Method for detecting diffusion range of post-grouting slurry of cast-in-place pile

Abstract

The invention provides a method for detecting the diffusion range of post-grouting slurry of a cast-in-place pile. The method comprises the steps that the center of a pile body serves as a path starting point, and a plurality of detection paths are arranged in the annular direction of the pile body; before grouting operation, the apparent resistivity of a plurality of measuring points distributed at equal intervals is measured along each detection path, and a first relation curve that the apparent resistivity of each path changes along with the distance from the pile body ring wall is generated; after the grouting operation is completed, the apparent resistivity of the same measurement point of each detection path is measured, and a second relation curve that the apparent resistivity of each path changes along with the distance from the pile body ring wall is generated; the first relation curve and the second relation curve of the same detection path are compared, and a remarkable mutation point appearing for the first time is recognized; the distance, corresponding to the sudden change point, from the annular wall of the pile body serves as the farthest diffusion distance of grout in the direction; the slurry diffusion range is calculated based on the farthest slurry diffusion distance in all the directions of the pile body in the annular direction; the slurry diffusion range is compared with a preset threshold value, and whether the grouting effect is qualified or not is judged.

Description

Technical Field

[0001] The present application relates to the technical field of post-grouting effect detection of pile foundation engineering, and in particular to a method for detecting the diffusion range of post-grouting slurry of cast-in-place piles. Background Art

[0002] Post-grouting technology refers to a technology that pre-sets grouting pipelines in bored piles and uses a grouting pump to pressurize cement slurry after the pile is formed to enhance the bearing capacity of the soil on the sides and ends of the pile, thereby improving the bearing capacity of the pile foundation and reducing the amount of settlement. However, since the solidified mixed structure of slurry and soil after grouting is buried deep underground, the grouting effect is difficult to test. Therefore, how to accurately judge whether the grouting effect meets the design standard has long been a difficult problem in construction. At present, the results of single pile static load tests are mostly used as the test standard for pile foundation grouting effects. Coring, standard penetration test, electromagnetic wave CT, dynamic and static load methods and other means can also be used for testing, but these methods have the following defects: The existing grouting effect detection methods can only be carried out after the pile concrete reaches the design strength, which makes it difficult to detect problems in time and take corresponding remedial measures.

[0003] Therefore, it is urgent to design an accurate and efficient grouting effect detection method. Summary of the Invention

[0004] An embodiment of the present application provides a method for detecting the diffusion range of post-grouting slurry of a bored pile to solve the technical problem in the prior art that the detection method for judging the grouting effect must wait until the pile body concrete reaches the design strength before being implemented, resulting in the inability to detect grouting defects in a timely manner.

[0005] In a first aspect, a method for detecting the diffusion range of post-grouting slurry of a bored pile is provided, which comprises: taking the center of the pile body as the starting point of the path, setting a plurality of detection paths along the circumference of the pile body; before the grouting operation, measuring the apparent resistivity of a plurality of equally distributed measuring points along each detection path, and generating a first relationship curve of the apparent resistivity of each path versus the distance from the pile body circumferential wall; after the grouting operation is completed, measuring the apparent resistivity of the same measuring point of each detection path, and generating a second relationship curve of the apparent resistivity of each path versus the distance from the pile body circumferential wall; comparing the first relationship curve and the second relationship curve of the same detection path, identifying the significant mutation point that first appears in the second relationship curve; and using the distance from the pile body (1) circumferential wall corresponding to the mutation point as the farthest diffusion distance of the slurry of the detection path; calculating the slurry diffusion range based on the farthest diffusion distance of the slurry of all detection paths; and comparing the slurry diffusion range with a preset threshold value to determine whether the grouting effect is qualified.

[0006] In some embodiments, four detection paths are arranged in a circular direction of the pile body, and adjacent detection paths are arranged to be perpendicular to each other.

