CN114720041B - Arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning - Google Patents
Arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning Download PDFInfo
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- CN114720041B CN114720041B CN202210291314.6A CN202210291314A CN114720041B CN 114720041 B CN114720041 B CN 114720041B CN 202210291314 A CN202210291314 A CN 202210291314A CN 114720041 B CN114720041 B CN 114720041B
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- 238000010276 construction Methods 0.000 title claims abstract description 80
- 238000012544 monitoring process Methods 0.000 title claims abstract description 73
- 238000000034 method Methods 0.000 title claims abstract description 51
- 238000005259 measurement Methods 0.000 claims abstract description 15
- 230000000694 effects Effects 0.000 claims abstract description 7
- 238000004873 anchoring Methods 0.000 claims description 9
- 230000010354 integration Effects 0.000 claims description 5
- 238000012360 testing method Methods 0.000 claims description 5
- 238000005070 sampling Methods 0.000 claims description 3
- 230000002411 adverse Effects 0.000 claims description 2
- 239000000725 suspension Substances 0.000 abstract description 5
- 230000009286 beneficial effect Effects 0.000 abstract description 4
- 238000004364 calculation method Methods 0.000 abstract description 3
- 238000005516 engineering process Methods 0.000 abstract description 3
- 238000011156 evaluation Methods 0.000 abstract description 2
- 230000001360 synchronised effect Effects 0.000 abstract 1
- 238000007716 flux method Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
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- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000007781 pre-processing Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/04—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for measuring tension in flexible members, e.g. ropes, cables, wires, threads, belts or bands
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/002—Measuring arrangements characterised by the use of optical techniques for measuring two or more coordinates
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Abstract
The invention provides a three-dimensional laser scanning-based arch bridge suspender construction cable force change monitoring method, and belongs to the technical field of bridge construction monitoring. According to the method, a three-dimensional laser scanning technology is utilized, a three-dimensional laser scanner is arranged on the bridge side, in the tensioning construction process of a certain suspender, adjacent suspenders to be detected are rapidly scanned in different construction stages, scanning results are imported into point cloud processing software, point cloud is fitted to obtain a suspender geometric model, the space positions of suspender monitoring characteristic points are extracted from the geometric model, the length of the suspender between the two monitoring characteristic points is calculated, the length change value of the suspender between the two monitoring characteristic points in each construction stage is obtained, and then the suspension rod cable force change value is calculated. Compared with the common cable force measuring method, the method is simple and convenient, has clear calculation principle, can realize quick, synchronous and accurate measurement of the cable force change value of the adjacent hanging rod during the construction of the arch bridge hanging rod, and is more beneficial to the safe performance of the hanging rod construction process and the construction effect evaluation so as to guide the construction to meet the expected target.
Description
Technical Field
The invention relates to the technical field of bridge construction monitoring, in particular to a three-dimensional laser scanning-based arch bridge suspender construction cable force change monitoring method.
Background
The suspension rod is an important force transmission component of the arch bridge and plays an important role in transmitting the bridge deck weight and the automobile load to the main arch ring. When an arch bridge is constructed, the cable force change of a tensioned hanging rod is required to be monitored in the tensioning process of a certain hanging rod of the arch bridge; during the operation of the arch bridge, when the suspender is damaged due to ageing of materials, rust of steel bundles and the like, the suspender should be replaced in time, and the cable force change of the adjacent suspender for replacing the suspender is also required to be monitored. The cable force change monitoring is an important monitoring content of the arch bridge suspender construction whether the suspender of the newly built arch bridge is in tensioning construction or the suspender of the existing arch bridge is in replacement construction. On the one hand, abnormal changes of the cable force state can be timely early warned through cable force change monitoring of the suspender in the construction process of the arch bridge, and the construction of the suspender of the arch bridge is facilitated to be safely carried out. On the other hand, through the monitoring to the boom cable force variation in the boom construction process, can also compare and effect evaluation with theoretical calculation result to ensure that the construction effect reaches the expected target. However, the cable force state of the suspension rod is complex and changeable under the influence of external environments such as construction load, temperature load and the like, and meanwhile, the boundary conditions of the suspension rod are difficult to accurately judge, so that the cable force test is difficult, and a more proper method is required to accurately measure the cable force change of the suspension rod in actual construction.
Common cable force measurement methods include oil pressure gauge method, magnetic flux method, and vibration frequency method. The oil pressure gauge measuring method is generally suitable for measuring the cable force of the current tensioning boom in the construction process, and has a large application range; the magnetic flux method has advantages in long-term monitoring, but needs to install electromagnetic sensors on the suspenders in advance when newly constructing bridges, and has still to be improved in terms of investment cost, convenience and the like.
