A New TDR-Based Sensing Cable for Improving Performance of Bridge Scour Monitoring
The use of time domain reflectometry (TDR) for real-time monitoring of bridge scour process has gone through several stages of development. The recently-proposed concept of bundled TDR sensing cable, in which two sets of insulated steel strands are twisted around and connected to a central coaxial c...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-11-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/20/22/6665 |
| _version_ | 1797547182675460096 |
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| author | Kai Wang Chih-Ping Lin Wei-Hao Jheng |
| author_facet | Kai Wang Chih-Ping Lin Wei-Hao Jheng |
| author_sort | Kai Wang |
| collection | DOAJ |
| description | The use of time domain reflectometry (TDR) for real-time monitoring of bridge scour process has gone through several stages of development. The recently-proposed concept of bundled TDR sensing cable, in which two sets of insulated steel strands are twisted around and connected to a central coaxial cable to form a compact sensing cable, is a major change that has several advantages including the bottom-up sensing mechanism. Nevertheless, there is big room for improving its measurement sensitivity and signal to noise ratio (SNR). Changes in waveguide configuration also need to be made to avoid the adverse effect of insulation abrasion observed in field implementation. This study evaluated three new conductor and insulator configurations for constructing the sensing waveguide, including a balanced two-conductor waveguide (Type I), an unbalanced three-conductor waveguide with insulation coating on the middle conductor (Type II) and an unbalanced three-conductor with insulation coating on the two outer conductors (Type III). In all cases, the spacing between the two sets of steel strands (i.e., the waveguide conductors) was especially enlarged by replacing some steel strands with non-conductor wires to increases measurement sensitivity and avoid shorted conditions due to insulation abrasion. Experimental results show that Type III has the best performance on all counts. A new improved TDR sensing cable was hence proposed based on Type III configuration. Its performance was further evaluated by a full-scale experiment to take into consideration the long range of measurement in most field conditions. Detailed discussions on improvements of measurement sensitivity and SNR, limitation of sensing range, and mitigating the adverse effect of insulation abrasion are presented. |
| first_indexed | 2024-03-10T14:40:37Z |
| format | Article |
| id | doaj.art-1baff8f85a2c4f75abbc73b7d1f057ed |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T14:40:37Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-1baff8f85a2c4f75abbc73b7d1f057ed2023-11-20T21:47:39ZengMDPI AGSensors1424-82202020-11-012022666510.3390/s20226665A New TDR-Based Sensing Cable for Improving Performance of Bridge Scour MonitoringKai Wang0Chih-Ping Lin1Wei-Hao Jheng2Department of Civil Engineering, National Chiao Tung University, No. 1001 Ta-Hsueh Rd., Hsinchu City 300, TaiwanDepartment of Civil Engineering, National Chiao Tung University, No. 1001 Ta-Hsueh Rd., Hsinchu City 300, TaiwanYijhu Township Office, No. 389, Renli Village, Yijhu Town, Chiayi County 624, TaiwanThe use of time domain reflectometry (TDR) for real-time monitoring of bridge scour process has gone through several stages of development. The recently-proposed concept of bundled TDR sensing cable, in which two sets of insulated steel strands are twisted around and connected to a central coaxial cable to form a compact sensing cable, is a major change that has several advantages including the bottom-up sensing mechanism. Nevertheless, there is big room for improving its measurement sensitivity and signal to noise ratio (SNR). Changes in waveguide configuration also need to be made to avoid the adverse effect of insulation abrasion observed in field implementation. This study evaluated three new conductor and insulator configurations for constructing the sensing waveguide, including a balanced two-conductor waveguide (Type I), an unbalanced three-conductor waveguide with insulation coating on the middle conductor (Type II) and an unbalanced three-conductor with insulation coating on the two outer conductors (Type III). In all cases, the spacing between the two sets of steel strands (i.e., the waveguide conductors) was especially enlarged by replacing some steel strands with non-conductor wires to increases measurement sensitivity and avoid shorted conditions due to insulation abrasion. Experimental results show that Type III has the best performance on all counts. A new improved TDR sensing cable was hence proposed based on Type III configuration. Its performance was further evaluated by a full-scale experiment to take into consideration the long range of measurement in most field conditions. Detailed discussions on improvements of measurement sensitivity and SNR, limitation of sensing range, and mitigating the adverse effect of insulation abrasion are presented.https://www.mdpi.com/1424-8220/20/22/6665bridge scourscour monitoringtime-domain reflectometry (TDR), TDR sensing waveguide |
| spellingShingle | Kai Wang Chih-Ping Lin Wei-Hao Jheng A New TDR-Based Sensing Cable for Improving Performance of Bridge Scour Monitoring Sensors bridge scour scour monitoring time-domain reflectometry (TDR), TDR sensing waveguide |
| title | A New TDR-Based Sensing Cable for Improving Performance of Bridge Scour Monitoring |
| title_full | A New TDR-Based Sensing Cable for Improving Performance of Bridge Scour Monitoring |
| title_fullStr | A New TDR-Based Sensing Cable for Improving Performance of Bridge Scour Monitoring |
| title_full_unstemmed | A New TDR-Based Sensing Cable for Improving Performance of Bridge Scour Monitoring |
| title_short | A New TDR-Based Sensing Cable for Improving Performance of Bridge Scour Monitoring |
| title_sort | new tdr based sensing cable for improving performance of bridge scour monitoring |
| topic | bridge scour scour monitoring time-domain reflectometry (TDR), TDR sensing waveguide |
| url | https://www.mdpi.com/1424-8220/20/22/6665 |
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