting test method. The apparatus utilizes a grouting unit, a loading unit, and a measurement unit to simulate the synergistic interaction between the tunnel, grouting body, and foundation in actual engineering projects, reflecting the influence of grouting on the surrounding strata disturbance and dynamic response. The grouting unit includes a grouting test bucket, a grouting pump, a grouting channel, and a grouting pipe; the loading unit includes a confining pressure loading mechanism and a servo-powered loading mechanism to simulate stratum pressure; and the measurement unit includes an earth pressure gauge, a pore pressure gauge, a piezoelectric bender, a displacement sensor, and a data acquisition system.

[0007] Chinese utility model patent CN210427566U discloses a three-dimensional visual permeable grouting model test device. This device, consisting of a test chamber, grouting equipment, and a measurement system, simulates the grouting of gravel and sandy soils under different grouting processes, grouting parameters, and slurry parameters. This allows analysis of the grouting reinforcement mechanism and effects, as well as research into slurry diffusion theory. The test chamber includes a bottom plate, top plate, and side plates; the grouting equipment includes an air compressor, slurry storage tank, and pressure-resistant grouting pipes; and the measurement system includes an electromagnetic flowmeter, pressure sensor, earth pressure gauge, and pore pressure sensor.

[0008] The main focus of current technology is to pursue the coupling of grouting, environmental conditions and load conditions, but it does not take into account whether the slurry can be smoothly injected into the test soil and how the slurry diffuses in the test soil. Moreover, the main innovation of the current grouting simulation test for monitoring or testing methods lies in the sensor measurement system. The system has soil pressure gauges, displacement sensors, pore water pressure gauges, electrical components, etc. built into the test soil. These sensor test components are all in fixed and discontinuous positions during the test. The test results are greatly affected by position, time and other factors, and cannot achieve real-time monitoring effects, which has great limitations. In addition, the test device is not integrated and intelligent enough, and the delivery pressure cannot be effectively controlled during the slurry delivery process, affecting the accuracy of the test results. Summary of the Invention

[0009] The purpose of the present disclosure is to provide a test device and method for simulating soil grouting based on an improved grouting pipe, so as to at least partially solve the problems existing in the current technology.

[0010] According to a first aspect of the present disclosure, a test device for simulating soil grouting based on an improved grouting pipe is provided. The test device includes a pressure source, a slurry delivery assembly and a grouting pipe. The slurry delivery assembly is coupled to the pressure source and includes an outer grouting pipe, and the slurry delivery assembly is configured to deliver slurry via the outer grouting pipe based on the pressure provided by the pressure source. The grouting pipe is fluidly coupled to the outer grouting pipe and includes a first slurry stopper, a slurry stopper plate, a second slurry stopper and a flower pipe connected in sequence, the flower pipe being at least partially inserted into the test soil during the test, wherein the first slurry stopper extends and becomes larger in a first direction and fits the slurry stopper plate, and the second slurry stopper extends and becomes larger in a second direction and fits the slurry stopper plate, the first direction including the direction of slurry delivery and being opposite to the second direction.

[0011] In some embodiments, at least one of the first stopper and the second stopper is a truncated cone stopper, a truncated pyramid stopper, or a frustum stopper.

[0012] In some embodiments, the test apparatus further includes a computing device, a connecting cable, and a plurality of electrodes, wherein the plurality of electrodes are communicatively coupled to the computing device via the connecting cable and are arranged in a preset shape in the test soil to collect and transmit target data to be analyzed by the computing device.

[0013] In some embodiments, the preset shape includes a 'M' shape or a 'H' shape and is symmetrically arranged with the grouting hole as the center.

[0014] In some embodiments, the pressure source is communicatively coupled to the computing device, and at least one of the first slurry stopper, the slurry stop plate, and the second slurry stopper is communicatively coupled to the computing device, so that the computing device can adjust the delivery pressure of the pressure source when the slurry leaks.

[0015] In some embodiments, the test device further includes: a model box for accommodating the test soil and having multiple groups of water level holes opened at a preset height from the bottom of the box to simulate a stable groundwater level condition.

[0016] In some embodiments, the slurry conveying assembly includes: a pressure barrel; a three-way valve, which is arranged outside the pressure barrel and has two passages coupled to the pressure barrel and the pressure source, respectively; an agitator, including an air connecting pipe, an air motor, a stirring shaft and blades, wherein one end of the air connecting pipe is coupled to the other passage of the three-way valve, and the other end is coupled to the air motor, the air motor is coupled to the stirring shaft and is suitable for driving the stirring shaft and the blades to rotate to stir the slurry; and a slurry discharger, including a suction plate, an inner slurry pipe, a flow meter and an outer slurry pipe connected in sequence, the slurry discharger is suitable for conveying the stirred slurry to the grouting pipe via the suction plate, the inner slurry pipe, the outer slurry pipe and the flow meter based on the pressure source and the three-way valve.

[0017] In some embodiments, the pressure source includes a starting valve, an air source pressure gauge, and an air source switching valve.

