Hydraulics Current Research

Optimum Bridge Deck Shapes to Minimize Pressure Flow Scour Phase II

The bridge of the future is likely to be one that is inundated from time to time where the flow through the bridge opening is under pressure and causes concerns about amplified scour. This study utilizes the Particle Imagery Velocimetry (PIV) capabilities and the shear force sensor that have been developed for the Federal Highway Administration's Turner-Fairbank Highway Research Center J. Sterling Jones Hydraulics Research Laboratory to characterize streamlines and shear stresses on the channel bed for a variety of bridge deck shapes and positions above the bed.

The bridge model in the channel.

The bridge model in the tilting flume.

Lift and Drag Forces on Bridge Decks Phase II

The bridge of the future is likely to be constructed of lighter and more durable high performance materials which will lead to more concern about storm surges sweeping the deck off of the foundations as occurred on I10 during the 2004 Hurricane Ivan in Florida. This study utilize high tech force measurement techniques that have been developed in the Federal Highway Administration's Turner-Fairbank Highway Research Center J. Sterling Jones Hydraulics Research Laboratory to derive lift and drag coefficients for inundated bridge decks for a variety of approach flow conditions.

The force balance measures the drag and lift forces on the bridge deck.

Effects of Water Flow and Shaking on Scouring of Bridge Piers Phase

This study is collaboration between the Hydraulics Lab and seismic research program under Phillip Yen. This second phase of the multihazard research effort will use a shaker that can excite the soil recess section of the flume. The response of the bridge pier will simulated using a free vibration and forced vibration technique. The scouring process will be monitored to capture changes after the earthquake event. The test results and experiences made with this study will be used to make recommendations and to develop design ideas for a big scale test facility.

Laboratory Experiments to Determine Wave Forces and Moments on Typical US Highway Bridge Decks

In the past two years, hurricanes have caused devastating failures to a number of US highway bridges along the Gulf Coast. These failures have been attributed to the combination of storm surge and wave loading on the bridge superstructure. There are many bridges throughout the country that are vulnerable to this type of loading. A review of the public domain literature regarding the ability to accurately predict both lateral and uplift forces on bridge spans as a function of wave parameters (height, period, steepness) and the elevation of the span relative to mean water level clearly show the need for carefully planned and executed laboratory experiments.

The objectives of this proposed research are to obtain lateral (horizontal), uplift (vertical) forces and moments on typical US highway bridge structures as a function of:

1. Vertical location relative to the still water level
2. Wave height
3. Wave period
4. Wave steepness and for irregular waves
5. Wave spectra parameters

Typical bridge deck wave response.

Pier Scour Countermeasures Using Fluidic Devices

This study will include developing countermeasures by streamlining the shape/form of a bridge pier. A force balance to measure drag force will be used in the streamlining procedure. The streamlining process will be supported using a 3-D (3 dimensional) Volume PIV. We will also study the influence of roughness elements and shields mounted on the side of bridge piers using a shear force device.