Local scour around bridge abutments under ice covered condition-an experimental study

The local scour around bridge abutments has been an active research topic for many decades.But very few studies have been conducted regarding the impacts of ice cover on the local scour phenomenon around bridge abutments.A series of ice covered flume experiments were conducted in this study.The shape factors of different abutment types in the local scour were compared.Under ice cover,the shape factor for semi-circular abutments ranges from 0.66～0.71.Three different non-uniform sediments were used with D50s of 0.58 mm,0.50 mm,and0.47 mm respectively.Two types of ice cover,namely smooth and rough cover,were created to simulate the impacts of ice cover around the abutments.Maximum scour depth was analyzed under different conditions.The contours of the scour holes were plotted to show the bed morphology and sediment deposition around bridge abutments.An empirical relationship between maximum scour depth,densimetric Froude number and sediment size was developed.