Abstract: The Folsom Dam Auxiliary Spillway Joint Federal Project was undertaken to increase the spillway capacity of Folsom Reservoir in order to meet the demands imposed by an updated assessment of the probable maximum flood. Staged construction allowed the spillway to be completed without impacting operation of Folsom Reservoir. A cofferdam including a temporary embankment and seepage cutoff wall reduced construction risk but required excavation in-the-wet. Consideration of rock slope stability and hydraulic performance was required in developing the grading of the approach channel, the adjacent reservoir shoreline, and geometry of the approach walls upstream of the gated control structure. Low lake levels during construction resulted in the majority of the hard-rock excavation occurring in the dry, with only a small amount of excavation and cleanup of the final surface needing to be performed from barges.

Bio: Dr. Newman is a geotechnical engineer with over 14 years of experience. He joined AECOM (formerly URS) after completing his PhD at the University of Illinois at Urbana-Champaign in 2007. He has worked on and managed projects relating to slope stability, static and seismic evaluation of dams and levees, numerical modeling of liquefaction and ground improvement, dynamic soil-structure interaction modeling, foundation design, rock mechanics, construction engineering, and design of slope stabilization measures. Dr. Newman’s dissertation research was in paleoseismology and liquefaction of natural soil deposits. His other research interests included the shear strength and durability of geosynthetic liners and residual shear strength of soils.