Testing device and testing method for testing influence of grouting on structure lifting

Abstract

The invention relates to the technical field of grouting engineering, in particular to a test device and a test method for testing the influence of grouting on building lifting. The test device comprises a model box, a simulant, a grouting unit and a monitoring unit, the model box is filled with transparent soil; the simulant is buried in the transparent soil and comprises a structure model and an isolation plate, and the isolation plate is arranged at the bottom of the side face of the structure model; the grouting unit comprises grouting needles which are arranged on the periphery of the simulant. The monitoring unit comprises a pressure monitoring module, a dial indicator and a strain gauge, the pressure monitoring module monitors pressure on the peripheries of the grouting needle, the structure model and the isolation plate, the dial indicator abuts against the structure model, and the strain gauge is attached to the bottom of the structure model. Reliable data support is provided for actual engineering, and then visual tests of grouting on building lifting in different environments in reality and the diffusion rule of grouting slurry are restored.

Description

Technical Field

[0001] The invention relates to the technical field of grouting engineering, and in particular to a test device and a test method for testing the influence of grouting on the lifting of a structure. Background Art

[0002] Most municipal subway tunnels are built in areas with dense urban buildings (structures), which imposes strict restrictions on disturbances to the surrounding environment. The construction of subways and foundation pits near buildings (structures) will inevitably cause deformation of the surrounding strata, which poses a threat to the structural safety and operational safety of the buildings (structures). In order to protect the safety of buildings (structures), active grouting technology is often used in engineering for reinforcement control. When buildings and structures settle, grouting is also used to lift them. Different grouting pressures, grouting distances, and grouting volumes have different lifting effects on structures. Differences in strata will also have significant differences in grouting diffusion and lifting effects. Some structures are even surrounded by deeper retaining structures that affect the grouting lifting effect.

[0003] In traditional transparent soil experiments, only the visual properties of transparent soil are usually used to study the grouting diffusion law. No other structure models are set up in the experiment, and the study of the grouting uplift of the structure is not considered with multiple control variables. In addition, traditional grouting model tests mostly study the grouting effect by controlling the grouting parameters, and it is impossible to visualize the slurry diffusion law for structures with isolation plates. Summary of the invention

[0004] In view of the deficiencies in the prior art, an embodiment of the present invention aims to provide a test device for testing the effect of grouting on the uplift of a structure, which is used to simulate and test the effect of grouting on the uplift of a structure, and the diffusion law of slurry in the soil layer.

[0005] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions: A test device for testing the effect of grouting on the lifting of a structure, comprising: a model box, a simulation object, a grouting unit and a monitoring unit; the model box is filled with transparent soil; the simulation object is buried in the transparent soil, comprising a structure model and an isolation plate, and the isolation plate is arranged at the bottom of the side of the structure model; the grouting unit comprises a grouting needle, and the grouting needle is arranged around the simulation object; the monitoring unit comprises a pressure monitoring module, a micrometer and a strain gauge, the pressure monitoring module monitors the pressure of the grouting needle, the structure model and the isolation plate, the micrometer is against the structure model, and the strain gauge is attached to the bottom of the structure model.

[0006] An embodiment of the present invention also provides a test method using the test device for testing the effect of grouting on the uplift of a structure as described above, comprising: setting a simulated object and transparent soil in a model box, burying the simulated object in the transparent soil, and arranging a pressure monitoring module at a predetermined position; burying the bottom of a grouting needle in the transparent soil, adjusting the distance between the grouting needle and the simulated object, installing a micrometer and resting it on the bottom plate of the model box; injecting grout into the grouting needle through a grouting unit; collecting soil pressure and pore water pressure around the grouting needle, soil pressure and pore water pressure around the structure model, soil pressure and pore water pressure around the isolation plate, internal force and displacement of the bottom plate of the model box, and photographing the slurry diffusion; studying the slurry diffusion law and its effect on the uplift of the structure through soil pressure, pore water pressure at different positions and internal force and displacement of the bottom plate of the model box, combined with the photographed images.

