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Title:Insights from Depth Averaged Numerical Simulation of Flow at Bridge Abutments in Compound Channels
Authors:Reinaldo Morales and Robert Ettema
Publication Date:Jul 2011
Report #:MPC-11-237
Project #:MPC-307
TRID #:01354611
Keywords:bridge abutments, channel flow, flood plains, hydraulic structures, numerical analysis, simulation

 

Abstract

Two-dimensional, depth-averaged flow models are used to study the distribution of flow around spill-through abutments situated on floodplains in compound channels and rectangular channels (flow on very wide floodplains may be treated as rectangular channels). The study leads to useful insights regarding distributions of flow velocity, unit discharge, and boundary shear stress at spill-through abutments. It also presents insights from extensive assessment of uncertainty associated with the use of depth-averaged modeling of flow at abutments. The study, by showing how abutment flow fields adjust in response to variations of abutment length, floodplain width, and main channel dimensions, yields important trends regarding the magnitude of amplification factors for depth-averaged velocity, unit discharge, bed shear stress, and distance to peak unit discharge. The study comprises a much broader range of abutment lengths, channel shapes, and floodplain dimensions than heretofore reported in the literature. The study's insights, from its assessment of uncertainty associated with the use of depth-averaged modeling of flow at abutments, yield a relationship for estimating the optimum mesh size for use with depth-averaged models. The study also gives focused recommendations for topics requiring further investigation.

How to Cite

Morales, Reinaldo, and Robert Ettema. Insights from Depth Averaged Numerical Simulation of Flow at Bridge Abutments in Compound Channels, MPC-11-237. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2011.

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