[0018] According to the second aspect of the present disclosure, a test method for simulated soil grouting based on an improved grouting pipe is provided, which is used for monitoring test soil in a simulated indoor soil grouting test. The method uses the test device according to the first aspect of the present disclosure and includes: S01: placing the test soil in a model box; S02: installing a plurality of electrodes on the test soil, wherein the plurality of electrodes are in a predetermined shape and the spacing between adjacent electrodes in the plurality of electrodes is associated with the monitoring depth and accuracy; S03: coupling the electrodes of the same monitoring profile in the plurality of electrodes to a computing device via a connecting cable; S04: starting the computing device before grouting the test soil, and collecting the apparent resistivity of each monitoring profile of the test soil in real time; and S05: grouting the test soil using the test device, and monitoring the apparent resistivity of each monitoring profile of the test soil in real time until the apparent resistivity does not change.

[0019] According to the third aspect of the present disclosure, a test method for simulating soil grouting based on an improved grouting pipe is provided, which is used to simulate the monitoring of indoor grouting tests on a soil-rock binary structure slope composed of weakly cemented soil and underlying rock layers. The method uses the test device according to the first aspect of the present disclosure and includes: S11: Based on the similarity theory, an indoor scaled test slope model with a similar relationship to the slope prototype is established in a model box, the test slope model includes bottom bedrock, base-cover interface and weakly cemented soil layer; S12: a grouting hole is reserved at the center position of the top of the weakly cemented soil layer, and the grouting pipe is installed in the grouting hole; S13: a plurality of electrodes are arranged in a "M"-shaped monitoring profile on the top of the weakly cemented soil layer, the distance between adjacent electrodes of the plurality of electrodes is 5 cm, and the plurality of electrodes are coupled to a computing device via a connecting cable; S14: cement slurry is loaded into the pressure barrel of the slurry conveying assembly, and the slurry conveying assembly is started. The pressure source is turned on and off until the pressure source reaches a predetermined pressure; S15: the agitator of the slurry conveying assembly is driven by the pressure provided by the pressure source to stir the cement slurry, and after the cement slurry is evenly stirred, the cement slurry is continued to be conveyed to the grouting pipe by the pressure of the pressure barrel; S16: before grouting the test slope model, the computing device is started to collect the apparent resistivity of each monitoring section of the test soil in real time; and S17: the test slope model is grouted by the test device, and the apparent resistivity of each monitoring section of the test slope model is monitored in real time until the apparent resistivity does not change.

[0020] According to various embodiments of the present disclosure, at least the following technical effects can be achieved:

[0021] The specific composition structure of the grouting pipe combines the fluid characteristics of slurry overflow, and can perform external pressure intervention in time when it senses that the slurry is about to leak, avoiding slurry leakage and unexpected rising of the grouting pipe during the grouting process, ensuring smooth slurry injection.

[0022] The test device uses preset-shape electrodes to monitor the test soil during simulated grouting. The electrodes are evenly distributed in the test soil, avoiding measurement errors or mistakes caused by the fixed and discontinuous positions of sensors or electrical components such as soil pressure gauges, displacement sensors, and pore water pressure gauges, ensuring the accuracy of the measurement results and enabling real-time monitoring.

[0023] The entire grouting process is carried out by connecting a three-way valve to a pressure source. The stirring and squeezing of the slurry are both controlled by pneumatic pressure. The grouting pressure of the grouting pipe can be fed back in time during grouting. Combined with the use of a specific shape electrode matrix, the entire test device can be integrated and intelligent, ensuring that the grouting process can be carried out continuously without interruption, significantly improving the test efficiency and accuracy.

[0024] The model box is equipped with a water level hole, which can simulate stable groundwater level conditions and expand the applicable scenarios of the test device.

[0025] It should be understood that the contents described in the Summary of the Invention section are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other objects, features and advantages of the embodiments of the present disclosure will become readily understood by reading the following detailed description with reference to the accompanying drawings, in which several embodiments of the present disclosure are shown by way of example and not limitation, in which:

[0027] Figure 1 shows a schematic structural diagram of a test device according to some embodiments of the present disclosure;

[0028] Figure 2 A schematic diagram of a grouting pipe structure according to some embodiments of the present disclosure is shown;

[0029] Figure 3 A schematic diagram of a model box structure according to some embodiments of the present disclosure is shown;

[0030] Figure 4 A schematic diagram of a "M"-shaped arrangement of electrodes according to a monitoring method according to some embodiments of the present disclosure is shown;

[0031] Figure 5 A schematic diagram showing a "well"-shaped arrangement of electrodes according to a monitoring method according to some embodiments of the present disclosure; and

[0032] Figure 6 A schematic diagram of grouting for a soil-rock binary structure slope according to some embodiments of the present disclosure is shown.

[0033] In the various drawings, the same or corresponding reference numerals denote the same or corresponding parts. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0035] As used herein, the term "including" and its variations represent open inclusion, i.e., "including but not limited to." Unless otherwise stated, the term "or" means "and / or." The term "based on" means "based at least in part on." The terms "one example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one additional embodiment." The terms "first," "second," etc. may refer to different or identical objects.