[0007] In some embodiments, two detection paths located on the same straight line utilize a measuring device and a power supply device to acquire the apparent resistivity of the measuring points, wherein the measuring device includes a measuring electrode, a measuring wire, and a measuring instrument; the power supply device includes a power supply electrode, a power supply wire, and a power supply. The arrangement of the measuring device and the power supply device includes the following steps: On two detection paths on the same straight line, power supply electrodes are set symmetrically about the pile body, and the two power supply electrodes are connected to the power supply through power supply wires to form a closed loop; measuring electrodes are arranged at the midpoints of adjacent measuring points; using a measuring instrument, the measuring wires are connected to the measuring electrodes on both sides of the target measuring point to calculate and obtain the apparent resistivity of the target measuring point.

[0008] In some embodiments, among the multiple measuring electrodes on each detection path, the measuring electrode closest to the center of the pile body is arranged to fit against the outer wall of the pile body.

[0009] In some embodiments, when power supply electrodes symmetrically arranged about the pile body are provided on two detection paths on the same straight line, the distance between the two power supply electrodes is confirmed, which includes the following steps: The height of the pile body is obtained; and a distance between two power supply electrodes of two detection paths located on the same straight line is adjusted to be equal to a first preset multiple of the height.

[0010] In some embodiments, the method further includes determining a standard spacing between adjacent measurement points, which includes the following steps: A first standard spacing is obtained based on spherical diffusion theory; a first target spacing is generated based on the first standard spacing; and a plurality of measuring electrodes are arranged based on a criterion that the spacing between adjacent measuring points is less than the first target spacing.

[0011] In some embodiments, calculating and obtaining the apparent resistivity of a target measurement point includes the following steps: Obtain the current and potential difference between two measuring electrodes adjacent to the target measurement point; calculate the arrangement coefficient based on the distance between the two measuring electrodes and the two power supply electrodes located on the line connecting them; and calculate and obtain the apparent resistivity of the target measurement point based on the current, potential difference, and arrangement coefficient in combination with the second formula.

[0012] In some embodiments, obtaining the first standard spacing based on spherical diffusion theory includes the following steps: Based on the permeability coefficient of the grouting soil layer, the viscosity ratio of the slurry to water, the radius of the grouting hole, the grouting time, the grouting pressure head and the porosity of the grouting soil layer, and combined with the first formula, the first standard spacing is calculated.

[0013] In some embodiments, the slurry diffusion range is calculated based on the farthest diffusion distance of the slurry in all detection paths, which includes the following steps: Calculate the sum of the maximum diffusion distances of the slurry on all detection paths; divide the sum by the number of detection paths to obtain the theoretical radius; take the center of the pile as the origin, and use the value of the theoretical radius as the radius to obtain the range of the circle; subtract the area occupied by the pile from the range of the circle to obtain the slurry diffusion range.

[0014] In some embodiments, after the grouting operation is completed, the apparent resistivity measurement of the same measuring point of each detection path is completed within a first preset time.

[0015] The beneficial effects of the technical solution provided by this application include: The embodiment of the present application provides a method for detecting the diffusion range of post-grouting slurry of a bored pile, wherein the core logic of the method is to realize detection by utilizing the resistivity difference between the slurry and the soil, that is, before grouting, the soil around the pile is the original state with a specific apparent resistivity; after grouting, the medium in the slurry diffusion area becomes a mixture of slurry and soil, and the apparent resistivity will change significantly, thereby determining the slurry diffusion area that can be used to judge the grouting effect, and accurately locating the farthest diffusion distance of the slurry through the mutation point, combined with the circumferential multi-path measurement, it can fully reflect the diffusion of the slurry in all directions. This detection method does not rely on the strength of the pile body concrete, that is, there is no need to wait for it to reach the design strength, and it can be carried out immediately after grouting, realizing timely detection. It solves the technical problem that the existing grouting effect detection method cannot detect grouting defects and take remedial measures in time because it needs to wait until the pile body concrete reaches the design strength before implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 A schematic diagram of a post-grouting slurry diffusion range detection device for a bored pile provided in an embodiment of the present application; Figure 2 Schematic diagram of measuring apparent resistivity of soil around pile before grouting provided in an embodiment of the present application; Figure 3 Schematic diagram of measuring apparent resistivity of soil around pile after grouting provided in an embodiment of the present application; Figure 4 A schematic diagram of the arrangement of measuring electrodes provided in an embodiment of the present application; Figure 5 Schematic diagram of the measurement framework provided in an embodiment of the present application; Figure 6A schematic diagram of the principle of determining the slurry diffusion range provided in an embodiment of the present application; Figure 7 Schematic diagram of the flow chart of the method for detecting the diffusion range of post-grouting slurry of bored piles provided in an embodiment of the present application.

