The CSVT project is one that has long been in the making. Traffic has been growing in the corridor of routes 15 and 147 in Northumberland, Union, and Snyder counties for decades.
In the 1970s, PennDOT began construction of the Selinsgrove-Shamokin Dam Bypass. However, construction stopped in 1978 due to a lack of funds. Only the Selinsgrove portion was completed. You can see part of the bypass when you continue onto the freeway section at U.S. 11/15 in Selinsgrove. The freeway section ends at a partially abandoned interchange with U.S. Route 522.
Once the CSVT project is completed in 2027, it will create approximately 13 miles of new four-lane, limited access highway, Smith said. Overall, it involves four interchanges, 22 highway structures, and approximately 9 million cubic yards of earthwork. Its footprint will be approximately 800 acres, and its total estimated cost is $865 million (including design, right-of-way, utilities, environmental mitigation, construction, and inflation).
The Central Susquehanna Valley Transportation (CSVT) project entails the construction of approximately 12.4 miles of new, limited access, four-lane highway extending from the existing U.S. Route 11/15 Interchange in Monroe Township (north of Selinsgrove) in Snyder County to PA Route 147 in West Chillisquaque Township (at a location just south of the PA Route 45 interchange near Montandon) in Northumberland County. The new highway includes a connector to PA Route 61 in Shamokin Dam and a new bridge crossing over the West Branch of the Susquehanna River extending from Union Township, Union County to Point Township, Northumberland County.
The Northern Section included the construction of a new bridge, approximately 4,500 feet long, to cross over the West Branch of the Susquehanna River. In addition to the new bridge across the West Branch of the Susquehanna River, the Northern Section includes two new interchanges: the Winfield Interchange which is an interchange with U.S. Route 15 just north of the Snyder/Union County line in Union Township, Union County and the PA Route 147 Interchange that includes a relocated Ridge Road (Township Road 703/State Route 1024) in Point Township, Northumberland County.
The new bridge over the West Branch Susquehanna River is 4,545 feet long. It includes 15 spans, with piers that range in height from approximately 60 feet to 180 feet. Its cross-section includes eight steel beams that are approximately 10-feet high. It has been constructed of approximately 62000 cubic yards of concrete and approximately 20,000 tons of steel. It is PennDOT’s eighth-longest bridge.
As with any bridge construction, there are many challenges encountered along the way. Construction continued throughout the winter months when possible, and also had to deal with the winter and spring flooding on multiple occasions. As the causeway was removed halfway through the project, that left 2 ½ spans of the bridge over water and a new placement procedure had to be developed. This new placement method consisted of pumping the concrete 1000 – 1200 feet over the water. A new mix design was developed to aid in the pumping of the concrete and GGBFS was an integral part of the mix.
Over 35700 cubic yards of Mass Concrete was used in the footer, plinths, and piers while over 9800 yards of bridge deck mix was pumped over 1000 feet for placement.
The mix designs for all classes of concrete incorporated GGBFS from 25% – 50% of total cementitious.