A method and system for monitoring tower deformation based on high-speed automatic tracking and measurement technology.

Abstract

This invention provides a method and system for monitoring the deformation of lifting towers based on high-speed automatic tracking and measurement technology, particularly suitable for the overall lifting process of large segments of steel-concrete composite arch bridges. The method uses finite element analysis to determine key monitoring points and utilizes a measuring robot and a 360° prism for high-precision, high-frequency automatic measurement to monitor the three-dimensional deformation state of the lifting tower in real time. By setting thresholds, this method can issue early warnings when the deformation of the lifting tower exceeds a safe range, guiding construction adjustments and ensuring the smoothness and safety of the lifting process. This invention effectively addresses the shortcomings of traditional measurement methods in monitoring the deformation of lifting towers, improving the automation level of monitoring and construction safety.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction technology, specifically relating to a method and system for monitoring tower deformation based on high-speed automatic tracking and measurement technology. Background Technology

[0002] Concrete-filled steel tubular (CTB) is a composite material formed by filling concrete inside a steel tube. It fully utilizes the advantages of both steel and concrete, possessing high strength, good ductility, and convenient construction, and has been widely used in engineering. The mountainous terrain of western China is ideal for constructing long-span arch bridges, as they can replace suspension bridges and cable-stayed bridges with much larger spans when crossing deep valleys and river valleys with good foundations. Construction methods for CTB arch bridges mainly include cable-stayed installation, rotation, scaffolding, and integral lifting. However, due to factors such as the construction environment and other considerations, and taking into account economic and construction convenience, some CTB arch bridges may also adopt the integral lifting method. The integral lifting process offers advantages such as fewer temporary supports, smaller footprint, higher precision, faster construction, and less traffic disruption.

[0003] Meanwhile, during the overall lifting of large-segment steel-concrete composite sections, the posture of the large segments is a key factor affecting the smoothness of the lifting process. Whether the deformation of the lifting tower meets specifications during the lifting of large segments is also a crucial factor influencing the stability and smoothness of the lifting. Due to the large tonnage and long span of the large segments being lifted, especially during the process of the large segments detaching from the supports and when the center of gravity of the large segments exceeds the height of the lifting points, the displacement and deformation of the lifting tower are quite complex due to the cumulative effects of various working conditions. Therefore, it is necessary to conduct deformation monitoring of the lifting tower. To ensure the smooth and stable lifting of the large segments during the overall lifting process, dynamic, accurate, and rapid monitoring of key parts of the lifting tower is required. Because the key parts of the lifting tower are in a continuously changing three-dimensional spatial state, traditional measurement methods cannot meet the requirements for high-precision, high-frequency, and automated monitoring.

[0004] Therefore, how to provide a high-precision, high-frequency, all-weather automated method for monitoring the deformation of lifting towers has become a problem to be solved in this technical field. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention proposes a method and system for monitoring the deformation of lifting towers based on high-speed automatic tracking and measurement technology. The aim is to determine key monitoring points through finite element analysis and utilize a measuring robot and a 360° prism for high-precision, high-frequency automatic measurement to monitor the three-dimensional deformation state of the lifting tower in real time. By setting a threshold, this method can issue an early warning when the deformation of the lifting tower exceeds a safe range, guiding construction adjustments and ensuring the smoothness and safety of the lifting process. This solves the problem that traditional measurement methods are unable to quickly, automatically, and accurately describe the spatial state of the lifting tower during the overall lifting of steel-concrete composite arch bridges, thus affecting the smoothness and success of the overall arch rib lifting. The invention achieves high-speed, automatic, and precise capture of the three-dimensional coordinates of key parts of the lifting tower during the overall arch bridge lifting process, obtaining the spatial state of the lifting tower, ensuring the smoothness and safety of the overall lifting process of the steel-concrete composite arch bridge, and ultimately ensuring the precise construction of the steel-concrete composite arch bridge.

[0006] To achieve the above objectives, the specific solution of the present invention is as follows:

[0007] The method for monitoring the deformation of lifting towers based on high-speed automatic tracking and measurement technology includes the following steps:

[0008] S1. Based on the construction drawings of the steel-concrete composite arch bridge and the actual site conditions, the key parts of the lifting tower were determined by finite element modeling and calculation analysis. Measuring points were set at the key parts, and a 360° prism was set up at each measuring point. At the same time, the three-dimensional coordinates of the measuring point were determined.

[0009] S2, A measuring robot is set up at the measuring station. The measuring robot is used to aim and observe the measuring point to obtain the initial three-dimensional coordinates of the measuring point in the coordinate system of the measuring station, thus completing the initial learning of the measuring point.

