A method for detecting the effect of post-grouting of the bottom of a bridge cast-in-place pile and related device

Abstract

This application discloses a method and related apparatus for detecting the post-grouting effect at the bottom of bridge cast-in-place piles, relating to the field of bridge pile foundation engineering technology. The method includes: before grouting, acquiring initial readings from a marker monitoring device to obtain a baseline state before the grout layer expands; integrating the marker monitoring device onto the grout layer; lowering the grout layer to the bottom of the bridge cast-in-place pile along with the grouting device; performing grouting and acquiring real-time signal change data from the marker monitoring device; and generating a visual image of the grout layer morphological changes based on the signal change data. The method provided in this application is simple, easy to implement, and provides intuitive feedback on the post-grouting effect at the pile end.

Description

Technical Field

[0001] This application relates to the field of bridge pile foundation engineering technology, and in particular to a method and related device for detecting the effect of post-grouting at the bottom of bridge cast-in-place piles. Background Technology

[0002] To improve the bearing capacity of bridge cast-in-place piles, a composite post-grouting process can be adopted at the bottom of existing bridge cast-in-place piles. This involves inserting a ring-shaped steel plate under the pile bottom and performing composite post-grouting after the pile is completed and passes the pile inspection.

[0003] However, the main problems in engineering applications are as follows: the evaluation methods for grouting effect are complex, post-grouting at the pile bottom is a concealed project, and the expansion of the grout skin and the formation of the enlarged head at the pile end are currently mainly assessed using the cross-hole elastic wave CT method and the side-hole method. Both methods require drilling additional holes around the pile, which is inconvenient for rapid and large-scale testing. Therefore, there is an urgent need to provide a simple, easy-to-implement, and visually intuitive method for detecting the post-grouting effect at the pile end. Summary of the Invention

[0004] The purpose of this application is to provide a method and related device for detecting the post-grouting effect of bridge cast-in-place piles. This method can intuitively and accurately obtain the expansion morphological changes of the pile bottom bladder during the grouting process, thereby clearly reflecting the grouting filling range and the formation effect of the pile end enlarged head. It eliminates the need for additional drilling around the pile, greatly simplifies the detection process, reduces detection costs, and enables in-situ real-time monitoring of the post-grouting effect at the pile bottom.

[0005] To achieve the above objectives, this application provides the following solution: Firstly, this application provides a method for detecting the post-grouting effect at the bottom of bridge cast-in-place piles, including: Step 1: Before grouting, the initial readings of the marking and monitoring device are collected to obtain the baseline state before the bladder expands; the marking and monitoring device is integrated on the bladder; the bladder is lowered to the bottom of the bridge cast-in-place pile along with the grouting device; Step 2: Perform grouting and collect signal change data from the marker monitoring device in real time; Step 3: Generate a visual image of the morphological changes of the cystic skin based on the signal change data.

[0006] Secondly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for detecting the post-grouting effect at the bottom of a bridge cast-in-place pile as described in any one of the above-mentioned methods.

[0007] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for detecting the post-grouting effect at the bottom of a bridge cast-in-place pile as described above.

[0008] Fourthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method for detecting the post-grouting effect at the bottom of a bridge cast-in-place pile as described above.

[0009] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a method and related device for detecting the grouting effect at the bottom of bridge cast-in-place piles. By integrating the marking and monitoring device onto the grouting bladder, which is lowered to the bottom of the pile synchronously with the grouting device, the detection process is simplified without the need for additional drilling around the pile. At the same time, it can perform in-situ real-time monitoring of the grouting process. By collecting the signal changes of the marking and monitoring device, the visual morphology of the bladder expansion can be reconstructed, which can intuitively and clearly reflect the diffusion range of the grout at the bottom of the pile and the actual formation effect of the enlarged head at the pile end. This allows technicians to quickly determine whether the grouting effect meets the design requirements, promptly identify problems of insufficient grouting, and arrange supplementary grouting operations. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is an application environment diagram of a method for detecting the post-grouting effect at the bottom of a bridge cast-in-place pile according to an embodiment of this application; Figure 2 A flowchart illustrating a method for detecting the post-grouting effect at the bottom of a bridge cast-in-place pile, provided in an embodiment of this application; Figure 3 A schematic diagram of a scheme for detecting the post-grouting effect at the bottom of a bridge cast-in-place pile, provided in an embodiment of this application; Figure 4 This is a diagram showing the contracted and folded state of the cystic skin according to an embodiment of this application; Figure 5 This is a diagram showing the state of the skin after expansion, provided in an embodiment of this application. Figure 6 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application.