[0007] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: This test device can be used to better simulate grouting with different pressures and different grouting volumes, as well as controlling the grouting distance (i.e., the positional relationship with the structure), changing the grouting stratum medium conditions and whether or not to set up isolation plates, and other working conditions. It can also be used to influence the uplift of the structure and the stress and displacement fields of the surrounding strata, as well as the diffusion law of the slurry in the medium, providing reliable data support for actual close-proximity grouting reinforcement projects.

[0008] Advantages of additional aspects of the present invention will be given in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0010] Figure 1 is an overall schematic diagram of the test device provided in Example 1 of the present invention; Figure 2 is a schematic diagram of a model box provided in Example 1 of the present invention; Figure 3 is a schematic diagram of a simulant provided in Example 1 of the present invention; Figure 4 is a schematic diagram of a grouting unit provided in Example 1 of the present invention; Figure 5 is a schematic diagram of a monitoring unit provided in Example 1 of the present invention; Figure 6This is a schematic diagram of the installation of a micrometer provided in Example 1 of the present invention; Figure 7 It is a schematic diagram of the arrangement of the grouting needle, the micrometer and the simulant provided in Example 1 of the present invention; Figure 8 It is a schematic diagram of the experimental method provided in Example 2 of the present invention.

[0011] In the figure: 1. model box; 11. scale; 12. grid line; 2. simulation object; 21. structure model; 211. hole; 22. isolation board; 3. grouting unit; 31. air compressor; 32. pressure regulating valve; 33. slurry storage barrel; 34. grouting pipe; 35. control switch; 36. flow meter; 37. grouting needle; 38. bracket; 4. monitoring unit; 41. high-speed camera; 42. data acquisition instrument; 43. computer; 44. pressure monitoring module; 45. micrometer; 46. magnetic base; 47. displacement transmission rod; 48. strain gauge; 5. operating platform. DETAILED DESCRIPTION

[0012] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0013] Example 1 In order to solve the technical problems mentioned in the background technology, this embodiment proposes a test device for testing the effect of grouting on the uplift of structures, simulating the effect of grouting on the uplift of structures under different environments, and visually testing the diffusion law of slurry in the soil layer; by controlling grouting parameters and soil layer conditions, studying the influence of different factors on the uplift effect of structures; providing accurate measurement of key data such as structure displacement, internal force, soil pressure and pore water pressure, providing reliable data support for actual projects, and then restoring the visual test of grouting on the uplift of structures in different environments in reality and the diffusion law of grouting slurry.

[0014] like Figure 1 As shown in FIG. 1 , the device comprises a model box 1, a simulant 2, a grouting unit 3 and a monitoring unit 4. The model box 1 is filled with transparent soil, and the simulant 2 is buried in the transparent soil. Figure 3 As shown, the simulation object 2 includes a structure model 21 and an isolation plate 22, and the isolation plate 22 is arranged at the bottom of the side of the structure model 21. Figure 4 As shown, the grouting unit 3 includes a grouting needle 37, and the grouting needle 37 is arranged on the side of the simulated object 2. Figure 5 , Figure 6 , Figure 7 As shown, the monitoring unit 4 includes a pressure monitoring module 44, a micrometer 45 and a strain gauge 48. The pressure monitoring module 44 monitors the pressure on the grouting needle 37, the structure model 21 and the surrounding pressure of the isolation plate 22. The micrometer 45 is against the structure model 21, and the strain gauge 48 is attached to the bottom of the structure model 21.

[0015] In this embodiment, the design of the model box 1 allows the diffusion of the slurry in the transparent soil during the grouting process to be observed, and the setting of the simulant 2 simulates the lifting effect of the actual structure during the grouting process. The grouting needle 37 of the grouting unit 3 directly acts on the side of the simulant 2, and simulates the pressure conditions in the actual grouting process by controlling the grouting pressure and flow. The pressure monitoring module 44 of the monitoring unit 4 can monitor the pressure changes in the grouting process in real time, and the micrometer 45 and the strain gauge 48 respectively monitor the displacement and internal force of the structure model 21.

