Research: Geotechnical Research

Estimating Critical Shear Stress of Bed Sediment for Improved Prediction of Bridge Contraction Scour in Georgia (RP 06-17)

Previous GDOT research has resulted in an approximate method for estimating critical shear stress for initiation of motion of river bed sediment to be used in bridge pier scour prediction methods applied to Georgia bridges.

A related research need is to improve bridge contraction scour estimation, which depends not only on characterizing critical shear stress properties of the sediment but also on predicting the flow field and its interaction with the bed sediment as a result of the flow contraction caused by the bridge opening. Contraction scour was the dominant failure mechanism for some 125 bridges that had to be replaced in Georgia after Tropical Storm Alberto in 1994.

The objective of the present research is to improve the predictive relationship for critical shear stress in terms of easily measured sediment properties so that it can be utilized in a proposed contraction scour formula that is more realistic than the current one, which is based on idealized flow conditions.

For further information, please contact David Jared at 404-363-7569.

Interpretation of Cone Penetration Tests for Pile Design Applications at the Georgia Department of Transportation (SRS 07-21)

Development of design guidance to integrate pile design methods for GDOT.

For further information, please contact Neoma Cole at 404-675-6251.