Deflection Monitoring Method for Simply Supported Girder Bridges Using Strain Response under Traffic Loads
Deflection measurements are usually used as a key index in civil engineering for performing structural assessments of bridge safety. However, owing to technical or cost issues, it may be difficult to implement long-term monitoring of bridge deflection, especially for short- or medium-span bridges. T...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-12-01
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| Series: | Buildings |
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| Online Access: | https://www.mdpi.com/2075-5309/14/1/70 |
| _version_ | 1797340030887264256 |
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| author | Yongsheng Tang Jigang Cang Bohan Zheng Wei Tang |
| author_facet | Yongsheng Tang Jigang Cang Bohan Zheng Wei Tang |
| author_sort | Yongsheng Tang |
| collection | DOAJ |
| description | Deflection measurements are usually used as a key index in civil engineering for performing structural assessments of bridge safety. However, owing to technical or cost issues, it may be difficult to implement long-term monitoring of bridge deflection, especially for short- or medium-span bridges. Therefore, this study presents a novel method for measuring the deflection of simply supported girder bridges. In the proposed method, the strain measurement was implemented under traffic loading at only one position, such as middle span, and then the strain distribution along the girder was reconstructed to calculate the girder deflection with basic structural mechanical theory. To implement the method, the theory was constructed based on the displacement reciprocal theorem at first to assess the strain distribution along the girder from the strain measurement at some position during traffic loads passing across the bridge. Second, a strain measurement method, namely long-gauge fibre Bragg grating (FBG) sensing technology, was introduced to take strain measurements for a concrete bridge. Third, various finite element (FE) bridge models were developed to validate the proposed method’s accuracy, the results from which indicated that the method accurately implemented deflection measurement with an approximately 5% calculation error. In addition, the influence of some key parameters, such as vehicle type, vehicle speed, and structural damage, was investigated. The simulation results revealed that damage to the hinge joint in the middle location could significantly influence the proposed method’s accuracy such that the error may exceed 10%. Finally, on-site experiments were conducted on a simply supported girder bridge to further validate the proposed method’s accuracy, and an approximately 8% deflection assessment error was found. Considering the additional advantages of FBG sensing technology, the proposed method can also be effective for long-term deflection measurements of short- or medium-span bridges. |
| first_indexed | 2024-03-08T09:57:02Z |
| format | Article |
| id | doaj.art-96e51769c90d419596c019d61f41a1f5 |
| institution | Directory Open Access Journal |
| issn | 2075-5309 |
| language | English |
| last_indexed | 2024-03-08T09:57:02Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Buildings |
| spelling | doaj.art-96e51769c90d419596c019d61f41a1f52024-01-29T13:48:30ZengMDPI AGBuildings2075-53092023-12-011417010.3390/buildings14010070Deflection Monitoring Method for Simply Supported Girder Bridges Using Strain Response under Traffic LoadsYongsheng Tang0Jigang Cang1Bohan Zheng2Wei Tang3College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, ChinaCollege of Civil and Transportation Engineering, Hohai University, Nanjing 210098, ChinaCollege of Civil and Transportation Engineering, Hohai University, Nanjing 210098, ChinaCollege of Civil and Transportation Engineering, Hohai University, Nanjing 210098, ChinaDeflection measurements are usually used as a key index in civil engineering for performing structural assessments of bridge safety. However, owing to technical or cost issues, it may be difficult to implement long-term monitoring of bridge deflection, especially for short- or medium-span bridges. Therefore, this study presents a novel method for measuring the deflection of simply supported girder bridges. In the proposed method, the strain measurement was implemented under traffic loading at only one position, such as middle span, and then the strain distribution along the girder was reconstructed to calculate the girder deflection with basic structural mechanical theory. To implement the method, the theory was constructed based on the displacement reciprocal theorem at first to assess the strain distribution along the girder from the strain measurement at some position during traffic loads passing across the bridge. Second, a strain measurement method, namely long-gauge fibre Bragg grating (FBG) sensing technology, was introduced to take strain measurements for a concrete bridge. Third, various finite element (FE) bridge models were developed to validate the proposed method’s accuracy, the results from which indicated that the method accurately implemented deflection measurement with an approximately 5% calculation error. In addition, the influence of some key parameters, such as vehicle type, vehicle speed, and structural damage, was investigated. The simulation results revealed that damage to the hinge joint in the middle location could significantly influence the proposed method’s accuracy such that the error may exceed 10%. Finally, on-site experiments were conducted on a simply supported girder bridge to further validate the proposed method’s accuracy, and an approximately 8% deflection assessment error was found. Considering the additional advantages of FBG sensing technology, the proposed method can also be effective for long-term deflection measurements of short- or medium-span bridges.https://www.mdpi.com/2075-5309/14/1/70deflection measurementstrain responsesimply supported girder bridgelong-gauge FBG sensortraffic loads |
| spellingShingle | Yongsheng Tang Jigang Cang Bohan Zheng Wei Tang Deflection Monitoring Method for Simply Supported Girder Bridges Using Strain Response under Traffic Loads Buildings deflection measurement strain response simply supported girder bridge long-gauge FBG sensor traffic loads |
| title | Deflection Monitoring Method for Simply Supported Girder Bridges Using Strain Response under Traffic Loads |
| title_full | Deflection Monitoring Method for Simply Supported Girder Bridges Using Strain Response under Traffic Loads |
| title_fullStr | Deflection Monitoring Method for Simply Supported Girder Bridges Using Strain Response under Traffic Loads |
| title_full_unstemmed | Deflection Monitoring Method for Simply Supported Girder Bridges Using Strain Response under Traffic Loads |
| title_short | Deflection Monitoring Method for Simply Supported Girder Bridges Using Strain Response under Traffic Loads |
| title_sort | deflection monitoring method for simply supported girder bridges using strain response under traffic loads |
| topic | deflection measurement strain response simply supported girder bridge long-gauge FBG sensor traffic loads |
| url | https://www.mdpi.com/2075-5309/14/1/70 |
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