Scouring in long contraction with an upstream erodible gradually contracting section

• Main Author: Koh, Weijie.
• Other Authors: Lim Siow Yong
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/53881
• Institution: Nanyang Technological University

This report presents the result on the correlation of the maximum equilibrium scour depth in a contracting channel and the aim is to propose a predictive equation that was simplicity for practical usage. The parameters affecting the scour depth have been identified based on the use of dimensional analysis and physical reasoning’s. A total of 252 experimental data points were collected from the present and past studies and used in the analysis, out of which 206 data points were under clear water scour conditions and 46 data points were under lived bed condition. The well known predictive equation proposed by Laursen (1960) was revisit and improved by implementing the incomplete self-similarity theory and regression analysis. Similarly a second set of equation was derived base on incomplete self-similarity argument, regression analysis and by considering the interaction term of each independent variable. A comparison between the measured scour data and the two proposed equations confirmed that both equations are sufficiently accurate. The comparison result also illustrate a significantly improvement in the accuracy by implementing the incomplete self-similarity theory in the analysis. The equation is applicable to both clear water and lived bed-scouring condition.