- U.S. Army Corps of Engineers, Jacksonville District
- Okeechobee, Florida
- Our Role
- Geotechnical, Foundation Investigation.
- Provided geotechnical engineering for final design of rehabilitation
- Provided foundation investigation and design
- Provided seepage and slope stability analysis and foundation design.
Lake Okeechobee is surrounded by Herbert Hoover Dike, a 143-mile-long earth embankment with a crest elevation that varies from 35 to 45 feet and a base elevation of about 14 feet. The lake has historically maintained a depth of 10 to 15 feet above sea level until 1995 and 1998, when the water levels rose to approximately 17 feet. During these high-water events, significant seepage occurred through and beneath the embankment, causing sinkholes, boils, and internal erosion.
Gannett Fleming provided geotechnical engineering services for the final design of rehabilitation of Reach 1B, including 3.7 miles of dike, a spillway structure, and a culvert. Our project team analyzed seepage through and beneath the dike embankment for eight stages of construction. Design specifications included a seepage berm, relief trench and relief wells, drainage swale, and a new hurricane-resistant, solar-powered instrumentation system. The system provides five level piezometer instruments through the cross section of the dike and a weir flow instrument to monitor relief trench flows. These instrument clusters are located at four critical cross sections along the reach.
Our firm provided foundation investigation and design for the 10-foot-diameter gated culvert, structure C-13. The structure is used to provide irrigation flow to the farmers in the area. We performed seepage and slope stability analysis and hydraulic analysis, as well as structural designs and 90 percent design drawings for the rehabilitation of the structure. The project had progressed to 95 percent complete when it was halted by the USACE due to a change in repair strategy by the Government.
- Preliminary design of rehabilitation alternatives
- Alternate analysis
- Seepage and stability analysis
- Filter and drain compatibility evaluation
- Quantities and cost estimates
- Geological characterization
- Seismic and liquefaction analysis.
- The system is solar powered and utilizes radio communications to concentrate data to one convenient uplink point on the reach.