[0012] Figure label: 102-Terminal, 104-Server, 1-Sheath; 2-Communication cable; 3-Hub; 4-Data acquisition and processing system; 5-Pile body; 6-Closed grouting pipe; 7-Open grouting pipe; 8-Pile end enlargement head. Detailed Implementation

[0013] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0014] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] The method for detecting the post-grouting effect at the bottom of bridge cast-in-place piles provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be set up independently, integrated into server 104, or placed in the cloud or on another server.

[0016] The terminal 102 can be, but is not limited to, various desktop computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, and smart in-vehicle devices. Portable wearable devices can include smartwatches, smart bracelets, and head-mounted devices. The server 104 can be implemented using a standalone server or a server cluster composed of multiple servers, or it can be a cloud server.

[0017] In one exemplary embodiment, such as Figure 2 As shown, a method for detecting the post-grouting effect at the bottom of bridge cast-in-place piles is provided. This method is executed by computer equipment, specifically by a terminal or server alone, or by both a terminal and a server. In this embodiment, the method is applied to... Figure 1 Taking server 104 as an example, the explanation includes steps 1 to 4. Wherein: Step 1: Before grouting, the initial readings of the marking and monitoring device are collected to obtain the baseline state of the outer skin 1 before expansion; the marking and monitoring device is integrated on the outer skin 1; the outer skin 1 is lowered to the bottom of the bridge cast-in-place pile along with the grouting device; the marking and monitoring device is a sensing unit, an electromagnetic beacon, or a distributed optical fiber; Step 2: Perform grouting and collect signal change data from the marker monitoring device in real time; Step 3: Generate a visual image of the morphological changes of the cystic skin 1 based on the signal change data.

[0018] In one exemplary embodiment, when the identification monitoring device is a sensing unit, steps 1-3 specifically include: Before grouting, the initial readings of each sensing unit are collected to obtain the baseline state of the bladder 1 before expansion. Grouting is performed, and resistance change data in each sensing unit is collected in real time; The resistance change data in each of the aforementioned sensing units is mapped to strain values ​​to generate a two-dimensional color thermogram. By mapping a two-dimensional color heatmap onto a three-dimensional surface, a three-dimensional visualization image of the morphological changes of the cystic skin is generated.

[0019] Specifically, the detection principle of this sensing unit is as follows: First, a large number of sensing units are integrated on the surface of the capsule skin 1, forming a sensing grid covering the surface of the capsule skin 1, enabling multi-point synchronous acquisition. Then, as the capsule skin 1 undergoes structural deformation, each sensing unit converts the local strain it senses into a change in resistance, completing the signal conversion. The data acquisition and processing system 4 then synchronously reads the signals from all sensing units, achieving synchronous acquisition. Next, the resistance change is mapped to a strain value, generating a corresponding color thermogram, completing two-dimensional imaging. Finally, combined with a known geometric model, the obtained two-dimensional strain distribution is mapped onto a three-dimensional surface, generating a visualized image, completing three-dimensional reconstruction.

[0020] In the preparation stage, the following steps were performed in sequence: calibrating the strain-resistance relationship of the laboratory matrix sensor and recording the calibration curve; cleaning the surface of the capsule 1 to ensure it was free of oil and dust; using a special adhesive to attach the matrix sensor to the surface of the capsule 1 without air bubbles; connecting all lead wires into the waterproof junction box and fixing it to the post-grouting device before connecting the communication cable 2; connecting the data acquisition and processing system 4; checking the signals of each channel and recording the initial readings.

