Vertical plates as scour countermeasure for bridge abutments

Abstract

ABSTRACT Failure of an important bridge is not affordable due to severe effects on economy of the area. Failure of a structurally sound bridge due to scour around its foundations is even more distressing. Understanding of mechanism of flow modification around bridge elements is necessary to design efficient scour countermeasures. Many scour prevention devices have been tested in laboratories and field in last few decades to safeguard bridges against scouring. Spurs, mainly used as river training structures, are also used as scour countermeasures around abutments along with other devices like Riprap, Geo-bags, Cable tied blocks, hard points, Collar plates, Sleeves, etc. The present laboratory study aims to address to the problem of scour around short bridge abutments and achieve the scour protection by providing a spur like thin vertical plate to its upstream, in steady uniform flow at incipient conditions. Protruding length of plate and its clear spacing from abutment model are varied for optimizing its performance. Flow altering capability of the plate is also visualized. Scour protection is found to vary from 41% for semicircular abutment to a maximum of around 71% for vertical wall abutment. Results for vertical wall abutments are presented in the form of performance contours.