A bridge unlike any other takes shape
Since 1934, erosion has doomed five spans built over Indian River Inlet
By MOLLY MURRAY / The News Journal
03/06/2005
William L. Quesada never talked much about that day in 1948 when a caravan of three vehicles headed across the Indian River Inlet Bridge from Bethany Beach.
Or that two never made it to the north side.
"I [regained consciousness] that afternoon at about 2 o'clock, and I shook for two days getting myself thawed out," he said in 1974 of his fall into the icy inlet when the bridge gave way under pressure from pack ice. He was one of two survivors that February morning.
The first car made it across. But a truck was caught as a crack formed in the south section of the bridge. Quesada and three other men in the trail car leaped out to try to help, but the bridge section collapsed, plunging men, machines and steel into the inlet. Three men died.
Delaware officials are getting ready to spend $160 million to make sure a similar fate does not befall the current bridge. The state will build a new span that should be ready by 2008 - a 1,300-foot-long structure unlike any bridge across open water in the world.
The existing bridge is not unsound, but the turbulent waters moving back and forth from the bays to the Atlantic Ocean have worn deep depressions around the base of the pillars that support the structure. Long-term, that's a problem, state officials said.
"These holes have a lot of people concerned," said Sen. George H. Bunting Jr., D-Bethany Beach, who has lobbied for a new bridge for more than 10 years.
Transportation Secretary Nathan Hayward II said engineers finally concluded that a new bridge, built in a new way was the only sure solution.
"We can't ignore the fact that Mother Nature at some point is going to take the existing bridge away," he said.
The span is a critical link between the northern and southern beaches. Without it, the 12-mile trip between Rehoboth and Bethany beaches would be three times as long - 36 miles over an inland route.
"It would be a good little ride," said Millville Fire Chief Eddie Hammond. The delay would be a problem for ambulances headed to Beebe Medical Center in Lewes, and it would hurt businesses.
Hayward said he thinks the new bridge will help an area dependent on tourism.
Officials hope the arched structure will not only endure, but serve as a landmark and a destination. It will include a walkway for pedestrians and cyclists.
"I love the arch," Hayward said. "And I love the notion that it's very, very graceful."
Rough site for bridges
The arch, however, is more than an architectural statement. It is the solution chosen by engineers to solve the problem of erosion of support pillars that has doomed all five bridges strung across the inlet since 1934.
The first bridge was little more than an all-timber platform and was replaced in 1938 by the concrete-and-steel bridge that fell in 1948. It was replaced in 1952.
The existing bridge was built in two parts, with the north lanes built as part of the two-lane Del. 14 in 1965. The span was widened to four lanes in 1976.
In 1965, the inlet was about 28 feet deep in the center and 23 feet deep around the bridge piers. Erosion has deepened the inlet to about 60 feet. In the places where deep holes have formed, the bottom is 90 to 100 feet down.
Indian River Inlet is one of the most inhospitable places in Delaware for a bridge, buffeted by high winds, bathed in salty spray and undermined by strong tidal currents and pack ice during the coldest of winters.
During Hurricane Gloria in 1985, 70-mph winds toppled a row of telephone poles nearby, waves chewed away at the beach and a blanket of sand covered the bridge approaches.
During Hurricane Isabel in 2003, so much water rushed from the ocean into Indian River Bay and back that there was concern the support pilings had been compromised. The bridge was closed until a survey confirmed the structure remained sound.
State officials have been fighting erosion since 1988, when rough stone was added to protect the piers from the currents. In December 1987, an underwater survey found erosion had exposed parts of the 60 piers that support the north side of the 880-foot-long bridge. Recent underwater images show holes are deepening.
An average of 16,280 vehicles cross the bridge every day, but the numbers climb way up in summer. The bridge is part of resort Del. 1, which is one of the few emergency evacuation routes from beach communities to the south.
A brand-new approach
To build a bridge that could stand up to the conditions, state officials concluded a way had to be found that would not rely on pilings in the inlet floor.
"We wanted to span the entire inlet," said Dennis M. O'Shea, assistant director of design for DelDOT.
The state hired Figg Engineering Group and set up a 70-member committee of local residents and leaders. Figg designed the Del. 1 bridge over the Chesapeake and Delaware Canal.
The design relies on two concrete piers sunk 100 feet into the ground on both sides of the waterway. Special steel, rubber bearings and a Teflon-like substance will be layered inside the piers to allow for expansion and contraction.
O'Shea said the arch system works like a bow and arrow. Much of the bridge will be made of concrete, which isn't great at holding things in tension, he said. So steel reinforcing will tie the concrete together.
The end result is a bridge built with a material that can withstand the salt air that is held together with steel cables - some that people will see radiating from the arch to the deck.
The concept was enough of a challenge that it served as a model for study - and testing - by civil engineering students at the University of Delaware.
Last summer, undergraduates used computer models to assess the design, finding that it "appears to work."
Michael J. Chajes, chairman of UD's Department of Civil and Environmental Engineering, said the most critical stage will come as the concrete arch is poured. As the two pieces extend from the shores, their weight will be a problem only solved when the final piece is in place over the center of the inlet.
The state will build temporary towers to support the arch pieces until they are done.
"Without that, you couldn't build it," said Chajes, who likes the design.
"I like the way the cables come in like the rays of the sun would," he said.
Construction to start this summer
Julia West, a graduate student working on the project, said UD students will continue to be involved.
Students will check special sensors in the concrete to monitor subtle changes in the material and how the bridge reacts to wind. They also will create a computer model to track changes.
Construction awards for the roadway are to be made this month. Bids for the bridge itself will go out this month with contracts awarded in May. Construction is expected to start this summer.
Work should wrap up in fall 2008, but it will take another year or two to demolish the old bridge. It will be used in artificial reef construction off the Delaware coast, said Michael Williams, a DelDOT spokesman.
Hayward said state and federal money will be used for the project.
Wayne Stacey, of Ocean View, a commander at Indian River Coast Guard Station from 1992 to 1996, said he appreciates the desire to design a landmark, but the way something looks is not as important as the function.
"As long as it functions and it'll last and do the job," he said, "I am very grateful as a resident."
Contact Molly Murray at 856-7372 or mailto:mmurray@delawareonline.com
