Blockage effects on scouring downstream of box culverts under unsteady flow

This experimental study is concerning scouring at the outlet of partially blocked box culverts under unsteady flow condition. The blockage of culverts is considered as an important factor on the scouring pattern at the outlet of the blocked box culverts. To investigate the effect of blockage on scouring pattern downstream of a box culvert under unsteady flow, some experimental tests were carried out in a laboratory flume located in the Hydraulics Laboratory of the University of Technology Sydney. The experimental tests were carried on in both partially blocked and non-blocked conditions and consequentially the effect of blockage on scour pattern is investigated. It was found that 88% to 98% of maximum scour depth occurs in the rising limb of the hydrograph.