A multi-index detection device and detection method for sidewall grouting

Abstract

A multi-index detection device and detection method for sidewall grouting, including a transparent cylinder body, with an upper cover plate and a lower cover plate detachably connected to both ends of the transparent cylinder body respectively. A perforated plate is arranged inside the cylinder body. A grouting pipe is communicated on the upper cover plate, and a plurality of air leakage ports are opened on the lower cover plate. The grouting pipe is communicated with the bottom of a slurry storage tank, and the top of the slurry storage tank is communicated with an air compressor through an air inlet pipe. A first adjustable pressure reducing valve, a first pressure gauge and a first stop valve are installed on the air inlet pipe. The present invention can simulate grouting under different working conditions (particle size, particle gradation, particle shape, undisturbed soil), and measure different properties of the slurry by various detection methods to obtain a series of multi-index data.

Description

Technical Field

[0001] The present invention relates to the overall effect of indoor multi-index measurement of calcium sand sidewall grouting. More specifically, it is especially a multi-index detection device and detection method for sidewall grouting. Background Art

[0002] Calcium sand is a special geotechnical medium composed of calcium carbonate and other insoluble carbonate substances. To a certain extent, calcium sand retains the fine voids in the biological skeleton, resulting in irregular shapes, more internal pores, easy particle breakage, and easy inter-granular cementation of calcium sand. Different from traditional foundations, calcium sand has properties such as looseness, larger pores, and easy breakage. Traditional slurry walls cannot be well applied to calcium sand foundations. In response to this problem, grouting is adopted to press the slurry into the sidewall of the pile hole, reinforce the sidewall of the pile hole, limit the continuous expansion of the expansion pile, and improve the bearing capacity of the pile body. In the existing measurement system, it mostly focuses on the comprehensive bearing capacity of the pile body and does not measure and judge the overall effect of the grouting of the pile hole sidewall itself. Therefore, it is very important to invent a research that can simulate pile side grouting indoors and obtain the mechanical properties after the slurry solidifies the calcium sand layer. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a multi-index detection device and detection method for sidewall grouting, which can simulate grouting under different working conditions (particle size, particle gradation, particle shape, undisturbed soil), and use a variety of detection methods to measure different properties of the slurry to obtain a series of multi-index data.

[0004] To solve the above problems, the technical solution of the present invention is as follows:

[0005] A multi-index detection device for sidewall grouting, including a transparent cylinder body, with an upper cover plate and a lower cover plate detachably connected to both ends of the transparent cylinder body respectively. A hole plate is provided inside the cylinder body. A grouting pipe is communicated on the upper cover plate, and a plurality of air leakage ports are opened on the lower cover plate. The grouting pipe is communicated with the bottom of the slurry storage tank, and the top of the slurry storage tank is communicated with an air compressor through an air inlet pipe. A first adjustable pressure reducing valve, a first pressure gauge, and a first stop valve are installed on the air inlet pipe.

[0006] A method for a multi-index detection device for sidewall grouting,

[0007] S1: Fill calcium sand into the cylinder according to different simulated working conditions, compact it, and then tilt the cylinder 90° and place it flat on the ground;

[0008] S2: After pouring the prepared slurry into the slurry storage tank, connect the slurry storage tank with the grouting pipe and the air compressor. After starting the air compressor, the slurry is sent into the cylinder under the action of air pressure. When the slurry fills the gap between the orifice plate and the upper cover plate, start to record the time and the real-time penetration distance of the slurry, calculate the penetration rate of the slurry under different conditions, and change different grouting volumes, grouting pressures, and calcareous sand particle sizes to simulate the working conditions under various different environments.