[0021] Subsequently, initial state measurements were conducted. The post-grouting device, connected to communication cable 2, was slowly lowered to the bottom of the hole and connected to the ground data acquisition and processing system 4. Initial readings of all sensor units were collected as zero points, and the integrity of the sensors without open circuits or short circuits was verified. Then, the post-grouting process was monitored. When grouting began, a continuous acquisition mode with a sampling frequency of 1-10Hz was started simultaneously to generate a strain distribution thermogram in real time to observe the expansion process. The grouting flow rate and pressure were recorded simultaneously and correlated with the strain data. After grouting was completed, the final readings were collected and the entire process data was exported.

[0022] Finally, data post-processing and imaging were carried out, including data cleaning to remove outliers and smooth the data, strain distribution calculation to convert resistance changes into strain values ​​based on calibration curves, generation of two-dimensional thermograms to map the strain values ​​of the sensing unit into color images, and three-dimensional surface mapping to project the two-dimensional strain distribution onto the surface of the three-dimensional model of the cyst skin 1. Finally, dynamic images of the morphological change process of the cyst skin 1 were generated according to the time series.

[0023] In one exemplary embodiment, when the identification monitoring device is an electromagnetic beacon, steps 1-3 specifically include: Before grouting, the initial relative coordinates of each electromagnetic beacon are measured using a three-dimensional laser scanner. The initial point cloud model is then established with the center of the grouting device as the origin. The initial point cloud model is used to represent the baseline state of the bladder skin 1 before expansion. Grouting was performed, and coordinate change data of each electromagnetic beacon was collected in real time to generate displacement-time history curves for each electromagnetic beacon. The displacement-time history curves of each electromagnetic beacon were coupled to obtain a dynamic three-dimensional cloud map of the morphological changes of the cyst skin 1.

[0024] Specifically, the implementation process of the pre-embedded electromagnetic positioning array is as follows: Electromagnetic beacons are deployed along the maximum outer circumference of the shell 1. The deployment spacing is reasonably set according to the measurement accuracy requirements. After the beacon deployment is completed, before lowering the grouting device, a 3D laser scanner is used to measure the initial relative coordinates of all beacons (with the center of the grouting device as the origin). An initial point cloud model is established to complete the beacon numbering and coordinate calibration. Then, the preparation stage begins: First, the signal cable is connected to each electromagnetic beacon, with sufficient length reserved. The signal cable is then tied and fixed to the reinforcing cage. Next, the receiving array is deployed on the ground. The 3D coordinates of each receiving coil are accurately calibrated using RTK. Finally, all equipment is connected, and system self-testing and signal testing are performed. After the preparation work is completed, the initial state measurement is carried out: First, the grouting device is lowered... The device is lowered to the bottom of the pile hole and its orientation is fixed. Then, the transmitter sends an excitation signal to make all beacons respond. The receiving array then collects the response signals of each beacon. The initial three-dimensional coordinates are calculated by the positioning calculation software. Finally, the calculation results are compared with the initial calibration data to verify the measurement accuracy. After the accuracy verification is qualified, post-grouting monitoring and data processing are carried out: After grouting begins, the continuous acquisition mode is started simultaneously. The data acquisition interval can be set to 5 seconds to 20 seconds to record the changes in the coordinates of each beacon in real time and generate displacement-time history curves. During the process, abnormal signals such as beacon failure and sudden displacement are monitored and early warnings are issued in a timely manner. After the post-grouting is completed, the final coordinates of all beacons are measured. Finally, the entire process data is exported, and the displacement-time history curves of all beacons are coupled to generate a dynamic three-dimensional cloud map.

[0025] In one exemplary embodiment, when the identification monitoring device is a distributed optical fiber, steps 1-3 specifically include: Before grouting, the skin 1 was scanned at zero position using the full optical path to obtain the initial strain distribution ε0(s) and temperature distribution T0(s); Grouting was performed, and the bending strain and temperature change of the optical fibers in the distributed optical fibers were collected in real time. The Rayleigh scattering spectral shift along the fiber was obtained by an optical frequency domain reflectance demodulator, and the bending strain was obtained after temperature compensation and zero-point subtraction. Based on the strain-curvature conversion principle, the curvature along the fiber is calculated, and the three-dimensional surface shape of the capsule skin is reconstructed by curve integration to generate a visual image.