The vibration frequency method is widely applied to measuring the vibration frequency of the boom through the sensor, but the theory of the method is based on the string vibration theory, and is suitable for boom cable force measurement with definite boundary conditions, but the actual boundary conditions of the boom are complex, and the constraint condition of the boom boundary is difficult to distinguish in actual engineering. Particularly, when the short boom is used for measuring, the boom cable force measurement is greatly influenced by the boundary, and even if the test is repeated, ideal waveforms are difficult to capture in frequency, the cable force data acquisition time is long, and the measurement accuracy is low.
Disclosure of Invention
The invention provides a three-dimensional laser scanning-based arch bridge suspender construction cable force change monitoring method aiming at the defects.
The invention adopts the following technical scheme:
the invention discloses a three-dimensional laser scanning-based arch bridge suspender construction cable force change monitoring method, which comprises the following steps of:
Step1, placing a three-dimensional laser scanner on one side outside a bridge, determining two known coordinate points in a monitoring arch bridge as measurement datum points, and performing back vision intersection through the two measurement datum points to obtain three-dimensional coordinates of the three-dimensional laser scanner;
step 2, hanging rods at two sides of a hanging rod in current tensioning construction are hanging rods to be detected, and two monitoring characteristic points are respectively arranged on the hanging rods to be detected; the position of the monitoring characteristic point is slightly far away from the anchoring positions of the upper end and the lower end of the suspender;
Step 3, scanning a boom to be detected by a three-dimensional laser scanner before stretching construction of the current boom, introducing scanning point cloud data into point cloud processing software, performing preprocessing such as registration, denoising and sampling to obtain an accurate boom point cloud image, and building a cylindrical geometric model of the current boom by fitting the boom point cloud image with point cloud;
Step 4, extracting the space coordinates of two monitoring characteristic points of the boom to be detected from the cylindrical geometric model established in the step 3, and obtaining the initial length l 0 of the boom between the two monitoring characteristic points before tensioning construction by performing line integration between the two characteristic points along the cylindrical geometric model of the boom;
And 5, repeating the step 3 and the step 4 to re-scan the boom to be measured when the current boom is in the tensioning construction t stage, performing three-dimensional laser scanning and point cloud data processing on the boom to be measured to obtain the length l t of the boom to be measured between two monitoring characteristic points of the boom to be measured in the construction t stage, and comparing the length l t of the boom to be measured between the two monitoring characteristic points in the construction t stage with the initial length l 0 before tensioning construction according to the following formula to obtain the length change value of the boom to be measured:
Δlt＝lt-l0；
step 6, obtaining a length change value of the boom to be detected according to the step five, and according to the following formula:
calculating to obtain a cable force change value of the boom to be tested in the construction t stage; wherein E is the elastic modulus of the boom to be tested, and A is the sectional area of the boom to be tested. And comparing the obtained cable force change value with a theoretical value, and evaluating the construction effect.
According to the arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning, the scanning result can be synthesized into an accurate suspender point cloud picture by adopting point cloud processing software, a cylindrical geometric model of the suspender is built by fitting the point cloud, and the space coordinates of two monitoring characteristic points can be accurately extracted.
According to the arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning, a method of performing line integration between two monitoring characteristic points is adopted, namely, the length dl of an adjacent point between the characteristics of the two monitoring points is accumulated, so that the suspender length between the two monitoring characteristic points in a construction t stage, i= Σdl, can be accurately obtained.
According to the three-dimensional laser scanning-based arch bridge suspender construction cable force change monitoring method, the monitoring characteristic points on the current monitoring suspender are respectively close to the upper anchoring end and the lower anchoring end of the current monitoring suspender and are separated from the anchoring end by a certain distance, so that local adverse effects are eliminated, and the testing precision is improved.
Advantageous effects
The invention provides a three-dimensional laser scanning-based arch bridge suspender construction cable force change monitoring method, which is combined with three-dimensional laser scanning to determine and obtain a simple arch bridge suspender construction cable force change monitoring method.
The arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning provided by the invention avoids the problems of non-ideal frequency waveform and low measurement precision caused by complex suspender boundary in the application process of a vibration frequency method.
The arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning provided by the invention overcomes the problems that in the suspender construction process, the vibration frequency method has large measurement workload, long measurement time and complex vibration frequency analysis, and is not beneficial to rapid monitoring of the construction process due to a plurality of construction stages.
The monitoring method provided by the invention is based on three-dimensional laser scanning, has the advantages of high scanning process speed, non-contact, high automation degree, high scanning result precision, simple and clear calculation principle and high practicability.
Drawings
FIG. 1 is an application schematic diagram of an arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning;
Fig. 2 is a flowchart of an implementation of a method for monitoring the construction cable force change of an arch bridge suspender based on three-dimensional laser scanning.
