Lee Roy Selmon’s name is well known to Tampa residents. Having played for the Tampa Bay Buccaneers, Selmon is currently the athletic director at the University of South Florida and has restaurants located throughout the city. Now, the expansion of an expressway bearing his name is under way.
The expressway (also known as the Crosstown), owned and operated by the Tampa-Hillsborough Expressway Authority, is a 26-year-old limited-access highway linking Interstate 75 in eastern Hillsborough County to Gandy Boulevard and Dale Mabry Highway in south Tampa. The $350-million project is 9 mi. (14.4 km) long, including a 5.1-mi. (8.2 km) elevated reversible lane bridge.
The majority of the project will be built in the median of the existing expressway. The new bridge was designed by FIGG Engineering Group and is being built by PCL Civil Constructors Inc.
The existing expressway, a four-lane toll road, is being improved because of an increase in traffic volume over the last 15 years. Every day, approximately 75,000 vehicles travel the valuable corridor.
One important change to the expressway is the construction of the elevated reversible bridge, which will be used specifically for cars and express buses.
Once completed, traffic on the new span will always move in the same direction. During morning rush hour, the reversible bridge will have three lanes carrying traffic –– in one direction –– from Brandon and I-75 into downtown Tampa. Later in the day, the same three lanes of traffic will be reversed, and traffic will move away from downtown Tampa into the suburbs connecting to I-75.
The main accesses on the reversible span will be located at each end of the elevated roadway. Meanwhile, underneath the elevated bridge, traffic will be flowing in both directions and motorists will be allowed to enter and exit along the way.
According to Cheryl Maze, director of Lasting Impressions of FIGG Engineering Group, the reversible lanes bridge will be the only facility of its kind in the entire Southeast. In addition to providing the design of the elevated reversible bridge, FIGG also is providing construction engineering inspection services.
Another notable feature of the project is that it’s the first toll facility in the United States to operate exclusively with electronic tolling or without toll booths. As an alternative, toll collection will be done through SunPass, Florida’s electronic toll collection system. A cash collection option will still be offered on the existing roadway below.
Construction on the expressway began in February 2003 and is anticipated to be complete in July 2005. PCL’s contract, worth approximately $145 million, is for the construction of most of the elevated portion including a section passing over I-75. The bridge is being erected in the 40-ft. (12.2 m) median strip of the existing expressway. In order to minimize congestion and traffic delays, construction crews will not work during peak travel times in the peak direction.
“Initially it was a challenge, but we engineered it to overcome that challenge,” said Scott Updegrave, PCL Construction Manager.
The reversible bridge will include 3,032 reinforced concrete segments sitting upon graceful piers that are 6 ft. (1.8 m) wide at the base. Typically, segments are 9 ft., 4 in. (2.8 m) long and cost approximately $10,000 each.
PCL is constructing the bridge segments off site at a 25-acre casting yard at nearby Port of Tampa. The 60 to 78 ton (54 to 71 t) segments are formed by pouring concrete into large steel molds. The concrete is reinforced to withstand extreme pressure –– 6,000 lbs. (2,722 kg) per square inch. Gerdau Ameristeel’s Tampa Fabricated Reinforcing Steel Division is supplying more than 17,000 tons (15,422 t) of fabricated reinforcing steel for the piers and roadway segments.
When finished, each segment is transported, along with its corresponding segment, on flatbed trucks to the construction site for installation. Match casts, or custom matches, are used to ensure a smooth fit so that the segments will sit together perfectly for the entire length of the bridge. PCL is producing segments at the rate of 45 per week.
The company has crews using Caisson drills to drill shafts to depths of nearly 70-ft. (21.3 m). Unlike the segments, the 220 vertical concrete piers are cast in place.
“Three drill rigs are operating right now, and 170 of the 220 piers have been poured,” said Updegrave.
For the work to be performed from above the existing roadway and median, a steel truss, or erection girder, has been placed between the piers at the construction site to temporarily support the segments while they are being assembled. Using an overhead crane, the segments are lowered onto the truss where they are pulled together with steel cables inside the bridge and the erection girder is launched into the next span.
“The underslung self-launching erection truss is capable of carrying in excess of 1,200 tons of bridge segments,” explained Updegrave.
The crews are currently putting up bridge segments in multiple locations. To do this, PCL rented two Manitowoc 4100S crawler cranes from Maxim Crane Works of Orlando. Underneath the cranes are oak timber mats that, according to Updegrave, “keep the cranes stable and help to distribute the load, which minimizes the potential of instability.”
South Eastern Timber Corp., Coral Springs, FL, is supplying the approximately 140 Oak Crane Mats to PCL for use on this project. The mats are 12 in. (30.5 cm) thick, 5 ft. (1.5 m) wide, and 24 ft. (7.3 m) long. The timbers are bolted together with 1.25 in. (3.2 cm) steel rods, countersunk. This allows the mats to stick together while the bolts are flat. The mats also have exposed bolts for ease in handling with cranes.
Diane Murray, vice president of South Eastern Timber, said the company “puts a preservative coating on the ends to extend the life span of the mats. [Companies] can use them until they wear out.”
Most of the bridge segments are hollow and roomy, providing space for traffic control and transportation technologies. These weatherproof, hollow cores will contain utilities, fiber optics, and specialized “intelligent transportation system” equipment that will automatically activate electronic motorist information services and the automatic toll collection system.
Orlando-based Hubbard Construction Co. was awarded the $34.4 million contract to construct the at-grade 3-mi. (4.8 km) portion of the project as well as a retaining wall, noise wall, storm drainage, storm water ponds, signing and pavement marking roadway lighting, landscaping traffic signals and traffic maintenance.
Jones Bros., Lake Mary, FL, is working on the feeder roads that lead to the expressway. Kimmins Construction Co., Orlando, will be performing railroad relocation for the project, and Cone & Graham Inc., Tampa, will be working on the Meridian Ave. gateway into downtown.
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