[0010] S3, add the measurement points that have completed the initial learning to the automatic roving measurement group, set the number of automatic measurement cycles and the measurement interval time, and through the set automatic roving measurement group, the measurement robot obtains the data of the measurement points within the observation range and records the three-dimensional coordinates of the measurement points after the movement;

[0011] S4, calculate the coordinate change of the measuring point under the geodetic coordinate system, and project the coordinate change onto the construction coordinate system;

[0012] S5, calculate the difference in coordinate changes at different measuring points on the same tower, and determine the three-dimensional deformation state of the lifting tower by the sign and magnitude of the difference;

[0013] S6 determines the deformation of the lifting tower by comparing the difference between the set threshold and the coordinate change. If the deformation exceeds the threshold, an early warning message is issued and the lifting jack is adjusted accordingly.

[0014] Furthermore, the calculation formula for the initial learned three-dimensional coordinates of the measuring point in the measuring station coordinate system mentioned in step S2 is as follows:

[0015]

[0016] In the formula, i = 1, 2, 3...n represents each measuring point T. i The coordinates of X; A Y A Z A S represents the coordinates of the station; S is the slope distance, i.e., the distance between the station and the measured point; β represents the coordinate azimuth, and α represents the coordinates of point T. i The vertical angle between the line connecting the station A and the station A.

[0017] Furthermore, the formula for calculating the coordinate change of the measuring point in geodetic coordinates in step S4 is as follows:

[0018]

[0019] In the formula, ΔX D ΔY D ΔZ D This represents the change in coordinates of the measuring point under geodetic coordinates; i = 1, 2, 3...n are the three-dimensional coordinates of the measuring point after it has moved;

[0020] The calculation formula for projecting the coordinate change onto the construction coordinate system is as follows:

[0021]

[0022] In the formula, ΔX S ΔY S This represents the change in coordinates under the construction coordinate system; θ is the rotation angle of the coordinate axis.

[0023] Furthermore, the formula for the difference in coordinate changes at different measuring points on the same tower as described in step S5 is as follows:

[0024]

[0025] In the formula, ΔX f ΔY f ΔZ f This represents the difference in coordinate changes between different measuring points on the same tower. Indicates measuring point T P The coordinate changes in the X, Y, and Z directions over two consecutive measurement cycles; Indicates measuring point T Q The coordinate changes in the X, Y, and Z directions over two consecutive measurement cycles.

[0026] Furthermore, the formula for determining the deformation of the lifting tower in step S6 is as follows:

[0027]

[0028] In the formula, the threshold μ X =μ Y =μ Z =20cm.

[0029] The monitoring system for implementing the aforementioned tower deformation monitoring method includes an automatic monitoring system comprising a data acquisition system and a data analysis system installed in a computer. The data acquisition system includes a measuring robot, a wireless transmission unit, and a 360° prism installed at each measuring point. The measuring robot is connected to the 360° prism via the wireless transmission unit. The coordinate data of each measuring point obtained by the data acquisition system is transmitted to the data analysis system via a data cable. The data analysis system consists of a MySQL database and performs data recording, data processing, data querying, and result output operations on the coordinate data transmitted by the data acquisition system.

[0030] Furthermore, the data analysis system can set a threshold for the difference between the coordinates of the measuring points. When the difference between the measured value and the theoretical design value of each measuring point reaches the threshold, the data analysis system quickly issues a safety warning to the construction unit.

[0031] Advantages of the present invention

[0032] (1) The present invention is a method for monitoring the deformation of lifting towers based on high-speed automatic tracking measurement technology. It addresses the problem that traditional manual optical measurement methods cannot achieve rapid and accurate coordinate measurement of multiple target points of the lifting tower during the overall lifting of steel-concrete composite arch bridges. By using high-speed tracking automatic measurement technology, the method achieves high-speed, high-frequency, and unattended monitoring of the three-dimensional spatial coordinates of key points of the lifting tower, thus solving the problems of long time consumption, low efficiency, and low accuracy of traditional manual measurement methods when applied to the overall lifting of steel-concrete composite arch bridges.

[0033] (2) This invention addresses the problem that the deformation of the lifting tower becomes complex when the steel-concrete composite arch bridge is lifted as a whole due to the large tonnage of the large sections and the continuous increase in lifting height. By calculating the difference in coordinate changes of key parts of the lifting tower, the deformation of the lifting tower can be reflected intuitively. A deformation threshold is set, and when the calculated result of the monitoring data exceeds the threshold, the monitoring equipment can issue an early warning and send instructions to guide the adjustment of the lifting jacks to ensure the smooth and safe lifting of the large sections.

