Method for determining lateral displacement of pile based on distributed fiber optic strain sensing

Abstract

The application provides a pile lateral displacement determination method based on distributed optical fiber strain sensing, comprising: obtaining strain data of each node of a pile body collected by a distributed optical fiber, wherein at least one distributed optical fiber is arranged on the lateral wall of the pile body along the axial direction of the pile body to measure the strain data of each node position uniformly spaced along the axial direction of the pile body; determining the direction factor of each section of the pile body according to the strain difference collected by the adjacent two nodes of the pile body; and calculating the total displacement of the pile body in the horizontal direction based on the strain data of the nodes and the direction factor of each section of the pile body. The application calculates the direction factor through the strain difference between the adjacent two nodes, dynamically corrects the lateral displacement of the pile body by introducing the direction factor and the nonlinear pattern conversion mechanism, realizes the accurate synthesis and direction dynamic calibration of the deep displacement of the pile body, and thus improves the calculation accuracy of the lateral displacement of the pile body.

Description

Technical Field

[0001] This invention relates to the field of pile foundation engineering technology, and in particular to a method for determining the lateral displacement of piles based on distributed optical fiber strain sensing. Background Technology

[0002] Foundation pit support structures and slope anti-sliding structures are typical horizontally loaded piles. The deep horizontal displacement of these piles is a key indicator for assessing the safety and stability of foundation pits and slopes. Traditional methods primarily use inclinometers for direct measurement, which is simple to operate, provides intuitive data, and can obtain the horizontal displacement curve of the pile along its depth, providing important data for foundation pit support and slope stability analysis. However, it has significant limitations: it can only provide discrete point data, its measurement accuracy is easily affected by environmental interference, and it is difficult to achieve long-distance real-time monitoring. In recent years, distributed fiber optic strain sensing technology has been widely used in geotechnical engineering monitoring due to its advantages such as fully distributed measurement, high precision, corrosion resistance, and resistance to electromagnetic interference. Compared to traditional inclinometer holes that require protection from damage, embedded fiber optic sensors do not have this problem.

[0003] However, existing displacement calculation methods based on fiber optic strain data still suffer from a core bottleneck: the uncertainty of strain direction. Therefore, conventional displacement calculation methods based on fiber optic strain are usually deflection-based, neglecting the influence of direction during calculation. This leads to a systematic deviation between the calculated lateral displacement results based on fiber optic strain data and the actual results. Summary of the Invention

[0004] This invention provides a method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing, which solves the problem of inaccurate calculation results caused by ignoring directional parameters when converting strain into displacement in the prior art, and realizes a more accurate method for calculating the lateral displacement of a horizontally loaded pile.

[0005] This invention provides a method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing, comprising: Strain data of each node of the pile body is acquired by distributed optical fiber, wherein at least one distributed optical fiber is set along the axial direction of the pile body on the side wall of the pile body to measure strain data of each node position at uniform intervals along the axial direction of the pile body. Based on the strain difference values ​​collected from two adjacent nodes of the pile, the direction factor of each segment of the pile is determined. The pile between two adjacent nodes is considered as a segment, and the direction factor indicates that the actual lateral displacement direction of the segment is consistent with the direction of the lowest segment. Based on the strain data of the nodes and the direction factors of each segment of the pile, the total horizontal displacement of the pile is calculated. According to the present invention, a method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing, the step of determining the orientation factor of each segment of the pile body based on the strain difference value collected from two adjacent nodes of the pile body specifically includes: Calculate the strain difference between the upper and lower nodes of the lowest segment of the pile, determine the sign of the calculated strain difference, and set its direction factor to positive. For any other segment of the pile, calculate the strain difference value collected between its upper and lower nodes. If the sign of this strain difference value is the same as the sign of the strain difference value calculated for the bottommost segment, determine that the direction factor of this segment is positive, indicating that it is consistent with the direction of the bottommost segment. Otherwise, the direction factor of that segment is determined to be negative, indicating that it is opposite to the direction of the bottommost segment.