[0009] S3: Wait for the slurry to coagulate for a period of time, start the air extraction pump, extract the slurry on the surface of the cylinder, and measure the anti-suction strength of the slurry under different ratios, grouting volumes, grouting pressures, and calcareous sand particle sizes according to the relationship between the suction force and time;

[0010] S4: After the slurry solidifies, conduct a CT scan to measure the overall penetration depth of the slurry in the calcareous sand and the penetration range of each cut surface, as well as the density of each area inside the calcareous sand after the slurry penetrates, and summarize the penetration law and penetration path of the slurry;

[0011] S5: After the CT scan test is completed, remove the upper cover plate and the orifice plate, turn the top surface of the cylinder upward, and freely hammer the surface of the solidified slurry with a fixed-height heavy hammer. According to the law of conservation of energy, conduct the heavy hammer test until the slurry cracks and fails, record the total number of hammer blows on the surface where the prepared slurry ruptures, and obtain the corresponding relationship between the strength formed after the slurry coagulates in the calcareous sand and the number of blows.

[0012] S6: Remove the lower cover plate, turn the bottom surface of the cylinder upward, with the solidified slurry at the bottom, apply different loads on the upper part to simulate the earth pressure or water pressure generated by the side walls of pile holes at different depths in the calcareous sand, conduct the loading test, measure its anti-lateral force strength, and obtain the anti-lateral force strength at different depths according to the Q-S curve.

[0013] The beneficial effects of the present invention are as follows: By simulating the grouting process indoors and cooperating with various detection methods such as CT scan, loading test, anti-suction test, and heavy hammer test, different properties of the side wall slurry are obtained, and the penetration rate, penetration depth of the slurry under different particle sizes, particle gradations, grouting pressures, grouting volumes, and particle shapes, as well as the surface strength, anti-lateral force strength, and anti-suction strength after the slurry is injected into the side wall are obtained, clarifying the slurry wall protection effect; obtaining the diffusion and penetration law of the slurry under different grouting volumes, grouting pressures, calcareous sand particle sizes, particle gradations, and particle shapes, clarifying the influence range of slurry reinforcement, forming a complete set of specification systems for different detection methods of the slurry side wall, providing a certain theoretical basis for the effect detection of the actual construction of pile hole side wall grouting in the later stage, and having stronger guarantee. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The following further describes the present invention with reference to the accompanying drawings:

[0015] Figure 1 is a schematic structural diagram of the present invention;

[0016] Figure 2 This invention relates to a method for CT scanning and analysis of internal calcareous sand;

[0017] Figure 3 This invention relates to a Q-S curve graph of sidewall slurry loading;

[0018] In the figure: grouting pipe 1, upper cover plate 2, orifice plate 3, cylinder 4, air leakage port 5, lower cover plate 6, slurry storage tank 7, air compressor 8, air extraction pump 9, first stop valve 10, first pressure gauge 11, first adjustable pressure reducing valve 12, second stop valve 13, second pressure gauge 14, second adjustable pressure reducing valve 15, scale 16. Specific embodiments

[0019] The following further explains the embodiments of the present invention with reference to the accompanying drawings. This device can simulate different working conditions in calcareous sand and adopt different detection methods to test the properties of the slurry on the sidewall of the pile hole, and finally form a complete multi-index detection method for the slurry on the sidewall of the pile hole:

[0020] As Figure 1 shown, a multi-index detection device for sidewall grouting includes a transparent cylinder 4. The two ends of the transparent cylinder 4 are respectively detachably connected with an upper cover plate 2 and a lower cover plate 6 through flanges. An orifice plate is arranged in the cylinder 4. A grouting pipe 1 is communicated on the upper cover plate 2, and a plurality of air leakage ports 5 are opened on the lower cover plate 6. The grouting pipe 1 is communicated with the bottom of the slurry storage tank 7. The top of the slurry storage tank 7 is communicated with the air compressor 8 through an air inlet pipe. A first adjustable pressure reducing valve 12, a first pressure gauge 11 and a first stop valve 10 are installed on the air inlet pipe. The orifice plate is used to prevent the calcareous sand from collapsing when the cylinder 4 is tilted and laid flat, and on the other hand, it better simulates the actual grouting on the sidewall of the pile hole.

