• Sponsors: Iowa Department of Transportation (IDOT)
• Objective: To develop a culvert design that prevents blockage by sedimentation and vegetation — a self-cleaning system that would flush out the sediment deposits using the power of the stream flow itself.
Understand the mechanics of the sedimentation process at culverts for various flow events
Meet the IDOT’s requirements for a new solution to the problem of sedimentation in culverts
Refining the Geometry
Sedimentation: A problem for midwestern multi-box culverts
Multi-box culverts are frequently blocked by sediment deposits and vegetation, but the mechanics of the sedimentation process had not previously been studied
This sediment blockage can obstruct the flow and cause the culvert to overtop during storms, producing local flooding and property damage
Clean-up is costly in terms of time and effort, and must be repeated often at many culvert sites
Muste first built 1:20 scale three-box culvert models to test new designs. Next, he used numerical simulations to refine the geometry and test them under a range of flow conditions. Finally, Muste and his team implement the solution in situ and has monitored operations there since 2013. The fillet-based design has performed well at natural scale
How Can a Culvert Clean Itself?
The successful self-cleaning culvert design is “fillet-based,” meaning that the channel leading up to the culvert entrance is shaped to better resemble the natural cross-section
The fillets are set on the stream bottom immediately upstream of the culvert.
They slope toward the banks to bring the culvert site back to the original streambed shape
The fillets direct the sediment through the central barrel and restrict the extent of low-velocity areas on the sides that are prone to sedimentation
This design maintains the effectiveness of the flow conveyance over a range of flows