[0036] As mentioned above, the main innovation of the existing grouting simulation test lies in the grouting test device, which pursues the coupling of grouting, environmental conditions and load conditions, but lacks targeted research on essential issues such as whether the slurry can be injected smoothly and how the slurry diffuses. Moreover, the main innovation of the existing grouting simulation test for monitoring or testing methods lies in the sensor measurement system, which is mostly soil pressure gauges, displacement sensors, pore water pressure gauges or electrical components built into the test soil. These sensor test components are all in fixed and discontinuous positions during the test. The test results are greatly affected by position, time and other factors, and cannot achieve the effect of real-time monitoring, which has great limitations. The embodiments of the present disclosure provide multiple implementation methods to solve the above problems. In the following, reference will be made to Figures 1 to 6 The principles of the present disclosure are described in detail with reference to exemplary embodiments.

[0037] Figure 1 FIG. 1 shows a schematic structural diagram of a test device 100 according to some embodiments of the present disclosure. Figure 1 As shown, the test apparatus 100 generally includes a pressure source 1, a slurry delivery assembly 2, a model box 3, and a computing device 4. In this embodiment, the pressure source 1 is coupled to the slurry delivery assembly 2 and is capable of delivering the slurry to be injected into the model box 3. During the injection process, the computing device 4 performs real-time data collection and analysis of the grouting process.

[0038] In some embodiments, reference Figure 1 The pressure source 1 may be an air compressor, and the pressure source 1 may include a start valve 11, an air source pressure gauge 12, and an air source switch valve 13. Figure 1 As shown, the outlet of the pressure source 1 can be controlled by the air source switch valve 13 and connected to the air inlet of the three-way valve 23 of the slurry conveying assembly 2 via the air supply pipe 14, which will be described in more detail below. In another embodiment, the pressure source 1 can also be other pressure providing devices, which is not limited by the present disclosure.

[0039] In some embodiments, reference Figure 1 The slurry conveying assembly 2 may include a pressure barrel 21, a pressure relief valve 22, a three-way valve 23, an agitator, a slurry discharger, and a slurry barrel pressure gauge 211. The pressure barrel 21 may be an inner barrel capable of withstanding a certain pressure and having a certain amount of space. The slurry can be evenly mixed within the pressure barrel 21 and extruded out of the pressure barrel. The pressure relief valve 22 may be provided on the pressure barrel 21 to open and release pressure when the pressure exceeds a threshold or in other situations requiring pressure relief. The three-way valve 23 includes an air inlet, an air supply on-off valve 24, and a motor on-off valve 25. As previously described, the air inlet of the three-way valve 23 is coupled to the pressure source 1. The air supply on-off valve 24 is coupled to the pressure barrel 21, and the motor on-off valve 25 is connected to the pneumatic motor 27 on the pressure barrel 21. The pneumatic motor 27 is the power unit of the agitator and will be described in more detail below. This allows pressurized gas from the pressure source 1 to enter the pressure barrel 21 when the air supply on-off valve 24 is open and the motor on-off valve 25 is closed. When the gas supply switch valve 24 is closed and the motor switch valve 25 is opened, the pressurized gas from the pressure source 1 can enter the pneumatic motor 27, thereby driving the pneumatic motor 27 to stir the slurry.

[0040] In some embodiments, continue to refer to Figure 1 The agitator may include an air connection pipe 26, an air motor 27, an agitation shaft 28, and blades 29. One end of the air connection pipe 26 may be coupled to the motor switch valve 25, and the other end may be coupled to the air motor 27. The air motor 27 is coupled to the agitation shaft 28 and is adapted to drive the agitation shaft 28 to rotate. Blades 29 may be provided on the agitation shaft 28 for agitating the slurry to be injected.

[0041] In some embodiments, continue to refer to Figure 1The slurry discharger may include a suction plate 213, an inner slurry delivery pipe 212, an outer slurry delivery pipe 214, and a flow meter 215. The suction plate 213 is located inside the pressure barrel 21 and is sequentially coupled to the inner slurry delivery pipe 212 and the outer slurry delivery pipe 214. The inner slurry delivery pipe 212 may be located inside the pressure barrel 21 and the outer slurry delivery pipe 214 may be located outside the pressure barrel 21. The flow meter 215 may be set at a specific position on the outer slurry delivery pipe 214 to measure parameters such as the slurry discharge flow rate or pressure. In one embodiment, the outlet of the flow meter 215 is connected to the grouting pipe 32 of the model box 3, which will be described in more detail below. In such an embodiment, after the stirring of the slurry to be injected is completed, the motor switch valve 25 can be closed and the air supply switch valve 24 can be opened. The slurry to be injected is transported to the grouting pipe 32 under the pressure of the pressure source 1 through the suction plate 213, the inner slurry delivery pipe 212, the outer slurry delivery pipe 214, and the flow meter 215 for simulating grouting.

[0042] In some embodiments, reference Figure 1 The model box 3 may include a test soil 31 and a grouting pipe 32. In another embodiment, the model box 3 may be a separate component, and the test soil 31 and the grouting pipe 32 are arranged inside the model box 3 during the grouting test. Figure 3 The transparent uncovered cubic box shown is formed by gluing together a bottom plate 312, side plates 310, a back plate 311, and a front plate 39. The length, width, and height of the cubic box can each be, for example, 1 meter. The bottom plate 312 can be, for example, 1.1 meters by 1.1 meters, the side plates 310 and the back plate 311 can be, for example, 1 meter by 1 meter, and the front plate 39 can be, for example, 1 meter by 0.5 meters. The plate material of the cubic box can be, for example, organic glass. In other embodiments, the box body material of the model box 3 can be any transparent material and its combination, such as acrylic transparent plate, PVC transparent plate, PC transparent plate, etc., which is not limited by the present disclosure. The box body size of the model box 3 can be determined according to the scale ratio of the test prototype, which is not limited by the present disclosure.