[0034] (3) By converting the coordinate change values ​​under the geodetic coordinate system to the coordinate change values ​​under the construction coordinate system, this invention enables the deformation of the lifting tower to be intuitively reflected in the changes in the transverse and longitudinal bridge directions, providing more effective guidance for the construction process. Attached Figure Description

[0035] Figure 1 This is a flowchart of the method for monitoring the deformation of lifting towers based on high-speed automatic tracking and measurement technology according to the present invention.

[0036] Figure 2 for Figure 1 Prism installation diagram of the measuring points on the lifting tower.

[0037] Figure 3 for Figure 1 Schematic diagram of the layout of measuring points and measuring stations on the lifting tower.

[0038] Figure 4 for Figure 1 A schematic diagram of the three-dimensional coordinate measurement of each measuring point under the set station coordinates.

[0039] Figure 5 for Figure 1 A schematic diagram of displacement calculation of the measurement point in the geodetic coordinate system projected onto the construction coordinate system.

[0040] In the picture:

[0041] 1. Measuring robot; 2. Measurement station A. Detailed Implementation

[0042] The present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. It should be noted that the specific embodiments are not intended to limit the scope of the present invention.

[0043] like Figures 1 to 5As shown, this specific embodiment is based on the Pinglu Canal Jiuzhou Grand Bridge, which adopts a (3×40+34.49)m simply supported then continuous prestressed concrete box girder + a 260m (calculated span) under-deck steel-concrete tied arch bridge + (2×40)m simply supported then continuous prestressed concrete box girder, with a total bridge length of 525.184m. The main arch foot and the main pier adopt a fixed system, and the horizontal thrust of the arch rib is balanced by tensioning flexible tie rods between the arch foot. The main bridge adopts an under-deck steel-concrete tied arch bridge with a calculated span of 260m. The main arch adopts a steel-concrete truss structure and a whole bundle of extruded steel strand suspension cable system. Meanwhile, due to the poor geological conditions and limited construction conditions at the site of the Pinglu Canal Jiuzhou Grand Bridge, which is located in a geologically fractured zone, the bridge could not be constructed using a cable-stayed system. Therefore, the arch bridge adopted a large-segment steel pipe arch integral lifting method for segmental construction. This required precise assembly of arch rib segments on the ground or on low-level supports, and the use of a portal lifting tower for integral lifting and closure. The low-level assembly span of the arch rib was 202m, the lifting weight was 1800t, and the lifting height was 63m. Such an integral lifting process for arch ribs with such large weight, long span, and high lifting height is rare in the construction of similar steel pipe concrete arch bridges. This specific embodiment provides a method and system for monitoring the deformation of the lifting tower based on high-speed automatic tracking measurement technology. The monitoring method includes the following steps:

[0044] S1. Based on the design drawings of the Pinglu Canal Jiuzhou Grand Bridge and the actual site conditions, and using the finite element software Midas Civil, the lifting tower was modeled during the overall lifting process. Finite element simulation was used to analyze the locations of significant deformation of the lifting tower during the lifting process, thereby identifying several key components. Measuring points T were then placed at these key components. i Let i = 1, 2, 3…n. In this embodiment, a total of 4 measuring points are set, so n = 4. Each measuring point T… i Miniature 360° prisms are evenly distributed, and the 360° prisms are installed as follows: Figure 2 As shown; then, the three-dimensional coordinates of the measurement station A, where the measurement robot is placed, are determined through the deployed measurement control network. To ensure stable 24-hour monitoring, as well as measurement accuracy and ease of operation, it is necessary to ensure that the setting of measurement station A can be seen through all measurement points T. i Furthermore, the robot's line of sight is minimally affected during construction. Based on finite element simulation calculations and on-site investigations, the measurement point T on the lifting tower... i The location relative to station A, such as Figure 3 As shown.

[0045] S2. Complete step S1 at the arch bridge construction site and set up measuring points T. i After reaching measurement point A, a measuring robot is set up at measurement point A, and the measuring robot is used to measure point T. i Aim at the observation point and obtain the measurement point T. iThree-dimensional coordinates at station A in the coordinate system i = 1, 2, 3…n, n = 4. After this step is completed, the measuring robot has finished learning the initial position of the measuring point. For example… Figure 4 As shown, the location of station A is point A(X). A Y A Z A Let X be the north coordinate in geodetic coordinates, Y be the east coordinate in geodetic coordinates, and Z be the vertical direction. Then, for measuring point T... i The three-dimensional coordinates are shown in equation (1):

[0046]

[0047] In equation (1), i = 1, 2, 3...n represents each measuring point T. i The coordinates of X; A Y A Z A S represents the coordinates of the station; S is the slope distance, i.e., the distance between the station and the measured point; β represents the coordinate azimuth, and α represents the coordinates of point T. i The vertical angle between the line connecting the station A and the station A.

