Hydraulic Performance of End-of-Bridge Deck Drainage

Abstract Submission: The new TDOT (Tennessee Department of Transportation) standard for end-of-bridge bridge-deck drainage comprises a side-inlet located next to the roadway, at the end of the bridge, which connects to a riprap-lined flume or chute that runs down the embankment. This feature is similar to a curb-opening inlet but opened at the top, so it acts as a lateral weir or spillway. The hydraulic performance (capture efficiency, bypassed flows, water spreads and depths on the pavement, flow depths and velocities in the flume, potential for embankment erosion, etc.) of this standard under a range of bridge conditions (longitudinal slope, cross-slope, number of lanes or width, etc.) and rainfall intensities should be determined, so engineering recommendations can be given for the placement of the flume and configuration of its inlet. To quantify how stormwater flowing over the bridge deck and approach slab interacts with the design and placement of the inlet, for a range of bridge conditions, under design discharges, a full-scale physical model is used to reproduce actual conditions, along with high-fidelity computational fluid dynamics (CFD) simulations. Results from both the physical model and CFD simulations (validated with the laboratory measurements), are used for developing a design method and proposing engineering recommendations for the placement and configuration of this new drainage standard, to minimize water depths and spreads on the deck, decreasing traffic interruptions, risk of hydroplaning as well as splashing that diminishes visibility.

Learning Objectives/Expected Outcome (Optional) :