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

Abstract

The invention provides a pile lateral displacement determination method based on distributed optical fiber strain sensing, which comprises the following steps: acquiring strain data of each node of a pile body acquired by distributed optical fibers, at least one distributed optical fiber being arranged on the side wall of the pile body along the axial direction of the pile body so as to measure the strain data of each node position uniformly spaced along the axial direction of the pile body; and according to the strain difference value collected by the two adjacent nodes of the pile body, the direction factor of each segment of the pile body is determined, and the total displacement of the pile body in the horizontal direction is calculated based on the strain data of the nodes and the direction factor of each segment of the pile body. According to the method, the direction factor is calculated through the strain difference value between the two adjacent nodes, the lateral displacement of the pile body is dynamically corrected by introducing the direction factor and a nonlinear pattern conversion mechanism, accurate synthesis and direction dynamic calibration of the deep displacement of the pile body are achieved, and therefore the calculation precision of the lateral displacement of the pile body is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pile foundation engineering, and particularly relates to a pile lateral displacement determination method based on distributed optical fiber strain sensing. BACKGROUND

[0002] The foundation pit supporting structure and the slope anti-sliding structure belong to typical horizontal load piles, and the deep horizontal displacement of the horizontal load pile is a key index for evaluating the safety and stability of the foundation pit, the slope and the like. The traditional method mainly uses the inclinometer for direct measurement, which is simple to operate, intuitive in data, and can obtain the horizontal displacement curve of the pile body along the depth direction, thereby providing an important basis for the foundation pit supporting and the slope stability analysis. However, the traditional method has significant limitations: only discrete point data can be provided, the measurement accuracy is easily affected by environmental interference, and long-distance real-time monitoring is difficult to achieve. In recent years, the distributed optical fiber strain sensing technology has been widely applied in the field of geotechnical engineering monitoring due to its advantages of full-distributed measurement, high precision, corrosion resistance and anti-electromagnetic interference. Compared with the traditional inclinometer which needs to be protected from damage, the embedded optical fiber sensor does not have such problems.

[0003] However, the existing displacement calculation method based on optical fiber strain data still has a core bottleneck: the uncertainty of the strain direction. Therefore, the conventional displacement calculation method based on optical fiber strain is usually a deflection-based calculation method, which does not consider the influence of the direction when calculating, thereby causing systematic deviation between the lateral displacement calculation result based on the optical fiber strain data and the actual result. SUMMARY

[0004] The present application provides a pile lateral displacement determination method based on distributed optical fiber strain sensing, which solves the defect that the directionality parameter is ignored when converting strain into displacement in the prior art, and realizes a more accurate lateral displacement calculation method for horizontal load piles.

[0005] The present application provides a pile lateral displacement determination method based on distributed optical fiber strain sensing, which includes: Obtaining strain data of each node of the pile body collected by the distributed optical fiber, wherein at least one distributed optical fiber is arranged on the side 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 segment of the pile body according to the strain difference collected by the adjacent two nodes of the pile body, wherein the pile body between the adjacent two nodes is regarded as a segment, and the direction factor represents the consistency of the actual lateral displacement direction of the segment and the direction of the lowermost segment; Calculating the total displacement of the pile body in the horizontal direction based on the strain data of the node and the direction factor of each segment of the pile body 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 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.

[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 n Segmented displacement, For the first n Segmented direction factor, For the first n Segmented fiber strain difference; 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] The application provides a pile lateral displacement determination method based on distributed optical fiber strain sensing, and the interval between two adjacent nodes is 0.05 m.

[0010] The application further provides a pile lateral displacement determination system based on distributed optical fiber strain sensing, which comprises the following steps. The acquisition module is used for acquiring strain data of each node of the pile body collected by the 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 strain data of each node position uniformly spaced along the axial direction of the pile body. The determination module is used for determining the direction factor of each section of the pile body according to the strain difference collected by two adjacent nodes of the pile body, wherein the pile body between the two adjacent nodes is regarded as a section, and the direction factor represents the consistency of the actual lateral displacement direction of the section and the direction of the lowermost section. The calculation module is used for 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.

[0011] The application further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the pile lateral displacement determination method based on distributed optical fiber strain sensing according to any one of the above.

[0012] The application further provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program is executable by a processor to implement the pile lateral displacement determination method based on distributed optical fiber strain sensing according to any one of the above.

[0013] The application further provides a computer program product comprising a computer program, wherein the computer program is executable by a processor to implement the pile lateral displacement determination method based on distributed optical fiber strain sensing according to any one of the above.

