Dam Construction Project
February
27,
2018
Location: Folsom Dam Modification Phase IV, California
Project Overview: Contain construction sediments within each reservoir’s work zones used to provide seismic and hydraulic upgrades at the three reservoirs built between 1888. Demolition, new tunnel liners, refurbishment or replacement of water management infrastructure with frequent barge traffic with turbidity managed to utilize 9,150’ of tapered TYPE 3 HD turbidity curtains.
ABASCO Contribution: Design engineering, manufacture & installation support
- TYPE 3 HD Curtains ranging from 1’ to 120’ in 50’ sections
- Dual 5/16” or 3/8” SS top tension cables
- 3/8” or 1/2” HG chain ballast chain with tension plates
- Skirt welded in vertical lengths
- Furling lines constructed with 3/16” SS coated cable secured to guides at the waterline
- USACE Specification No. 1859, Section #35 31 10
- 6” grommet centers with 35 oz PVC reinforcement around keder
- 22 oz PVC base fabric with skirt corners reinforced using 40oz PVC
- Universal Slide Connectors with ASTM pins
Project Challenges and Features –
- Type 3 HD curtains provided down to 120’ water depths
- California drought caused water depth reduction with the lake at 14% capacity
- Restricted NTU release
- Concrete deadweight anchors and Danforth anchors
- Long-term application from August 2013 to December 2016
- SS cable furling lines required for multiple site relocations