[0043] In some embodiments, reference Figure 3 Two water level holes 313 are provided at a certain height in the model box 3 to simulate the operating conditions of a prototype stratum with a stable groundwater level. The water level holes 313 may be, for example, 2 cm in size or any other suitable size. The water level holes 313 may be, for example, circular or any other suitable shape. It should be understood that the location, size, and number of the pre-opened water level holes 313 in the box can be determined based on the simulated test conditions and are not limited in this disclosure.

[0044] In some embodiments, the soil in the test soil 31 refers to the soil or rock mass to be simulated and tested in a broad sense, and therefore can also be called a test rock soil or test rock mass. Figure 6The slope body shown is a soil-rock dual structure consisting of weakly cemented soil and underlying rock strata, which will be introduced in more detail below.

[0045] In some embodiments, the grout pipe 32 may be fluidly coupled to Figure 1 The outer slurry pipe 214 and flow meter 215 are inserted into the test soil 31 during the grouting test. Figure 2 To introduce the specific example structure of the grouting pipe.

[0046] Figure 2 A schematic diagram of the structure of the grouting pipe 32 according to some embodiments of the present disclosure is shown. Figure 2 Overall, the grouting pipe 32 may include a first grouting stopper 33, a grouting plate 34, a second grouting stopper 35, a flower pipe 37, a circular hole 36 in the flower pipe, and a pipe plug 38. During the grouting test, the flower pipe 37 is at least partially inserted into the test soil 31, so that the slurry is injected into the test soil 31 through the circular hole 36 in the flower pipe.

[0047] In some embodiments, in order to prevent the slurry from overflowing and the grouting pipe 32 from rising during the grouting process, the first slurry stopper 33 extends and becomes larger in the direction of slurry delivery and fits the slurry stopper 34, and the second slurry stopper 35 extends and becomes larger in the opposite direction of slurry delivery and fits the slurry stopper 34. That is, the first slurry stopper 33 and the second slurry stopper 35 are both size-gradient bodies. For example, the first slurry stopper 33 and the second slurry stopper 35 can be a prism slurry stopper, a frustum slurry stopper, a pyramid slurry stopper, a Figure 2 As shown, the truncated cone stopper or any other suitable regular gradient or irregular gradient. In this way, the bottom surface of the first stopper 33 and the second stopper 35 with a larger area fits tightly with the stopper plate 34 to form an integral stopper structure. In some embodiments, as Figure 2 As shown, the first grouting stopper 33 can be located at the top and the second grouting stopper 35 can be located at the bottom, and the two can sandwich the grouting plate 34 to form a grouting stopper structure. In this way, the specific structure of the grouting pipe can be combined with the fluid characteristics of slurry overflow and can promptly intervene with external pressure when slurry leakage is detected, preventing slurry leakage and undesirable upward movement of the grouting pipe during the grouting process, ensuring smooth slurry injection.

[0048] Specifically, Figure 2Taking the example embodiment in which both the first grouting stopper 33 and the second grouting stopper 35 are frustum-shaped grouting stoppers as an example, the second grouting stopper 35, located at the bottom, has its larger frustum bottom surface at the top and its smaller bottom surface at the bottom. This structure facilitates insertion into the grouting hole of the test soil 31 with less force. Correspondingly, the first grouting stopper 33, located at the top, has its larger frustum bottom surface at the bottom and its smaller bottom surface at the top. The plate-like grouting stopper 34 is located between the first grouting stopper 33 and the second grouting stopper 35 and fits tightly with the larger bottom surfaces of the first and second grouting stopper 33 and 35. This structure concentrates gravity at the head of the grouting pipe 32, effectively utilizing its own gravity to resist the undesirable upward movement of the grouting pipe 32 caused by uneven or excessive pressure during grouting. When the pressure is too great and its own gravity cannot resist it, a counterweight or manual pressure can be applied to the first grouting stopper 33 to prevent slurry overflow or upward movement of the grouting pipe 32. Furthermore, because the slurry stop plate 34 is a plate-like structure and the second slurry stopper 35 is an inverted truncated cone structure, when the slurry is expected to overflow, it needs to extend upward along the inverted truncated cone structure of the second slurry stopper 35 to the lower surface of the slurry stop plate 34. At this time, the slurry needs to continuously overcome its own gravity to adhere to the slurry stop plate 34. At this time, if the grouting pressure is not too high, the slurry will automatically fall back into the grouting hole on the lower surface of the slurry stopper 34, thereby preventing the slurry from overflowing. In addition, in this embodiment, the larger lower surface of the first slurry stopper 33 is in close contact with the slurry stopper 34, providing a good sealing effect, preventing the slurry from overflowing from between the first slurry stopper 33, the second slurry stopper 35, and the slurry stopper 34, thereby affecting the accuracy of the measurement results.

