Author(s): Inchan Park; Woncheol Cho; Jongkook Lee; Korea
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Keywords: Scour; Real-time monitoring; GPR; Scour countermeasure; Scour prediction
Abstract: In this study, a real-time bridge scour monitoring system and surface-geophysical techniques, Ground-Penetrating Radar (GPR) methods were used to measure real scour depths and improve assessment of erosional and depositional pattern around piers in several sites. The acquired data from these monitoring systems include continuous scour depths and water velocity measurements that are the main reason of scour at the fixed point of bridge piers as well as profiles of the shallow stratigraphy of subsurface deposits around piers. The highest peak discharge during the monitoring period was 12, 109 cms in July of 2004. In the present study, Maximum water velocity was measured up to 1. 33 m/s and 2. 17 m/s at Mapo and Hannam grand bridge respectively. There is no significant scour that eroded over 1 m. This is the result reflected real field condition such as the complex interaction of the river flow and complicated bed characteristics so that real scour depth and scourability can be determined through the result. Moreover, the result of real scour monitoring system and GPR methods can present reasonable bridge scour countermeasure that will substantially reduce the expense of foundations for new bridges and avoid the costly replacement of existing bridges due to anticipated scour that is overestimated by scour equations. This is the result reflected real field condition such as the complex interaction of the river flow and complicated bed characteristics so that real scour depth and scourability can be determined through the result. Moreover, the result of present methods could be a fast, economical, and an effective system for characterizing scour holes, in-filled scour holes, and the subsurface profiling to present reasonable bridge scour countermeasure that will substantially reduce the expense of foundations for new bridges and avoid the costly replacement of existing bridges due to anticipated scour that is overestimated by scour equations. It is concluded that these methods can be effective in determining both the water depth and sub-bottom geological characteristics near bridge piers provided that the correct instrumentation and operational procedures are applied.
Year: 2007