[0026] Specifically, in this embodiment, a distributed fiber optic demodulator based on optical frequency domain reflection (OFDR) is used to realize distributed fiber optic strain sensing. Its core principle is that the "fingerprint" of Rayleigh scattering signal in single-mode fiber will undergo spectral shift with strain or temperature. Through continuous wave frequency sweep interference, strain and temperature distribution with a spatial resolution of 1 mm can be obtained along the fiber. When used with polyimide-coated bend-resistant fiber, the minimum bending radius of the fiber can be as low as 5 mm, which can meet the requirements of small surface curvature path detection when the cladding is folded.

[0027] The strain-curvature conversion principle involves continuously bonding the optical fiber tightly to the surface of the sheath 1. When the sheath 1 bends, an axial strain εb is generated in the optical fiber, which satisfies the following relationship with the local curvature κ: ; In the formula: The fiber bending strain is the total strain minus the temperature strain and initial value. The distance from the center of the optical fiber to the middle surface (neutral layer) of the outer sheath 1 is determined by the thickness of the adhesive layer and the wall thickness of the outer sheath 1.

[0028] When reconstructing the 3D surface shape of the capsule skin 1 using curve integrals, the Frenet-Serret curve integral method is employed, combined with the topological constraints of the capsule skin 1. For the hollow annular capsule skin 1, a multi-fiber constraint + planar assumption method is used. The outer and inner ring fibers are located in an approximately horizontal equatorial plane, which can be simplified to a planar circular ring reconstruction. The radial cross-sectional shape of the upper and lower ring surfaces is constrained by the fiber cross-section, and the torsion is determined by the common points of adjacent curves. Multiple curves are spliced ​​at the common points to obtain the annular surface skeleton, and then a visual 3D surface image is generated through skin interpolation.

[0029] A loosely tube-encapsulated fiber (with its core freely suspended) is arranged in parallel next to the sensing fiber, and is only sensitive to temperature. During measurement, the temperature-induced spectral shift at this location is subtracted from the strain fiber to obtain the pure bending strain.

[0030] The specific steps for implementing distributed fiber optic measurements can be as follows: During the fabrication of the outer sheath 1, a complete loop of fiber optic cable is pasted along the equator, the outermost diameter of the outer sheath 1, in a wavy pattern. Loose-tube fiber optic cables are arranged in parallel in key sections, or individually wound into stress-relief rings. All fiber optic terminals are fused with FC / APC connectors and converged into the top armored cable. The cable is then bound and fixed to the grouting pipe and led to the ground. After the fiber integration on the outer sheath 1 is completed, laboratory calibration is performed. The curvature-strain coefficient calibration involves sequentially winding the outer sheath 1 sample with the attached fiber optic cable onto a standard cylinder, collecting strain values, and fitting the data. To obtain practical effectiveness Temperature sensitivity calibration involves measuring the wavelength-temperature coefficient of the loose-tube optical fiber in a temperature-controlled chamber for temperature decoupling. Coordinate reference calibration uses optical photogrammetry on a calibration platform to determine the relative positions of the fiber path's start, end, and common points for 3D stitching. After calibration, on-site preparation and zero-point measurement are performed. After folding the jacket 1 down to the bottom of the hole, a zero-point full optical path scan is performed before grouting to record the initial strain distribution. and temperature distribution Meanwhile, it was confirmed that the optical loss of each segment of the optical fiber was ≤1.5dB and there were no breaks.