[0018] In the figure: 1. pile body; 2. power supply device; 201. power supply electrode; 202. power supply wire; 203. power supply; 3. measuring electrode; 4. measuring device; 401. measuring wire; 402. operation panel; 403. display screen; 404. measurement interface. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] In order to make the technical problem to be solved by this application clearer, the causes of the technical problem will be specifically analyzed below.

[0021] The core issue is that existing methods, such as static load testing, coring, and electromagnetic CT, require testing only after the pile concrete reaches its designed strength. This lag prevents timely detection of problems during construction, missing the optimal opportunity for remediation. Furthermore, existing technologies primarily rely on empirical parameters from test piles to infer the effectiveness of engineering piles, lacking direct and effective means for on-site testing of engineering piles. The device and method of the present invention, however, can be directly applied to engineering piles, enabling in-situ testing.

[0022] The present invention, which is based on the dual defects of the immediacy of grouting effect evaluation and the applicability of engineering piles, compares the changes in soil physical properties before and after grouting by apparent resistivity. After grouting is completed, the grouting spread range can be detected in real time to judge the grouting effect, without waiting for the concrete to harden, and at the same time avoids causing disturbance to the pile body.

[0023] The present application provides a method for detecting the diffusion range of post-grouting slurry of a bored pile, referring to Figure 1-7 , Figure 7 This is a flow chart of a method for detecting the diffusion range of post-grouting slurry of a bored pile provided in an embodiment of the present application. Figure 7 As shown, a method for detecting the diffusion range of post-grouting slurry of a bored pile comprises: S100, taking the center of the pile body 1 as the path starting point, setting multiple detection paths along the circumference of the pile body 1; S200, before the grouting operation, measuring the apparent resistivity of a plurality of equally spaced measuring points along each detection path, and generating a first relationship curve showing how the apparent resistivity of each path varies with the distance from the annular wall of the pile body 1; after the grouting operation is completed, measuring the apparent resistivity of the same measuring points along each detection path, and generating a second relationship curve showing how the apparent resistivity of each path varies with the distance from the annular wall of the pile body 1; S300, comparing a first relationship curve and a second relationship curve of the same detection path, identifying a significant mutation point that first appears in the second relationship curve; and using the distance from the annular wall of the pile body 1 corresponding to the mutation point as the maximum diffusion distance of the slurry in the detection path; S400, calculating the slurry diffusion range based on the farthest slurry diffusion distance of all detection paths; comparing the slurry diffusion range with a preset threshold to determine whether the grouting effect is qualified.

[0024] By setting up this method, the core logic is to use the resistivity difference between the slurry and the soil to achieve detection, that is, before grouting, the side of the pile body 1 is the original soil with a specific apparent resistivity; after grouting, the medium in the slurry diffusion area becomes a mixture of slurry and soil, and the apparent resistivity will change significantly, thereby determining the slurry diffusion area that can be used to judge the grouting effect. The maximum diffusion distance of the slurry is accurately located through the mutation point, and combined with the circumferential multi-path measurement, it can fully reflect the diffusion of the slurry in all directions. This detection method does not rely on the strength of the concrete of the pile body 1 itself, that is, there is no need to wait for it to reach the design strength, and it can be carried out immediately after grouting, realizing timely detection. It solves the technical problem that the existing grouting effect detection method cannot detect grouting defects and take remedial measures in time because it needs to wait until the pile body concrete reaches the design strength before implementation.

[0025] In some preferred embodiments, four detection paths are arranged in the circumferential direction of the pile body 1 , and adjacent detection paths are arranged to be perpendicular to each other.

