Danville-Riverside Bridge: The Making of a Community Landmark
By Kenneth D. Klingerman, P.E., PENNDOT District 3-0

The design process and construction of the Danville-Riverside Bridge was, to say the least, very unusual. It took nearly 15 years for the bridge to be designed with input into the design aspects from community groups, local public officials and multiple state agencies. The bridge itself was not only specially designed with architectural details, but the roadway approach to the bridge had to be located through the historic district of Danville. Even though the design and construction of the bridge encountered many challenges, they resulted in a beautiful landmark of which everyone involved can be proud.

First, here is a little background on the project. The original bridge that was replaced was a 7-span steel thru-truss that carried two narrow lanes on an open steel deck. The bridge was constructed in 1904 and spanned the North Branch of the Susquehanna River between Montour and Northumberland Counties in Pennsylvania. The bridge carried the heavy traffic of PA Route 54 that led through the congested downtown area of Danville. By the time the design process began, the bridge was antiquated and much money was spent to maintain the bridge every year.

At the beginning of the final design, PENNDOT's District 3-0 and the local communities formed the Danville-Riverside Community Design Group (CDG). The group ended up consisting of more than 30 residents and local officials who met 16 times during a year-and-a-half time span. Their mission was to work through a wish list of aesthetic treatments that were developed during the environmental phase of the project. Because of this group's dedication, the new bridge ties the two communities together functionally and aesthetically with a historical character rarely seen in today's modern structures.

The new bridge is a seven span structure that has its six piers and its abutments wrapped with concrete formliners to give the appearance of natural stone treatments. The original bridge's piers and abutments were constructed of natural cut stone. The bridge's beams are haunched steel girders fabricated from weathered steel. The main spans are 225 feet long and the end spans are 160 feet in length. The weathered steel was chosen because it represented the historical iron manufacturing heritage of the area. For the same reason the CDG chose a metal pedestrian railing with an antique look. A pedestrian alcove was placed over each pier that affords a comfortable spot from which to fish, socialize, or to view the beautiful scenery. The entrance of the bridge in Danville is graced with pylons with ornamental lighting, architectural detailing and brick masonry. This resembles the architectural elements of the Montour County Courthouse, which is located a block away in Danville.

The new bridge is located one block to the south of the original bridge on the Danville side of the river in order to alleviate traffic in downtown Danville and also to better align with the remainder of PA Route 54. The location of the new bridge resulted in the new highway going through the historic district of Danville. Because of the close location of historic homes to the highway, innovative ideas had to be used to avoid any damage to these homes. The historic district actually sits upon a small hill. It was decided to construct the highway at a lower level than the neighborhood to reduce the level of vehicular noise and avoid cutting the neighborhood in half.

The method to construct the underpass is called cut and cover. Cut and cover is a process where the ground is excavated vertically to the grade of the highway and a bridge structure is placed above the excavated area, which is at the same level as the original ground and streets. The end result looks much like a tunnel, but it is not bored. Because of the historical area, a pile driving method for soil stabilization was out of consideration. The process chosen to excavate the cut is called deep soil mixing. The deep soil mixing consisted of using a gang of 30-inch augers driven by a 150-ton crane. The augers mixed the soil and a cement slurry was introduced as they penetrated the ground to a final depth of 35 feet. After the augers were withdrawn, an H-pile was pushed into every other hole. The final product was a reinforced soil cement wall with the consistency of Play Doh. This did not have the strength to stand alone after excavation for the underpass was completed and had to be supplemented by internal braces and struts. The reinforced soil cement wall made the vertical excavation easier because the original soil, which was very sandy, was susceptible to collapse. Small, specialized equipment was used to excavate. The excavation was very slow in order to work around and under the struts. After this was completed, storm drainage was installed and construction of the concrete rigid frame began. Work for the cut and cover was completed in August 2000.

When the Community Day/Ribbon Cutting Ceremony was held in July 2001 for the new bridge, more than 1,000 residents attended to join in the celebration. It had taken 18 years to make the dream a reality.

In March 2002, the Danville-Riverside Bridge and Underpass Projects walked away with three statewide quality awards, including the highest honors, at the 7th Annual Pennsylvania Transportation Industry Spring Conference. The project took top honors in the categories of Community Support/Customer Focus and Design. It also took top honors in the coveted statewide best-of-the-best award-Project Recognition for the Pennsylvania Partnership for Highway Quality (PPHQ) Awards. In addition, the ribbon cutting won 1st place for special events at AASHTO's 2001 National Transportation Public Affairs Workshop.

The award honors PENNDOT Engineering District 3-0, contractors Susquehanna Supply Company (Williamsport, PA) and G.A. & F.C. Wagman (York, PA), preliminary and environmental engineering by McCormick, Taylor and Associates (Harrisburg, PA), final design by Gannett Fleming, Inc. (Camp Hill, PA), and inspection consultant Larson Design Group (Williamsport, PA).

The projects are a testament of how the input and coordination of various diverse groups and organizations can make a very challenging project become a success.

I would like to give credit to Judy Hricak (Gannett Fleming, Inc.), John Ryan, P.E. (McTish, Kunkel and Associates), and Rick Mason (PENNDOT District 3-0) for their contributions to this article.