Abstract
The available equations for scour prediction downstream of a ski-jump bucket are mostly deterministic in nature and do not consider uncertainties of various scouring parameters adequately. A reliability-based assessment of scour in such situations is of paramount importance in examining the relationship between safety factor and reliability, which are considered to be key parameters for decisions in foundation design. This paper presents a methodology for the reliability assessment of scour downstream of a ski-jump bucket using the first-order reliability method (FORM). To study the influence of various random variables on the reliability against scouring, a sensitivity analysis is carried out. To achieve a desirable safety level in the design of a foundation, reliability-based safety factors are also proposed. The influence of correlation among the random variables on the reliability is also studied.