Author(s): X. Chen; Y. K. Tung
Linked Author(s): Yeou-Koung Tung
Keywords: Bridge piers; Scour; Time-dependent reliability; Third-order polynomial normal transform; L-moments
Abstract: Local scour around bridge piers is known as an important factor threatening the safety of bridges. Because of the random nature and complexity of the scouring phenomenon around bridge piers, the risk of failure due to excessive local scour around a pier always exists during its service life. Thus, the uncertainty and time-dependent reliability analysis of local scour is essential in designing new bridges and in evaluating the vulnerability of existing bridges to local scour. In this paper, a time-dependent reliability analysis of local scour around bridge piers, which considers both hydrologic uncertainty as well as the hydraulic and model uncertainties, is implemented. Third-order polynomial normal transform (TPNT) technique based on L-moments method is incorporated to obtain the uncertainty features of load and resistance involved. The proposed technique facilitates the calculation with less restriction in dealing with correlated multivariate problems. A hypothetical example is used to illustrate the technique and to compare with a parametric procedure that identifies the distribution of resistance. The results of the hypothetical example show acceptable difference between the two procedures.