SR 528 INTERCHANGE

Background

The SR 528/Innovation Way Interchange was a $63 million design-build project. The objective of the interchange was to improve connectivity in the eastern Orange County, Florida region and accommodate the development of the Innovation Way Corridor. The project included construction of four new bridges: two ramp structures over the proposed All Aboard Florida (AAF) Railroad and two structures carrying Innovation Way over the AAF Railroad and SR 528. Also included in the project were the widening of the SR 528 bridge over ICP Blvd and the OUC Railroad, two toll plazas, new traffic lanes, and accommodations for a future high-speed passenger rail line. This Interchange was designed using leading-edge technologies and methodology to provide an advanced safe design and maximum structure life.

One of the key innovations on this project involved the use of cast-in-place, post-tensioned, straddle piers to support the precast, prestressed Florida I-Beams (FIBs) on the two ramp bridges. The original concept plans for these ramp bridges proposed using continuous steel I-Girders supported by integral steel box straddle bents. Through the Design-Build process, the DRMP structures team worked with Lane Construction to redesign the bridges to take advantage of the material and time cost savings of using concrete instead of steel. The two ramp bridges consisted of Florida-I Beams supported by post-tensioned, inverted-tee straddle piers founded on prestressed concrete piles. The straddle piers supporting these ramps are oriented at an approximate 60-degree skew angle to the superstructure and were required to span the alignment of and provide the necessary clearances to the AAF RR. The FIB shape accommodates more prestressing strands than the old Florida Bulb-T design, allowing bridges to be built with fewer beams and spans. The FIBs also had sufficient capacity to accommodate the curvature and skew of the alignment by casting the beams at different lengths and varying the width of the deck overhang along the bridge. Ultimately, this design enhancement provided the client with a net savings of over $2 million.

The speed and ease of construction of the precast FIBs also proved beneficial to this project when Hurricane Irma hit central Florida during construction of these bridges in September of 2017. The beams had been placed, but the deck had not yet been poured for the Innovation Way over SR 528 (a hurricane evacuation route) bridge at the time of the hurricane. DRMP performed additional calculations and modified the temporary beam bracing for the FIBs on this bridge based on the high predicted wind speeds. All bridges on the project, in various stages of construction, successfully weathered the storm.