[0026] In this embodiment, the layout of the detection paths is optimized to ensure full coverage of the pile perimeter and avoid blind spots. Four mutually perpendicular paths fully capture the anisotropic diffusion of the slurry on the horizontal plane. Compared to more paths, such as 8 or 16, four paths reduce measurement workload and equipment costs while ensuring detection effectiveness. Compared to fewer paths, such as 2, the risk of missing critical directions is avoided.

[0027] In some preferred embodiments, two detection paths located on the same straight line utilize a measuring device 4 and a power supply device 2 to acquire the apparent resistivity of the measuring point, wherein the measuring device 4 includes a measuring electrode 3, a measuring wire 401, and a measuring instrument, and the power supply device 2 includes a power supply electrode 201, a power supply wire 202, and a power supply 203. The arrangement of the measuring device 4 and the power supply device 2 includes the following steps: On two detection paths on the same straight line, power supply electrodes 201 are respectively set symmetrically about the pile body 1, and the two power supply electrodes 201 are connected to the power supply 203 through the power supply wire 202 to form a closed loop; the measuring electrode 3 is arranged at the midpoint of the adjacent measuring points; using a measuring instrument, the measuring wire 401 is connected to the measuring electrodes 3 on both sides of the target measuring point, so as to calculate and obtain the apparent resistivity of the target measuring point.

[0028] In this embodiment, it is important to note that the measuring device 4 also includes a current and voltage sampling circuit, a calculation module, a storage module, an output display module, and a power supply circuit module; the outside of the measuring device 4 is provided with an operation panel 402, a measurement interface 404, and a display screen 403 connected to the output display module; the measurement interface 404 is connected to two adjacent measuring electrodes 3 via a measuring wire 401; the power supply device 2 provides a stable electric field for the area around the pile; multiple measuring electrodes 3 are evenly spaced on the line connecting the power supply electrode 201 and the center of the pile body 1, which can accurately capture the apparent resistivity changes at different distances and provide a data basis for locating the slurry diffusion boundary; finally, the measuring device 4 is used to collect the apparent resistivity between adjacent measuring electrodes 3, and by comparing the data differences before and after grouting, the farthest diffusion point of the slurry can be directly determined, and then the diffusion range can be calculated. This device has a simple structure and is suitable for post-grouting detection of cast-in-place piles under different geological conditions. It does not require large equipment, which reduces the difficulty of on-site operation.

[0029] In some preferred embodiments, among the multiple measuring electrodes 3 on each detection path, the measuring electrode 3 closest to the center of the pile body 1 is arranged to fit against the outer wall of the pile body 1 .

[0030] In this embodiment, the area near the pile wall is the starting area for slurry diffusion. The electrodes are set in close contact with the pile wall to directly measure the apparent resistivity change when the slurry just leaves the pile body 1, avoiding the delay in identifying the mutation point due to excessive spacing; obtaining the apparent resistivity baseline at the pile wall provides a basis for accurately judging whether the slurry has effectively broken through the mud skin around the pile; for small radius diffusion, the close setting can avoid inaccurate mutation points detected due to excessive electrode spacing, which can improve the accuracy of the detection results.

[0031] In some preferred embodiments, when power supply electrodes 201 symmetrically arranged about the pile body 1 are respectively provided on two detection paths on the same straight line, the distance between the two power supply electrodes 201 is further confirmed, which includes the following steps: The height of the pile body 1 is obtained; and the distance between the two power supply electrodes 201 of the two detection paths located on the same straight line is adjusted to be equal to a first preset multiple of the height.

[0032] In this embodiment, the distance between the power supply electrodes is determined according to the pile height; if the power supply electrodes 201 are too close, the electric field is concentrated in the shallow area and cannot reflect the deep slurry diffusion; if they are too far, the electric field strength is insufficient, resulting in a weak measurement signal; the electric field coverage range is matched with the actual impact depth of the pile body 1. Figure 2 , the height of the pile body 1 is set to C, and the distance between the two power supply electrodes 201 of the two detection paths on the same straight line is set to D. During the implementation process, D=10C must be satisfied. Therefore, the distance between each power supply electrode 201 and the center of the pile body 1 should be 5C, so as to adjust the distance between the two power supply electrodes 201 of the two detection paths on the same straight line.

