摘要: |
The proposed research builds on of a sequence of Iowa Highway Research Board (IHRB) projects focused on sedimentation at culverts. The research started with laboratory studies on a new culvert design and ended with partial in-situ implementation. The new solution for mitigating sedimentation at multi-barrel culverts was developed at IIHR-Hydroscience & Engineering (IIHR), The University of Iowa with IHRB funding during 2006-2008 (TRB-545). The concept behind the newly developed technology relies on the use of the stream hydraulic power for passing downstream the culvert the suspended and bed loads carried by the stream during storms. The solution does not affect the current culvert design protocols rather it streamlines the areas adjacent to the culvert to enhance flow and sediment transport. The self-cleaning culvert concept was extensively tested at IIHR through laboratory and numerical simulation modeling and performed well in laboratory conditions. Following the research conducted through TR-545, IHRB requested to implement the new mitigation design to an actual culvert site for testing its performance in natural conditions. A 3-box culvert located on HWY 1 on Willow Creek in Iowa City (FHWA #031711) was identified as candidate for demonstrating the real-scale performance of the new self-cleaning design. Before implementation, the culvert had both lateral barrels silted over the entire culvert length with a sediment layer of 2-3 ft thick. Combined funds from Iowa Department of Transportation (IDOT) and Iowa City were used to retrofit the upstream part of the culvert. Monitoring of the culvert after culvert cleanup and after the culvert was retrofitted with the self-cleaning design was accomplished through TRB-619, Phases I and II
between 2010 and 2013 (Muste and Ho, 2013). During three years of post retrofitting operation, the culvert performance with respect to sediment and hydraulic conveyance has been excellent, regardless of the year�s season. |