[0049] Need to explain, Figure 2 The grouting stop structure shown is merely exemplary, and other suitable grouting stop structures may be used for grouting within the scope of improvement of the present disclosure, and the present disclosure does not impose any limitation thereto.

[0050] In some embodiments, the first and second stoppers 33, 35 of the grouting pipe 32 can be custom-made from rubber, plastic, or other flexible materials. This allows at least one of the first and second stoppers 33, 35 to have a certain degree of flexibility, allowing for a tighter fit within the grouting opening and further preventing slurry from overflowing. Furthermore, at least one of the first and second stoppers 33, 35 can be extrudable, allowing pressure to be applied to the slurry when it is about to overflow, thereby preventing it from overflowing.

[0051] In some embodiments, the grout stop plate 34 may be made of impervious plates of different materials, such as foam boards, polystyrene boards, woodworking boards, plastic boards. Also, in cases where it does not affect the electrode monitoring to be detailed below, impervious plates with a relatively large density, such as metal plates, alloy plates, etc., may be used. The present disclosure places no restrictions on this. This structural design and material selection of the grout stop plate 34, the first grout stop body 33, and the second grout stop body 35 can fully combine with the fluid characteristics of the slurry overflow, prevent the slurry from leaking out and the grouting pipe from rising, ensure the smooth injection of the slurry, and play a guarantee role for the subsequent accuracy of soil body monitoring.

[0052] In some embodiments, the grout stop plate 34, the first grout stop body 33, and the second grout stop body 35 may also be communicatively coupled to the computing device 4, making the test device 100 more integrated and intelligent. This will be introduced in more detail below in conjunction with the computing device 4.

[0053] Return reference Figure 1 In some embodiments, the test device 100 may further include a computing device 4. The computing device 4, the connection cable 42, and the plurality of electrodes 43 may jointly form the monitoring device of the test device 100. The plurality of electrodes 43 can be communicatively coupled to the computing device 4 via the connection cable 42 and form a preset shape in the test soil body 31 to collect and transmit target data to be analyzed by the computing device 4. The target data may be, for example, the apparent resistivity of the corresponding profile of the test soil body 31.

[0054] In some embodiments, the electrode spacing can be adjusted according to the monitoring sounding and accuracy requirements. The preferred scale for indoor tests is 5 cm, 7 cm, or other suitable sizes to facilitate the installation of the electrodes. Generally, the electrode installation can follow a linear monitoring profile of "horizontal in rows, vertical in columns, and diagonal in lines".

[0055] In some embodiments, the preset shape that can be adopted for the layout of the monitoring profile can be, for example, Figure 4 the "cross" shape as shown or Figure 5 the "grid" shape as shown, and each electrode 43 can be symmetrically arranged centered on the grouting hole 5. Among them Figure 4 shows a schematic diagram of the "cross" shape layout of the electrodes of the monitoring method according to some embodiments of the present disclosure, and Figure 5 shows a schematic diagram of the "grid" shape layout of the electrodes of the monitoring method according to some embodiments of the present disclosure.

[0056] In Figure 4 the shown embodiment, it can be arranged in a "cross" shape centered on the grouting hole 5, that is, one monitoring profile is arranged horizontally and vertically respectively passing through the center of the grouting hole, and one monitoring profile is arranged diagonally at 45° on both sides. In Figure 5In the embodiment shown, the monitoring sections can be arranged in a "well" shape with the grouting hole 5 as the center, that is, multiple rows and columns of mutually orthogonal monitoring sections are arranged at appropriate intervals in the horizontal and vertical directions. Figure 4 and Figure 5 In any embodiment of the present invention, the electrodes 43 of the same monitoring section are connected to the cable interface 41 of the computing device 4 for data acquisition and analysis using a connecting cable 42 .

[0057] Thus, the test device uses pre-set electrodes to monitor the test soil during simulated grouting. The electrodes are evenly distributed within the test soil, avoiding measurement errors or mistakes caused by the fixed or discontinuous positions of sensors or electrical components such as earth pressure gauges, displacement sensors, and pore water pressure gauges, thereby ensuring the accuracy of the measurement results. Furthermore, the specific distribution of electrodes 43 across various sections enables real-time monitoring of the test device 100.

[0058] In one embodiment, the pressure source 1 can be communicatively coupled to the computing device 4. Thus, the computing device 4 can operate the pressure source 1, control the working pressure of the pressure source 1, and realize controllable grouting pressure. In another embodiment, the stop plate 34, the first stop body 33, and the second stop body 35 can also be communicatively coupled with the computing device 4. For example, a sensor can be set in any one of the stop plate 34, the first stop body 33, and the second stop body 35. When the sensor senses abnormal grouting pressure or other abnormal conditions, any one of the stop plate 34, the first stop body 33, and the second stop body 35 can feed back the abnormal information to the computing device 4. The computing device 4 controls the pressure source 1 based on the received abnormal information, controls the grouting working pressure, and ensures that the grouting process proceeds smoothly. The abnormal information can be, for example, that the grouting pressure is too high, the grouting pipe is about to rise, or the grouting pressure is too low, or the slurry cannot be smoothly injected into the test soil 31. In another embodiment, when any of the grouting plate 34, the first grouting stop 33, or the second grouting stop 35 senses that the grouting pressure is too high or too low, the computing device 4 can issue a warning signal based on this information, prompting the tester to perform corresponding operations on the grouting pipe. For example, if the grouting pressure is too high and the grouting pipe is about to rise, the computing device 4 can prompt the tester to press down on the first grouting stop 33 or apply a counterweight to prevent the grouting pipe from rising.

