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 fi eld in the immediate vicinity of the trestle due to flow over the scou r zone around the pilings. Effects are minimal a short distance away f rom the trestle. Contrary to previous studies, stratification was not appreciably stronger during neap as compared to spring tide periods at the time of these se observations, but a tendency toward such a state was detected. Estimates of piling-induced destratification based on d irect observations of temperature, salinity, and currents near the pil ings indicate that piling. effects are substantially less than natural ly occurring destratification due to bottom and wind stresses.