ABSTRACT

Bridge piers produce a horizontal constriction of the flow, comparable to that caused by abutments. The local scour around bridge piers depends strongly on the geometry of the pier. Many publications are available that give specific information about the local scour near bridge piers. Unlike open-channel flows, these pressure flows create a severe scour potential. Wakes lead to significant turbulence levels, and the highly turbulent pressurised flow causes scouring of the channel bed. The process of local scour around bridge piers can be divided into several phases: initial phase, development phase, stabilisation phase and equilibrium phase. Several investigators examined the scour process around bridge piers. Scour relations were derived purely from curve fitting. The depth-averaged relative turbulence intensity in the scour hole represents the turbulent energy generated by the horseshoe vortices. Many parameters affect the flow pattern and the process of local scour around bridge piers.