Computational Design Tool for Bridge Hydrodynamic Loading in Inundated Flows of Midwest Rivers

The hydraulic forces experienced by an inundated bridge deck have great importance in the design of bridges. The proper estimation of loading exerted by the flow on the structure is important for design plans and is pertinent for evaluating its vulnerability. During a flood or hurricane highway bridges over the sea or other waterways may become partially or completely submerged. Flood flows add significant hydrodynamic loading on bridges, possibly resulting in the shearing or overturning of the bridge deck and failure of the bridge superstructures. The overall objective of the study was to establish validated computational practice to address research needs of transportation community in bridge hydraulics via computational fluid dynamic simulations. The reduced scale experiments conducted at the TFHRC hydraulics laboratory establish the foundations of validated computational practices to address the research needs of the transportation community. The simulations in this study were completed by using the supercomputers at the Argonne National Laboratory. The results of the study showed that the critical values of the drag coefficient occur when the bridge is well inundated, but the critical values of the lift and moment coefficients occur near the transition from partially to fully inundated. The critical lift coefficient is negative, which corresponds to a pull-down force. The CFD results match the experimental data in terms of the relationship between the inundation ratio and force measured at the bridge. The CFD methodology is used to transfer the recent supercomputer models of bridge inundation flows from laboratory scales to small scale and large scales and analyze the effect of scaling on turbulent flow and hydrodynamic forces obtained based on the Froude number similarity method. The results of the present research provide a tool for designing new and retrofitting existing bridges so that they are able to withstand the forces and moments that may result from partial or complete inundation