[0033] In some preferred embodiments, the method further includes confirming the standard spacing between adjacent measurement points, which includes the following steps: A first standard spacing is obtained based on the spherical diffusion theory; a first target spacing is generated based on the first standard spacing; and a plurality of measuring electrodes 3 are arranged based on the criterion that the spacing between adjacent measuring points is smaller than the first target spacing.

[0034] In this embodiment, if the spacing is too large, on the one hand, the mutation point will not be obvious, and on the other hand, the measured maximum diffusion distance of the slurry will have large errors. If it is too small, the measurement workload and cost will increase. The spherical diffusion theory, which states that the slurry diffuses in a spherical shape, provides a scientific basis for spacing calculation, but actual engineering needs to be adjusted according to geological conditions. The standard spacing is calculated based on different geological parameters, such as permeability coefficient and porosity. For example, in highly permeable sand, the slurry diffuses quickly, so the spacing can be appropriately increased; in clay, the spacing needs to be reduced. Combining theoretical calculations with engineering practice, a repeatable spacing determination method is formed, improving the scientific nature of the detection scheme.

[0035] In some preferred embodiments, calculating and obtaining the apparent resistivity of a target measurement point includes the following steps: Obtain the current and potential difference between the two measuring electrodes 3 adjacent to the target measurement point; calculate the arrangement coefficient based on the distance between the two measuring electrodes 3 and the two power supply electrodes 201 located on the line connecting them; calculate and obtain the apparent resistivity of the target measurement point based on the current, potential difference and arrangement coefficient, in combination with the second formula.

[0036] In this embodiment, the current and potential difference between adjacent measuring electrodes 3 are obtained, and the arrangement coefficient is calculated in combination with the distance between the electrode and the power supply electrode, and then the apparent resistivity is calculated. If the influence of the electrode arrangement on the measurement results is ignored, it will lead to calculation deviations; factors such as geological heterogeneity and electrode burial depth will affect the current distribution, and the arrangement coefficient can correct these deviations; the arrangement coefficient reflects the influence of the geometric position of the electrode on the measurement. Under complex geological conditions, such as the presence of low-resistance interlayers, the arrangement coefficient can compensate for the measurement error caused by current line distortion and improve data credibility; and it is applicable to different electrode arrangements, such as the Wenner device and the Schellenberg device. It only needs to adjust the arrangement coefficient calculation formula without changing the overall detection process. It should be noted that the apparent resistivity ρ is calculated by the second formula: , where I and ∆U are the current and potential difference between the two measuring electrodes 3 on both sides of the target measurement point, respectively. The two measuring electrodes are denoted as T and Y, respectively. The power supply electrodes 201 on the detection path where the two measuring electrodes 3 are located are denoted as E and R, respectively. K is the arrangement coefficient of the electrode arrangement. The calculation formula is: , where ET, EY, RT, and RY are the distances between E and T, E and Y, R and T, and R and Y, respectively.

[0037] In some preferred embodiments, the first standard spacing is obtained based on the spherical diffusion theory, which includes the following steps: based on the permeability coefficient of the grouting soil layer, the viscosity ratio of the slurry to water, the grouting hole radius, the grouting time, the grouting pressure head and the porosity of the grouting soil layer, and combined with the first formula, the first standard spacing is calculated.

[0038] In this embodiment, the radius of the pile body 1 is recorded as R, and the first formula is: , where r is the difference between the slurry diffusion distance and the radius R of the corresponding detection path, k is the permeability coefficient of the grouting soil layer, is the viscosity ratio of slurry to water, R0 is the radius of the grouting hole, t is the grouting time, s is the grouting pressure head, and n is the porosity of the grouting soil layer.