[0016] The test device also includes an operating platform 5, on which the model box 1 is placed. An opening is provided at the top of the model box 1, and the box wall is made of organic glass. The design of the operating platform 5 facilitates the assembly and operation of the test device. The opening at the top of the model box 1 facilitates the installation and adjustment of the transparent soil and the grouting needle 37, and the organic glass box wall provides good transparency, so that the grouting process and slurry diffusion can be clearly observed. In this embodiment, the model box 1 is a square box with an opening at the top, and the four sides of the box are transparent acrylic plates. The length of the model box 1 is 200 mm, and the width and height are both 100 mm.

[0017] like Figure 2 As shown, a scale 11 and grid lines 12 are arranged on the wall of the model box 1. The scale 11 is arranged at the bottom and side of the box wall, and the grid lines 12 are arranged on the wall surface of the box wall. This design allows the operator to accurately control the position of the grouting needle 37, as well as the position and depth of the simulant 2 in the transparent soil, thereby simulating different grouting conditions and structure lifting conditions.

[0018] The structure model 21 is a box structure with a top plate and a bottom plate. Since the structure model 21 is not an infinite rigidity body, there is a certain difference in the deformation of the top plate and the bottom plate under the action of external force. If the grouting pressure is relatively small relative to the deadweight of the structure model 21, under the action of the grouting pressure, a certain point or a certain area of ​​the bottom plate will be deformed, while the overall displacement of the model is small, and the top plate will not feedback the deformation. Based on this, in this embodiment, a hole 211 is provided on the top plate, and a displacement transmission rod 47 is installed at the bottom of the micrometer 45. The displacement transmission rod 47 passes through the hole 211 and rests on the bottom plate of the structure model 21. Such a design allows the micrometer 45 to accurately measure the vertical displacement of the structure model 21 during the grouting process. The design of the hole 211 enables the displacement transmission rod 47 to accurately measure the displacement of the bottom plate of the structure model 21, ensuring the accuracy of the measurement data.

[0019] The structure model 21 is made of polyethylene board (PE board), the isolation board 22 is fixed to the structure model 21 by screws, a 6 mm hole 211 is reserved on the top plate of the structure model 21, and the displacement transmission rod 47 is a stainless steel pipe with a diameter of 4 mm.

[0020] like Figure 4 As shown, the grouting unit 3 also includes a bracket 38, the bottom of the bracket 38 is fixed on the operating platform 5, the upper end of the grouting needle 37 is fixed on the bracket 38, and the lower end of the grouting needle 37 is buried in the transparent soil of the model box 1. This design allows the grouting needle 37 to be stably fixed in the model box 1, and the design of the bracket 38 also facilitates the adjustment of the position of the grouting needle 37 to adapt to different test conditions. The grouting needle 37 is a stainless steel tube with an inner diameter of 4mm and an outer diameter of 6mm, and an array of grouting holes with an aperture of 2mm are set on the bottom side wall of the stainless steel tube.

[0021] The grouting unit 3 further includes an air compressor 31, a slurry storage barrel 33 and a grouting pipe 34. The air compressor 31 and the slurry storage barrel 33 are connected through an air pipe, and the grouting pipe 34 is connected to the slurry storage barrel 33 and the grouting needle 37. This design enables the grouting unit 3 to control the pressure and flow of grouting. The air compressor 31 provides power, the slurry storage barrel 33 is filled with ultrafine cement slurry, and a color solution is added to the ultrafine cement slurry, and the grouting pipe 34 is responsible for transporting the slurry to the grouting needle 37.

[0022] A pressure regulating valve 32 is provided on the air pipe, and a control switch 35 and a flow meter 36 are provided on the grouting pipe 34. The pressure regulating valve 32 is used to stabilize the pressure provided by the air compressor 31 to ensure the stability of the grouting process; the control switch 35 and the flow meter 36 are used to accurately control the grouting process, including the start, stop and flow adjustment of the grouting.

