The effect of bridge piles on stratification in lower Chesapeake Bay

Tidally-forced flow beneath the existing trestle of the Chesapeake Bay Bridge-Tunnel causes significant distortion of the ambient density field in the immediate vicinity of the trestle due to flow over the scour zone around the pilings. Effects are minimal a short distance away from the trestle. Contrary to previous studies, stratification was not appreciably stronger during neap as compared to spring tide periods at the time of these observations, but a tendency toward such a state was detected. Estimates of piling-induced destratification based on direct observations of temperature, salinity, and currents near the pilings indicate that piling effects are substantially less than naturally occurring destratification due to bottom and wind stresses.