Experimental Investigation of the Effects of Slotted Cone-Shaped Piers on Scour Reduction Due to Steady Flows

摘要

Local scouring at bridge piers can be regarded as one of the main reasons for bridge collapses at river crossings. Bridge failure can cause severe damages and can result in serious injury or death. Hence, the investigation of the control of scouring at bridge piers plays an important role in bridge design. The main aim of this study was to evaluate the effectiveness of the slotted conical-shaped piers in reducing local scour when compared with a circular-shaped pier. Two sets of experimental tests were carried out under clear water conditions for the duration of eight hours and with relatively uniform sediments. For the first set, the model piers with different lateral slopes were tested, and the experimental results showed that the maximum scour depth was mainly reduced by a decrease in the lateral slope of the model piers. With the mildest lateral slope angle of 78.69 degrees the maximum scour depth was reduced by as much as 32%. In addition, the combination of the slotted and conical shape could further reduce the maximum scour depth by up to 55%. Thus, the experimental results showed that the combination of the slotted and conical shape can be regarded as a very effective countermeasure tool against local scouring at bridge piers.