Experimental Investigation of the Effects of Slotted Conical Shaped Piers on Scour Process due to Steady Flow

摘要

Local scouring is one of the main causes of bridge piers damages or collapses in river crossings. Bridge failure canrncause severe damage and can result in serious injury or death. Hence, investigation on the control of scouring at bridgernpiers plays an important role in bridge design. The aim of this study was to evaluate the effectiveness of slotted conicalrnshaped piers in reducing local scour, as compared to a circular shaped pier. Then, two sets of experimental tests wererncarried out under clear water conditions for duration of 8 hours and with relatively uniform sediments. For the first set,rnthe piers models with different lateral slopes were tested and the experimental results showed that the maximum scourrndepth mainly reduced when the lateral slope of piers decreased, with the mildest lateral slope angle of 78.69~0, thernequilibrium scour depth being reduced by as much as 31.7 %. In addition, a combination of slot and conical shapedrncould further reduce the maximum scour depth up to 55%. These results showed that the combination of a slot andrnconical shape might be a very effective countermeasure tool against local scouring at bridge piers.