In the figure, a three-dimensional laser scanner at the side of a bridge, 2, a measuring datum point, 3, a current construction boom, 4, two sides of which are adjacent to the boom to be measured, and 5, a monitoring characteristic point.
Detailed Description
In order to make the purpose and technical solutions of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without creative efforts, based on the described embodiments of the present invention fall within the protection scope of the present invention.
The invention provides a three-dimensional laser scanning-based arch bridge suspender construction cable force change monitoring method, which is characterized in that a three-dimensional laser scanning technology is utilized, a three-dimensional laser scanner is arranged at one side outside a bridge, in the whole construction process of a suspender, adjacent suspenders to be detected are rapidly scanned at different construction stages, a scanning result is imported into point cloud processing software to fit point cloud to obtain a suspender geometric model, two monitoring characteristic point space coordinates are extracted from the geometric model, the suspender length between two monitoring characteristic points is calculated, a suspender length change value between the two monitoring characteristic points at each construction stage is obtained, and then a suspender cable force change value is calculated.
The specific operation steps are as follows:
Step 1, two known coordinate points are used as measurement datum points 2, the measurement datum points 2 are required to be stable and not to deform, a construction control point which is arranged during bridge construction can be used generally, a three-dimensional laser scanner 1 is placed at a proper position on one side outside a bridge, and instrument position points are arranged on a proper foundation on the side face of the bridge, wherein the bridge is stable and convenient to observe; the three-dimensional coordinates of the three-dimensional laser scanner 1 are calculated by performing back vision intersection with the two measurement reference points 2.
And 2, arranging two monitoring characteristic points 5 on the hanging rods 4 to be detected on two sides of the hanging rod 3 for current tension construction, wherein the number of the hanging rods to be detected can be determined according to the requirement, and the positions of the monitoring characteristic points 5 are slightly far away from the anchoring positions of the upper end and the lower end, so that the length of the hanging rod between the two monitoring characteristic points 5 is as long as possible, and the testing precision is improved.
And 3, scanning the boom 4 to be tested through a three-dimensional laser scanner 1 before boom tensioning construction, introducing scanning point cloud data into point cloud processing software, such as common CloudCompare software, performing pretreatment such as registration, denoising, sampling and the like to obtain an accurate boom point cloud image, and building a cylindrical geometric model of the boom to be tested through fitting the point cloud.
Step 4, extracting the space coordinates of two monitoring characteristic points 5 of the boom 4 to be detected from the model established in the step 3, and obtaining the initial length l 0 of the boom between the two monitoring characteristic points 5 before tensioning construction along the cylindrical geometric model of the boom by performing line integration between the two characteristic points 5, namely accumulating the lengths dl of adjacent points between the two monitoring characteristic points 5, wherein l is = Σdl;
Step 5, when the boom is in the tensioning construction t stage, the original length of the boom 4 to be tested is changed in construction, so that the steps 3 and 4 are required to be repeated, three-dimensional laser scanning and point cloud data processing are carried out on the boom 4 to be tested again, the boom length l t between two monitoring characteristic points 5 of the boom to be tested in the construction t stage is obtained, and then the boom length l t between the two monitoring characteristic points of the boom to be tested in the construction t stage is compared with the initial length l 0 before tensioning construction, and the change value is Deltal t＝lt-l0;
step 6, in particular according to And calculating a cable force change value of the boom in the tensioning construction t stage. Wherein E is the elastic modulus of the boom to be tested, and A is the sectional area of the boom to be tested.
Based on the above steps 1-6 are repeated in the boom tensioning construction process, the cable force change value of the adjacent boom in the whole boom tensioning construction process can be timely obtained. The three-dimensional laser scanning technology is utilized to measure the characteristics of high speed, high synchronism and the like, and is beneficial to improving the measurement efficiency. The monitoring of the cable force change of adjacent hanging rods in the hanging rod tensioning construction process is beneficial to safe carrying out of hanging rod construction on one hand, and on the other hand, construction can be guided in time, so that the hanging rod construction achieves the expected effect.
The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.