[0006] According to the present invention, a method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing, the step of calculating the total horizontal displacement of the pile body based on the strain data of the nodes and the orientation factors of each segment of the pile body specifically includes: Based on the strain data of each node and the orientation factor of each segment of the pile, the displacement contribution of each segment of the pile is determined. The total horizontal displacement of the pile is obtained by integrating the displacement contributions of all segments.

[0007] According to the present invention, a method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing, the step of determining the displacement contribution of each segment of the pile body based on the strain data and direction factor of each node specifically includes: The displacement contribution of each segment is calculated based on the following formula. : ; In the formula, Indicates the first i Segmented displacement, For the first i Segmented direction factor, For the first i Segmented fiber strain difference H This represents the length of the pile, and n represents the number of segments. The total displacement of the pile is obtained by summing the displacement contributions of each segment.

[0008] According to the present invention, a method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing is provided. When the number of distributed optical fibers is greater than one, one distributed optical fiber is used as the main optical fiber and the remaining distributed optical fibers are used as backup optical fibers. If the main optical fiber is not damaged, the strain data of each node of the pile is obtained by the main optical fiber; otherwise, any backup optical fiber is used to measure the strain data of each node of the pile.

[0009] According to the present invention, a method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing is provided, wherein the interval between two adjacent nodes is 0.05 meters.

[0010] The present invention also provides a pile lateral displacement determination system based on distributed optical fiber strain sensing, comprising: The acquisition module is used to acquire strain data of each node of the pile body collected by distributed optical fiber, wherein at least one distributed optical fiber is set along the axial direction of the pile body on the side wall of the pile body to measure strain data of each node position at uniform intervals along the axial direction of the pile body. The determination module is used to determine the direction factor of each segment of the pile body based on the strain difference value collected between two adjacent nodes of the pile body. The pile body between two adjacent nodes is considered as a segment, and the direction factor represents the consistency between the actual lateral displacement direction of the segment and the direction of the bottommost segment. The calculation module is used to calculate the total horizontal displacement of the pile body based on the strain data of the node and the direction factors of each segment of the pile body.

[0011] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the pile lateral displacement determination method based on distributed fiber optic strain sensing as described above.

[0012] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the pile lateral displacement determination method based on distributed fiber optic strain sensing as described above.

[0013] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the pile lateral displacement determination method based on distributed fiber optic strain sensing as described above.

[0014] The present invention provides a method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing. It calculates the direction factor by the strain difference between two adjacent nodes, and dynamically corrects the lateral displacement of the pile by introducing the direction factor and a nonlinear pattern conversion mechanism. This achieves accurate synthesis and dynamic direction calibration of the deep displacement of the pile, thereby improving the calculation accuracy of the lateral displacement of the pile. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is one of the flowcharts illustrating the pile lateral displacement determination method based on distributed optical fiber strain sensing provided by the present invention. Figure 2 (a) is a schematic diagram of the support pile in the pile lateral displacement determination method based on distributed optical fiber strain sensing provided by the present invention; Figure 2 (b) is a schematic diagram of the nodes and segments in the pile lateral displacement determination method based on distributed optical fiber strain sensing provided by the present invention; Figure 3 This is a schematic diagram illustrating the calculation of segmented displacement contribution in the pile lateral displacement determination method based on distributed optical fiber strain sensing provided by the present invention. Figure 4 This is a comparison chart of the calculation results of the pile lateral displacement determination method based on distributed optical fiber strain sensing provided by the present invention; Figure 5 This is a schematic diagram of the pile lateral displacement determination system based on distributed optical fiber strain sensing provided by the present invention. Figure 6 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0018] When using distributed fiber optic sensing technology to monitor horizontally loaded piles, the measured data is the magnitude of the strain on the pile body. In theoretical analysis, strain refers to the change per unit length, which is dimensionless and has no direction.

[0019] However, in actual engineering, the strain of a horizontally loaded pile may be in the same direction as the sliding direction, or it may be at a certain angle to the sliding direction. In addition, when the pile is subjected to a horizontal load, there may be a turning point in the bending moment along the pile body. The strain of the horizontally loaded pile may undergo positive and negative transformations. Traditional methods (such as the inclination method and the strain difference integral method) ignore the directional parameter when converting strain into displacement, which may lead to inaccurate calculation results and affect the application of monitoring results and the evaluation of engineering safety.

