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Ancient Way Creates Span For Today

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By MARK DOUGLAS

mdouglas@wfla.com

Published: January 3, 2009

BELLEAIR BLUFFS - After nearly two years of detours, noise and traffic slowdowns, engineers say the new high-rise Belleair Causeway bridge, complete with 8-foot sidewalks and bike lanes in both directions, is just a few months away from handling traffic.

"The bridge is scheduled to be open in the spring, and it could be April or May," said Jonathon Addison, the senior engineer on the $72 million bridge project for Pinellas County.

Two weeks ago, Addison's bridge-building team reached a milestone in construction using a method inspired by the builders of the Egyptian pyramids.

For the second time in U.S. bridge-building history, construction workers employed a technique called "incremental launching" to drag 7,200 tons of concrete deck into place.

It works in the way some archeologists think the pyramids were built: by dragging huge construction components into place and aligning them.

The bridge workers used heavy-duty hydraulic jacks and Teflon pads, plus an ingredient found in every kitchen - dishwashing detergent.

Engineers buy the slick liquid by the case from Sam's Club.

Giant slabs of bridge deck were dragged across a series of piers to form the east and west approaches of the Belleair Causeway bridge.

Tony Horrnik, Pinellas County project engineer, uses an analogy more up-to-date than the pyramids. It's like a slow rocket launch to him, with the slabs poured and cured on land in succession then pulled one at a time up to 660 feet across support columns.

By the time the last slab on the west approach was cured, connected to the others and dragged into place, the bridge deck weighed about 7,200 tons.

Think of 500 vehicles, without wheels, dragged across the ground at the rate of about a quarter inch every seven seconds.

"It's more than people can comprehend," said John Meagher, who works as project manager for Johnson Brothers and Misener Marine, the general contractors. "It's a lot of weight."

Engineers say the dragging method is cheap, safe and simple. They will use traditional concrete beams lifted into place with cranes to span the center portion of the bridge.

After the new bridge opens for traffic, county engineers expect to complete the project with a new boat ramp, dog beach and demolition of the old bridge by November.

The high-rise span replaces a Bascule bridge across the Intracoastal Waterway that was built in the early 1950s.

Mark Douglas can be reached at (727) 709-2753.

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