Experiments and calculations of cnoidal wave loads on a coastal-bridge deck with girders

Horizontal and vertical forces on a 1:35 scale model of a typical two-lane coastal bridge due to cnoidal wave loads are investigated by conducting an extensive set of laboratory experiments and comparing the resulting data with CFD calculations and existing simplified, design-type equations. The experimental parameters tested cover a wide range of wave and inundation conditions that may occur during a major storm or hurricane. This includes a wave matrix of 40 waves and bridge model elevations covering a range where the top of the bridge is fully submerged below the still-water level (SWL) to where the bottom of the girders are elevated above the SWL. Measurements for surface elevation, vertical and horizontal forces are compared with calculations made by solving Euler’s equations using the CFD software OpenFOAM with good agreement. Vertical uplift and horizontal positive forces (forces measured in the direction of wave propagation) are compared with the simplified equations using the relations given in Douglass et al. (2006). This set of data provides a valuable benchmark for understanding wave loads on coastal bridges during a storm or hurricane.