[0020] Therefore, this invention considers directional factors and utilizes the conversion relationship between strain and displacement of horizontally loaded piles to establish a correction model for deep horizontal displacement of horizontally loaded piles, and proposes a method for calculating the lateral displacement of horizontally loaded piles based on fiber optic strain sensing technology.

[0021] The following is combined Figures 1 to 4 This invention introduces a method for determining the lateral displacement of a pile based on distributed fiber optic strain sensing, as follows: Figure 1 As shown, it includes: Step 101: Obtain strain data of each node of the pile body collected by distributed optical fiber, wherein at least one distributed optical fiber is set along the axial direction of the pile body on the side wall of the pile body to measure strain data of each node position at uniform intervals along the axial direction of the pile body. The lateral displacement measurement of piles based on distributed optical fibers adopts BOTDR (Brillouin Scattering Time Domain Reflectometry) technology. The physical quantity monitored by this technology is strain. The optical fiber serves as both a sensor and a transmission medium, enabling long-distance, real-time, and distributed monitoring.

[0022] Specifically, before measurement, distributed fiber optic sensors are attached at any position along the pile axis on the sidewall of the pile, and one end of the distributed fiber optic sensor is connected to a high-precision fiber optic data acquisition instrument such as AQ8603 to collect strain data in real time and continuously record the deformation dynamics of each point along the pile axis.

[0023] Optionally, the pile can be a horizontally loaded pile, a bearing pile, or other types of piles.

[0024] Among them, nodes are virtual points pre-divided along the axis of the pile body, representing different positions along the axis of the pile body, and the distance between any two adjacent nodes is equal.

[0025] Optionally, the number of nodes to be divided can be determined based on the length of the pile.

[0026] Based on the location of each node obtained from the division and the measurement data of the distributed optical fibers, the strain data of each node can be determined. (Strain values). In this embodiment, the strain data of each node is organized into a strain dataset. .

[0027] Step 102: Determine the direction factor of each segment of the pile body based on the strain difference value collected from two adjacent nodes of the pile body. The pile body between two adjacent nodes is considered as a segment. The direction factor represents the consistency between the actual lateral displacement direction of the segment and the direction of the lowest segment. If we consider the pile between two adjacent nodes as a segment, then we can divide the pile into n+1 nodes, which corresponds to n segments.

[0028] Based on this, the direction factor of the segment corresponding to the two adjacent nodes can be determined by using the difference between the strain data of the two adjacent nodes as the strain difference value.

[0029] The orientation factor indicates the consistency between the actual lateral orientation of the segments corresponding to two adjacent nodes and the orientation of the bottommost segment.

[0030] Understandably, since the anchoring end of the pile is at the bottom, the lateral displacement direction corresponding to the bottommost segment of the pile is considered to represent the sliding direction of the soil. The sliding direction of the soil is also the most likely direction of movement of the pile used for support in theory. Based on this, the present invention considers the measured displacement direction of the bottommost segment as the preset positive direction. Then, based on the strain difference value calculated from the upper and lower nodes corresponding to the other segments, the lateral displacement direction of the node is calculated, and it is determined whether the direction is consistent with the direction of the bottommost segment. If they are consistent, the actual displacement direction of the segment is considered to be in the same direction as the preset positive direction. Therefore, the direction factor is set to positive, i.e., "+".

[0031] Step 103: Based on the strain data of the node and the orientation factors of each segment of the pile, calculate the total displacement of the pile in the horizontal direction.

[0032] Based on this, the lateral displacement of the corresponding segment can be calculated based on the strain data of two adjacent nodes, and then the direction factor of the segment is used to assign directionality to the lateral displacement of the segment.

[0033] Then, based on the directional lateral displacement of each segment, the total horizontal displacement of the pile as a whole can be obtained by summing them up.

[0034] This invention calculates the direction factor by the strain difference between two adjacent nodes, and dynamically corrects the lateral displacement of the pile by introducing the direction factor and a nonlinear pattern conversion mechanism, thereby achieving accurate synthesis and dynamic direction calibration of the deep displacement of the pile and improving the calculation accuracy of the lateral displacement of the pile.

