First public groups tour completed inlet bridge
Dressed in hardhats, gloves and reflective vests, a group of 20 civilians crossed the new Indian River Inlet Bridge, from end to end, for the first time. They grinned as a DelDOT tour guide led them across the newly completed 10-foot closure pour, which connected the two halves of the new bridge. Motorists had become accustomed to seeing the incomplete north and south sections move closer together until Oct. 18, when the closure pour was completed.
On Oct. 27, Delaware Department of Transportation (DelDOT) officials, representatives of bridge design and construction contractor Skanska and approximately 40 civilians attended the monthly Construction Advisory Group meeting at the inlet.
These meetings have informed the public about the project for more than two years, since before construction began on the bridge.
“This has been a major milestone for us,” said Doug Robb, project engineer for DelDOT. “It’s a beautiful bridge, very high quality, and we’re very pleased with the project.”
“It’s a great sense of accomplishment,” said Peo Halvarrason, a construction project manager for Skanska.
He presented a series of time-lapse photographs taken while the first of two 300-ton travelers was removed from the bridge construction platform back in August. The travelers provided a base upon which to build the bridge over water. The bridge seemed to bounce up after releasing the massive traveler onto a barge, but officials said the work went smoothly. The second traveler was removed overnight on Oct. 31.
Crews are still busy with construction of the road approach ways, as well as electrical work, road surfaces, final repairs and more.
Robb pointed out several parts of the road surface where extremely fine hairline cracks had appeared earlier in construction. However, they were treated with an epoxy material and are no longer a concern, he said.
Drivers may be curious about a layer of red polyester polymer concrete that will cover the road surface where the bridge spans the water. Regular black asphalt will lead Coastal Highway up to the bridge, though.
The blue stay cables holding up the new bridge will be lit at night with aesthetic blue LED lights, which will be ready around January. Late at night, only the outer cables will be illuminated, producing the effect of a sailboat, as well as reducing electricity and light pollution for nearby campsites.
A pedestrian walkway will follow the northbound lane, on the ocean side.
The bridge was engineered to withstand up to 200-mile-per-hour winds. A series of joints overlap, expand and contract with the bridge, so the structure may appear to move, especially now, because dampers have not been installed to counterbalance gusts.
“The bridge was bouncing pretty good during the earthquake before the closure pour,” Robb said of the rare temblor that struck the East Coast on Aug. 23.
Once competed, Robb said, the bridge is more likely to close to maintain vehicular safety than bridge safety. The structure can handle extreme weather, but cars might not, he said.
And, after years of concerns about the stability of the existing Indian River Inlet Bridge, high-tech sensors will allow officials to monitor bridge conditions, even from 50 miles to the north in Dover. For instance, engineers can monitor levels of chloride, which corrodes steel, or see how the bridge behaves in different weather.
The question of erosion
At the Oct. 27 meeting, Robb had said dune erosion on the inlet’s north side was being monitored around the clock. He said three backup plans would, they hoped, keep the current road open for another 19 weeks, until the new bridge – which is both situated farther from the ocean and engineered not to rely on the dune system – opens.
“Right now, we feel we have a stable condition,” Robb said.
Although Robb said he did not anticipate a closure would be needed, the highway was indeed closed overnight on Wednesday, Nov. 2, to address dune erosion from the Halloween-weekend nor’easter.
“We did it as a safety precaution,” explained Shockley.
Delaware’s Department of Natural Resources and Environmental Control (DNREC) already regularly pumps sand from the south inlet beach to the north-side beach because the constructed jetty there prevents natural sand distribution in that direction. The recent storms and a malfunction in the sand bypass system have caused heavier-than-usual diminishment in the north-side beach.
If the tides were to wash away the beach dune, Shockley said, it would undermine the sand and soils under the road – hence, the closure. With the changes made during the closure, traffic has been moved from the northbound lanes to the southbound ones, which are farther from the beach. The traffic configuration has not changed.
The equipment is working again to pump sand and replenish the beach, but Shockley said DelDOT wanted to be proactive due to the safety concern and to ensure public confidence.
DelDOT aims to “ensure public confidence that we’re on top of the situation,” Shockley said. “We acknowledge the inconvenience.”
The new bridge should open in late December of 2011 or early 2012, with two lanes of traffic, one in each direction. All four lanes are expected to open in the spring of 2012, officials hope by Memorial Day.
Demolition of the existing bridge will take place by early spring 2012.