The gateway to the popular beach resorts of Maryland, Virginia, Delaware, and New Jersey is in the middle of a $60-million facelift. The renovation project involves the 30-year-old westbound span of the William Preston Lane Jr. Memorial Bridge, commonly known as the Bay Bridge because it crosses the Chesapeake Bay.
The Maryland Transportation Authority is funding the project as part of its preservation efforts for the bridge. The Transportation Authority is an independent organization from the Maryland State Highway Administration. Funding for its construction and maintenance projects is primarily earned through tolls collected at their five facilities statewide, including the Bay Bridge, Key Bridge (over the Baltimore Harbor), Nice Bridge (over the Potomac River 301S), Harbor and Fort McHenry Tunnels (under the Baltimore Harbor, I-895 and I-95), and I-95 North of Baltimore.
This particular project will be completed under two separate contracts, and will include removing and replacing portions of the concrete bridge deck and metal railings in the concrete beams, deck truss and steel-girder spans.
Baltimore’s Cianbro Corporation was awarded the first contract in October 2001. David Heaton, Cianbro project engineer, reported that the company’s original contract amount was $33 million. “Continuous changes and additions to the scope have persistently increased that value,” he said. “The projected final completion for this contract is May 20, 2005, and it is currently on schedule.”
Heaton explained that the westbound span of the Chesapeake Bay Bridge is a three-lane bridge — 38 ft. (11.6 m) wide — that was built in 1973. It contains 6,930 ft. (2,112 m) of prestressed concrete beam spans, 3,346 ft. (1,020 m) of continuous welded girder spans, 5,944 ft. (1,812 m) of deck cantilevered truss spans, 1,719 ft. (524 m) of through cantilevered truss spans, and 3,110 ft. (948 m) of cable suspension spans — for a total of 21,050 ft. (6,416 m).
“This rehabilitation contract includes replacing the concrete bridge deck in 2,735 linear feet of continuous welded girder spans and 1,134 linear feet of deck in the prestressed concrete beam spans,” Heaton said. “The entire deck cantilevered truss will be resurfaced with a two-inch milling and overlay operation, and the remaining 5,796 linear feet of prestressed concrete beams spans will also be resurfaced. In addition to the deck replacement and rehabilitation, approximately 13,000 linear feet of steel bridge rail is going to be removed and replaced with new and refurbished rail.”
Heaton explained that Gary D. Gorman, senior project manager of Cianbro Corporation, is ultimately responsible for the project construction activities. “He is diligently applying his 36 years of construction experience to manage the unique project challenges that this job has to offer,” he said.
Because the Bay Bridge is the main thoroughfare to Maryland’s Eastern Shore and numerous beach resort areas, the summer months bring heavy traffic volumes.
“The summer ’beach goers’ represent a significant portion of the 24-million cars per year that travel the Bay Bridge,” Heaton said. “Due to the usual heavy traffic during the summer months, the construction seasons for the rehabilitation work are constrained to the bitter winter months 200 feet above the Chesapeake Bay.”
Heaton explained that construction activities commence in the late fall months with the installation of approximately 15,000 ft. (4,572 m) of concrete traffic barrier for a single continuous lane closure from the middle of October through the Thanksgiving weekend. Prior to the Thanksgiving weekend, the temporary concrete barrier is removed from the bridge in order for the entire bridge to be open to three lanes of holiday traffic. Following the Thanksgiving weekend, the traffic barrier is again placed on the bridge for a continuous lane closure through the end of March.
“These annual activities are part of the contractual obligations to replace and rehabilitate approximately 16,000 linear feet of concrete deck across the three-lane bridge,” Heaton explained, “and to replace and refurbish 15,000 linear feet of steel bridge guardrail, all during the freezing temperatures of the winter months.”
This past winter proved to be even more challenging than previous ones.
“One of the extraordinary challenges experienced this past season was the inclement weather that burdened the Mid-Atlantic region,” Heaton noted. “With 70-year record snowfalls and temperatures falling below 10-year lows, means and methods for concrete demolition and placement were accelerated and modified to avoid the severe fines associated with not having the bridge open to traffic when required. These fines were in excess of $108,000 per day, and who can afford that?”
According to Heaton, a maintenance of traffic (MOT) array has been established to accommodate the traveling public with minimal traffic delays. The MOT fluctuates on a daily basis depending on traffic volume. Under contract stipulations, Cianbro must monitor the maintenance of traffic 24/7 throughout the project. They place temporary concrete traffic barriers adjacent to the demolition work areas and open and close lanes with traffic drums/cones on a daily basis and at the request of the Authority.
To assist with a second lane closure on a nightly basis, the Authority has leased a movable concrete barrier system on a trial basis. Based on utilization of the movable barrier for this project, the Authority intends to use the system as a traffic barrier to avoid the possibilities of a head-on collision while running two-way traffic across the bridge.
Following the deck rehabilitation of the truss, beam and girder spans contract, the Maryland Transportation Authority has preliminary intentions to replace and rehabilitate the through truss and suspensions spans on the westbound bridge.
During the construction season, Cianbro had approximately 55 employees on the project.
“In addition to managing their own forces,” Heaton noted, “Cianbro coordinates and depends on the efforts of 18 subcontractors located everywhere between North Carolina and New York.”
Heaton reported that Cianbro’s equipment list for the project includes excavators to remove deck slab pieces and hoist and position the concrete bucket during pours. They use a John Deere 3/4-yard 120 Metco and a Komatsu KM PL228US-2 with a 5,000-ft./lbs. hammer. Three Volvo VME L90D rubber-tired loaders are used to place and remove the concrete traffic barrier, load and unload project materials, and for concrete demolition and placement of slabs.
A Caterpillar 416C rubber-tired backhoe with a 1,000-ft./lbs. hydraulic hoe ram was used to hoe-ram the bridge deck prior to hand chipping and to remove the concrete debris from the bridge.
Trucks were important to provide transportation for the traffic barrier, concrete slabs and project materials. A boom truck was used to transport all materials and demolition debris from the work areas and yard.
Two air-powered Allen razorback screed machines were used to screed the concrete deck during placement, and deck heaters were utilized to pre- and post-heat concrete pours to more than 35 F.
Several cranes also are being used for various tasks such as placing and removing the concrete traffic barrier, loading and unloading materials in the yard, removing and reinstalling bridge railing, installing and removing underpinning beams, and mobilizing and demobilizing project tools and equipment. Cranes include a Grove 528C rough terrain 28 ton (25.2 t), a P&H CN128 rough terrain 28-ton (25.2 t), a Grove rough terrain 22 ton (19.8 t), and a Grove AP308 8.5 ton (7.7 t).
A 450-hp (335 kW) Grey Hound tug with a 30- by 60-ft. (9.1 by 18.3 m) barge provides water transportation and access and a marine work platform under the bridge while installing underpinning false work and debris shielding.
A Ford Bridge Inspector — SBC/BBC Snooper LT-8000 Snooper truck — provides access and a work platform while installing underpinning false work, debris shielding, and fiber optic conduit.