A CLEAR WATER SCOUR AROUND A CIRCULAR BRIDGE PIER UNDER STEADY FLOW FOR DIFFERENT OPENING RATIOS

Abstract

The loose non cohesive material through which a river flows is generally called sediment. Local scour at piers and abutments is the main reason for the collapse of bridges founded in alluvial sediments. Clear water scour refers to the situation where no sediment is supplied by the approaching flow in the zone of scour. Many investigators have studied various aspects of scour. However, the study on scour under steady condition for same discharge with same depth of flow for different pier diameters is limited. In present study laboratory experiment was conducted on different pier sizes of circular piers by keeping discharge constant under clear water scour condition. It is found that Non dimensional scour depth gradient is different up to opening ratio 0.8 having less slope and its slope is steep above 0.8 opening ratio.