Basket type arch bridge steel arch deformation monitoring method and equipment based on laser scanning radar

Abstract

The invention discloses a basket-type arch bridge steel arch deformation monitoring method and device based on laser scanning radar, and belongs to the field of bridge engineering, and the method comprises the steps: S1, radar arrangement: symmetrically arranging a plurality of groups of laser scanning radar devices at equal intervals at a reference point of a basket-type arch bridge, capturing three-dimensional point cloud data of the whole steel arch structure including a main arch rib, an auxiliary arch rib and a cross brace; s2, model construction: according to the three-dimensional point cloud data captured by the laser radar equipment, an initial three-dimensional digital model of the basket type arch bridge steel arch is constructed, the model accurately reflects the initial geometrical shape and spatial position relation of the steel arch, and meanwhile, denoising processing is performed on initial data; according to the basket type arch bridge steel arch deformation monitoring method and device based on the laser scanning radar, global, high-precision and non-contact automatic deformation monitoring of the basket type arch bridge steel arch structure is achieved, and the comprehensiveness, precision and reliability of monitoring are remarkably improved through multi-source data fusion verification.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, and in particular to a method and equipment for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar. Background Technology

[0002] Basket arch bridges, as an elegant bridge type, are widely used due to their structural stability and strong spanning capacity. Their core load-bearing structure—the steel arch—usually consists of two or more parallel main arch ribs, secondary arch ribs, and connecting cross braces, forming a complex spatial stress system. During long-term operation, the steel arch structure inevitably undergoes cumulative deformation under the influence of vehicle loads, environmental corrosion, and material aging. This includes downward deflection and lateral displacement of the main arch ribs, torsional deformation of the cross braces, and relative misalignment between the arch ribs. If these deformations are not detected and controlled in a timely manner, they will seriously threaten the structural safety and operational lifespan of the bridge.

[0003] Currently, deformation monitoring of bridge structures mainly relies on traditional measurement techniques and fixed-point sensors. Traditional measurement techniques, such as total stations and levels, while highly accurate, typically only acquire data from a few discrete control points on the structure. They cannot comprehensively and continuously capture the overall deformation field of a complex spatial structure like a basket-arch bridge, resulting in monitoring blind spots, low automation, and low efficiency. On the other hand, fixed-point sensors, such as strain gauges, fiber optic sensors, and inclinometers, while enabling continuous automated monitoring, still acquire information from local points, making it difficult to comprehensively reflect the spatial state of the entire steel arch. Summary of the Invention

[0004] The purpose of this invention is to address the problem that existing bridge structure deformation monitoring mainly relies on traditional measurement techniques and fixed-point sensors, which cannot comprehensively and continuously capture the overall deformation field of the complex spatial structure of basket arch bridges, and cannot fully reflect the spatial state of the entire steel arch. Therefore, this invention proposes a method and equipment for monitoring the deformation of basket arch bridge steel arches based on laser scanning radar.

[0005] To achieve the above objectives, the present invention employs the following technology: a method and equipment for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar, comprising the following steps: S1. Radar deployment: At the reference point of the basket-shaped arch bridge, multiple sets of laser scanning radar equipment are symmetrically and equally spaced to capture the three-dimensional point cloud data of the entire steel arch structure, including the main arch rib, secondary arch rib, and cross brace. S2. Model Construction: Based on the three-dimensional point cloud data captured by the lidar equipment, an initial three-dimensional digital model of the steel arch of the basket-type arch bridge is constructed. This model accurately reflects the initial geometric shape and spatial position relationship of the steel arch, while the initial data is denoised. S3. Real-time data acquisition and processing: During the operation of the basket-type arch bridge, the steel arch is continuously scanned by laser scanning radar according to the set scanning frequency to obtain real-time three-dimensional coordinate data. The real-time data is preprocessed to ensure the integrity and continuity of the data. S4. Calculation and Analysis: Compare and analyze the real-time three-dimensional coordinate data with the initial three-dimensional digital model to calculate the overall deformation field of the steel arch structure in three-dimensional space and the relative deformation of key components. S5. Data Fusion and Verification: The deformation data obtained by laser scanning radar monitoring is fused and analyzed with data obtained by other monitoring methods. By comparing the data from different monitoring methods, the effectiveness and consistency of the laser scanning radar monitoring results are verified.

[0006] As a further description of the above technical solution: In step S1, the reference points of the basket arch bridge include the top of the pier, the position of the arch foot, and the key section of the arch rib.

[0007] As a further description of the above technical solution: In step S1, each group of laser scanning radar equipment includes at least two laser scanning radars with different scanning angles and resolutions. Based on the geometric dimensions of the basket-shaped arch bridge, the characteristics of the steel arch structure, and the expected monitoring accuracy requirements, the scanning frequency, scanning range, and sampling point density parameters of the laser scanning radar are set.