[0035] In the pile lateral displacement determination method based on distributed fiber optic strain sensing of this invention, the step of determining the orientation factor of each segment of the pile body based on the strain difference value collected from two adjacent nodes of the pile body specifically includes: Calculate the strain difference between the upper and lower nodes of the lowest segment of the pile, determine the sign of the calculated strain difference, and set its direction factor to positive. For any other segment of the pile, calculate the strain difference value collected between its upper and lower nodes. If the sign of this strain difference value is the same as the sign of the strain difference value calculated for the bottommost segment, determine that the direction factor of this segment is positive, indicating that it is consistent with the direction of the bottommost segment. Otherwise, the direction factor of that segment is determined to be negative, indicating that it is opposite to the direction of the bottommost segment.

[0036] like Figure 2 As shown in the figure, in this embodiment, the pile body is divided into n segments along the axial direction by n+1 nodes, and these segments are numbered from bottom to top as the 1st to the nth segments. The sliding direction marked in the figure is the sliding direction of the soil, which is the theoretical positive direction of the bottom segment.

[0037] For the i-th segment out of n segments of the pile, the strain data corresponding to the next node is: The strain data corresponding to the upper node is One method for calculating the strain difference is as follows: .

[0038] The above method is used to first calculate the strain difference value of each segment of the pile body, and then determine the sign of the calculated strain difference value of each segment. Next, the sign of the strain difference value of the bottommost segment is determined, and the direction factor of the segment with the same sign is determined to be positive; otherwise, it is determined to be negative.

[0039] For example, first determine the direction factor. Then calculate the strain difference of the bottom segment. Then for other segments, if the calculated... If so, then the direction factor of that segment is determined to be positive, that is... =+1; if the calculated result is If so, then the direction factor of that segment is determined to be negative, that is... It is -1.

[0040] like Then for other segments, if the calculated... If so, then the direction factor of that segment is determined to be positive, that is... =+1; if the calculated result is If so, then the direction factor of that segment is determined to be negative, that is... It is -1.

[0041] In one specific implementation, based on the above logic, the Python function get_slope() is used to traverse the pre-built strain dataset and automatically generate a dynamic orientation factor set, which contains the orientation factors for each segment.

[0042] In the pile lateral displacement determination method based on distributed fiber optic strain sensing of this invention, the step of calculating the total horizontal displacement of the pile body based on the strain data of the nodes and the direction factors of each segment of the pile body specifically includes: Based on the strain data of each node and the orientation factor of each segment of the pile, the displacement contribution of each segment of the pile is determined. The total horizontal displacement of the pile is obtained by integrating the displacement contributions of all segments.

[0043] It is understandable that the horizontal displacement scalar of the corresponding segment can be calculated based on the strain data of two adjacent nodes. Then, based on the direction factor of each segment, the horizontal displacement of each segment is assigned a direction factor, so as to obtain the displacement contribution of each segment, which represents the displacement vector.

[0044] Based on this, by summing the displacement contributions of each segment, the total horizontal displacement S of the pile can be obtained: ; In the formula, S n This represents the displacement contribution of the nth segment.

[0045] In the pile lateral displacement determination method based on distributed fiber optic strain sensing of this invention, the step of determining the displacement contribution of each segment of the pile body based on the strain data and direction factor of each node specifically includes: The displacement contribution of each segment is calculated based on the following formula. : ; In the formula, Indicates the first i Segmented displacement, For the first i Segmented direction factor, For the first i Segmented fiber strain difference; The total displacement of the pile is obtained by summing the displacement contributions of each segment.

[0046] Specifically, according to the definition of strain in mechanics of materials: ; In the formula, H represents the length of the pile, and n represents the number of segments. L Indicates the length of the segment. Represents a segmented horizontal displacement scalar. This indicates linear strain.

[0047] Because of one of them The strain is linear, while the nodal strain data obtained by fiber optic measurement in this invention is point strain. Therefore, in this embodiment, the strain is linear. Indicates the first i Linear strain of each segment.

