Woodrow Wilson Bridge Project, DC, USA

The Woodrow Wilson Bridge, crossing the Potomac River in Washington DC, is being replaced with two new bridges to cope with the increasing demands placed upon it by commuter traffic. This has been the cause of excessive and difficult maintenance work on the bridge, which led to a decision to replace it entirely.

At a total cost of $2.476bn the Woodrow Wilson Bridge project has been undertaken by four main partners: the Federal Highway Administration (FHWA), Virginia Department of Transportation (VDOT), Maryland State Highway Administration (MSHA) and the District of Columbia Department of Public Works (DCDPW).

The general engineering consultants for the bridge (responsible for design, construction activities and environmental monitoring) include Potomac Crossing Consultants, Parsons Brinckerhoff, URS, Rummel, Klepper and Kahl LLP, A. Morton Thomas & Associates Inc, Belstar Inc, Coastal Resources Inc, Indam Engineers Inc, NXL Construction Services Inc, CAM Systems, Strat@comm, Continental Field Services Corp, Terra Company Inc.

FUNDING

The Woodrow Wilson Bridge received special federal funds totalling $1.581bn from sources including: the Woodrow Wilson Bridge Authority Act (1995), the Transport Equity Act for the 21st Century (TEA-21), General Revenue from Federal Public Law 106-346 and Revenue Aligned Budget Authority (RABA) legislation.

WOODROW WILSON BRIDGE PROJECT OBJECTIVES

The Woodrow Wilson Bridge project has two major objectives – the construction of two side-by-side drawbridges and the construction of four adjacent interchanges. The project area has a 7.5-mile corridor, beginning in Maryland and connecting, via the bridge, to Virginia.

The original bridge was constructed in 1961 and was designed to carry up to 75,000 vehicles a day. This design volume was reached in just eight years and up until recently almost 200,000 vehicles crossed the bridge each day.

This severe congestion was compounded by one of the worst bottlenecks in the US; the eight-lane Capital Beltway (I-95/I-495) narrows from eight-lanes into the six-lane bridge.

The demand for the new Woodrow Wilson Bridge was so great due to the extensive growth of the Maryland and Virginia suburbs and the urban regeneration of Washington DC.

The Woodrow Wilson Bridge project has two main aims, for the bridge(s) to unclog the bottleneck and the interchanges to alleviate traffic congestion and manage improved traffic flow.

BOX-GIRDER BASCULE DRAWBRIDGE

In 1998 a bridge design competition was held. This was won by Steinman and Deleuw who proposed a graceful, seamless bascule drawbridge. The box-girder bridge features V-shaped piers that appear as arches to give an open appearance. The Woodrow Wilson Bridge features two 6,075ft long multiple-span bascule draw-bridges, each with six lanes. Bridge design consultants included Parsons Transportation Group.

The total design and construction costs of the bridge and ramps run to $900m of the total budget and see the bridge doubling its lanes from six to 12. The new drawbridge also has a 70ft navigational clearance reducing the amount of yearly openings from approximately 260 to 65 per year, greatly reducing traffic interruptions. The bridge sits on steel piles bedded 150ft below the river and is supported by 18 of the V-shaped piers.

The new bridge deck has a New Jersey Barrier median and New Jersey parapets resulting in the roadway being 44ft wide, thus allowing a 7ft shoulder on the right of each roadway which the old bridge does not have.

WOODROW WILSON BRIDGE CONSTRUCTION PROGRAMME

The bridge construction programme was split into three main phases: dredging the riverbed; building the foundations; and constructing the actual bridge and approach roads (completed by 2009).

Construction began in October 2000 and the first of the two six-lane spans was opened on 18 May 2006. The second six-lane span is scheduled to be open by May 2008. The beltway approaches (from West of US Route 1) are ready to link up with the new bridge when it is completed and the remaining beltway reconstruction including the VA-241 Telegraph Road interchange and the MD-210 Indian Head Interchange are scheduled to be complete in 2011.

