Sunshine Skyway Bridge - 10 years later

The Sunshine Skyway Bridge, opened to traffic in April 1997, is performing very well after 10 years in an aggressive environment. The 1,200' long precast segmental, cable-stayed balanced cantilever main span and 160' high precast and cast-in-place elliptical piers are withstanding the salt waters of Tampa Bay. The concrete, along with corrosion inhibitors, has proven to be worth its weight in gold. Recent inspection has provided results indicating that when proper techniques are incorporated into the design, precast concrete can resist the harsh effects of the environment. The Florida Department of Transportation's rigorous maintenance and inspection has unveiled only minor repairs after the initial 10 years of service. Maintenance costs over the last ten years have been minimal for a bridge of this size. Some costs have been associated with repairs of damage to concrete barriers from direct lightning strikes. Most repairs are not directly related to the concrete or cable stays, but to routine components of the bridge. For example, repairs were needed to the large modular expansion joints at the transition to the 135' span-by-span, twin precast segmental box approaches and the 4,000' main span unit. Cleaning and painting of the mechanical sliding pot bearings at this same location was also done. The initial three-coat paint system of the cable stays has endured the salt air and relentless rays of the sun, requiring only minor touch up paint around the welds and grout port locations. All maintenance has been relatively routine and minor. There is no evidence of any adverse conditions for the stays, their components or connections. The superstructure deck is behaving as expected, responding to annual temperature changes and showing no evidence of any unanticipated deflection - all indicating good behavior. A review of the extensive maintenance and testing over the past 10 years attests to the bridge's ability to withstand the fury of Mother Nature. This structure is a testimony to what has been accomplished and what the future may hold for the precast segmental and cable-stayed bridge industry and were due to differential shrinkage. Both types of pylon cracks are considered insignificant.