Author(s): Cristina M. S. Fael; Antonio H. Cardoso
Linked Author(s): António Heleno Cardoso
Keywords: Vertical Abutments; Riprap; Matt
Abstract: This study addresses the use of riprap as a countenneasure against scouring near verticalWall bridge abutments under clear Water flow conditions. It deals with the diameter of riprap, Dr50, and the layer thickness, t. Experiments were performed on a rectangular sand-bed openchannel, by imposing different abutment lengths and by choosing three riprap stone sizes. It became obvious that i) the stone size depends on the ratio between the abutment length and the flow depth; ii) Winnowing can be avoided when the layer is predictable to act as a granular filter and the layer thickness exceeds 3Dr50 and iii) against intuition, the deepest scour holes for a given layer thickness may be observed at the shorter abutment, When the layer is not fully efficient to arrest scour.
Year: 2007