Adaptive Slope Stabilization for River Remediation: Fid-Bau Portal

Adaptive Slope Stabilization for River Remediation

Byle, Michael J. / Tamang, Rakam

Removal of contaminated sediment along a river bank at the base of over-steepened slopes required mitigation of slope impacts to permit the remedial action. The shoreline slopes were, at best, marginally stable as evidenced by near vertical banks, leaning trees, and visible shallow failures at multiple locations. The project has severe constraints due to very high upland slopes, multiple private owners of the upland areas, such that the stabilization measures could neither extend into the upland in many areas, nor could they reduce the river cross section to prevent increased flood hazards, as well as a need to preserve the character of the existing shoreline. This paper will discuss the evaluation and investigation of conditions as well as the selection and design of slope stabilization measures to mitigate the impact of dredging in consideration of competing objectives. This evaluation also considered social, political, hydrological, and technological issues as well as accessibility, and constructability aspects. The design basis development of performance-based specification and construction limitations will be presented. The process resulted in the selection of structural mitigation measures including piling, combi-walls, and submerged rock buttressing with no permanent impact to the upland from the in-river work.