[0048] S3. Measure the measurement points T that the robot has completed its initial learning in step S2. i Add the data to the automatic roving measurement group and set the number of automatic measurement cycles and the interval between cycles. Using the pre-set roving measurement group, before the overall lifting of the large steel-concrete composite section, start the measurement robot to periodically and continuously measure and acquire data at measurement points T within the observation range. i The data was recorded, and the measurement point T′ was recorded after the movement. i Transformed 3D coordinates i = 1, 2, 3...n, n = 4.

[0049] S4. Calculate the coordinate change ΔX of each measuring point in the geodetic coordinate system. D ΔY D And project it onto the construction coordinate system to make it easier to judge the deformation more intuitively, such as Figure 5 As shown, the construction change in the construction coordinate system is ΔX. S ΔY S The change in coordinates of the measuring point under geodetic coordinates, ΔX D ΔY D ΔZ D Its calculation formula is as shown in equation (2):

[0050]

[0051] In equation (2), ΔX D ΔY D ΔZD This represents the change in coordinates of the measuring point under geodetic coordinates; i = 1, 2, 3...n are the three-dimensional coordinates of the measuring point after it has moved.

[0052] The change in the construction coordinate system is calculated as ΔX. S ΔY S The calculation formula is as shown in equation (3):

[0053]

[0054] In equation (3), θ is the rotation angle of the coordinate axis.

[0055] S5. Calculate the coordinate variation difference ΔX between different measuring points on the same tower. f ΔY f ΔZ f The three-dimensional deformation state of the lifting tower is determined by the sign and magnitude of the difference, and the calculation formula is as shown in equation (4):

[0056]

[0057] In the formula Indicates measuring point T P The coordinate changes in the X, Y, and Z directions over two consecutive measurement cycles; Indicates measuring point T Q The coordinate changes in the X, Y, and Z directions over two consecutive measurement cycles.

[0058] S6, Pass the set threshold μ X μ Y μ Z The difference between the coordinate change and ΔX f ΔY f ΔZ f By comparing the results, the deformation of the lifting tower is determined, and the determination formula is (5):

[0059]

[0060] In equation (5), the threshold μ X μ Y μ Z Based on the "Code for Design of Steel Structures" (GB50017-2017) and actual construction requirements, μ was determined. X =μ Y =μ Z =20cm.

[0061] A safety early warning system for the lifting tower during the overall lifting of the arch bridge is implemented by setting a threshold for the difference between the coordinates of measuring points. This ensures the safety of the lifting tower during the overall lifting process of the steel-concrete composite arch bridge. When the difference between the measured values ​​and the theoretical design values ​​at each measuring point reaches the threshold for the difference between the coordinates of the measuring points, it indicates that the deformation of the lifting tower is too large during the overall lifting of the steel-concrete composite arch bridge, posing a certain construction risk. At this time, the automatic monitoring system issues an early warning. Subsequently, the construction unit conducts relevant safety assessments based on the early warning information obtained by the method in this embodiment and sends instructions to guide the adjustment of the lifting jacks, ensuring the smooth and safe overall lifting of large sections.

[0062] The automatic monitoring system for implementing the monitoring method of this specific embodiment includes a data acquisition system and a data analysis system installed in a computer, along with a measuring robot, a wireless transmission unit, and components installed at each measuring point T. i The prisms on the structure form a data acquisition system for the three-dimensional deformation of the lifting tower during the overall lifting process of the steel-concrete arch bridge. The measuring robot connects to the 360° prisms via a wireless transmission unit, which is a SMART DTU USR-G780 model. This is achieved by setting up measuring stations and deploying measuring points T. i The prism on the top is used to aim the measuring robot at each measuring point T. i The prism on the top achieves T at each measuring point. i Dynamic measurement; and the measurement of each measuring point T obtained in the data acquisition system. i The coordinate data is transmitted to the data analysis system via a data cable. This data analysis system consists of a MySQL database and performs data recording, data processing, data querying, and result output operations on the coordinate data transmitted by the data acquisition system. It can also set the measurement point T. i Coordinate difference threshold, when each measuring point T i When the difference between the measured value and the theoretical design value reaches a threshold, the data analysis system quickly issues a safety warning to the construction unit to ensure the safe construction of the arch bridge.

