More problems take toll on Clearwater's troubled bridge
The problem is serious enough that crews might have to redo work on the new Memorial Causeway Bridge.
By JENNIFER FARRELL
Published February 18, 2004
CLEARWATER - First, crews used explosives to drop an 80-foot section of the bridge span after it fell a foot and twisted in December 2002.
Then, this month, another part of the roadway fell 7 inches when scaffolding underneath it buckled.
Now four concrete columns holding up the highest section of the state's new Memorial Causeway Bridge are riddled with cracks. The problem is so serious, crews might need to tear down those supports and start over, state Department of Transportation officials said Tuesday.
Officials also could not rule out the possibility they will have to demolish and rebuild the 350-foot center span, which straddles Clearwater Harbor and is supported by the cracked columns.
For Clearwater, the news was another disappointing setback in a $69.3-million project planned as a city showpiece. Originally set to accept traffic in December 2003, the bridge has seen a string of mishaps. The cracks are the third structural flaw discovered in the past 14 months.
And while officials said the bridge is in no imminent danger of collapse, it could take engineers up to six weeks to figure out the scope of the problem and how to fix it and whether a design change caused the cracks.
Meanwhile, no one could say when it might open, replacing the existing drawbridge that carries traffic to the beach.
"We don't have all the answers," DOT District Secretary Ken Hartmann said. "There's still some work to be done."
Hartmann said it is too soon to tell what caused the problem and he declined to speculate on how long repairs might take or how much they might cost. He said extra costs will be absorbed by Canadian-based bridge builder PCL Civil Constructors, not taxpayers.
The cracks, discovered Jan. 27, extend 6 inches into the diamond-shaped support columns on both sides of the channel, according to William Nickas, DOT state structures design engineer. Four of the bridge's 16 columns are cracked.
During a news conference Tuesday morning in the shadow of the new bridge, Nickas said PCL's decision to change the bridge design might have contributed to the current problems.
"What he elected to do caused this issue," Nickas said.
Under its original design, by Tampa-based HDR, the bridge deck was to be fastened to its supports using "pot bearings." The bearings would have allowed the roadbed to rock back and forth during construction, helping distribute force along its surface, engineers said.
But after being awarded the contract, PCL hired Earth Tech of Raleigh, N.C., to redesign the project with an eye toward trimming costs and time. Using the new plans, which were approved by the DOT, the roadbed was connected directly to the support columns. That meant the columns tilted back and forth with the roadway as sections were added on each end.
"His engineering during construction became very critical," Nickas said of the bridge builder.
PCL Vice President Jerry Harder said the redesign was meant to save money for the state, which owns the bridge, and the contractor. He stood by the firm's construction methods, saying he would repeat them if he had it to do again.
Harder, who works out of PCL's Tampa office, said engineers are studying the problems and he pledged to live up to PCL's end of the contract.
State and city officials said redesigning projects to save time and money is common.
To build the bridge, workers are using a relatively new method called segmental cast-in-place. Instead of prefabricating bridge sections, then assembling them like blocks, crews pour the concrete directly onto the deck. Some sections are poured on top of scaffolding built up from the ground, while others are crafted using giant, yellow "form travelers," which crawl back and forth along the roadway framing 20-foot sections at a time.
Twice, scaffolding under different parts of the bridge has buckled. On Feb. 4, crews discovered a roughly 100-foot section of the roadbed had fallen about 7 inches overnight. And in December 2002, crews used explosives to topple the steel supports holding the damaged 80-foot section in place. Two blasts at 3 a.m. sent 1-million pounds of concrete crashing 40 feet to the ground.
Both of those problems were related to scaffolding flaws, DOT officials said Tuesday.
But the scaffolding problems were not connected to cracks in the columns, they said.
John Fisher, a professor emeritus of civil engineering at Lehigh University in Bethlehem, Pa., said the mishaps suggest mistakes in construction.
"Somebody's just screwed up," he said. "There's nothing wrong with the methods. It's when somebody screws up in the application."
Tampa-based engineering consultant Parsons Brinckerhoff was hired by the DOT to oversee the project. DOT must approve whatever fixes PCL proposes for the cracks and the fallen roadbed. Options range from demolishing the columns and roadway to jacking up the roadway and making repairs in place.
Bill Adams, a senior project engineer with Parsons Brinckerhoff, said the cracks range in width from 0.002 of an inch to 0.02 of an inch. He said they extend into the columns at least to the first layer of steel reinforcements. The cracks are present from the base of the columns all the way up to the bottom of the structure supporting the roadway.
Frustrated city officials lamented the string of problems that have befallen the new bridge.
"I'm disappointed in the whole thing, frankly," said Mayor Brian Aungst. "There certainly is no good news to come out of this."
Aungst said the city, which kicked in money to shave two decades off the state's schedule to replace the drawbridge, must rely on the DOT to make sure the bridge is safe.
"They're going to have to inspect it and double inspect to make sure it's right," he said. "Nobody's going to let anybody on that bridge until it's ready to go."
Officials had given up hope the new bridge might be ready for spring break. But a grand opening, planned with a ceremonial run sponsored by the YMCA, had been set for April 17. The grand opening and run have been postponed indefinitely, City Manager Bill Horne said.
Launched in February 2002, the new bridge was designed to replace the existing drawbridge, a narrow and aging structure that malfunctions frequently, backing up traffic to and from the beach.
The bridge was originally set to open to traffic in December 2003, and the contract with PCL calls for completion in July.
City and DOT officials stressed the bridge will not open until it is safe.
"Until and unless that occurs," Hartmann said, "it will not be open to traffic."
- Jennifer Farrell can be reached at 727 445-4160 or farrell@sptimes.com What's the problem?Florida Department of Transportation officials say cracks have formed in four columns supporting the highest span of the Memorial Causeway bridge under construction. The $69.3-million bridge is being built to replace an existing bridge connecting mainland Clearwater to Clearwater Beach.
Why did the columns crack?The roadbed is being built on top of the columns a section at a time. A state DOT engineer suspects that during construction, the roadbed was allowed to get too far out of balance. That likely created force that put stress on the columns.
What's next?Officials plan to spend two to six weeks investigating the scope of the problem and figuring out what repairs to make.
Is the bridge safe?Officials say the unfinished bridge is not in danger of collapsing. Boats can continue to use the channel beneath it. Cars and trucks will use the existing bridge to the beach.
Will sections of the unfinished bridge have to be torn down?That hasn't been determined. Officials said Tuesday they were figuring out whether they could make repairs to the columns and roadbed. They did not rule out that they would have to demolish the cracked columns and replace the roadway between them.