It’s getting a lot harder for people driving across the Indian River Inlet Bridge to see through the gap between north and south sides of the new bridge as they drive past, with the time for the final concrete pour of the project nearing and just 10 feet of space remaining between the two cantilevered portions of the bridge deck.
DelDOT officials reported this week that plans are being made for the bridge closure pour to occur sometime during the week of Oct. 17. Community Relations Officer Tina Shockley said the exact date for the closure pour would not be known until 24 hours prior to its scheduled start, due to the influence of weather conditions.
Peo Halvarsson, construction manager for design-build consultant Skanska, provided an update on the project during the final days of September, reporting that the last full edge girder of the bridge had been poured during the week prior to the Sept. 29 construction advisory group (CAG) meeting. The last deck slab was then set to be poured during the first weekend of October.
With both the north and south ends of the bridge cantilevered over the inlet, Halvarsson noted that there is a 3-foot elevation difference between the two sides of the bridge. He said that was expected, since the south side still has its deck-building form traveler attached and the north side has already had its form traveler removed.
The remaining form traveler, he said, will be advanced forward so that the two sides share the weight of the form traveler equally, which is expected to solve the height elevation difference prior to closure of the two sides.
Once the closure takes place, the bridge will undergo post-tensioning and will be re-stressed. There will also be surveying done to make sure everything is in alignment and that the bridge profile is correct, Halvarsson said.
Ongoing work on the bridge also includes installation of the pedestrian barriers and guardrails.
Inlet to be closed for removal of second form traveler
The bridge’s second form traveler is expected to be removed later this month, at which time the inlet itself will be closed for a period of hours, DelDOT officials warned.
DelDOT Project Manager Doug Robb noted that the removal process will be similar to what took place when the north-side form traveller was lowered and removed this summer. With the inlet under a posted closure of about 12 hours, a barge was carefully positioned beneath the traveler, at a slack tide, and the traveler was then lowered onto it and taken out to sea.
The travelers are being disassembled after their removal because they’re unique to the project and cannot be reused.
Advance notice of the upcoming inlet closure will be provided, Robb noted.
Project roughly on track for travel by end of year
Despite about a week of lost work time due to Hurricane Irene and Tropical Storm Lee, as well as the long spate of rainy weather in August, the project continues to be roughly on track for its planned opening to traffic by the end of 2011. Robb said the goal continues to be to have the bridge open to two lanes of traffic by the end of the year.
However, he noted that, as completion of the bridge gets closer, weather will play a greater role because there are fewer days to make up for time lost to weather constraints.
So, while the timeline is still set for the bridge to be open to traffic by the end of December, Robb said the most important thing is to do the job correctly and have a safe bridge, even if that means not finishing until January. He did emphasize, though, that there was enough of a cushion built into the schedule that all four lanes should be open to traffic by Memorial Day weekend of 2012, lessening a major concern for local residents, business owners and visitors.
Revamped approaches set to be ready when bridge is complete
Craig Stevens of DelDOT also provided an update to CAG members on Sept. 29 on the status of the related roadway and bridge demolition contract, which is currently in Phase 2. As part of Phase 2, road detours remain in place, with one lane of traffic running across the old bridge in each direction.
He said a lightweight foam concrete has been installed on the approach roadways, with more being installed on the south side approach roadway than on the north side approach roadway. Roadway contractor George & Lynch and Skanska have been working together, he said, to raise the elevation of the concrete by 2 feet at a time, until the proper approach roadway elevation has been reached.
The south side, Stevens said, is ready to be poured once the approach slab is ready, with the process being to pour the concrete from the bridge to the embankment. Once the approach slabs are poured, the barrier walls will be erected.
CAG members asked about any comparison between these new approach spans and the ones created for the prior bridge design, which had to be scuttled when it was discovered that the approaches were settling too much to be used. (The State of Delaware is still in litigation over the failed approaches, which not only could not be used but required the redesign of the bridge to account for their presence.)
Stevens said there are many differences between the new approach spans and the ones created for the previous bridge effort. He said the limits for the roadway approaches have been significantly reduced and the amount of weight is significantly lower. The expectation, Stevens said, is that the new roadway approaches will behave in the same manner as those constructed elsewhere in the state.
As the bridge itself nears completion, Stevens said the roadway project remains on schedule and that the roadway approaches will be ready when the bridge is complete. The roadway construction schedule calls for Phase 3 to begin when the bridge is open to two lanes of traffic, which will be in or before early 2012. Local road improvements will then begin, and the existing bridge will be demolished. In the summer of 2012, all four lanes are set to be open to traffic.
Stevens also told CAG members that the road should be completed prior to fall and winter temperatures reaching a level where it will affect the roadway. He noted that the bridge uses a different construction method so it is not affected by the impending colder weather.
The next CAG meeting is set for Thursday, Oct. 27, at the Skanska field office on Inlet Road, at 10 a.m. The meeting is set to include a site tour for CAG members, which will allow them to be some of the first people to walk across the completed bridge deck, assuming the closure pour goes as planned.
Shockley noted that all of the public site tours that were conducted over the summer were completely full. No more public site tours are planned prior to the completion of the bridge. The bridge design, though, includes pedestrian access, so the public will eventually have close-up access to the completed bridge.