[0023] The pressure monitoring module 44 is a soil pressure box and a pore water pressure gauge, which are purchased micro soil pressure boxes and micro pore water pressure gauges. The soil pressure box is used to monitor soil pressure, and the pore water pressure gauge is used to monitor water pressure. The micrometer 45 is installed on the magnetic base 46 through a universal rod, and the magnetic base 46 is adsorbed on the operating platform 5. This design allows the pressure monitoring module 44 to accurately monitor pressure changes at different positions. The universal rod design of the micrometer 45 provides a flexible measurement angle, and the magnetic base 46 facilitates the fixation and position adjustment of the micrometer 45.

[0024] like Figure 5As shown, the monitoring unit 4 also includes a high-speed camera 41, a data acquisition instrument 42 and a computer 43. The high-speed camera 41 is placed on the operating platform 5 and is respectively located in front of and on the side of the model box 1. The high-speed camera 41 is used to take real-time photos to more clearly show the grouting diffusion law. The pressure monitoring module 44 is electrically connected to the data acquisition instrument 42, and the data acquisition instrument 42 and the high-speed camera 41 are both electrically connected to the computer 43. This design allows the image data and monitoring data during the test to be collected in real time and stored on the computer 43, which is convenient for subsequent data analysis and research.

[0025] This experimental device studies the influence of different distances and grouting depths on the uplift of the structure by controlling the positional relationship between the grouting needle 37 and the structure model 21 and the isolation plate 22, studies the influence of grouting on the uplift of the structure under different pressures and grouting volumes by adjusting the parameters of the grouting unit 3, studies the diffusion law of slurry under different soil properties and the influence of grouting on the uplift of the structure by controlling the transparent soil ratio in the model box 1, studies the diffusion law of slurry under the isolation plate 22 and the influence of grouting on the uplift of the structure by controlling the isolation plate 22 set on the structure model 21, visualizes the test of the slurry diffusion law under these factors, and finally tests the displacement, bottom plate internal force, soil pressure, pore water pressure and other data of the structure model 21 through the pressure monitoring module 44, and photographs the slurry diffusion law and process through the high-speed camera 41, thereby accurately testing the influence of grouting on the uplift of the structure and the stress field and displacement field of the surrounding strata.

[0026] Example 2 This embodiment proposes a test method using the test device of embodiment 1, such as Figure 8 As shown, including: A simulated object 2 and transparent soil are arranged in the model box 1, and the simulated object 2 is buried in the transparent soil; the bottom of the grouting needle 37 is buried in the transparent soil, and the distance between the grouting needle 37 and the simulated object 2 is adjusted; grouting is injected into the grouting needle 37 through the grouting unit 3; the soil pressure and pore water pressure around the grouting needle 37, the soil pressure and pore water pressure around the structure model 21, the soil pressure and pore water pressure around the isolation plate 22, the internal force and displacement of the bottom plate of the model box 1 are collected, and the slurry diffusion is photographed; through the soil pressure, pore water pressure at different positions and the internal force and displacement of the bottom plate of the model box 1, and combined with the photographed images, the slurry diffusion law and the influence on the structure uplift are studied.

[0027] The test steps specifically include: S101: a structure model 21 and transparent soil are arranged in the model box 1, so that the structure model 21 is buried in the transparent soil, and a pressure monitoring module 44 is arranged at the bottom of the structure model 21, at the expected grouting outlet of the grouting needle 37, and at the inner side and / or outer side of the isolation plate 22. The pressure monitoring module 44 is arranged at multiple locations such as the structure model 21, the isolation plate 22, and the grouting needle 37, thereby expanding the monitoring range and improving the accuracy of the monitoring data.

[0028] S102 controls the distance between the grouting needle 37 and the structure model 21 according to the scale 11 and the grid line 12, sets the grouting needle 37 at different positions and depths of the transparent soil, and the micrometer 45 is against the bottom plate of the model box 1 through the displacement transmission rod 47.