[0014] The pile lateral displacement determination method based on distributed optical fiber strain sensing provided by the application calculates the direction factor through the strain difference between two adjacent nodes, dynamically corrects the lateral displacement of the pile body by introducing the direction factor and the nonlinear pattern conversion mechanism, realizes 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. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[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] To this end, the application considers the direction factor, establishes a deep horizontal displacement correction model of a horizontally loaded pile by using the conversion relationship between the strain and displacement of the horizontally loaded pile, and proposes a lateral displacement calculation method of a horizontally loaded pile based on fiber strain sensing technology.

[0021] The application will be described below in combination with Figures 1 to 4 The application discloses a pile lateral displacement determination method based on distributed optical fiber strain sensing, as shown in the accompanying drawings, which comprises the following steps. Figure 1 In step 101, strain data of each node of the pile body collected by the distributed optical fiber is obtained, wherein at least one distributed optical fiber is arranged on the side 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. The pile body lateral displacement measurement based on the distributed optical fiber adopts the BOTDR technology (Brillouin scattering optical time domain reflectometry), the physical quantity monitored by the technology is strain, the optical fiber acts as both a sensor and a transmission medium, and remote, real-time and distributed monitoring can be achieved.

[0022] Specifically, before measurement, the distributed optical fiber sensor is attached to the side wall of the pile body at any position along the axial direction of the pile body, and a section of the distributed optical fiber sensor is connected to a high-precision optical fiber data acquisition instrument such as AQ8603 to collect strain data in real time, and the deformation dynamics of each point on the axial direction of the pile body are continuously recorded.

[0023] Optionally, the pile body can be a horizontally loaded pile, a bearing pile or various pile bodies.

[0024] The node is a virtual point divided along the axial direction of the pile body in advance, represents different positions on the axial direction of the pile body, and the distance between any two adjacent nodes is equal.

[0025] Optionally, the number of nodes to be divided is determined according to the length of the pile body.

[0026] Based on the position of each node obtained by division and the measurement data of the distributed optical fiber, the strain data (strain value) of each node can be determined. In the embodiment, the strain data of each node is arranged into a strain data set .

[0027] In step 102, the direction factor of each section of the pile body is determined according to the strain difference collected by the adjacent two nodes of the pile body, wherein the pile body between the adjacent two nodes is regarded as a section, and the direction factor represents the consistency of the actual lateral displacement direction of the section with the direction of the lowermost section. The pile body between the adjacent two nodes is regarded as a section, so that the pile body is divided into n nodes, and n-1 sections are obtained correspondingly.

[0028] ​On this basis, the difference between the strain data between the two adjacent nodes of the pile body is taken as the strain difference value, and the direction factor of the corresponding section of the two adjacent nodes is determined.

[0029] The direction factor represents the consistency of the actual lateral direction of the corresponding section of the two adjacent nodes with the direction of the lowermost section.

[0030] It can be understood that, generally, since the anchoring end of the pile body is downward, it is considered that the lateral displacement direction of the lowermost section of the pile body can represent the sliding direction of the soil body, and the sliding direction of the soil body is also the most possible moving direction of the pile body for support in theory; on this basis, the measured displacement direction of the lowermost section is considered as the preset positive direction, and then the strain difference values calculated according to the upper node and the lower node of each section are used to calculate the lateral displacement direction of the node, and the consistency of the direction with the direction of the lowermost section is judged, if consistent, it is considered that the actual displacement direction of the section is the same as the preset positive direction, and therefore the direction factor is positive, that is, "+".

[0031] In step 103, the total displacement of the pile body in the horizontal direction is calculated based on the strain data of the node and the direction factor of each section of the pile body.

[0032] On this basis, the lateral displacement of the corresponding section can be calculated based on the strain data of the two adjacent nodes, and then the directionality of the lateral displacement of the section is given by using the direction factor of the section.

[0033] Then, the total displacement of the pile body in the horizontal direction as a whole can be obtained by adding up the lateral displacement of each section with directionality.

[0034] The present application calculates the direction factor based on the strain difference value between the two adjacent nodes, and dynamically corrects the lateral displacement of the pile body by introducing the direction factor and the nonlinear pattern conversion mechanism, so as to realize the accurate synthesis and direction dynamic calibration of the deep displacement of the pile body, thereby improving the calculation accuracy of the lateral displacement of the pile body.