[0031] After the detection begins, first complete the zero-position scan and save it. , Check the optical signal-to-noise ratio of the demodulator to confirm that the bending radius of the folded optical fiber is >5mm, and complete the state recording before grouting. After grouting begins, switch the demodulator to a fast continuous acquisition mode with a complete scan every 3 seconds, and display the average strain curve of the outer ring optical fiber in real time. When the strain value jumps from the initial folded state to the 400~500με plateau, and the curve fluctuation is less than ±10με, it is determined that the bladder 1 has started to unfold. At the same time, double verification is performed by the change of grouting pressure from the flow pressure to the holding pressure. If a certain section is found during the monitoring process... An abnormal decrease in strain, i.e., sudden relaxation or violent shaking, immediately triggers an early warning and stops grouting, completing real-time monitoring of the grouting process. Once the grouting pressure or volume reaches the design requirements, a high-precision scan with an average of 10 scans is immediately performed to improve the signal-to-noise ratio, recording the strain and temperature distribution across the entire fiber optic cable, as well as the grouting volume and holding time, completing the final-state geometric dimension acquisition. Finally, retests are performed approximately 8-12 hours after the initial setting of the cement grout and 24 hours after the final setting to observe the minute morphological changes caused by hydration heat and shrinkage, verifying dimensional stability.

[0032] After the detection process is completed, data collection and processing are carried out: First, raw data is acquired, and the Rayleigh scattering spectral shift Δν(s) at each point in the optical frequency domain is output by the demodulator. Then, the data is processed using the formula... The strain is calculated; where The data is then resampled at a spatial resolution of 1 mm and stored in the time series database to obtain the photoelastic coefficient. Next, data preprocessing will be carried out, starting with the formula... ,in Complete temperature compensation, then use the formula After zero-point subtraction, a Savitzky-Golay filter with a 5mm window width is used to eliminate high-frequency noise while preserving the bending strain trend. Then, curvature calculation and curve integration are performed. The processed... Substitute into the formula After obtaining the fiber curvature along the path, the outer loop curve is reconstructed. Set under known conditions From the starting point , The initial integration yields an approximate planar curve, which is then optimized using the closure condition, i.e., the distance between the first and last points. Small-amplitude modulation ensures that the curve closure error is less than 1 mm, thereby determining the true spatial position of the outer ring. Finally, 3D surface reconstruction and image generation were carried out. First, the reconstructed outer ring curve was discretized into 360 uniform points to form circumferential control lines. Then, the circumferential contour lines were used to generate the skin surface, resulting in a complete annular surface mesh. Next, the mesh was aligned with the designed skin CAD model using the formula r(u,v)=r 实测 -r 设计 The deviation is calculated, and a pseudo-color image is generated, where blue represents depressions, red represents convexities, and green represents ideal areas. At the same time, 3D PDF and STL files are output, which can be rotated and scaled by any 3D viewer to achieve intuitive 3D image display.

[0033] The above testing methods can realize the detection of the entire post-grouting process, covering real-time monitoring of three stages: during grouting, after grouting, and after grout solidification. Moreover, the test results are presented intuitively in the form of images, which has practical guiding significance for the overall quality control of post-grouting construction and the real-time adjustment of grouting parameters.

[0034] Among them, such as Figure 3 and Figure 4 As shown, before grouting, the grouting sleeve 1 is in a folded state. The closed grouting pipe 6 and the open grouting pipe 7 are installed in the pile body 5, respectively, for grouting the grouting sleeve 1. The hub 3 is connected to the grouting sleeve 1 through the communication cable 2. Figure 5 As shown, upon completion of post-grouting, under the grouting pressure, the interior of the bladder 1 is gradually filled with cement grout, pushing the bladder 1 to expand outwards until the designed grouting volume or designed expansion volume is reached, at which point grouting stops. The pile end enlargement head 8 is used to improve the pile end bearing capacity and eliminate the adverse effects of sediment at the pile bottom.

[0035] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 6As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs in the non-volatile storage media to run. The database stores detection data on the post-grouting effect of bridge pile foundations. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for detecting the post-grouting effect of bridge pile foundations.

[0036] Figure 6 The structures shown are merely block diagrams of some structures related to the present application and do not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than shown in the figures, or combine certain components, or have different component arrangements. In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0037] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0038] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0039] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with relevant regulations and be authorized by the owner of the corresponding device.