[0029] In this embodiment, it is necessary to control the grouting needle 37 to be buried in different positions of the model box 1 to reflect the positional relationship with the structure model 21, so as to simulate and study the influence of different grouting distances and grouting depths on the lifting of the structure.

[0030] S103 After the grouting needle 37 and the structure are set up, the grouting control switch 35 is turned on to inject grout into the grouting needle 37 through the grouting unit 3.

[0031] S104 controls different grouting pressures and grouting volumes through the air compressor 31 , the pressure regulating valve 32 and the flow meter 36 according to the grouting requirements.

[0032] In this embodiment, the grouting pressure in the grout storage barrel 33 is controlled by connecting the pressure regulating valve 32 of the air compressor 31 , and the grouting amount of the grouting needle 37 is controlled by controlling the flow meter 36 connected to the grout storage barrel 33 .

[0033] S105 The high-speed camera 41 takes pictures, the pressure monitoring module 44, the micrometer 45 and the strain gauge 48 collect data, and the taken pictures and the collected data such as soil pressure, pore water pressure, displacement and internal force are input into the computer 43.

[0034] In this embodiment, the pressure monitoring module 44 collects data such as the displacement, internal force, soil pressure at different positions and pore water pressure of the structure model 21, and shoots the slurry diffusion through the high-speed camera 41. The data acquisition device 42 sends the acquired data to the host computer, thereby accurately testing the lifting and mechanical properties of the structure and the slurry diffusion characteristics caused by grouting under different factors.

[0035] After the data collection is completed in S106, the transparent soil ratio in the model box 1 is adjusted to simulate different soil layers, and the above test steps are repeated.

[0036] In this embodiment, transparent soils of different properties need to be set to simulate the grouting slurry diffusion law in different strata and the impact on the uplift of the structure.

[0037] S107 In addition, the grouting needle 37 can be adjusted to be located on the side of the model box 1 with the isolation plate 22 or the side without the isolation plate 22, so as to study the effect of the isolation plate 22 on the slurry diffusion law and the effect of grouting on the lifting of the structure.

[0038] This embodiment controls the grouting needle 37 to be buried at different sides of the structure, thereby simulating the grouting slurry diffusion law and the influence on the lifting of the structure under two working conditions, with and without the isolation plate 22. The reading of the micrometer 45 reflects the lifting of the structure, the strain gauge 48 reflects the change of the internal force of the bottom plate of the structure, and the micro-earth pressure box and the pore water pressure gauge reflect the stress field of the soil around the structure. The slurry diffusion posture can be collected by shooting with a high-speed camera 41, and the diffusion image is post-processed by particle image velocimetry to obtain the slurry diffusion characteristics.

[0039] In summary, the distance between the grouting needle 37 and the structure model 21 is controlled by the scale 11 and the grid line 12 on the model box 1, and the grouting needle 37 is adjusted in the transparent soil position and at different depths to simulate the positional relationship between the grouting pipe 34 and the structure. The air compressor 31, the pressure regulating valve 32 and the flow meter 36 are controlled to adjust the grouting pressure and the output slurry in the slurry storage barrel 33 to achieve different grouting pressures and grouting volumes. By controlling the isolation plate 22 set on the structure model 21, the slurry diffusion law under the isolation plate 22 and the effect of grouting on the lifting of the structure are studied. The proportion of the transparent soil in the model box 1 can also be adjusted to simulate the slurry diffusion characteristics in different soil layers and the effect of grouting on the lifting of the structure. Finally, the displacement, internal force, soil pressure at different positions and pore water pressure of the structure model 21 are collected through the pressure monitoring module 44, and the slurry diffusion is photographed by the high-speed camera 41, thereby accurately reflecting the lifting and mechanical properties of the structure caused by grouting and the slurry diffusion characteristics under different factors.

