DEVELOPMENT AND TESTING OF RIVERBANK-STABILITY ANALYSIS

The ability to predict the stability of eroding riverbanks is a prereq uisite for modeling alluvial channel width adjustments and a requireme nt for predicting bank-erosion rates and sediment yield associated wit h bank erosion. However, there are a number of limitations of existing bank-stability analyses that limit their physical basis and predictiv e ability. Some of these limitations are addressed through the develop ment of a new bank-stability analysis. The new approach is applicable to steep, cohesive, nonlayered riverbanks that fail along planar failu re surfaces. Pore-water and hydrostatic confining pressure terms are i ncluded in the analysis. The failure plane is not constrained to pass through the toe of the bank. The predictive abilities of four bank-sta bility analyses (Lohnes and Handy 1968; Huang 1983; Osman and Theme 19 88; and the present analysis) were assessed using field data. The new analysis is the most successful of the tested analyses in terms of pre dicting the stability of riverbanks with respect to mass failure.