[0035] In the present application, the step of determining the direction factor of each section of the pile body according to the strain difference value collected by the two adjacent nodes of the pile body, specifically comprises: The strain difference value collected by the upper node and the lower node of the lowermost section of the pile body is calculated, and the positive and negative of the calculated strain difference value is determined, and the direction factor is determined as positive; For any other section of the pile body, the strain difference value collected by the upper node and the lower node is calculated, and in the case that the positive and negative of the strain difference value is the same as that of the strain difference value calculated by the lowermost section, the direction factor of the section is determined as positive, indicating that it is consistent with the direction of the lowermost section. 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 n Segmented displacement, For the first n Segmented direction factor, For the first n 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 the 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 3As 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 horizontal displacement scalar of the i-th segment is the square difference between the strain of the 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 obtained.

[0049] Substituting the material mechanics formulas and the direction factor, the displacement contribution of each segment can be obtained. : ; In the formula, Indicates the first n Segmented displacement, For the first n Segmented direction factor, For the first n 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, compared with the method, that is, the conventional application of the optical fiber for measuring the lateral displacement of the pile body, since the measurement results of the two optical fibers at the front and rear edges of the pile body at the same height position of the pile body are relied on, on the one hand, at least two optical fibers are required, and on the other hand, the two optical fibers are required to be at opposite positions, and if any one of the two optical fibers fails, the data of the two optical fibers cannot be used, and the laying of the measurement optical fiber and the standby optical fiber has a higher requirement; in the method of the present application, even if a plurality of optical fibers are laid to realize redundancy, there is no limitation on the relative positions of the plurality of optical fibers, and the plurality of optical fibers can be laid at convenient positions, which not only improves the measurement accuracy, but also further reduces the laying requirement of the optical fibers.

[0063] Compared with the measurement method of the inclinometer, on the one hand, the laying of the optical fiber is greatly simplified compared with the laying of the inclinometer, and on the other hand, with reference to Figure 4 It can be found from the measurement results of the present application that the overall trend of the direction change of each position in the pile axis direction is basically the same as that of the measurement results of the inclinometer, which indicates that the results of the present application and the inclinometer are more capable of reflecting the strain direction of each micro-section compared with the conventional optical fiber measurement method, and on this basis, by comparing the curves of the present application and the inclinometer, it can be known that the strain direction of the present application is more subtle compared with the results of the inclinometer, and can more accurately reflect the strain direction of each micro-section of the pile body, so that a more accurate lateral displacement result can be calculated compared with the measurement results of the inclinometer.

[0064] The pile lateral displacement determination system based on distributed optical fiber strain sensing provided by the present application will be described below, and the pile lateral displacement determination system based on distributed optical fiber strain sensing described below can be correspondingly referred to the pile lateral displacement determination method based on distributed optical fiber strain sensing described above.

[0065] As shown in Figure 5 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 for acquiring the strain data of each node of the pile body collected by the distributed optical fiber, wherein at least one distributed optical fiber is arranged on the side wall of the pile body in 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. The pile body lateral displacement measurement based on the distributed optical fiber adopts the BOTDR technology (Brillouin scattering optical time domain reflection technology), the physical quantity monitored by the technology is strain, the optical fiber is used as a sensor and a transmission medium, and remote, real-time and distributed monitoring can be realized.

[0066] Specifically, before measurement, a distributed optical fiber sensor is attached to the side wall of the pile body at any position along the axial direction of the pile body, and a section of the distributed optical fiber sensor is connected to a high-precision optical fiber data acquisition instrument such as AQ8603 to collect strain data in real time, and the deformation dynamics of each point on the axial direction of the pile body are recorded continuously.

[0067] Optionally, the pile body can be a horizontal load pile, a bearing pile, and various pile bodies.

[0068] Among them, the node is a virtual point divided along the axial direction of the pile body in advance, representing different positions on the axial direction of the pile body, and the distance between any two adjacent nodes is equal.

[0069] Optionally, the number of nodes to be divided is determined according to the length of the pile body.

[0070] Based on the position of each node obtained by division and the measurement data of the distributed optical fiber, the strain data of each node (strain value) can be determined. In this embodiment, the strain data of each node is arranged into a strain data set .

[0071] The determination module 502 is configured to determine a direction factor of each segment of the pile body according to the strain difference collected by the two adjacent nodes of the pile body, wherein the pile body between the two adjacent nodes is regarded as a segment, and the direction factor represents the consistency of the actual lateral displacement direction of the segment with the direction of the lowermost segment. The pile body is divided into n nodes, and n-1 segments are obtained correspondingly.

[0072] On this basis, the strain difference between the strain data of the two adjacent nodes can be determined as the strain difference, and the direction factor of the segment corresponding to the two adjacent nodes can be determined.