[0040] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A test device for testing the effect of grouting on the lifting of a structure, characterized in that: include: Model boxes, simulants, grouting units and monitoring units; The model box is filled with transparent soil; The simulant is buried in the transparent soil and includes a structure model and an isolation plate, wherein the isolation plate is arranged at the bottom of the side of the structure model; The grouting unit comprises a grouting needle head, and the grouting needle head is arranged on the peripheral side of the simulation object; The monitoring unit includes a pressure monitoring module, a micrometer and a strain gauge. The pressure monitoring module monitors the pressure of the grouting needle, the structure model and the surrounding side of the isolation plate. The micrometer is against the structure model, and the strain gauge is attached to the bottom of the structure model.

2. The test device for testing the effect of grouting on the lifting of a structure as claimed in claim 1, characterized in that: The test device also includes an operating platform, the model box is placed on the operating platform, an opening is arranged on the top of the model box, and the box wall of the model box is made of organic glass.

3. The test device for testing the effect of grouting on the lifting of a structure as claimed in claim 2, characterized in that: The box wall of the model box is provided with a scale and grid lines, the scale is provided at the bottom and the side of the box wall, and the grid lines are provided on the wall surface of the box wall.

4. The test device for testing the effect of grouting on the lifting of a structure as claimed in claim 2, characterized in that: The structure model is a box structure having a top plate and a bottom plate. The top plate is provided with holes. A displacement conduction rod is installed at the bottom of the micrometer. The displacement conduction rod passes through the hole and rests on the bottom plate of the structure model.

5. The test device for testing the effect of grouting on the lifting of a structure as claimed in claim 2, characterized in that: The grouting unit also includes a bracket, the bottom of which is fixed on the operating platform, the upper end of the grouting needle is fixed on the bracket, and the lower end of the grouting needle is buried in the transparent soil of the model box.

6. The test device for testing the effect of grouting on the lifting of a structure as claimed in claim 5, characterized in that: The grouting unit also includes an air compressor, a slurry storage barrel and a grouting pipe. The air compressor and the slurry storage barrel are connected through an air pipe, and the grouting pipe is connected to the slurry storage barrel and the grouting needle.

7. The test device for testing the effect of grouting on the lifting of a structure as claimed in claim 6, characterized in that: The air pipe is provided with a pressure stabilizing valve, and the grouting pipe is provided with a control switch and a flow meter.

8. The test device for testing the effect of grouting on the lifting of a structure as claimed in claim 2, characterized in that: The pressure monitoring module is a soil pressure box and a pore water pressure gauge, the soil pressure box is used to monitor soil pressure, the pore water pressure gauge is used to monitor water pressure, the micrometer is installed on a magnetic base through a universal rod, and the magnetic base is adsorbed on the operating platform.

9. The test device for testing the effect of grouting on the lifting of a structure as claimed in claim 2, characterized in that: The monitoring unit also includes a high-speed camera, a data acquisition instrument and a computer. The high-speed camera is placed on the operating platform and is respectively located in front of and on the side of the model box. The pressure monitoring module is electrically connected to the data acquisition instrument, and the data acquisition instrument and the high-speed camera are both electrically connected to the computer.

10. A test method using the test device for testing the effect of grouting on the lifting of a structure as claimed in any one of claims 1 to 9, characterized in that: include: A simulant and transparent soil are arranged in the model box, the simulant is buried in the transparent soil, and a pressure monitoring module is arranged at a predetermined position; The bottom of the grouting needle is buried in the transparent soil, and the distance between the grouting needle and the simulant is adjusted. The micrometer is installed and pressed against the bottom plate of the model box; Inject grout into the grouting needle through the grouting unit; Collect the soil pressure and pore water pressure around the grouting needle, the soil pressure and pore water pressure around the structure model, the soil pressure and pore water pressure around the isolation plate, the internal force and displacement of the bottom plate of the model box, and take photos of the slurry diffusion; The soil pressure, pore water pressure at different positions, the internal force and displacement of the bottom plate of the model box are used to study the slurry diffusion law and its influence on the uplift of the structure in combination with the captured images.

Images