This first phase of dredging was necessary to create a channel for construction equipment to safely access the locations for the foundations to be built through a submerged aquatic mitigation bed (SAV). An estimated 330,600yd³ of river soil was dredged during the course of this first phase. The contractor for this phase was Weeks Marine Inc (Contract BR1-Dredging, the contract was for just under $14.5m). The dredging contract was completed in February 2001.

FOUNDATIONS AND BULKHEAD IMPROVEMENTS

The second phase involved the foundations being put in place so that they did not conflict with the existing bridge and bulkhead improvements in certain areas for the construction staging areas.

The foundations included steel pipe piles of 42in to 66in for the river piers (11 piers) and Pier V-2, the first pier on the Virginia shore. The other Virginia piers were constructed from square pre-stressed concrete piles (six piers).

The contractors for this phase were Tidewater Construction Co/Kiewit Construction Co/ The Clarke Construction Group Inc Joint Venture of Virginia Beach (Contract BR2-Foundations was completed for $125.4m). The foundations contract was completed in June 2003.

SUPERSTRUCTURE CONSTRUCTION

The final phase, and the most contentious, was the building of the bridge itself, a contract which included the balance of the foundations, pre-stressed concrete V-piers, steel box girders, a control centre, a concrete deck, electrical controls, signs and lighting. Following the completion of this stage (first bridge opened in May 2006) the old bridge was to be demolished on 29 August 2006 and the construction of the second span was started using the foundations completed in 2003. The second span is due to be opened in May 2008.

Only one bid for the superstructure construction was received. Kiewit, Tidewater and Clarke (the foundation contractors) bid $860m, a figure 70% more than the bridge authority's estimate of $450 to $500m.

Consequently the bid was rejected and the contract cancelled and split up into three smaller contracts before being resubmitted for tender. This held up the construction for six months. Three contracts were won for the bascule portions, one for the outer bridge's over-water segment (Maryland Approach) and one for the outer bridge's over-land section (Virginia Approach). Construction needed to start by spring 2003 to keep the bridge on schedule.

BASCULE SPAN

The Bascule span contract was awarded to American Bridge Co/Edward Kraemer and Sons of Coraopolis PA for a bid of $186m. This was still 11% above the estimate of $168m but was deemed to be within the acceptable range.

The contract included the construction the bascule sections of both of the six lane spans as well as construction of a bridge operating tower and demolition of the old six-lane bridge (Contract 3A).

VIRGINIA APPROACH

The Virginia Approach span was awarded to Virginia Approach Constructors, a joint venture of Granite Construction Co of Watsonville and Corman Construction of California, for a bid of $115.5m. This bid was below the $160m estimate and had the effect of taking the bridge to 8% below the estimated budget at that time.

The contract involved the construction of seven of the bridge's new 18 spans, six of which were on land in Alexandria's Jones Point Park (Contract 3B).

MARYLAND APPROACH

The Maryland Approach span was awarded to Potomac Constructors, a joint venture of the American Bridge Co and Edward Kraemer and Sons, for a bid of $191m. The contract involved the construction of the bridge from the abutment in Maryland to the draw span just off the Alexandria shore. Crossing more than three quarters of the Potomac River the contract involved the construction of ten of the 18 spans, which are all over water (Contract 3C).

Contracts 3A to C have a deadline of August 2008 and are costing a total of $632.5m (saving around $230m on the single contract approach).

INTELLIGENT TRANSPORTATION SYSTEM

$1.5m has been invested in an Intelligent Transportation System (ITS) to provide effective traffic information and quick incident response. Contracted out to MASTEC North America, Inc. the ITS system includes variable message signs, CCTV and radio alert signs to improve VDOT's operations control centre's ability to facilitate incident and traffic management. Road users and the operations control centre will benefit from near real-time traffic information and immediate emergency response.

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