[0040] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0041] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0042] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0043] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for detecting the grouting effect at the bottom of a bridge cast-in-place pile, characterized in that, include: Step 1: Before grouting, the initial readings of the marking and monitoring device are collected to obtain the baseline state before the bladder expands; the marking and monitoring device is integrated on the bladder; the bladder is lowered to the bottom of the bridge cast-in-place pile along with the grouting device; Step 2: Perform grouting and collect signal change data from the marker monitoring device in real time; Step 3: Generate a visual image of the morphological changes of the cystic skin based on the signal change data.

2. The method for detecting the grouting effect at the bottom of a bridge cast-in-place pile according to claim 1, characterized in that, The identification monitoring device is a sensing unit, an electromagnetic beacon, or a distributed optical fiber.

3. The method for detecting the grouting effect at the bottom of a bridge cast-in-place pile according to claim 2, characterized in that, When the identification monitoring device is a sensing unit, steps 1-3 specifically include: Before grouting, the initial readings of each sensing unit are collected to obtain the baseline state of the cyst before expansion. Grouting is performed, and resistance change data in each sensing unit is collected in real time; The resistance change data in each of the aforementioned sensing units is mapped to strain values ​​to generate a two-dimensional color thermogram. By mapping a two-dimensional color heatmap onto a three-dimensional surface, a three-dimensional visualization image of the morphological changes of the cystic skin is generated.

4. The method for detecting the grouting effect at the bottom of a bridge cast-in-place pile according to claim 3, characterized in that, When the identification monitoring device is an electromagnetic beacon, steps 1-3 specifically include: Before grouting, the initial relative coordinates of each electromagnetic beacon are measured using a three-dimensional laser scanner. The initial point cloud model is then established with the center of the grouting device as the origin. The initial point cloud model is used to represent the baseline state before the cyst expands. Grouting was performed, and coordinate change data of each electromagnetic beacon was collected in real time to generate displacement-time history curves for each electromagnetic beacon. The displacement-time history curves of each electromagnetic beacon are coupled to obtain a dynamic three-dimensional cloud map of the morphological changes of the capsule skin.

5. The method for detecting the grouting effect at the bottom of a bridge cast-in-place pile according to claim 4, characterized in that, When the identification monitoring device is a distributed optical fiber, steps 1-3 specifically include: Before grouting, the skin of the bladder was scanned at zero position using the full optical path to obtain the initial strain distribution ε0(s) and temperature distribution T0(s); Grouting was performed, and the bending strain and temperature change of the optical fibers in the distributed optical fibers were collected in real time. The Rayleigh scattering spectral shift along the fiber was obtained by an optical frequency domain reflectance demodulator, and the bending strain was obtained after temperature compensation and zero-point subtraction. Based on the strain-curvature conversion principle, the curvature along the fiber is calculated, and the three-dimensional surface shape of the capsule skin is reconstructed through curve integration to generate a visual image.

6. The method for detecting the grouting effect at the bottom of a bridge cast-in-place pile according to claim 5, characterized in that, The formula for the strain-curvature conversion principle is as follows: ； In the formula, This represents the bending strain value of the optical fiber. This is the distance from the center of the optical fiber to the mid-surface of the fiber sheath. For local curvature.

7. The method for detecting the grouting effect at the bottom of a bridge cast-in-place pile according to claim 1, characterized in that, After performing step 3, the following is also included: The visualized image is compared with the preset grouting range morphology threshold at the bottom of the pile to determine whether the diffusion range of the grouting at the bottom of the pile meets the design requirements. If the morphology and size of the expanded cyst reaches the preset threshold, the grouting effect is deemed to meet the requirements; otherwise, the grouting effect is deemed not to meet the requirements, and supplementary grouting is required.

8. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that the processor executes the computer program to implement a method for detecting the post-grouting effect at the bottom of a bridge cast-in-place pile according to any one of claims 1-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements a method for detecting the post-grouting effect at the bottom of a bridge cast-in-place pile, as described in any one of claims 1-7.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements a method for detecting the post-grouting effect at the bottom of a bridge cast-in-place pile, as described in any one of claims 1-7.

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