Palmer Engineering designed two bridges within 1,500’ of one another over Lloyd Creek and Branch of Lloyd Creek in Jefferson County, Florida. Palmer was responsible for the bridge, drainage, and roadway design on both projects. Located immediately east of the intersection of CR-158 (Old Lloyd Road) and Lloyd Creek Road, the new bridge over Lloyd Creek replaced a 140’-long, 25.5’-wide structure constructed in the late 1950s that was functionally obsolete and structurally deficient. The new bridge is 148’ long and 43’ wide with three equal spans of 48.7’. During construction, a temporary bridge was constructed to maintain traffic across Lloyd Creek.
Located between CR-158 (Old Lloyd Road) and SR 59, the new bridge over Branch of Lloyd Creek replaced a 160’-long, 25.5’-wide structure constructed in the late 1950s that was also functionally obsolete and structurally deficient. The new bridge is 172’ long and 43’ wide with 4 equal spans of 42.5’.
The projects were designed to Florida Greenbook standards and constructed according to FDOT Standard Specifications. Lloyd Creek normally flows into a sinkhole located just south of Lake Miccosukee. Large storm events create too much flow into the sinkhole, resulting in all flow routing to the Branch of Lloyd Creek and subsequently into the Aucilla River. For both bridges, rigorous hydraulic analysis determined the bridge opening, clearance above the 100-year flood elevation, and extent of scour-mitigating rip rap.
Reinforced concrete-filled steel pipe piles support the new bridges, which are founded on limerock. The bridge decks have a 6.5” nominal thick deck of reinforced concrete that was poured on nine 12” thick prestressed concrete slabs units (PSUs), all of which were cast full span length. An as-built Load Rating was performed on both bridges after construction.