The SR826/Palmetto Expressway and SR24/Okeechobee Road Interchange Improvement Project is located in Miami-Dade County, FL near the cities of Medley and Hialeah Gardens. The interchange serves critical roles in the surrounding are including linking major freeways such as I-75, I-95, and the SR836/Dolphin Expressway, and as a major freight route from Port Miami and Miami International Airport to the Town of Medley warehouse area. Three new steel box flyover ramps for a total bridge length of 7,241 feet, with spans up to 240 feet, providing direct connection between SR826 and SR25, as well as improvements to Okeechobee Road are designed to alleviate congestion and improve safety at the existing intersection. The existing Northbound SR826 Offramp Bridge over the Miami Canal will also be widened to improve safety at the Okeechobee Road Intersection by providing turbo lanes for Eastbound Okeechobee traffic. The expected construction cost of the project is approximately $150 Million dollars.
FINLEY is serving as the Engineer of Record for flyover Ramp B, flyover Ramp C, and the widening of the existing bridge over the Miami Canal. Ramp B is comprised of 9 spans with 2 continuous twin steel box girder units and one simple span, accommodating the gore area at the beginning of Ramp C, with an overall bridge length of 1,695 feet. Ramp C is comprised of 12 spans with 3 continuous twin steel box girder units. Each ramp was a deck width varying from 30’ to 33’ to accommodate stopping sight distances for the highly curved ramps with radii down to 330 feet. Four steel straddle bents ranging from 160 to 170 feet are also utilized at locations where the substructure for the bridges cannot be founded directly under the superstructure due to existing roadways or the Miami Canal. Air splices are proposed for erecting the steel girders in this highly urban environment to eliminate the need for temporary towers adjacent to traffic and lower the impacts to the travelling public. Additionally, auger cast piles are provided to minimize foundations while providing increased foundation capacity, decreased pile installation times, and minimizing impacts to the public over driven piles by eliminating vibrations during pile installation. The existing bridge over the Miami Canal is comprised of a three span continuous mildly reinforced concrete flat slab superstructure with prestressed concrete piles and reinforced concrete bent caps.