[0021] The top of the slurry storage tank 7 is communicated with the air extraction pump 9 through an air extraction pipe. A second adjustable pressure reducing valve 15, a second pressure gauge 14 and a second stop valve 13 are installed on the air extraction pipe.

[0022] Six scales 16 are pasted outside the cylinder 4, and each scale 16 is evenly distributed around the axis of the cylinder 4. The scale 16 is convenient for recording time later and measuring the penetration rate of the slurry in calcareous sand under different grouting pressures, grouting volumes and particle sizes.

[0023] Sealing rings are provided between the upper cover plate 2 and the lower cover plate 6 and the cylinder 4 for sealing to prevent air leakage.

[0024] A method for operating a multi-index detection device for sidewall grouting, characterized by including the following steps:

[0025] S1: Open the upper cover plate 2, fill in calcareous sand according to different simulated working conditions, compact it, close the upper cover plate 2, and tilt the cylinder 4 by 90° and lay it flat on the ground;

[0026] S2: After pouring the prepared slurry into the slurry storage tank 7, connect the slurry storage tank 7 to the grouting pipe 1 and the air compressor 8. After starting the air compressor 8, the slurry is sent into the cylinder body 4 under the action of air pressure. When the slurry fills the gap between the orifice plate and the upper cover plate 2, start recording the time and the real-time penetration distance of the slurry, calculate the penetration rate of the slurry under different pressure intensities, and change different grouting volumes, grouting pressures, and calcareous sand particle sizes to simulate the working conditions under various different environments;

[0027] Among them, the weight ratio of the slurry is: cement 100 - 150: water 110 - 160: expansion agent 5 - 10: accelerating agent 1 - 2. The cement is CGM 800-mesh cement; the pressure intensity can be adjusted by the first adjustable pressure reducing valve, and the test results are shown in Table 1.

[0028]

[0029] Table 1

[0030] S3: Wait for the slurry to coagulate for a period of time, close the first stop valve 10, start the air extraction pump 9 and open the second stop valve 13 to extract the slurry on the surface of the cylinder body 4. According to the relationship between the air extraction force - time, measure the anti-air extraction strength of the slurry under different ratios, grouting volumes, grouting pressures, and calcareous sand particle sizes, as shown in Table 2 in detail. It can be analyzed that as the cement slurry with different water-cement ratios is pressed into the calcareous sand, the smaller the particle size, the greater the anti-air extraction force of the sidewall slurry and the longer the required time. Because after the slurry enters the calcareous sand, the smaller the particle size, the higher the cohesion between the calcareous sands. The size of the suction force can be adjusted by the second adjustable pressure reducing valve 15.

[0031]

[0032] Table 2

[0033] S4: After the slurry solidifies, conduct a CT scan to measure the overall penetration depth of the slurry in the calcareous sand and the penetration range of each cross-section, as well as the density of each area inside the calcareous sand after the slurry penetration, and summarize the penetration law and penetration path of the slurry, as Figure 2 shown;

[0034] S5: After the CT scan test is completed, remove the upper cover plate 2 and the orifice plate, turn the top surface of the cylinder 4 upward, and freely hammer the surface of the solidified slurry with a fixed-height heavy hammer. According to the law of conservation of energy, conduct the heavy hammer test until the slurry cracks and fails. Record the total number of hammer blows when the surface of the prepared slurry ruptures, and obtain the corresponding relationship between the strength and the number of blows of the slurry formed after coagulation in calcareous sand. For example, at the same particle size of 2.36 and within 1 minute, grout is applied at pressures of 0.1 Mpa, 0.2 Mpa, and 0.3 Mpa respectively. After the slurry on the sidewall solidifies, hammer the sidewall of the slurry. The total number of hammer blows is 10 times at 0.1 Mpa, 12 times at 0.2 Mpa, and 15 times at 0.3 Mpa, indicating that the greater the pressure, the denser the slurry fills the calcareous sand and the higher the strength of the slurry sidewall.

