|Project Name:||Smart Scour Countermeasures|
Office of Infrastructure Research and Development |
|Team:||Hazard Mitigation Team|
Infrastructure Research and Technology Strategic Plan and Roadmap|
|Project Description:||Bridge pier scour is a major concern; it is a dynamic phenomenon that varies with water depth and angle of flow, pier shape and width, and other factors. If scour at a pier can affect the stability of a bridge, countermeasures to protect the pier should be considered. The current design philosophy in the Hydraulic Engineering Circular No. 18 (HEC-18) to estimate scour at bridge piers does not recommend using countermeasures to protect the pier as part of the design. The reason for this approach is that important data to evaluate the performance of countermeasures on a continuing basis is missing. Comprehensive data on monitoring the performance of scour countermeasures for pier protection is needed before a change in design philosophy can be considered. Current policy in the United States considers riprap placed at bridge piers to be only a temporary countermeasure against pier scour. Federal guidance requires that riprap placed at bridge piers to be monitored periodically by visual inspection or by fixed instruments. This policy stems from the challenge in adequate sizing of riprap to withstand the turbulence and hydraulic stress generated in the vicinity of a bridge pier under flood-flow conditions. Therefore, the use of smart countermeasure can increase the confidence of using countermeasure around bridge piers as well as abutments.|
J. Sterling Jones Hydraulics Laboratory|
|Start Date:||November 15, 2011|
|End Date:||October 14, 2013|
The key project objective of this research is to start developing comprehensive data to assess the long-term performance of scour countermeasures for bridge foundation protection.
|Test Methodology:||Various forms of armoring “smart countermeasures” will be investigated. The smart countermeasure will have embedded active/passive sensors, which will be used for monitoring their position wirelessly and under water. Smart countermeasure alternatives will be evaluated analytically and through a flume study at the Turner-Fairbank Highway Research Center (TFHRC) J. Sterling Jones Hydraulics Research Laboratory. Following the laboratory evaluation, one armoring countermeasure will be chosen for field installation. The contractor shall work with bridge owner agencies to select a bridge site for field installation of the selected smart countermeasure armoring system. The contractor shall also devise the instrumentation plan for the selected smart countermeasure system.|
|Expected Benefits:||This research will be beneficial in: (1) Gaining confidence by the bridge owners in the use of countermeasure by monitoring their performance and positions, especially post-flood events. (2) Providing preliminary data for developing American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) specifications for countermeasures. (3) Providing initial guidance that can be used in developing future protocols that manufacturers can use in field installations. (4) Long-term countermeasure performance monitoring can eventually lead to change the design philosophy in HEC-18.|
|Deliverables:||Name: Smart countermeasure.|
Product Type(s): Research report, Hardware
Description: The deliverable will be a laboratory prototype and research report.
Hydraulics and Hydrology|