Abstract

MONCADA M, Alix T; AGUIRRE-PE, Julián  and  MONCADA M, Marbella C. Reduction of scour around circular piers. Rev. Téc. Ing. Univ. Zulia [online]. 2015, vol.38, n.1, pp.3-11. ISSN 0254-0770.

In this paper new protection methods that allow reducing the local scour around bridge circular piers are proposed. The effect produced by the placing of collars around a circular pier of 7.3 cm diameter on the scour was analyzed. Initially a concentric collar and other eccentric were used. These were placed separately around the pier at the bed level. Experiments, by device, were made, maintaining the flow conditions used in the reference experiments. Then, experiments that consisted in combining two collars, one at the bed level and other to certain distance above the bed were carried out. Moreover, the effect produced by the elevation of the eccentric collar with regard to the bed on the scour depth was studied. Subsequently, it was proposed to diminish the piers local scour using a vertical wall perpendicular to flow, upstream of the pier. For each experiment, the space among the pier and the vertical wall was varied. It was studied the effect produced by the size of the vertical wall, by varying the width. For each experiment, the scoured bed profile was measured. This allowed determining the maximum scour depth. It was found that devices employed reduce reasonably well the local scour depth.

Keywords : scour at bridge circular piers; scour holes; reduction of local scour; collar and vertical wall as devices for scour protection.