Bridge Over Susquehanna Gets Sorely Needed Rehab

Wed March 10, 2004 - Northeast Edition
Brenda Ruggiero

After 50 years of constant use, a Pennsylvania bridge is getting a much-needed update.

The M. Harvey Taylor Bridge crosses the Susquehanna River from Harrisburg in Dauphin County to Wormleysburg in Cumberland County. At the time of its construction in 1952, the bridge was expected to handle 20,000 vehicles a day, which was approximately 40 percent of the traffic load of the 50,000 vehicles per day on the Walnut Street and Market Street Bridges. Originally, it was not intended to be part of a regional beltway or bypass system but was designed to relieve local traffic congestion by providing a third bridge over the Susquehanna. Today, the average daily traffic on the M. Harvey Taylor Bridge totals 35,000, and is expected to rise to 50,000 by 2020.

A $30-million rehabilitation and widening project was contracted by Pennsylvania Department of Transportation (PennDOT) with GA & FC Wagman Inc. of York, PA. Scott A. Miller is the project manager. Funding will be split between 80 percent federal and 20 percent state funds.

Construction began in July 2001 and is expected to take three years to complete. The current bridge is approximately 1 mi. in length and carries two lanes of traffic in each direction. The contract includes replacement of the existing bridge deck, structure widening to accommodate a 42-in. (107 cm) high concrete barrier to separate a new pedestrian walkway and a bicycle way on each side of the bridge from traffic, new roadway lighting, painting the entire structure and two new retaining walls on the west approach.

PennDOT noted, “Because the bridge carries more than 35,000 vehicles per day, we required that all four lanes had to be open for weekly rush hour. Every effort was taken to minimize the impacts that construction had on traffic. As with all major projects, the goal was to keep traffic flowing smoothly while construction is under way. All traffic lanes were open during the weekday peak commuting hours [6 a.m. to 9:30 a.m. and 3 p.m. to 8:00 p.m., Monday through Friday].

According to PennDOT, the contractor was permitted to restrict traffic to a single lane in each direction between 9:30 a.m. to 3:00 p.m., Monday through Friday. The bridge was closed to traffic with the implementation of a detour on weeknights from 8 p.m. to 6 a.m. and on weekends, between 8 p.m. Friday and 6 a.m., Monday. The majority of the bridge re-decking occurred during the weekend hours.

PennDOT retained the consulting engineering firm Michael Baker Jr. Inc., Harrisburg, to provide construction management services for this project, as well as several other highway and bridge projects in south central Pennsylvania.

According to Mark F. Raup, construction engineer, of Michael Baker Jr. Inc., the project is currently 96 percent complete and more than two months ahead of schedule. Raup noted that the re-decking method for construction consisted of panelized replacement of the bridge deck with a modular concrete-filled galvanized steel grid deck system to minimize the inconvenience to traffic during construction.

The individual steel grid deck panels, measuring approximately 8-ft. (2.4 m) long by 27.5-ft. (8.4 m) wide, fit across the longitudinal steel stringers in two lanes, extending from the bridge centerline to the inside edge of the proposed raised sidewalk along the bridge fascia. A separate series of panels was installed in similar fashion for the opposite two lanes.

The typical weekend panel erection sequence consisted of removal of sections of the existing deck, removal of existing lead-based paint from the stringer top flanges, welding of shear studs, painting of the stringer top flanges, placement of the new deck panels and casting of rapid-setting concrete in the block-out regions to complete the modular panel.

Existing 5-ft. (1.5 m) wide sidewalks along both sides of the bridge were widened to 8 ft. to accommodate the addition of a 4-ft. (1.2 m) wide bicycle lane on each side of the bridge.

On weekends, crews averaged replacing more than 30 (approximately 250 ft. [76.2 m]) sections of bridge deck. The new pre-built 8-ft. by 27-ft. (2.4 by 8.2 m) “panels” weighed approximately 6 tons (5.4 t).

“The contractor replaced all 78 existing bridge bearings with a system that allowed the contractor access to all work from the bridge deck above,” Raup said. “No access from the water level was required. Due to the complex structure steel configuration, a complex custom jacking system was used to raise the bridge safely to remove the old bearings and install the new bearings. The old bearings weighed approximately 7,000 pounds each, with the new seismic isolation bearings weighing approximately 2,000 pounds each.”

To date, the job has included 232,000 sq. ft. (21,553 sq m) of concrete-filled galvanized steel grid deck, 1,300 cu. yds. (993 cu m) of class AAA lightweight cement concrete, 1,220 cu. yds. (933 cu m) of class AA lightweight cement concrete, 24,120 sq. yds. (20,167 sq m) of high early strength latex modified concrete wearing surface one and a quarter-in. (3.1 cm) depth. In addition, 144,000 shear connectors have been used.

Raup said, “All concrete placed on the structure was lightweight cement concrete. Rapid set concrete was used in the beam haunches to complete the connection between the new deck panels and the bridge structural steel. This allowed for quick strength gain in the concrete to allow the bridge to be opened to daily daytime traffic. The bridge deck was replaced in grid panel sections approximately 8 by 27.5 feet. The contractor started the project with replacing 12 panels in a weekend bridge closure, and by the end of the project over 50 panels were replaced on a typical weekend bridge closure. The new bridge deck included adjusting the cross slope from 1 percent to 2 percent to assist with storm damage.”

Architectural light standards and luminaire heads were used to closely match existing street lights within the city of Harrisburg. Abutment widening details required using architectural stone treatments to match the existing stone facing.

Approximately 80 workers were on the job at the peak of activities. This included 50 from Wagman and 30 subcontractors.

Major subcontractors for the job include Peter Mitchell Inc., bridge painting; Morganrail Inc., pedestrian railing and parapet mounted hand railing; and Ronald R. Herr Traffic Signals Inc., bridge lighting.

Major equipment used on the job includes a Grove RT528C 28-ton (25.2 t) crane, a P&H Century 128 28-ton crane, a Terex RT335 35-ton (31.5 t) hydraulic crane, a mobile concrete mixer, and a Mack DM6905 truck with a Zimmerman ZM410 mixer.