Successful Implementation of Grouted Boulder Grade Control Structures on Drainageways in the Denver Metropolitan Area

by John M. Pflaum, (M.ASCE),

Document Type: Proceeding Paper

Part of: North American Water and Environment Congress & Destructive Water


This paper describes the development of design guidelines for the Grouted Sloping Boulder drop structure as an alternative for the sloping riprap drop structure. A number of partial failures of sloping riprap drop structures in the Denver Metropolitan Area prompted the Denver Urban Drainage and Flood Control District to conduct a complete evaluation of drop structures and develop specific guidelines for design of drop structures on Metro Denver drainageways. The paper provides a general review of the design of a Grouted Sloping Boulder drop structure including force analysis and selected design criteria for application on grass-lined channels with design flows up to 7,500 cfs (212.4m?/s) and maximum depth and velocity limits of 5 ft./sec. (1.5 m/s) and 7 ft./sec. (2.1 m/s). Critical design factors are seepage cutoff and relief and pressure fluctuations associated with the hydraulic jump. Numerous Grouted Sloping Boulder drops have been constructed in the Denver area over the past ten years and they have proven to be functional, attractive, and cost effective structures.

Subject Headings: Drop structures | Hydraulic design | Slopes | Grouting | Erosion | Boulders | Hydraulic structures | Denver | Colorado | United States

Services: Buy this book/Buy this article


Return to search