[0035] S6: Remove the lower cover plate 6, turn the bottom surface of the cylinder 4 upward, with the solidified slurry at the bottom, and apply different loads on the upper part to simulate the earth pressure or water pressure generated by the sidewalls of pile holes at different depths in calcareous sand. Conduct the loading test until the slurry on the bottom sidewall ruptures, stop loading, measure its lateral resistance strength, and obtain the lateral resistance strength of the slurry at different depths according to the Q-S curve. The test results are shown in Table 3.

[0036]

[0037] Table 3.

Claims

1. A multi-index detection method for sidewall grouting, characterized in that: The detection device used in the multi-index detection method of sidewall grouting, the detection device includes a transparent cylinder body (4), upper and lower covers (2) and (6) are detachably connected to both ends of the transparent cylinder body (4) respectively. A perforated plate is provided in the cylinder body (4). A grouting pipe (1) is communicated with the upper cover (2). A plurality of air leakage ports (5) are opened on the lower cover (6). The grouting pipe (1) is communicated with the bottom of the slurry storage tank (7). The top of the slurry storage tank (7) is communicated with an air compressor (8) through an air inlet pipe. A first adjustable pressure reducing valve (12), a first pressure gauge (11) and a first stop valve (10) are installed on the air inlet pipe; the top of the slurry storage tank (7) is communicated with an air extraction pump (9) through an air extraction pipe. A second adjustable pressure reducing valve (15), a second pressure gauge (14) and a second stop valve (13) are installed on the air extraction pipe; The method includes the following steps: S1: Fill the cylinder body (4) with calcareous sand according to different simulated working conditions, compact it, and then tilt the cylinder body (4) by 90° and place it flat on the ground; S2: After pouring the prepared slurry into the slurry storage tank (7), connect the slurry storage tank (7) with the grouting pipe (1) and the air compressor (8). After starting the air compressor (8), the slurry is sent into the cylinder body (4) under the action of air pressure. When the slurry fills the gap between the perforated plate and the upper cover (2), start to record the time and the real-time penetration distance of the slurry, and calculate the penetration rate of the slurry under different pressure intensities. Change different grouting volumes, grouting pressures, and calcareous sand particle sizes to simulate the working conditions in various different environments; S4: Wait for the slurry to coagulate for a period of time, start the air extraction pump (9), extract the slurry on the surface of the cylinder body (4), and measure the anti-suction strength of the slurry under different ratios, grouting volumes, grouting pressures, and calcareous sand particle sizes according to the suction force-time relationship; S5: Wait for the slurry to solidify and then perform a CT scan to measure the overall penetration depth of the slurry in the calcareous sand and the penetration range of each cross-section, as well as the density of each area inside the calcareous sand after the slurry penetration, and summarize the penetration law and penetration path of the slurry; S6: After the CT scan test is completed, remove the upper cover (2) and the perforated plate, turn the top surface of the cylinder body (4) upward, and freely hammer the surface of the solidified slurry with a fixed-height weight. According to the law of conservation of energy, perform a weight hammer test until the slurry cracks and fails, record the total number of hammer blows when the surface of the prepared slurry ruptures, and obtain the corresponding relationship between the strength and the number of blows formed by the slurry after coagulation in the calcareous sand; S7: Remove the lower cover (6), turn the bottom surface of the cylinder body (4) upward, with the solidified slurry at the bottom, apply different loads on the upper part to simulate the earth pressure or water pressure generated by the side walls of pile holes at different depths in the calcareous sand, and perform a loading test to measure its anti-side force strength. According to the Q-S curve, obtain the anti-side force strength of the slurry at different depths.

2. The multi-index detection method for sidewall grouting according to claim 1, wherein: A plurality of scales (16) are pasted outside the cylinder body (4), and each scale (16) is evenly distributed around the axis of the cylinder body (4).

3. The multi-index detection method for sidewall grouting according to claim 1, wherein: Sealing rings are provided between the upper cover (2) and the lower cover (6) and the cylinder body (4).

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