[0008] As a further description of the above technical solution: In step S2, the initial data denoising process adopts a denoising algorithm based on wavelet analysis to remove noise data caused by environmental interference, equipment errors and other factors.

[0009] As a further description of the above technical solution: In step S3, the preprocessing of real-time data includes data alignment and coordinate transformation, unifying data collected from different locations and at different times into the same coordinate system, and interpolating missing data.

[0010] As a further description of the above technical solution: In step S4, the calculated relative deformation includes the change in spatial distance between the projection points of the two ends of the same cross brace on the axis of the main arch rib and the secondary arch rib connected to it, and the torsional angle of the center line of the cross brace relative to its initial position, thereby quantifying the degradation of the lateral stability between the arch ribs unique to basket-type arch bridges.

[0011] As a further description of the above technical solution: In step S5, other detection methods include, but are not limited to, data detected by strain gauges and acceleration sensors.

[0012] A monitoring device for the deformation of the steel arch of a basket-type arch bridge based on laser scanning radar, wherein the monitoring device applies the monitoring method described in any one of the above descriptions.

[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: By introducing laser scanning radar and non-contact measurement methods, compared with traditional discrete point measurement methods such as total stations and levels, and local contact monitoring methods such as strain gauges and fiber optic sensors, a leap from local point monitoring to full-field deformation field perception has been achieved. It can simultaneously capture the overall deformation state of complex spatial structures such as main arch ribs, secondary arch ribs, and cross braces, completely eliminating monitoring blind spots. In addition, through a multi-source data fusion verification mechanism, laser scanning data is cross-compared with other monitoring methods to construct a multi-verification system, effectively ensuring the accuracy and reliability of monitoring results and providing a more scientific decision-making basis for bridge safety assessment. Attached Figure Description

[0014] Figure 1 A principle block diagram provided according to an embodiment of the present invention is shown. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Reference Figure 1 The method and equipment for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar provided in this embodiment include the following steps: S1. Radar deployment: At the reference point of the basket-shaped arch bridge, multiple sets of laser scanning radar equipment are symmetrically and equally spaced to capture the three-dimensional point cloud data of the entire steel arch structure, including the main arch rib, secondary arch rib, and cross brace. S2. Model Construction: Based on the three-dimensional point cloud data captured by the lidar equipment, an initial three-dimensional digital model of the steel arch of the basket-type arch bridge is constructed. This model accurately reflects the initial geometric shape and spatial position relationship of the steel arch, while the initial data is denoised. S3. Real-time data acquisition and processing: During the operation of the basket-type arch bridge, the steel arch is continuously scanned by laser scanning radar according to the set scanning frequency to obtain real-time three-dimensional coordinate data. The real-time data is preprocessed to ensure the integrity and continuity of the data. S4. Calculation and Analysis: Compare and analyze the real-time three-dimensional coordinate data with the initial three-dimensional digital model to calculate the overall deformation field of the steel arch structure in three-dimensional space and the relative deformation of key components. S5. Data Fusion and Verification: The deformation data obtained by laser scanning radar monitoring is fused and analyzed with data obtained by other monitoring methods. By comparing the data from different monitoring methods, the effectiveness and consistency of the laser scanning radar monitoring results are verified.

[0017] In step S1, the reference points for the basket-type arch bridge include the top of the piers, the arch foot, and the key cross-section of the arch rib. Each set of laser scanning radar equipment includes at least two laser scanning radars with different scanning angles and resolutions. Based on the geometric dimensions of the basket-type arch bridge, the characteristics of the steel arch structure, and the expected monitoring accuracy requirements, the scanning frequency, scanning range, and sampling point density parameters of the laser scanning radar are set.

[0018] Among them, the benchmark points achieve full structural coverage monitoring. The key sections of the bridge pier top, arch foot, and arch rib constitute a stable monitoring benchmark system, avoiding local monitoring blind spots. By configuring equipment with different scanning angles and resolutions, it is possible to achieve no dead angles and high-precision collaborative observation of the complex spatial structure of the basket arch bridge. By strictly customizing the scanning frequency, range, and sampling density according to the bridge's geometric dimensions, structural characteristics, and expected monitoring accuracy, the optimal allocation of monitoring resources and efficient control of data quality are achieved.

[0019] In step S2, the initial data denoising process employs a wavelet analysis-based denoising algorithm to remove noise data caused by environmental interference, equipment errors, and other factors. Noise components are specifically stripped away while fully preserving the effective point cloud signals of the steel arch structure surface, avoiding the loss of effective geometric information. The clean data after noise removal ensures that the initial 3D digital model can accurately reproduce the geometry, dimensions, and spatial relationships of the steel arch.

