New Baltimore Slide Remediation for the Pennsylvania Turnpike Commission Nears Completion

Typical Somerset County winters involve multiple feet of snow and trips to the local ski resorts. For Independence Excavating (IX), winter meant multiple earth moving spreads and thousands of trips to the fill. The New Baltimore Slide Remediation project turned up the heat as temperatures dropped in the town of New Baltimore, Pennsylvania. The 33 million dollar project for the Pennsylvania Turnpike Commission (PTC) entered its most difficult and important phase late in 2015. The project had two main purposes:  first—and most notably—is to fix the New Baltimore Slide which has been plaguing the PTC since the original highway was built in the 1940s; second was to widen and re-align a 4 degree curve.  Also, the job involved installing new drainage for the future total reconstruction of the turnpike in this area. The project objective was to help make the most dangerous and accident prone section of the Turnpike safer for thousands of drivers.

The first phase of the project revolved around the roadway itself. The objective was to move traffic away from the eventual work area to keep the traveling public safe. To accomplish this goal, multiple traffic phases were implemented to incrementally install new drainage, barrier wall, glare screen, asphalt and pavement markings for the new traffic alignments. Crews worked day and night in tight quarters to finish. Nightly lane closures had to be precisely coordinated due to the limited timeframe allowed for working hours to reduce the impact to the traveling public.  Work on “America’s first Super-Highway” is dangerous and demanding, but our partners at the PTC, Stahl Sheaffer Engineering and our subcontractors pulled together to finish safely and within our tight schedule windows.

Once the traffic was safely moved, the main event was ready to start. Four million cubic yards of dirt and rock were the next target for the IX team. The 4 degree curve was the first cut to be dug into, clocking in at a sizable 1.6 million cubic yards. The impressive Hitachi EX1900-6 excavator lead the charge, fitted with a massive 16 cubic yard bucket. This machine, along with five Caterpillar 777’s, was supplied by Bill Miller Equipment. Material was dug, ripped and blasted day and night from the bank and the fill area at a breakneck pace, in an attempt to stay ahead of the looming winter.  The fill area was a convenient waste site directly adjacent to the 4 degree cut.  This site was owned by the St. John’s Catholic Church, a historic landmark located on the edge of the turnpike.  Even though it was a mild winter, given the reputation of Somerset County, the environment still managed to make things difficult for the team. Three—sometimes four— full-time mechanics worked around the clock to keep equipment operating for both shifts. Both the Pittsburgh and Cleveland heavy shop provided support, along with our partners at Bill Miller, Caterpillar, John Deere, Good Tire Service, and Hitachi. It was all hands on deck with over 80,000 man hours spent on the job through the end of winter. Local 66 Operating Engineers, Local 419 laborers and Local 1058 laborers were integral in supplying skilled workers for this project.

An active landslide is a very problematic place to perform a 2.6 million cubic yard mass excavation, but the IX project team attacked the challenge head on. A carefully planned remediation sequence was created by geotechnical engineers and geologists after many years of studying the area. The plan included 24 parallel “slots” to be cut along the hillside down to the source of the landslide, a mud seam termed “the failure plane”.  The failure plane was excavated out and benches were installed into competent rock as the cut progressed down the hill. Waste material was hauled up the mountain and then used as fill from the top down, continually covering the benches. Excavation progressed swiftly down the hill as the organized chaos of excavators, trucks and bulldozers moved the overburden and remediated the failure plane. Over 30 pieces of equipment worked in tight quarters moving as much as 30,000 yards a day and, sometimes over treacherous hauls 200 feet up the mountain on 20% grades.

Spring finally made it to the Allegheny Mountains and dirt moving was completed. Over the summer and into the fall, focus of work shifted back to the roadway. Stages five, six and seven involved significant drainage improvements, maintenance of traffic, profile milling, and asphalt paving on the Turnpike mainline. The goal of this work was to restore traffic back to its original configuration in preparation for future phases of the Turnpike widening project. Work was completed on the roadway in late October of 2016 and the project reached substantial completion 7 months ahead of schedule. Final erosion control measures and site stabilization is scheduled to occur spring of 2017 with project completion in June of 2017. Our partners at the Pennsylvania Turnpike Commission and Stahl Sheaffer Engineering have continued to work with us to deliver a project we can all be proud of, even if it is only seen as you speed past at 70 miles per hour!