The document discusses several case studies and lessons learned from roller compacted concrete (RCC) overtopping construction projects at dams. It summarizes the existing conditions and dam safety upgrades made for projects at Poe Dam in Centre County, PA and Lake Oneida Dam in Butler County, PA. These included replacing or modifying spillways, conduits, and embankment armoring using RCC. Construction details are provided such as phased RCC placement, reinforcing, and completed project costs and quantities. Additional project examples are discussed from Kentucky, Virginia, New Jersey, and Pennsylvania.
#9: May reconsider headwall for future designs. Could impinge on overtopping flow. Vertical obstruction.
#10: WWF included to prevent crack at upstream edge of apron if cutoff were undermined and foundation support was compromised.
No. 4 bars were allowed as a substitute for WWF
Design intent not fully communicated to construction staff. Bars installed incorrectly.
#11: WWF included to prevent crack at upstream edge of apron if cutoff were undermined and foundation support was compromised.
No. 4 bars were allowed as a substitute for WWF
Design intent not fully communicated to construction staff. Bars installed incorrectly.
#22: Full pool during construction required stream diversion/phased construction sequence
#23: Contractor proposed phased RCC placement to expedite construction
Phase 1.1 concurrent with spillway construction
#24: Note sheet pile cutoff. Selected since sheet piles were used for cofferdam and diversion
#25: Rebar added to tie conventional concrete at sheetpile to RCC
#26: KC project
Conventional concrete placed concurrent with RCC and PRIOR to compaction
Issues with compacted concrete face being lower than conventional concrete duh
Needed to smooth transition with grout/mortar
#27: Unformed compacted steps ok
But poor treatment prior to placing conventional concrete training walls
Needed to dry pack/injection grout fix
#29: Better success placing conventional concrete on formed steps