[0073] The direction factor represents the consistency of the actual lateral displacement direction of the segment corresponding to the two adjacent nodes with the direction of the lowermost segment.

[0074] It can be understood that, in general, since the anchoring end of the pile body is downward, it is considered that the lateral displacement direction of the lowermost segment of the pile body can represent the sliding direction of the soil body, and the sliding direction of the soil body is also the most possible moving direction of the pile body for supporting in theory. On this basis, the measured displacement direction of the lowermost segment is considered as a preset positive direction, and then the lateral displacement direction of the node is calculated according to the strain difference calculated by the upper node and the lower node of each segment, and the consistency of the direction with the direction of the lowermost segment is judged. If they are consistent, it is considered that the actual displacement direction of the segment is the same as the preset positive direction, so the direction factor is positive, that is, "+".

[0075] The computing module 503 is configured to calculate the total displacement of the pile in the horizontal direction based on the strain data of the nodes and the directional factors of the segments of the pile.

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

[0077] Then, the total displacement of the pile in the horizontal direction as a whole can be obtained by adding up the lateral displacement of each segment with directionality.

[0078] The present application calculates the directional factor based on the strain difference between the two adjacent nodes, and dynamically corrects the lateral displacement of the pile by introducing the directional factor and the nonlinear pattern conversion mechanism, so as to realize the accurate synthesis and direction dynamic calibration of the deep displacement of the pile, thereby improving the calculation accuracy of the lateral displacement of the pile.

[0079] Figure 6 An example of an entity structure diagram of an electronic device is shown in Figure 6 As shown, the electronic device can include a processor 610, a communications interface 620, a memory 630, and a communications bus 640, wherein the processor 610, the communications interface 620, and the memory 630 communicate with each other through the communications bus 640. The processor 610 can invoke the logical instructions in the memory 630 to execute the pile lateral displacement determination method based on distributed optical fiber strain sensing, which includes: acquiring strain data of each node of the pile collected by the distributed optical fiber, wherein at least one distributed optical fiber is arranged on the side wall of the pile along the axial direction of the pile to measure the strain data of each node position uniformly spaced along the axial direction of the pile; determining the directional factor of each segment of the pile based on the strain difference collected by the two adjacent nodes of the pile, wherein the pile between the two adjacent nodes is regarded as a segment, and the directional factor represents the consistency of the actual lateral displacement direction of the segment with the direction of the lowermost segment; calculating the total displacement of the pile in the horizontal direction based on the strain data of the nodes and the directional factors of the segments of the pile.

[0080] In addition, the logic instructions in the memory 630 described above can be implemented in the form of software functional units and sold or used as independent products, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0081] In another aspect, the present application also provides a computer program product, which comprises a computer program, the computer program can be stored on a non-transitory computer readable storage medium, and the computer program can be executed by a processor to enable a computer to execute the distributed optical fiber strain sensing based pile lateral displacement determination method provided by the above-mentioned methods. The method comprises: acquiring 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 side 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 segment of the pile body according to the strain difference collected by the adjacent two nodes of the pile body, wherein the pile body between the adjacent two nodes is regarded as a segment, and the direction factor represents the consistency of the actual lateral displacement direction of the segment and the direction of the lowermost 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 application also provides a non-transitory computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the distributed optical fiber strain sensing based pile lateral displacement determination method provided by the above-mentioned methods. The method comprises: acquiring 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 side 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 segment of the pile body according to the strain difference collected by the adjacent two nodes of the pile body, wherein the pile body between the adjacent two nodes is regarded as a segment, and the direction factor represents the consistency of the actual lateral displacement direction of the segment and the direction of the lowermost 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.

[0083] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purposes of the embodiments according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0084] Through the description of the above embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software and the necessary general hardware platform, and of course can also be realized by hardware. Based on such understanding, the above technical solutions can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment 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 application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining the lateral displacement of a pile based on distributed optical fiber 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 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 displacement of the pile in the horizontal direction is calculated.

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 determining the orientation factor of each segment of the pile based on the strain difference value collected from two adjacent nodes of the pile 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.

3. 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 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.

4. The method for determining the lateral displacement of a pile based on distributed optical fiber strain sensing according to claim 3, 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 n Segmented displacement, For the first n Segmented direction factor, For the first n Segmented fiber strain difference; The total displacement of the pile is obtained by summing the displacement contributions of each segment.

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, 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.

6. 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.

7. 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 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.

8. 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 6.

9. 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 6.

10. 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 6.

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