[0039] In some preferred embodiments, the slurry diffusion range is calculated based on the farthest diffusion distance of the slurry in all detection paths, which includes the following steps: Calculate the sum of the farthest diffusion distances of the slurry on all detection paths; divide the sum by the number of detection paths to obtain the theoretical radius; take the center of pile body 1 as the origin, and use the value of the theoretical radius as the radius to obtain the range of the circle; subtract the area occupied by pile body 1 from the range of the circle to obtain the slurry diffusion range.

[0040] In this embodiment, reference Figure 4The difference between the slurry diffusion distance and the radius R in the four detection directions is recorded as A1, A2, A3, and A4, respectively. The farthest slurry diffusion points in the four detection directions are recorded as M, N, P, and Q, respectively. The slurry diffusion range of the pile is ultimately obtained by taking the average of A1, A2, A3, and A4 in the four detection directions, calculated as r = (A1 + A2 + A3 + A4) / 4. Alternatively, the theoretical radius can be obtained by directly calculating the average of the farthest slurry diffusion distances along all detection paths. A circular range is formed with the center of the pile as the origin, and the area occupied by the pile is subtracted from this to obtain the slurry diffusion range.

[0041] In some preferred embodiments, after the grouting operation is completed, the apparent resistivity measurement of the same measuring point of each detection path is completed within a first preset time.

[0042] In this embodiment, the apparent resistivity measurement is completed within a first preset time after the grouting operation is completed. This highlights the core advantage of the present invention of real-time detection; it seamlessly integrates with the grouting construction, avoiding extensions to the construction period due to waiting for measurement; and timely measurement can quickly identify grouting defects and facilitate adjustment of construction parameters.

[0043] What you need to know is that Figure 6 As shown, the value of the horizontal axis gradually decreases from the origin to the positive direction, that is, it shows the apparent resistivity of the measuring points from far to near the pile body 1.

[0044] The beneficial effects brought about by the present invention include: A method for detecting the diffusion range of slurry after grouting of bored piles is proposed. The core logic is to use the resistivity difference between the slurry and the soil to achieve detection. That is, before grouting, the side of the pile body 1 is the original soil with a specific apparent resistivity. After grouting, the medium in the slurry diffusion area becomes a mixture of slurry and soil, and the apparent resistivity will change significantly, thereby determining the slurry diffusion area that can be used to judge the grouting effect. The maximum diffusion distance of the slurry is accurately located by the mutation point. Combined with circumferential multi-path measurement, it can fully reflect the diffusion of the slurry in all directions. This detection method does not rely on the strength of the concrete of the pile body 1 itself, that is, there is no need to wait for it to reach the design strength. It can be carried out immediately after grouting, realizing timely detection. It solves the technical problem that the existing grouting effect detection method must wait until the pile body concrete reaches the design strength before implementation, resulting in the inability to detect grouting defects and take remedial measures in a timely manner.

[0045] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0046] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0047] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0048] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0049] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0050] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, or the part that contributes to the existing technology, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of this application.

[0051] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for detecting the diffusion range of post-grouting slurry of a bored pile, characterized in that: It includes: Taking the center of the pile body (1) as the starting point of the path, multiple detection paths are set along the circumferential direction of the pile body (1); Before the grouting operation, the apparent resistivity of a plurality of equally spaced measuring points along each detection path is measured to generate a first relationship curve of the apparent resistivity of each path versus the distance from the pile body (1) ring wall; after the grouting operation is completed, the apparent resistivity of the same measuring points along each detection path is measured to generate a second relationship curve of the apparent resistivity of each path versus the distance from the pile body (1) ring wall; Comparing the first relationship curve and the second relationship curve of the same detection path, identifying the significant mutation point that first appears in the second relationship curve; and using the distance from the pile body (1) corresponding to the mutation point as the maximum diffusion distance of the slurry in the detection path; The slurry diffusion range is calculated based on the farthest diffusion distance of the slurry in all detection paths; the slurry diffusion range is compared with a preset threshold to determine whether the grouting effect is qualified.

2. The method for detecting the diffusion range of post-grouting slurry of a bored pile according to claim 1, characterized in that: Four detection paths are arranged in a circular direction of the pile body (1), and adjacent detection paths are arranged to be perpendicular to each other.

