The HHD Reach 1 Gap Closure Project awarded to main contractor TREVIICOS included construction of sections to close the gap between cutoff walls and existing structures at different points around Herbert Hoover Dike, the 143 earthen dike surrounding Lake Okeechobee.
To complete the task TREVIICOS employed two types of cutoff wall technologies: first, cutoff wall by jet grouting abutting the existing structures, a two-phase process combining pre-drilling of the native soils and jet grouting. The pre-drilling, specified to due to the presence of the hard rock layer, consisting of 239 columns with an average depth 55 ft. After completion, the task called for drilling and jet grouting columns down to the design depth.
The second technology, the self-hardening slurry (SHS), developed for the first time by TREVIICOS during the work previously performed as part of the HHD Reach 1 Cutoff wall, was also divided into two phases. After the clamshell excavated down to the rock layer the hydromill took its place and continued excavation down to design depth.
One of the main challenges was to manage logistics between project sites, situated as far as 30 miles from each other, a task TREVIICOS performed in total safety as reflects its superior record
The rehabilitation works are part of the Army Corps of Engineer’s $870+ million investment in projects and safety measures at Lake Okeechobee to reduce the risk of catastrophic failure and flooding for a large area of South Florida.
Installation of over 50 miles of cutoff wall around the lake, along with replacing old water control structures, commonly known as culverts, are some of the steps being taken to protect the area.
TREVIICOS, in addition to the GAP closure, is now working on the Eastern Section of the lake in the Reach 1 Extension and the MATOC Task Order 2 for a total of over 3.5 million sq. Ft. developing over approximately 12 miles of cutoff wall.