[0020] In step S3, the preprocessing of real-time data includes data alignment and coordinate transformation, unifying data collected from different locations and times into the same coordinate system, and interpolating missing data. This unifies real-time data collected by different radar devices and during different scanning periods into a coordinate system consistent with the initial 3D model, eliminating coordinate deviations caused by differences in device placement and scanning time. This avoids systematic errors in subsequent deformation calculations and ensures the consistency of the 3D coordinate data of the steel arch structure in both time and space, providing a unified reference standard for accurate calculation of the overall deformation field.

[0021] Specifically, in step S4, the calculated relative deformation includes the change in spatial distance between the projection points of the two ends of the same cross brace on the axis of the main arch rib and the secondary arch rib connected to it, as well as the torsional angle of the center line of the cross brace relative to its initial position, thereby quantifying the degradation of the lateral stability between the arch ribs unique to basket-type arch bridges.

[0022] Specifically, in step S5, other detection methods include, but are not limited to, data detected by strain gauges and accelerometers. The deformation results monitored by lidar can be corroborated by the stress changes of strain gauges and the vibration characteristics of accelerometers, avoiding potential misjudgments from single geometric data (such as non-structural deformation interference). The mutual corroboration of multi-dimensional data significantly improves the reliability of the monitoring results and provides a more comprehensive basis for bridge safety assessment.

[0023] A monitoring device for the deformation of the steel arch of a basket-type arch bridge based on laser scanning radar, wherein the monitoring device applies the monitoring method described in any one of the above descriptions.

[0024] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar, characterized in that, Includes the following steps: S1. Radar deployment: At the reference point of the basket-shaped arch bridge, multiple sets of laser scanning radar equipment are symmetrically and equally spaced to capture the three-dimensional point cloud data of the entire steel arch structure, including the main arch rib, secondary arch rib, and cross brace. S2. Model Construction: Based on the three-dimensional point cloud data captured by the lidar equipment, an initial three-dimensional digital model of the steel arch of the basket-type arch bridge is constructed. This model accurately reflects the initial geometric shape and spatial position relationship of the steel arch, while the initial data is denoised. S3. Real-time data acquisition and processing: During the operation of the basket-type arch bridge, the steel arch is continuously scanned using a laser scanning radar at a set scanning frequency to obtain real-time three-dimensional coordinate data. The real-time data is preprocessed to ensure the integrity and continuity of the data. S4. Calculation and Analysis: Compare and analyze the real-time three-dimensional coordinate data with the initial three-dimensional digital model to calculate the overall deformation field of the steel arch structure in three-dimensional space and the relative deformation of key components. S5. Data Fusion and Verification: The deformation data obtained by laser scanning radar monitoring is fused and analyzed with data obtained by other monitoring methods. By comparing the data from different monitoring methods, the effectiveness and consistency of the laser scanning radar monitoring results are verified.

2. The method for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar according to claim 1, characterized in that, In step S1, the reference points for the basket arch bridge include the top of the pier, the arch foot, and the key section of the arch rib.

3. The method for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar according to claim 2, characterized in that, In step S1, each group of laser scanning radar equipment includes at least two laser scanning radars with different scanning angles and resolutions. Based on the geometric dimensions of the basket-shaped arch bridge, the characteristics of the steel arch structure, and the expected monitoring accuracy requirements, the scanning frequency, scanning range, and sampling point density parameters of the laser scanning radar are set.

4. The method for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar according to claim 1, characterized in that, In step S2, the initial data is denoised using a wavelet analysis-based denoising algorithm to remove noise data caused by environmental interference, equipment errors, and other factors.

5. The method for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar according to claim 1, characterized in that, In step S3, the preprocessing of real-time data includes data alignment and coordinate transformation, unifying data collected from different locations and at different times into the same coordinate system, and interpolating missing data.

6. The method for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar according to claim 1, characterized in that, In step S4, the calculated relative deformation includes the change in spatial distance between the projection points of the two ends of the same cross brace on the axes of the main arch rib and the secondary arch rib they are connected to, as well as the torsional angle of the center line of the cross brace relative to its initial position, thereby quantifying the degradation of the lateral stability between the arch ribs unique to basket-type arch bridges.

7. The method for monitoring the deformation of steel arches in basket-type arch bridges based on laser scanning radar according to claim 1, characterized in that, In step S5, other detection methods include, but are not limited to, data detected by strain gauges and accelerometers.

8. A basket-type arch bridge steel arch deformation monitoring device based on laser scanning radar, characterized in that, The detection device uses the monitoring method described in any one of claims 1-7.

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