[0048] Based on this, the horizontal displacement scalar calculation for each segment is based on a geometric projection model, such as... Figure 3 As shown, when there are a sufficient number of segments, the horizontal displacement scalar of each segment, the segment length, and the deformed optical fiber can be abstracted into a triangle. Then, the horizontal displacement scalar of each segment can be calculated based on the Pythagorean theorem. : ; That is, the first i The horizontal displacement scalar of each segment is the square difference between the strain of that segment (the sum of the strain difference scalar and the segment length) and the segment length, and then the square root of the difference is calculated.

[0049] Substituting the material mechanics formulas and direction factors, the displacement contribution of each segment can be obtained. : ; In the formula, Indicates the first i Segmented displacement, For the first i Segmented direction factor, For the first i Segmented fiber strain difference.

[0050] Based on this, the displacement contribution of each segment is calculated separately, and the total displacement of the pile is obtained by summing the displacement contribution of each segment.

[0051] This invention eliminates the cumulative error caused by abrupt changes in the strain direction of micro-segments by using a square root function instead of a traditional linear integral model. By dynamically adjusting the set of direction factors, the displacement direction deviation of each micro-segment is corrected in real time, thereby obtaining more accurate lateral displacement measurement results.

[0052] In the pile lateral displacement determination method based on distributed optical fiber strain sensing of the present invention, when the number of distributed optical fibers is greater than one, one distributed optical fiber is used as the main optical fiber and the remaining distributed optical fibers are used as backup optical fibers. If the main optical fiber is not damaged, the strain data of each node of the pile body is obtained by the main optical fiber; otherwise, any backup optical fiber is used to measure the strain data of each node of the pile body.

[0053] Although this invention only requires one distributed optical fiber to measure and calculate the lateral displacement of the pile, if multiple distributed optical fibers are pre-deployed, one fiber can be selected as the main fiber and the remaining distributed optical fibers can be used as backup fibers. In the event that the main fiber is damaged or the data is abnormal, the strain data obtained by measuring the backup fiber can be used to calculate the lateral displacement of the pile.

[0054] In the pile lateral displacement determination method based on distributed optical fiber strain sensing of this invention, the interval between two adjacent nodes is 0.05 meters.

[0055] The interval between two adjacent nodes, which is the length of each micro-segment, is smaller. The more segments can be divided, the more accurate the direction of each segment can be determined, and the better the location of the strain direction change can be identified. However, it consumes more computing resources and requires reading and calculating more fiber strain data.

[0056] The larger the length of the micro-segment, the fewer segments are required, resulting in less computational resource consumption, but the less accurate the identification of abrupt changes in strain direction.

[0057] Therefore, in order to balance the consumption of computing resources and the accuracy of segmented strain direction identification, in this embodiment, the interval between two adjacent nodes, that is, the length of each micro-segment, is determined to be 0.05 meters.

[0058] In a specific example, for a concrete support pile with a pile length H of 37.5 meters, BOTDR technology was used to symmetrically deploy distributed fiber optic sensors on both sides of the pile. Measurement micro-segments were divided along the pile length at fixed intervals of 0.05m, and a high-precision fiber optic data acquisition instrument AQ8603 was used to collect strain data in real time and record the dynamic deformation of the pile.

[0059] Based on the collected data, the calculation method of this invention is compared with conventional fiber optic applications based on deflection and calculation results based on inclinometer tubes.

[0060] The comparative method is based on the static cantilever beam assumption and calculates the top displacement using strain layered integration. It utilizes fiber optic strain data and derives the displacement distribution through two integrals of curvature and displacement to obtain the displacement at a certain depth of the pile. z Displacement at point satisfy: ; In the formula, and The strain measured by optical fibers at the front and rear edges of the pile body; and This is a fixed distance between the fiber and the neutral axis (assuming the position of the neutral axis does not change with time / depth).

[0061] In the inclinometer-based measurement method, the displacement at the top of the inclinometer is obtained by accumulating the displacement increments in layers. The calculation results are shown in Figure 4. It can be seen that, compared to the deflection-based measurement method in traditional fiber optic applications, the calculation method of this invention better reflects the displacement changes at each height position along the axial direction of the pile. Compared to the comparative method, due to the higher accuracy of the displacement of each micro-segment, the calculated total lateral displacement of the pile is also more accurate.

