Strong Current Dredging Project
February
27,
2018
Location: Biscayne Bay, Watson Island, Miami, Florida
Project Overview: Contain bucket dredge sediments within several work zones exposed to high tidal currents, limit sediment migration at several defined mitigation areas, adjacent Miami Cruise Ship Terminal with requirement for frequent barge traffic. Provided 30,300’ of Heavy Duty Type 3 curtains along with specialty turbidity curtains in assigned project areas.
ABASCO Contribution: Design engineering, manufacture & site support
- TYPE 2 DOT with 3/8” chain used in interior mitigation areas
- TYPE 3 HD with ½” chain used in primary dredge area and outer mitigation
- TYPE 3 HD with additional belting in primary dredge area
- Custom heavy curtains – 35 oz PVC, 2 each ½” chains for high load areas
- High tensile strength belting, D-rings and fasteners used on some higher load areas
Project Challenges and Features –
- Type 3 HD and specialty curtains exposed to 4-5 knot currents
- Strong winds up to 45mph
- Release restricted to low NTU levels, multiple samplings per day
- Pilings and deadweight anchors
- Curtain restrictions related to Manatee movements
- Dredge area, sponge/seagrass mitigation areas, and spoils area
- Fine silt coral sediment in the dredge area (baby powder)
- High profile location