SCOUR AT CULVERT OUTLETS IN MULTIBED MATERIALS

An investigation of scour at culvert outlets in noncohesive and SC-type cohesive materials is presented. A series of empirical equations was derived to predict the depth, width, length, and volume of scour downstream of culvert outlets under various field and laboratory conditions. The rate of scour was determined for each material. The effects of culvert shape, tailwater depth, and headwall presence were correlated with the ultimate scour dimensions. The area affected by the scour process was quantified as a function of culvert diameter and discharge. General observations on scour-hole formation, growth, and stabilization are reported. (Author)