[0062] It is worth mentioning that the comparative method, which is the conventional application of fiber optic measurement of the lateral displacement of the pile, relies on the measurement results of two optical fibers at the front and rear edges of the pile at the same height. Therefore, it requires at least two optical fibers and that the two optical fibers be in relative positions. If either of the two optical fibers fails, the data from both fibers cannot be used, which places high demands on the deployment of the measuring optical fibers and the backup optical fibers. In the method of this invention, even if multiple optical fibers are deployed to achieve redundancy, there are no restrictions on the relative positions of the multiple optical fibers. They can be deployed in convenient locations, which improves the measurement accuracy and further reduces the requirements for the deployment of optical fibers.

[0063] Compared to the inclinometer tube measurement method, on the one hand, the fiber optic cable layout is greatly simplified; on the other hand, referring to... Figure 4 It is not difficult to find that in the measurement results of the present invention, the overall trend of the directional change at each position along the pile axis is roughly the same as that of the inclinometer measurement results. This indicates that the results of the present invention and the inclinometer are better able to reflect the strain direction of each micro-segment than the conventional fiber optic measurement method. On this basis, comparing the curves of the present invention and the inclinometer, it can be seen that the method of the present invention reflects the strain direction more subtly than the results of the inclinometer, and can more accurately reflect the strain direction of each micro-segment of the pile body. Thus, it can calculate a more accurate lateral displacement result than the measurement results of the inclinometer.

[0064] The pile lateral displacement determination system based on distributed optical fiber strain sensing provided by the present invention will be described below. The pile lateral displacement determination system based on distributed optical fiber strain sensing described below can be referred to in correspondence with the pile lateral displacement determination method based on distributed optical fiber strain sensing described above.

[0065] like Figure 5 As shown, the pile lateral displacement determination system based on distributed optical fiber strain sensing includes an acquisition module 501, a determination module 502, and a calculation module 503. The acquisition module 501 is used to acquire strain data of each node of the pile body collected by distributed optical fiber, wherein at least one distributed optical fiber is arranged along the axial direction of the pile body on the side wall of the pile body to measure strain data of each node position at uniform intervals along the axial direction of the pile body. The lateral displacement measurement of piles based on distributed optical fibers adopts BOTDR (Brillouin Scattering Time Domain Reflectometry) technology. The physical quantity monitored by this technology is strain. The optical fiber serves as both a sensor and a transmission medium, enabling long-distance, real-time, and distributed monitoring.

[0066] Specifically, before measurement, distributed fiber optic sensors are attached at any position along the pile axis on the sidewall of the pile, and one end of the distributed fiber optic sensor is connected to a high-precision fiber optic data acquisition instrument such as AQ8603 to collect strain data in real time and continuously record the deformation dynamics of each point along the pile axis.

[0067] Optionally, the pile can be a horizontally loaded pile, a bearing pile, or other types of piles.

[0068] Among them, nodes are virtual points pre-divided along the axis of the pile body, representing different positions along the axis of the pile body, and the distance between any two adjacent nodes is equal.

[0069] Optionally, the number of nodes to be divided can be determined based on the length of the pile.

[0070] Based on the location of each node obtained from the division and the measurement data of the distributed optical fibers, the strain data of each node can be determined. (Strain values). In this embodiment, the strain data of each node is organized into a strain dataset. .

[0071] The determination module 502 is used to determine the direction factor of each segment of the pile body based on the strain difference value collected from two adjacent nodes of the pile body. The pile body between two adjacent nodes is considered as a segment, and the direction factor represents the consistency between the actual lateral displacement direction of the segment and the direction of the bottommost segment. If we consider the pile between two adjacent nodes as a segment, then we can divide the pile into n+1 nodes, which corresponds to n segments.

[0072] Based on this, the direction factor of the segment corresponding to the two adjacent nodes can be determined by using the difference between the strain data of the two adjacent nodes as the strain difference value.

[0073] The orientation factor indicates the consistency between the actual lateral orientation of the segments corresponding to two adjacent nodes and the orientation of the bottommost segment.

