Experimental Investigation of Local Scour around Complex Bridge Pier

In this study, local scour around complex pier experimentally investigated. Complex pier consisted of a column, a pile cap which is rested on array of piles. Experiments were conducted on clear-water condition. To see the geometric parameters (pile cap upstream extension, pile group arrangement, pile group upstream extension, and pile cap thickness) effect on scour depth, six physical models of complex pier were built and applied in this study. These experimental results were compared with theoretical equations. The results showed that some of the existing theoretical existing equations provide an appropriate estimation for scour depth. On the other hand, others did not provide acceptable values. The result showed that, by increasing pile cap thickness, the pile cap undercutting elevation was decreased. When the number of piles in line with flow increased the maximum scour depth was also decreased.