...upriver. Besides good looks, the new crossing had to provide enough capacity and keep maintenance costs to a minimum. "Of course there are a lot of difficulties in achieving that," says Shafer. Arches were ruled out because of soft soils and the presence of a bascule. Instead, Parsons turned to V-shaped piers that aim to mimic arches.
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| Solid. Long-line precasting (top) is producing piers for Maryland and Virginia approaches. |
On the Maryland and Virginia approaches, the concrete piers are pre-cast and are "very difficult to build," says Michael D. Bonin, area bridge engineer for PCC and URS. For one thing, heights vary, from about 39 ft to slightly more than 100 ft. Moreover, they have "a very complex shape," Bonin says. The Vs have reveals and curve and flare out as they rise.
"Its all different geometry," says Lyell Tripp, Maryland approach project director for Edward Kraemer & Sons Inc., Plain,Wis., which is teamed with American Bridge, Coraopolis, Pa., and Trumbull Corp., West Mifflin, Pa. "Its hard to control geometry...when everythings changing all the time," Bonin adds.
On both approaches, the unusual shape prompted contractors to use long-line precasting, in which the formwork is all in place to make an entire leg of a V.
The Virginia approach precast operation is situated beneath the new southern bridge, where space is limited and access is tight, says Bob McTavish, area manager for Granite Construction, Watsonville, Calif., which is teamed with Corman Construction Inc., Annapolis Junction, Md., on that approach contract. McTavish expects to finish his part of the new southern bridge ahead of schedule. But on the new northern bridge, "the amount of work weve got to do and the amount of time will be much tougher," he says. One factor is the limited access until the old bridge is demolished.
The bascule section also has the V-piers, but they are cast in place, using a series of incremental concrete pours. The reason is that the bascule legs have to be much more muscular than their neighbors because they must support the eight bascule "leaves," which weigh between 1,900 and 2,200 tons each. Each bascule pier therefore has three Vs, while the approach piers each have two. In section, each of the four walls of the bascules hollow legs is at least 2 ft thick, compared with 1 ft, 3 in. on the approach pier legs.
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| Brawny. Cast-in-place bascule piers are larger and more numerous than others in order to support heavy leaves. |
Officials with the bascule segments team, American Bridge and Kraemer, say an important element in their job is the custom-built steel falsework that they developed with Janssen & Spaans Engineering Inc., Indianapolis. Each pier face has three falsework sections, about 70 ft tall and 30 ft wide. The sections are movable and reusable. Ken Hirschmugl, Kraemers bascule project official, says the falsework was 80% designed on the November 2002 bid day, "because that was the real trick to understanding how you would build this thing." 
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Having multiple contractors for the superstructure saved the project, but it complicated management. "The tradeoff for the affordable bid is an increase in owner risk for managing the interfaces," says Jim Ruddell, PB vice president and PCC construction manager.
Good coordination is imperative because of the many interchange contracts and benchmark dates to hit. Fuhrman, a former Army major general and Corps of Engineers civil works director, likens the project to organizing for combat. Part of that battle plan includes periodic "corridor coordination meetings" for contractors, says Ruddell.
An extensive partnering program is another important element, officials say. It undoubtedly laid the groundwork for the steel pact, Pedersen says. "You have to have a genuine partnering process in place so trust has been built to resolve problems as quickly as possible," he says.
So far, project officials have met bidding, foundation and steel problems. But they are vigilant. Says Fuhrman: "Who knows what it might be tomorrow?"
| Both Sides Have Novel Approaches and Interchanges of Ideas
The new bascule bridge may be the heart of the Wilson Bridge reconstruction, but major interchanges on both sides of the river constitute the major arteries. Rebuilding them on unstable soils in one of the nations busiest corridors is like performing multiple angioplasties, with methods both new and tried-and-true. Maryland and Virginia approach and interchange contracts are geared to tie into a May 2006 switchover of traffic from the existing Woodrow Wilson Bridge to the new bridge outer loop lanes. The outer loop local lanes will carry interim traffic. The future outer loop express lanes temporarily will serve inner loop traffic going in the opposite direction for about 2 years. In summer 2008, traffic will switch over from the outer loop lanes to the new inner loop lanes. James Brookshire III now is managing Virginias Route 1 interchange at the Beltway for the Virginia Beach-based joint venture Tidewater/Skanskas $146-million contract. He is a veteran of the foundations contract, which included suspended cofferdams, 6,000-cu-yd pours and an underwater hydraulic hammer from Norway. The project still is in the initial stages, with 40-ft-deep piles driven into soft soils, capped and covered with fill. Overhead power lines are buried to allow for piledriving. Since the lines travel beneath Route I, "we used jack-and-bore instead of digging a trench," says Chip Fiore, Potomac Crossing Consultants lead project engineer. "We dug a pit on either side of the road, hydraulically jacked a 42-in. steel casing through and augered out the dirt inside the pipe."
