PIER AND ABUTMENT SCOUR: INTEGRATED APPROACH. DISCUSSIONS AND CLOSURE

Two discussions of a paper with the aforementioned title by B.W. Melville, published in this journal (Volume 123, Number 2, February 1997), are presented. The first discusser, who conducted classic bridge scour work at Iowa during the 1950s and 1960s, shows that his equations predict very similar scour depths to those predicted by the method presented in the paper. In addition, he elaborates on the importance of recognizing both the big picture and all the details. Richardson and Richardson criticize the methodology presented in the paper for the principal reason that it may lead to conservative estimates of scour depth, the finding of conservatism arising apparently from a comparison with field data. Conversely, they criticize the pier scour method in the paper for being less conservative than the method in the Hydraulic Engineering Circular (HEC-18), the Colorado State University equation. Discussions are followed by closure from the author.