Memorial Bridge Soars High Above Clearwater Harbor

Tue October 26, 2004 - Southeast Edition
Brenda Ruggiero

Despite numerous challenges that have recently included hurricanes, a $48-million bridge project near Clearwater, FL, is steadily moving toward its December 2005 completion date under the direction of the Florida Department of Transportation (FDOT).

According to FDOT’s Bruce Trott, the job contract calls for twin cast-in-place segmental bridges on S.R. 60, spanning the Clearwater Harbor between the city of Clearwater and Clearwater Beach. The two bridges will replace the existing bascule bridge, which will be demolished upon completion of the new structures.

FDOT noted that the new high-span design will provide a faster evacuation route in emergency situations and will improve traffic flow between the mainland and the beach. Funding is provided by FDOT, Pinellas County, the federal government and the city of Clearwater.

Trott explained that the project was bid under the traditional design-bid-build process, and out of four bidders, PCL Civil Constructors Inc. was the lowest.

“A Value Engineering Change Proposal [VECP] was submitted and accepted by the owner, FDOT, that returned a portion of the savings to the FDOT,” Trott explained. “The VECP modified the contract payment structure from unit price to lump sum, and changed the contract format to design-build for the bridge substructure and superstructure. Design changes were made to the drilled shafts, footings, columns and superstructure.”

Each bridge consists of nine spans that total in length 2,340 lineal ft (713.2 m).

“Of the nine spans,” Trott noted, “four will be constructed by balanced cantilevers using form travelers. The remaining five will be constructed on falsework. Two piers are accessible only by barge, with the others accessible by land.”

The roadway approaches to the bridges total 2,500 linear ft. (762 m), and the embankment is constructed with mechanically stabilized earth walls. Under each footing are four drilled shafts measuring 7 ft. (2.1 m) in diameter and installed an average of 70 ft. (21.3 m) into the bay bottom. Overall, the project scope includes lighting, aluminum handrails, drainage, utilities, signalization, signage, parking lot reconstruction and removal of the existing bascule bridge and fishing pier.

The project includes 3,035 tons (2,753 t) of asphalt, 34,472 cu. yds. (26,356 cu m) of concrete, 4.2 million lbs. (1.9 million kg) of reinforcing steel, and 2.1 million lbs. (952,543 kg) of post-tensioning steel.

Trott noted that balanced cast-in-place segmental construction is relatively new in Florida, with the Memorial Causeway being the second bridge of this type constructed in the state.

At peak production, 25 staff and 120 craftspeople are assigned to the job under PCL project manager Sean Bush and PCL roadway project manager Gayle Wells.

According to Trott, the equipment list for the job includes four Form Travelers, each custom-designed and built for the project.

“However,” he said, “they can be used on other cast-in-place bridges –– i.e. they are for sale …”

Cranes used on the project include a Tadano 30T RT, a Terex 60T RT, a Manitowoc 4000 crawler crane and an American 9310 crawler crane. On site, there are two spud barges measuring 180 by 60 by 12 ft. and 90 by 50 by 8 ft. There also are two material barges measuring 90 by 30 by 9 ft. and 140 by 36 by 9 ft.

Also in use on the job are several manlifts ranging from 60 ft. to 125 ft. (mainly JLG and Genie) as well as a Cat IT28 front-end loader.

Major suppliers include Florida Rock Industries for concrete, SMI for reinforcing steel and VSL for the post-tensioning system.