Lead Civil Engineer US Army Corps of Engineers Lakewood, CO
Abstract Description: Final design efforts were completed by the U.S. Army Corps of Engineers in June of 2024 to rehabilitate the existing spillway and raise the crest of the Prado Dam spillway. Construction of the project will address three risk driving potential failure modes and increase flood storage at the facility. The project consists of constructing a new spillway within the footprint of the existing spillway with an estimated construction duration of approximately six years. The spillway is founded on interbedded low strength and expansive mudstone and high permeability sandstone that is near vertically bedded in a region of high seismicity resulting in numerous structural design challenges. This presentation will highlight risk informed design considerations used in conjunction with established design criteria for the structural design of the major project features including the labyrinth control structure, the spillway chute slabs, and the spillway chute walls.
Learning Objectives:
The purpose of the paper is to advance application of the risk informed design process using a recent dam safety modification final design example.
The paper also shares key structural design considerations for a significant spillway rehabilitation project with challenging foundation conditions and challenging seismic loading considerations.
Finally, the paper describes constructability challenges in the context of life safety risks during construction and the agency decision to consider early contractor involvement procurement strategies.