Ronaldo "Nick" Nicholson, Virginia Dept. of Transportations Wilson Bridge project manager, notes that the Route 1 corridor includes infrastructure from the 1800s. While installing utility duct banks, "we found another [unexpected] layer 5 ft deep." While penalties could reach up to $80,000 a day for late delivery, the joint venture also has five milestone incentives and a "no excuse" bonus for the sixth. "If we complete the interim milestone 6 five months early, it could be a $5 million bonus," says Brookshire. Total potential bonuses could reach $7 million. "The contractor takes the risk...but were willing to prioritize the elements" that the contractor requests through value engineering and innovative proposals, says Nicholson. The other major Virginia interchange, at Telegraph Road, includes 11 bridges and $175 million of work. Utility work up to $20 million will be advertised in March, and up to $90 million worth of work is expected to begin in 2007. Currently, the $250 million of Wilson Bridge-related work under way in Virginia is on time and on budget with no major claims to date, says Nickerson. That also includes a $54-million contract for a six-lane tie-in to the future Wilson Bridge and a $39-million contract for ramps and flyovers. The work also includes 7,000 ft of utility microtunneling beneath I-95, auger-drilled columns injected with concrete, lightweight geofoam blocks in embankments and a cementitious flowable fill that achieves stability within six weeks. Fiore says the geofoam blocks, which vary in size, will be used on a 100 ft x 200 ft abutment as a change order due to an unexpected sewer line. "We needed to make the embankment light enough to avoid settlement of the sewer line," he says. Transparent noise walls made of a light epoxy-coated glass satisfied community aesthetics while providing anti-graffiti benefits, says Nicholson. Discovered by VDOT officials in Europe, the glass panelswith filaments to prevent bird crasheshave been used in the U.S. only once before, in New Jersey. They are triple the cost of standard walls. VDOT will complete all right-of-way acquisitions this year, another task that required flexible solutions and negotiations. Those included a $62-million agreement with the city of Alexandria for VDOT to build local street improvements and parks in exchange for the city dropping a lawsuit. Officials reached another deal by buying 23.5 acres of land that included 645 apartmentsand acting as landlord. Tenants were successfully offered in-centives to move and other agencies now are looking at similar programs, says VDOTs Stuart Waymack, right of way and utilities director. The apartments now house bridge workers.
In Maryland, the $200-million Interstate 295 interchange work is well under way. Its fourth and final contract will be bid next month, says David Wallace, approach manager for PCC. Initial work included 10,000 linear ft of wick drains and settlement plates to preconsolidate some 550,000 cu yd of fill for the new outer loop lanes, says Glenn Evans, PCC area engineer. York, Pa.-based G.A. and F.C. Wagman Inc. is completing two contracts worth a total of $87 million, including outer loop ramps and flyovers. "The hardest aspect was getting material to the site," says Craig Lease, MDOT resident engineer. The last contract to build the inner loop will utilize geofoam blocks because of the limited time for settlement in the schedule. Wagman also holds an $18.7-million contract to build noisewalls at the Maryland 210 interchange. A $45-million contract to build a new bridge carrying 210 over the beltway will be awarded in March, says Wallace. A $60-million contract for MD 210 inner and outer loops will be awarded this fall. In March 2003, PCC sent outreach letters with specs and other information to 375 firms to encourage them to bid on the $45-million contract and a $90-million contract on I-295 that will include 10 bridges and a pedestrian link to major riverside development. Both will be awarded this spring. "Contractors appreciated the six-month heads-up," Wallace says. |