[0059] In this way, combined with the foregoing, in the preferred embodiment of the present disclosure, the pressure source 1, the agitator and the slurry discharger are set up with a three-way valve during the grouting process, and stirring and slurry discharge are achieved through the pressure of the pressure source 1, and the pressure of the entire operation process can be timely fed back and controlled, and the electrode matrix can be monitored in real time, and the monitoring results are accurate, so that the entire test device 100 has a high degree of integration and intelligence, ensuring that the grouting process can be carried out continuously without interruption, significantly improving the test efficiency and accuracy, and facilitating operation and monitoring.

[0060] In one embodiment, the test device 100 can be used to simulate soil grouting to achieve the purpose of monitoring the test soil of the soil grouting test indoors. The method may include the following steps:

[0061] S01: Place the test soil 31 in the model box 3. Alternatively, a model of the test soil 31 can be made in the model box 3.

[0062] S02: A plurality of electrodes 43 are installed on the test soil 31 . The plurality of electrodes 43 are in a predetermined shape, and the intervals between adjacent electrodes in the plurality of electrodes 43 are related to the monitoring depth and accuracy.

[0063] In one embodiment, the electrode spacing can be adjusted according to the monitoring depth and accuracy requirements. In order to facilitate the installation of electrodes, the indoor test scale is preferably 5 cm. The preferred monitoring profile layout can be as follows: Figure 4 or Figure 5 The form is: with the grouting hole 5 as the center, it is arranged in a "M" shape; or with the grouting hole 5 as the center, it is arranged in a "Well" shape.

[0064] S03: The electrodes of the same monitoring section among the plurality of electrodes 43 are coupled to the computing device 4 via the connecting cable 42. For example, the electrodes 43 of the same monitoring section are connected to the cable interface 41 of the data acquisition and analysis computing device 4 using one connecting cable 42.

[0065] S04: Before grouting the test soil 31, the computing device 4 is activated to collect real-time data on the apparent resistivity of each monitoring section of the test soil 31. For example, the data acquisition and analysis computing device 4 may be activated before grouting the test soil 31 to collect real-time data on the apparent resistivity of each monitoring section of the test soil 31.

[0066] S05: Grouting is performed on the test soil 31 using the test device 100, and the apparent resistivity of each monitoring section of the test soil 31 is monitored in real time until the apparent resistivity does not change, thereby achieving the monitoring purpose.

[0067] The following will be combined Figure 6 The following describes in more detail the simulation test method for a soil-rock dual structure slope composed of weakly cemented soil and underlying rock using the test device 100. Figure 6 In the example, the test slope model includes a bottom bedrock 316, a base-cover interface 315, and a weakly cemented soil layer 314. The grouting pipe 32 has been inserted into the test slope model, and the electrodes 43 have been arranged in a predetermined shape in advance. The multiple electrodes 43 are coupled to a computing device 4 via a connecting cable 42 to record and analyze the collected data. The method may include the following steps:

[0068] S11: Based on similarity theory, an indoor scaled test slope model having a similar relationship to the slope prototype is established in the model box 3. The test slope model includes a bottom bedrock 316, a base-cover interface 315, and a weakly cemented soil layer 314.

[0069] In one embodiment, the base rock 316 of the test slope model can be constructed of fired bricks, the base-to-cover interface 315 can be finished with cement mortar, and the weakly cemented soil layer 314 can be composed of fine-grained soil, gravel, and gypsum layered in a specific ratio. In one embodiment, when the weakly cemented soil layer 314 is loaded into the model box 3, the water consumption is calculated based on the natural moisture content of the original soil layer, and water is evenly applied. Static pressure or hammering is also used to achieve the original ground density.

[0070] S12: A grouting hole 5 is reserved at the center of the top of the weakly cemented soil layer 314, and a grouting pipe 32 is installed in the grouting hole 5. The purpose of the grouting hole 5 is to facilitate the insertion of the grouting pipe 32. The reserved grouting hole can be made by pre-buried hard plastic pipes or steel bars of corresponding diameter, which can be pulled out after the model is completed.

[0071] S13: A plurality of electrodes 43 are arranged in a “M”-shaped monitoring profile on the top of the weakly cemented soil layer 314 , with a distance between adjacent electrodes of the plurality of electrodes 43 being 5 cm. The plurality of electrodes 43 are coupled to a computing device 4 via a connecting cable 42 .

[0072] S14: Cement slurry is loaded into the pressure barrel 21 of the slurry delivery assembly 2, and the pressure source 1 is started until the pressure source 1 reaches a predetermined pressure and then closed. The cement slurry can have a water-cement ratio of 1:1 and is loaded into the pressure barrel 21 of the slurry delivery assembly 2.

[0073] S15: The pressure provided by the pressure source 1 is used to drive the agitator of the slurry conveying assembly 2 to stir the cement slurry, and after the cement slurry is evenly stirred, the pressure of the pressure barrel 21 is continued to be used to convey the cement slurry to the grouting pipe 32.

