Streambank Protection by Use of Spur Dikes
Abstract
The use of nearly-impermeable spur dikes made of rockfill and stone riprap as a bank protection technique is examined with a literature review, model study and field investigation. The results of the literature review are summarized, including general design features, recommended spur dike orientation angles, spacing/length ratios and local scour prediction equations. Local scour and streambed and streambank adjustments to a new spur dike field on the Willamette River, Oregon are documented. Flow patterns, current velocities and water depths in the dike field are reported. A scale-model study is used to evaluate several spur dike design parameters and to examine the prototype spur dike arrangement and several alternative arrangements. The principal conclusions of the model study include: (1) the degree of bank protection provided by spur dikes is a function of the spur dike length, orientation angle and spacing; (2) as spur dike length increases, the protected distance downstream increases, but not proportionately with the increasing dike length; the model dikes could protect a bank from 2.5 to 4.5 times their own length; (3) upstream-oriented spur dikes are more efficient than downstream-oriented dikes in deflecting the river current away from the bank and thus provide bank protection farther downstream from the dike tip; and (4) upstream-oriented spur dikes cause more extensive scour holes than do downstream-oriented spur dikes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1984
- Accession Number
- ADA140049
Entities
People
- Scott M. Kehe
Organizations
- Oregon State University