Submitted to: Proceedings of the World Water and Environmental Resources Congress
Publication Type: Proceedings
Publication Acceptance Date: 3/31/2005
Publication Date: 7/22/2005
Citation: Li, H., Kuhnle, R.A., Barkdoll, B. 2005. Spur dikes as an abutment scour countermeasure. Proceedings of the World Water and Environmental Resources Congress. May 15-May 19, 2005; Anchorage, AK. p. 444. 10.1061/40792(173)444. Interpretive Summary: Unstable channel boundaries are often associated with agricultural watersheds. Erosion of the unstable channel boundaries may threaten valuable agricultural lands and structures such as bridge supports. Erosion countermeasures have the potential to provide protection to structures, channel banks and adjacent agricultural lands. The evaluation of channel erosion countermeasures is necessary information that is needed to fulfill objectives of the Conservation Evaluation Assessment Program (CEAP). A study was conducted in the laboratory using a model stream channel to develop methods to prevent erosion near a model bridge support located on a model stream bank. In this study, a suite of designs of spur dikes were tested to prevent erosion from occurring near the bridge support or channel bank. Spur dikes are defined as structures projecting from the stream bank which direct the stream flow away from the bank and bridge support and prevent local erosion. These successful spur dike designs will provide additional technology for use in the prevention of erosion in the streams of agricultural and other watersheds. This technique will increase the tools available for managers to control the erosion threatening structures and lands. This type of information is necessary for effective environmentally-aware management of watersheds.
Technical Abstract: Experiments using spur dikes as a countermeasure to local scour at wingwall abutments were made in a laboratory flume channel. Flow velocity ratios of 0.9, 1.5 and 2.3 times the incipient motion of the bed material sediment were used in a compound channel with a model abutment. The bed material was sand with a median diameter of 0.8 mm and a standard deviation of 1.37. A series of configurations of spur dikes with varying lengths, spacings, number, and positions with respect to the abutment were tested. The most effective configuration to prevent local scour at the abutments consisted of three spur dikes composed of rock located upstream of the abutment and at the two corners.