[0074] In one embodiment, combined Figure 1 , you can close the air source switch valve 13 of the pressure source 1, press the start valve 11 to start the pressure source 1, and when the reading of the air source pressure gauge 12 is higher than the required grouting pressure, close the start valve 11 to stop the pressure source 1. Furthermore, you can close the air supply switch valve 24, open the air source switch valve 13 and the motor switch valve 25, so that the pneumatic motor 27 runs, the stirring shaft 28 and the blades 29 rotate, and fully stir the cement slurry in the pressure barrel 21. Subsequently, you can close the motor switch valve 25 and the slurry supply switch valve 210, open the air supply switch valve 24, and adjust the air release valve 22 so that the reading of the slurry barrel pressure gauge 211 reaches the required grouting pressure, thereby achieving the transportation of cement slurry.

[0075] S16: Before grouting the test slope model, the computing device 4 is started to collect the apparent resistivity of each monitoring section of the test soil 31 in real time.

[0076] S17: Grouting is performed on the test slope model using the test device 100, and the apparent resistivity of each monitoring section of the test slope model is monitored in real time until the apparent resistivity does not change.

[0077] In one embodiment, it can be confirmed that the air source switch valve 13 and the air supply switch valve 24 are in the open state, and the motor switch valve 25 is in the closed state. The slurry supply switch valve 210 is opened, so that the slurry is injected into the weakly cemented soil layer 314 through the suction plate 213, the slurry supply inner pipe 212, the slurry supply outer pipe 214, the flow meter 215 and the grouting pipe 32 under the action of the pressure in the barrel. During the grouting process, it is necessary to observe whether the reading of the slurry barrel pressure gauge 211 decreases. If so, it is necessary to press the start valve 11 to start the pressure source 1 for pressure compensation; the grouting process continues in step S17 until the data does not change; during the grouting process, when grouting abnormality is detected, the first slurry stopper 33 and the slurry stop plate 34 of the grouting pipe 32 can be manually pressed or covered with a counterweight to prevent the grouting pipe 32 from rising; the entire grouting process needs to be synchronized with the time.

[0078] In one embodiment, grouting is concluded when, under normal operating conditions, the slurry has overflowed from the top surface of the weakly cemented soil layer 314 or the flow meter reading at the set pressure has stopped increasing. At this point, the start valve 11 and the slurry delivery on / off valve 210 must be closed, and the pressure relief valve 22 must be opened until the readings of the air source pressure gauge 12 and the slurry barrel pressure gauge 211 are both 0. At this point, even if grouting has concluded, the data collection and analysis of the computing device 4 must continue until the apparent resistivity shows no change, at which point the test can be terminated.

[0079] According to the various embodiments of the present disclosure, in order to solve the problems of difficulty in injecting slurry and inability to monitor the slurry diffusion process in real time in existing indoor grouting model tests, an indoor test scheme for simulating soil grouting is proposed, which can not only realize grouting simulation tests controlled by multiple conditions, but also monitor the dynamic changes of the slurry diffusion range over time in real time. The specific composition structure of the grouting pipe is combined with the fluid characteristics of slurry overflow, and when it is sensed that the slurry is about to leak, it can timely perform external pressure intervention to avoid slurry leakage and grouting pipe rising during the grouting process, ensuring smooth slurry injection. Moreover, the test device uses preset shape electrodes to monitor the test soil during simulated grouting. The electrodes are evenly distributed in the test soil, avoiding measurement errors or errors caused by fixed and discontinuous positions of sensors or electrical components such as soil pressure gauges, displacement sensors, pore water pressure gauges, etc., ensuring the accuracy of the measurement results and enabling real-time monitoring. The entire grouting process is carried out by connecting a pressure source to a three-way valve. Stirring and extruding the slurry are achieved by controlling pneumatic pressure. The grouting pressure in the grouting pipe can be fed back during grouting. Combined with the use of a specially shaped electrode matrix, the entire test device is integrated and intelligent, ensuring uninterrupted and continuous grouting, significantly improving test efficiency and accuracy. Furthermore, the model box is equipped with a water level hole to simulate stable groundwater levels, expanding the test device's applicable scenarios.

