Experimental investigation time changes of maximum depth of scouring on control scouring of slot with rectangular slot section (comparison between triangular and invers triangular shape)

Bridges are one the most important and useful river structure and as a key of Communication ways are very significant. Local Scouring is one the most reason of Instability of bridges and finally its failure annually immense human and financial cost to the government imposes. So far, several studies on ways to control and reduce scouring around piers of the bridges has been done among them, the slot is at the base of the bridge. The purpose of this study is experimental investigation of maximum change of scouring over to time. For this purpose, two slot with Triangular and inverse triangular with same area and two levels of location, 1.5 and 3 cm over the bed at two discharges 25.6 and 32 lit/s on sediment with 0.5 mm diameter are investigated. The results of this study show that, at all of the cases slot caused reduce the local scouring and reduced the maximum volume hole scouring also the maximum scouring depth and volume of scouring hole with level of location to bed and Froude number and time has direct relationship.