3. The method for detecting the diffusion range of post-grouting slurry of a bored pile according to claim 2, characterized in that: The two detection paths located on the same straight line utilize a measuring device (4) and a power supply device (2) to obtain the apparent resistivity of the measuring point, wherein the measuring device (4) includes a measuring electrode (3), a measuring wire (401) and a measuring instrument, and the power supply device (2) includes a power supply electrode (201), a power supply wire (202) and a power supply (203). The arrangement of the measuring device (4) and the power supply device (2) includes the following steps: On the two detection paths on the same straight line, power supply electrodes (201) are respectively provided which are symmetrical with respect to the pile body (1), and the two power supply electrodes (201) are connected to the power supply (203) via the power supply wires (202) to form a closed loop; Measuring electrodes (3) are arranged at the midpoints of adjacent measuring points; and a measuring instrument is used to connect measuring wires (401) to the measuring electrodes (3) on both sides of a target measuring point, thereby calculating and obtaining the apparent resistivity of the target measuring point.

4. The method for detecting the diffusion range of post-grouting slurry of a bored pile according to claim 3, characterized in that: Among the plurality of measuring electrodes (3) on each detection path, the measuring electrode (3) closest to the center of the pile body (1) is arranged to fit the outer wall of the pile body (1).

5. The method for detecting the diffusion range of post-grouting slurry of a bored pile according to claim 3, characterized in that: When power supply electrodes (201) symmetrical about the pile body (1) are respectively provided on two detection paths on the same straight line, the distance between the two power supply electrodes (201) is also confirmed, which includes the following steps: Get the height of the pile (1); The distance between the two power supply electrodes (201) of the two detection paths located on the same straight line is adjusted to be equal to a first preset multiple of the height.

6. The method for detecting the diffusion range of post-grouting slurry of a bored pile according to claim 3, characterized in that: It also includes confirming the standard spacing between adjacent measurement points, which includes the following steps: Obtaining a first standard spacing based on spherical diffusion theory; and generating a first target spacing based on the first standard spacing; The plurality of measuring electrodes (3) are arranged according to the criterion that the spacing between adjacent measuring points is smaller than the first target spacing.

7. The method for detecting the diffusion range of post-grouting slurry of a bored pile according to claim 3, characterized in that: Calculating and obtaining the apparent resistivity of the target measurement point includes the following steps: Obtaining the current and potential difference between two measuring electrodes (3) adjacent to a target measurement point; Calculating an arrangement coefficient based on the distance between the two measuring electrodes (3) and the two power supply electrodes (201) located on the line connecting the two measuring electrodes (3); According to the current, potential difference and arrangement coefficient, and in combination with the second formula, the apparent resistivity of the target measurement point is calculated and obtained.

8. The method for detecting the diffusion range of post-grouting slurry of a bored pile according to claim 6, characterized in that: Obtaining a first standard spacing based on spherical diffusion theory includes the following steps: The first standard spacing is calculated based on the permeability coefficient of the grouting soil layer, the viscosity ratio of the slurry to water, the radius of the grouting hole, the grouting time, the grouting pressure head and the porosity of the grouting soil layer, and in combination with the first formula.

9. The method for detecting the diffusion range of post-grouting slurry of a bored pile according to claim 1, wherein: The slurry diffusion range is calculated based on the farthest diffusion distance of the slurry in all detection paths, which includes the following steps: Calculate the sum of the maximum diffusion distances of the slurry on all detection paths; The sum is divided by the number of detection paths to obtain a theoretical radius; the center of the pile body (1) is taken as the origin, the value of the theoretical radius is used as the radius to obtain the range of the circle, and the area occupied by the pile body (1) is subtracted from the range of the circle to obtain the slurry diffusion range.

10. The method for detecting the diffusion range of post-grouting slurry of a bored pile according to claim 1, wherein: After the grouting operation is completed, the apparent resistivity measurement of the same measuring point of each detection path is completed within a first preset time.

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