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Flow obstruction by bridge piers causes backwater to rise up on the upstream of bridges. This backwater effects may cause flooding and cause havoc on the immediate transport infrastructure such as roads and railway. The backwater effects depend on both flow characteristics as well as geometrical characteristics of the piers. This report provides a step by step simulation process for backwater effects due to bridge piers using HEC-RAS. Different bridge piers (Square Nose and Tail, semi-circular nose and tail and Triangular Nose with 90 degrees) were considered in the analysis. Simulations were also carried out to identify how backwater effects depend on opening ratio, width of bridge piers and number of bridge piers. The parameters of interest in the study included water surface elevation, Froude number and flow velocity on the bridge upstream. The results indicated that the rise in backwater at the upstream of bridge piers for subcritical flow is inversely proportional to the opening ratio. It was also observed that, the Froude number and flow velocity upstream of the bridge are directly proportional to the opening ratio. Additionally, it was noted that backwater rise, flow velocity and Froude number are directly proportional with flowrate. A further analysis of the results also indicated that since opening ratio is a function of both the number and width of piers, it is the most significant parameter when analysing backwater effect due to bridge piers and should be the main focus during bridge pier design when addressing flow obstruction. Finally, the result showed that all types of bridge piers produce backwater effects. However, the magnitude of these effects entirely depends on drag coefficient (CD) and Yarnell’s Pier Coefficient (K) values. Thus, bridge pier shapes with lower drag coefficient (CD) and Yarnell’s Pier Coefficient (K) values should be selected during bridge design. Make this purchase and get a sample complete engineering thesis report on this topic as well as HEC-RAS files and Excel Spreadsheet