The Effect of the Piles Cap Elevation on Local Scour around Complex Bridge Piers

Bridges are built to facilitate transportation between the two banks of rivers and waterways. They usually supported by piers with geometric shapes that differ from one bridge another, such as a complex pier. Due intersection water flow, many vortices generated, causing local scour around piers. Local is affected factors, including geometry other hydraulic factors. In this study, number laboratory experiments were conducted investigate effect pile cap elevation depth on pier using materials regular gradient under condition sediment-free flow. Eight ratios thickness Z/Tpc studied, ranging -32% 50%, six different flow depths (y) 10.5 cm 18 cm. The results showed maximum was recorded be 10.8 when partially covered sand bed (Z/TPC = 50%), increased increase in up 13.5 cm, then slight, although Increasing intensity due presence piles covering prevent impact these reaching soil surface.