[0063] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention includes, but is not limited to, the specific implementation methods described above. Furthermore, the specific implementation methods described above are merely illustrative descriptions of the present invention. Those skilled in the art can, under the guidance of the content and specific implementation methods of the present invention, and based on the actual construction conditions of the lifting tower during the overall lifting process of the steel-concrete composite arch bridge, make changes to adapt to the actual construction without departing from the scope of protection of the claims of the present invention. All such changes fall within the scope of protection of the present invention.

Claims

1. A method for monitoring the deformation of a lifting tower based on high-speed automatic tracking and measurement technology, characterized in that, Includes the following steps: S1. Based on the construction drawings of the steel-concrete composite arch bridge and the actual site conditions, the key parts of the lifting tower were determined by finite element modeling and calculation analysis. Measuring points were set at the key parts, and a 360° prism was set up at each measuring point. At the same time, the three-dimensional coordinates of the measuring point were determined. S2, A measuring robot is set up at the measuring station. The measuring robot is used to aim and observe the measuring point to obtain the initial three-dimensional coordinates of the measuring point in the coordinate system of the measuring station, thus completing the initial learning of the measuring point. S3, add the measurement points that have completed the initial learning to the automatic roving measurement group, set the number of automatic measurement cycles and the measurement interval time, and through the set automatic roving measurement group, the measurement robot obtains the data of the measurement points within the observation range and records the three-dimensional coordinates of the measurement points after the movement; S4, calculate the coordinate change of the measuring point under the geodetic coordinate system, and project the coordinate change onto the construction coordinate system; S5, calculate the difference in coordinate changes at different measuring points on the same tower, and determine the three-dimensional deformation state of the lifting tower by the sign and magnitude of the difference; S6 determines the deformation of the lifting tower by comparing the difference between the set threshold and the coordinate change. If the deformation exceeds the threshold, an early warning message is issued and the lifting jack is adjusted accordingly.

2. The method for monitoring the deformation of a lifting tower as described in claim 1, characterized in that, The formula for calculating the initial three-dimensional coordinates of the measuring point in the measuring station coordinate system mentioned in step S2 is as follows: In the formula, Indicates each measuring point T i The coordinates of X; A Y A Z A S represents the coordinates of the station; S is the slope distance, i.e., the distance between the station and the measured point; β represents the coordinate azimuth, and α represents the coordinates of point T. i The vertical angle of the line connecting the station A to the measurement point.

3. The method for monitoring the deformation of a lifting tower as described in claim 1, characterized in that, The formula for calculating the coordinate change of the measuring point in geodetic coordinates in step S4 is as follows: In the formula, ΔX D ΔY D ΔZ D This represents the change in coordinates of the measuring point under geodetic coordinates; The three-dimensional coordinates of the measuring point after it has moved; The calculation formula for projecting the coordinate change onto the construction coordinate system is as follows: In the formula, ΔX S ΔY S This represents the change in coordinates under the construction coordinate system; θ is the rotation angle of the coordinate axis.

4. The method for monitoring the deformation of a lifting tower as described in claim 1, characterized in that, The formula for the difference in coordinate changes at different measuring points on the same tower mentioned in step S5 is as follows: In the formula, ΔX f ΔY f ΔZ f This represents the difference in coordinate changes between different measuring points on the same tower. Indicates measuring point T P The coordinate changes in the X, Y, and Z directions over two consecutive measurement cycles; Indicates measuring point T Q The coordinate changes in the X, Y, and Z directions over two consecutive measurement cycles.

5. The method for monitoring the deformation of a lifting tower as described in claim 1, characterized in that, The formula for determining the deformation of the lifting tower in step S6 is as follows: In the formula, the threshold μ X =μ Y =μ Z =20cm.

6. An automatic monitoring system for implementing the deformation monitoring method for lifting towers as described in claim 1, characterized in that, The automatic monitoring system includes a data acquisition system and a data analysis system installed in a computer. The data acquisition system includes a measuring robot, a wireless transmission unit, and a 360° prism installed at each measuring point. The measuring robot is connected to the 360° prism through the wireless transmission unit. The coordinate data of each measuring point obtained by the data acquisition system is transmitted to the data analysis system through a data cable. The data analysis system consists of a MySQL database and performs data recording, data processing, data querying, and result output operations on the coordinate data transmitted by the data acquisition system.

7. The automatic monitoring system as described in claim 6, characterized in that, The data analysis system sets a threshold for the difference between the coordinates of the measuring points. When the difference between the measured value and the theoretical design value of each measuring point reaches the threshold, the data analysis system quickly issues a safety warning.

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