[0074] Understandably, since the anchoring end of the pile is at the bottom, the lateral displacement direction corresponding to the bottommost segment of the pile is considered to represent the sliding direction of the soil. The sliding direction of the soil is also the most likely direction of movement of the pile used for support in theory. Based on this, the present invention considers the measured displacement direction of the bottommost segment as the preset positive direction. Then, based on the strain difference value calculated from the upper and lower nodes corresponding to the other segments, the lateral displacement direction of the node is calculated, and it is determined whether the direction is consistent with the direction of the bottommost segment. If they are consistent, the actual displacement direction of the segment is considered to be in the same direction as the preset positive direction. Therefore, the direction factor is set to positive, i.e., "+".

[0075] The calculation module 503 is used to calculate the total horizontal displacement of the pile body based on the strain data of the node and the direction factors of each segment of the pile body.

[0076] Based on this, the lateral displacement of the corresponding segment can be calculated based on the strain data of two adjacent nodes, and then the direction factor of the segment is used to assign directionality to the lateral displacement of the segment.

[0077] Then, based on the directional lateral displacement of each segment, the total horizontal displacement of the pile as a whole can be obtained by summing them up.

[0078] This invention calculates the direction factor by the strain difference between two adjacent nodes, and dynamically corrects the lateral displacement of the pile by introducing the direction factor and a nonlinear pattern conversion mechanism, thereby achieving accurate synthesis and dynamic direction calibration of the deep displacement of the pile and improving the calculation accuracy of the lateral displacement of the pile.

[0079] Figure 6 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 6As shown, the electronic device may include a processor 610, a communication interface 620, a memory 630, and a communication bus 640, wherein the processor 610, the communication interface 620, and the memory 630 communicate with each other through the communication bus 640. The processor 610 can call logical instructions in the memory 630 to execute a method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing. The method includes: acquiring strain data of each node of the pile body collected by distributed optical fiber, wherein at least one distributed optical fiber is arranged along the axial direction of the pile body on the sidewall of the pile body to measure the strain data of each node position at uniform intervals along the axial direction of the pile body; determining the direction factor of each segment of the pile body according to the strain difference value collected between two adjacent nodes of the pile body, wherein the pile body between two adjacent nodes is considered as a segment, and the direction factor characterizes the consistency between the actual lateral displacement direction of the segment and the direction of the lowest segment; and calculating the total displacement of the pile body in the horizontal direction based on the strain data of the nodes and the direction factors of each segment of the pile body.

[0080] Furthermore, the logical instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0081] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the pile lateral displacement determination method based on distributed optical fiber strain sensing provided by the above methods. The method includes: acquiring strain data of each node of the pile body collected by distributed optical fiber, wherein at least one distributed optical fiber is arranged along the axial direction of the pile body on the sidewall of the pile body to measure strain data of each node position at uniform intervals along the axial direction of the pile body; determining the direction factor of each segment of the pile body according to the strain difference value collected between two adjacent nodes of the pile body, wherein the pile body between two adjacent nodes is considered as a segment, and the direction factor characterizes the consistency between the actual lateral displacement direction of the segment and the direction of the lowest segment; and calculating the total displacement of the pile body in the horizontal direction based on the strain data of the nodes and the direction factor of each segment of the pile body.

[0082] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the pile lateral displacement determination method based on distributed optical fiber strain sensing provided by the above methods. The method includes: acquiring strain data of each node of the pile body collected by distributed optical fiber, wherein at least one distributed optical fiber is disposed along the axial direction of the pile body on the sidewall of the pile body to measure strain data at uniformly spaced node positions along the axial direction of the pile body; determining the direction factor of each segment of the pile body based on the strain difference value collected from two adjacent nodes, wherein the pile body between two adjacent nodes is considered as a segment, and the direction factor characterizes the consistency between the actual lateral displacement direction of the segment and the direction of the lowest segment; and calculating the total horizontal displacement of the pile body based on the strain data of the nodes and the direction factors of each segment of the pile body.

