|COMMISSION NEWS RELEASE|
|Pier Cap Construction, Rock Excavation Continue|
Construction Update: August 24, 2009
Pier Cap Construction Progressing at New Pohopoco Creek Bridges Rock Excavation Continues Along Turnpike's Southbound Shoulder
Late-summer construction on the Pennsylvania Turnpike's new bridges over the Lehigh River and Pohopoco Creek finds workers at one location building up and those at another bringing down.
Excavation continues on the towering outcropping at the southern end of the existing bridge over the Lehigh River. Utilizing heavy equipment and controlled blasting, crews are systematically loosening and removing tons of rock from the hillside along the Turnpike's southbound shoulder. The excavated material is being deposited on the opposite side of the Turnpike to extend the existing slope.
The hillside is being cut back to provide room to shift the Turnpike to the west when the new bridges, under construction on the upstream side the extension, are completed in 2011. Full stoppages may occur on the Turnpike between 10 a.m. and 2 p.m. Tuesdays through Thursdays whenever blasting occurs at this location. The contractor has been conducting most of the blasts as close to 12 noon as possible.
Progress on the Pohopoco
As workers prepare to pour concrete for the formed caps, construction continues in various stages on the remainder of the 12 piers that are under construction along the banks and in the streambed of the Carbon County waterway that runs parallel to the Lehigh River.
Operators of drilling rigs set up on temporary causeways that were built in the creek in early spring continue to methodically sink shafts for foundations for in-stream supports. Once drillers reach a solid footing and steel casings are in place, concrete is poured into the deep shaft to complete each foundation.
With foundations in place, reinforcing steel cages - which are assembled horizontally on the ground - are lifted and lowered into place atop the hardened concrete. Formwork is then assembled around the exposed vertical cages, and additional concrete is poured in tapered segments to complete the pier stems.
Crews then construct the T-shaped caps atop each pier to finish the bridge's sub-structure. When all the piers are built, pre-stressed concrete bridge beams - up to 165-feet long - will be set atop the caps. Steel deck pans placed on the beams will hold the new bridge's reinforced concrete deck to complete the superstructure of each span.
At the northern end of the Turnpike work zone, traffic has been shifted slightly to the east and temporary construction barrier is in place to provide a secure work area for all of the activities along the southbound side to progress. Behind the barrier, abutments are under construction on both sides of the Pohopoco Creek. And excavation has begun for a retaining wall that will support the roadway where it shifts onto the new alignment approaching the new Pohopoco Creek Bridge.
All ongoing work is part of Stage 1 construction on the $101.56 million contract to replace the separate northbound and southbound bridges carrying the Northeastern Extension (I-476) over the Lehigh River and Pohopoco Creek.
A separate but adjacent project to reconstruct the ramp bridge over the Turnpike at the Mahoning Valley Interchange (Exit #74) also is currently underway. The ramp bridge is being constructed a half-at-a-time, with crews now working on the southern half of the structure. Temporary traffic signals are in place to control the flow of a single lane of ramp traffic across the span.