Claims (4)
1. The arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning is characterized by comprising the following steps of:
Step1, placing a three-dimensional laser scanner on one side outside a bridge, determining two known coordinate points in a monitoring arch bridge as measurement datum points, and performing back vision intersection through the two measurement datum points to obtain three-dimensional coordinates of the three-dimensional laser scanner;
step 2, hanging rods at two sides of a hanging rod in current tensioning construction are hanging rods to be detected, and two monitoring characteristic points are respectively arranged on the hanging rods to be detected; the position of the monitoring characteristic point is slightly far away from the anchoring positions of the upper end and the lower end of the suspender;
Step 3, scanning a boom to be detected through a three-dimensional laser scanner before stretching construction of the current boom, introducing scanning point cloud data into point cloud processing software, performing registration, denoising and sampling pretreatment to obtain an accurate boom point cloud image, and building a cylindrical geometric model of the current boom to be detected through fitting point cloud of the boom point cloud image;
Step 4, extracting the space coordinates of two monitoring characteristic points of the boom to be detected from the cylindrical geometric model established in the step 3, and obtaining the initial length l 0 of the boom between the two monitoring characteristic points before tensioning construction by performing line integration between the two characteristic points along the cylindrical geometric model of the boom;
And 5, repeating the steps 3 and 4 to rescan the to-be-measured boom when the current boom is in the tensioning construction t stage to obtain the length l t of the to-be-measured boom between two monitoring characteristic points of the to-be-measured boom in the t stage, and comparing the length l t of the to-be-measured boom between the two monitoring characteristic points in the t stage with the initial length l 0 before tensioning construction, and obtaining the length change value of the to-be-measured boom according to the following formula:
Δlt＝lt-l0；
step 6, obtaining a length change value of the boom to be detected according to the step 5, and according to the following formula:
Calculating to obtain a cable force change value of the boom to be tested in the construction t stage; wherein E is the elastic modulus of the boom to be tested, and A is the sectional area of the boom to be tested.
2. The arch bridge boom construction cable force change monitoring method based on three-dimensional laser scanning as claimed in claim 1, wherein the method comprises the following steps: the point cloud processing software is adopted to synthesize the scanning result into an accurate suspender point cloud image, and a cylindrical geometric model of the suspender is built by fitting the point cloud, so that the space coordinates of the two monitoring characteristic points can be accurately extracted.
3. The arch bridge boom construction cable force change monitoring method based on three-dimensional laser scanning as claimed in claim 1, wherein the method comprises the following steps: by adopting a method of performing line integration between two monitoring characteristic points, namely a mode of accumulating the lengths dl of adjacent points between the characteristics of the two monitoring points, the length l= Σdlof the suspender between the two monitoring characteristic points in the t stage of tensioning construction of a suspender can be accurately obtained.
4. The arch bridge boom construction cable force change monitoring method based on three-dimensional laser scanning as claimed in claim 1, wherein the method comprises the following steps: and the monitoring characteristic points on the current monitoring suspender are respectively close to the upper anchoring end and the lower anchoring end of the current monitoring suspender and are separated from the anchoring ends by a certain distance, so that the local adverse effect is eliminated, and the testing precision is improved.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210291314.6A CN114720041B (en) | 2022-03-23 | 2022-03-23 | Arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning |
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| CN202210291314.6A CN114720041B (en) | 2022-03-23 | 2022-03-23 | Arch bridge suspender construction cable force change monitoring method based on three-dimensional laser scanning |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN207019819U (en) * | 2017-06-23 | 2018-02-16 | 交通运输部公路科学研究所 | A kind of realization device of cable force measurement technology |
| CN111238710A (en) * | 2020-01-13 | 2020-06-05 | 武汉理工大学 | Bridge cable force state monitoring device and monitoring method based on weak grating array |
| CN112857218A (en) * | 2021-01-11 | 2021-05-28 | 中铁建大桥工程局集团南方工程有限公司 | Steel truss arch bridge construction line shape monitoring method based on three-dimensional laser scanning |
| CN113483932A (en) * | 2021-05-31 | 2021-10-08 | 周银 | System and method for testing accurate stay cable force based on cable shape measurement |
| CN113848010A (en) * | 2021-10-25 | 2021-12-28 | 中冶建筑研究总院有限公司 | Non-contact high-precision laser steel cable force monitoring system and monitoring method |
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- 2022-03-23 CN CN202210291314.6A patent/CN114720041B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN207019819U (en) * | 2017-06-23 | 2018-02-16 | 交通运输部公路科学研究所 | A kind of realization device of cable force measurement technology |
| CN111238710A (en) * | 2020-01-13 | 2020-06-05 | 武汉理工大学 | Bridge cable force state monitoring device and monitoring method based on weak grating array |
| CN112857218A (en) * | 2021-01-11 | 2021-05-28 | 中铁建大桥工程局集团南方工程有限公司 | Steel truss arch bridge construction line shape monitoring method based on three-dimensional laser scanning |
| CN113483932A (en) * | 2021-05-31 | 2021-10-08 | 周银 | System and method for testing accurate stay cable force based on cable shape measurement |
| CN113848010A (en) * | 2021-10-25 | 2021-12-28 | 中冶建筑研究总院有限公司 | Non-contact high-precision laser steel cable force monitoring system and monitoring method |
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