[0083] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0084] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the lateral displacement of a pile based on distributed fiber optic strain sensing, characterized in that, include: Strain data of each node of the pile body is acquired by distributed optical fiber, wherein at least one distributed optical fiber is set along the axial direction of the pile body on the side wall of the pile body to measure strain data of each node position at uniform intervals along the axial direction of the pile body. Based on the strain difference values ​​collected from two adjacent nodes along the axial direction of the pile, the direction factor of each segment of the pile is determined. The pile between two adjacent nodes is considered as a segment, and the direction factor indicates that the actual lateral displacement direction of the segment is consistent with the direction of the lowest segment. Based on the strain data of the nodes and the orientation factors of each segment of the pile, the total displacement of the pile in the horizontal direction is calculated. The step of determining the orientation factor of each segment of the pile body based on the strain difference value collected from two adjacent nodes of the pile body specifically includes: Calculate the strain difference between the upper and lower nodes of the lowest segment of the pile, determine the sign of the calculated strain difference, and set its direction factor to positive. For any other segment of the pile, calculate the strain difference value collected between its upper and lower nodes. If the sign of the strain difference value is the same as the sign of the strain difference value calculated for the bottommost segment, determine that the direction factor of the segment is positive, indicating that it is consistent with the direction of the bottommost segment. Otherwise, the direction factor of that segment is determined to be negative, indicating that it is opposite to the direction of the bottommost segment.

2. The method for determining pile lateral displacement based on distributed optical fiber strain sensing according to claim 1, characterized in that, The step of calculating the total horizontal displacement of the pile body based on the strain data of the nodes and the direction factors of each segment of the pile body specifically includes: Based on the strain data of each node and the orientation factor of each segment of the pile, the displacement contribution of each segment of the pile is determined. The total horizontal displacement of the pile is obtained by integrating the displacement contributions of all segments.

3. The method for determining pile lateral displacement based on distributed optical fiber strain sensing according to claim 2, characterized in that, The step of determining the displacement contribution of each segment of the pile body based on the strain data and direction factor of each node specifically includes: The displacement contribution of each segment is calculated based on the following formula. : ； In the formula, Indicates the first i Segmented displacement, For the first i Segmented direction factor, For the first i Segmented fiber strain difference H This represents the length of the pile, and n represents the number of segments. The total displacement of the pile is obtained by summing the displacement contributions of each segment.

4. The method for determining pile lateral displacement based on distributed optical fiber strain sensing according to claim 1, characterized in that, When the number of distributed optical fibers is greater than one, one distributed optical fiber is used as the main optical fiber and the rest are used as backup optical fibers. If the main optical fiber is not damaged, the strain data of each node of the pile body is obtained by measuring the main optical fiber. Otherwise, use any spare optical fiber to measure the strain data of each node of the pile.

5. The method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing according to claim 1, characterized in that, The interval between two adjacent nodes is 0.05 meters.

6. A pile lateral displacement determination system based on distributed fiber optic strain sensing, characterized in that, include: The acquisition module is used to acquire strain data of each node of the pile body collected by distributed optical fiber, wherein at least one distributed optical fiber is set along the axial direction of the pile body on the side wall of the pile body to measure strain data of each node position at uniform intervals along the axial direction of the pile body. The determination module is used to determine the direction factor of each segment of the pile body based on the strain difference value collected from two adjacent nodes along the axial direction of the pile body. The pile body between two adjacent nodes is considered as a segment, and the direction factor represents the consistency between the actual lateral displacement direction of the segment and the direction of the bottommost segment. The calculation module is used to calculate the total horizontal displacement of the pile body based on the strain data of the node and the orientation factors of each segment of the pile body. The determination module is specifically used to calculate the strain difference value collected at the upper node and the lower node of the lowest segment of the pile, determine the positive or negative value of the calculated strain difference value, and determine its direction factor as positive. For any other segment of the pile, calculate the strain difference value collected between its upper and lower nodes. If the sign of the strain difference value is the same as the sign of the strain difference value calculated for the bottommost segment, determine that the direction factor of the segment is positive, indicating that it is consistent with the direction of the bottommost segment. Otherwise, the direction factor of that segment is determined to be negative, indicating that it is opposite to the direction of the bottommost segment.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the pile lateral displacement determination method based on distributed optical fiber strain sensing as described in any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the pile lateral displacement determination method based on distributed optical fiber strain sensing as described in any one of claims 1 to 5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the pile lateral displacement determination method based on distributed optical fiber strain sensing as described in any one of claims 1 to 5.

Images