[0080] While various embodiments of the present disclosure have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A test device (100) for simulating soil grouting based on an improved grouting pipe, characterized in that: The test device (100) comprises: Stressors (1); A slurry transport assembly (2) coupled to the pressure source (1) and comprising an external slurry transport pipe (214), wherein the slurry transport assembly (2) is configured to transport slurry via the external slurry transport pipe (214) based on the pressure provided by the pressure source (1); as well as A grouting pipe (32) is fluidically coupled to the outer grouting pipe (214) and comprises a first grouting stopper (33), a grouting plate (34), a second grouting stopper (35) and a flower pipe (37) connected in sequence, wherein the flower pipe (37) is at least partially inserted into the test soil (31) during the test, wherein the first grouting stopper (33) extends and becomes larger in a first direction and fits the grouting plate (34), and the second grouting stopper (35) extends and becomes larger in a second direction and fits the grouting plate (34), wherein the first direction includes the direction of slurry transportation and is opposite to the second direction; wherein the slurry transportation assembly (2) comprises: Pressure barrel (21); A three-way valve (23) is arranged outside the pressure barrel (21) and has two passages coupled to the pressure barrel (21) and the pressure source (1) respectively; an agitator comprising an air connection pipe (26), an air motor (27), an agitating shaft (28), and blades (29), wherein one end of the air connection pipe (26) is coupled to another passage of the three-way valve (23), and the other end is coupled to the air motor (27), the air motor (27) is coupled to the agitating shaft (28) and is suitable for driving the agitating shaft (28) and the blades (29) to rotate to agitate the slurry; and The slurry discharger comprises a suction plate (213), an inner slurry delivery pipe (212), a flow meter (215) and an outer slurry delivery pipe (214) connected in sequence. The slurry discharger is suitable for conveying the stirred slurry to the grouting pipe (32) via the suction plate (213), the inner slurry delivery pipe (212), the outer slurry delivery pipe (214) and the flow meter (215) based on the pressure source (1) and the three-way valve (23), so that the grouting pressure of the grouting pipe can be fed back in time during grouting and the grouting process can be carried out continuously without interruption.

2. The test device (100) according to claim 1, characterized in that At least one of the first slurry stopper (33) and the second slurry stopper (35) is a truncated cone slurry stopper, a prism slurry stopper, or a frustum slurry stopper.

3. The test device (100) according to claim 1, characterized in that The test apparatus (100) further comprises a computing device (4), a connecting cable (42) and a plurality of electrodes (43), wherein the plurality of electrodes (43) are communicatively coupled to the computing device (4) via the connecting cable (42) and are arranged in a preset shape in the test soil (31) to collect and transmit target data to be analyzed by the computing device (4).

4. The test device (100) according to claim 3, characterized in that The preset shape includes a cross shape or a well shape and is symmetrically arranged with the grouting hole as the center.

5. The test device (100) according to claim 3, characterized in that The pressure source (1) is communicatively coupled to the computing device (4), and at least one of the first slurry stop (33), the slurry stop plate (34), and the second slurry stop (35) is communicatively coupled to the computing device (4), so that the computing device (4) can adjust the delivery pressure of the pressure source (1) when slurry leakage occurs.

6. The test device (100) according to any one of claims 1 to 5, characterized in that The test device (100) further comprises: The model box (3) is used to accommodate the test soil (31) and has multiple groups of water level holes (313) at a preset height from the box bottom to simulate a stable groundwater level condition.

7. The test device (100) according to any one of claims 1 to 5, characterized in that The pressure source (1) comprises a starting valve (11), an air source pressure gauge (12) and an air source switching valve (13).

8. A test method for simulated soil grouting based on an improved grouting pipe, used for monitoring a test soil (31) for simulating an indoor soil grouting test, characterized in that: The method uses a test device (100) according to any one of claims 2 to 7 and comprises: S01: Place the test soil (31) in the model box (3); S02: installing a plurality of electrodes (43) on the test soil (31), wherein the plurality of electrodes (43) are in a predetermined shape and the spacing between adjacent electrodes in the plurality of electrodes (43) is associated with the monitoring depth and accuracy; S03: coupling electrodes of the same monitoring profile among the plurality of electrodes (43) to a computing device (4) via a connecting cable (42); S04: before grouting the test soil (31), starting the computing device (4) to collect the apparent resistivity of each monitoring section of the test soil (31) in real time; and S05: Grouting the test soil (31) using the test device (100) and monitoring the apparent resistivity of each monitoring section of the test soil (31) in real time until the apparent resistivity does not change.

9. A test method for simulating soil grouting based on an improved grouting pipe, used for monitoring indoor grouting tests on slopes simulating a soil-rock binary structure consisting of weakly cemented soil and underlying rock strata, characterized in that: The method uses a test device (100) according to any one of claims 2 to 7 and comprises: S11: Based on the similarity theory, an indoor scaled test slope model having a similar relationship to the slope prototype is established in the model box (3). The test slope model includes the bottom bedrock (316), the base-cover interface (315), and the weakly cemented soil layer (314); S12: reserving a grouting hole (5) at the center of the top of the weakly cemented soil layer (314), and installing a grouting pipe (32) in the grouting hole (5); S13: Arranging a plurality of electrodes (43) in a "M"-shaped monitoring profile on the top of the weakly cemented soil layer (314), wherein the distance between adjacent electrodes of the plurality of electrodes (43) is 5 cm, and the plurality of electrodes (43) are coupled to a computing device (4) via a connecting cable (42); S14: loading cement slurry into the pressure barrel (21) of the slurry delivery assembly (2), and starting the pressure source (1), and then shutting down the pressure source (1) when the pressure source (1) reaches a predetermined pressure; S15: using the pressure provided by the pressure source (1) to drive the stirrer of the slurry conveying assembly (2) to stir the cement slurry, and after the cement slurry is evenly stirred, continue to use the pressure of the pressure barrel (21) to convey the cement slurry to the grouting pipe (32); S16: before grouting the test slope model, starting the computing device (4) to collect the apparent resistivity of each monitoring section of the test soil (31) in real time; and S17: Grouting is performed on the test slope model using the test device (100), and the apparent resistivity of each monitoring section of the test slope model is monitored in real time until the apparent resistivity does not change.

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