On Track Magazine, Winter 2016
Sargent Corporation has completed phase 1 of a plan by the Maine Turnpike Authority (MTA) to reconfigure Exit 63 (Gray-New Gloucester) and eliminate the southbound on- and off-ramp bridge and the maintenance associated with it.
The $1.2 million project included construction of a new Park and Ride facility on Route 26A in Gray and preliminary construction of a new exit area, which has been pre-loaded with 64,000 cubic yards of common borrow.
The exit area was preloaded based on recommendations by a geotechnical engineer hired by the MTA, which indicated that the underlying soils are soft. Sargent crews brought in the borrow and created the shape of the new southbound on- and off-ramps, but built it higher to a fixed elevation to provide enough weight to compress the soils and prevent the ramps from settling after the job is completed.
The contractor for phase 2, which is expected to take place in 2016, will cut the pre-loads down to the design subgrade elevation and use the material elsewhere on the project. The side slope grading will remain intact up to the subgrade elevation.
Phase 2 will be a full reconstruction of the entire exit, including moving the exit ramp toll plaza from the east side to the west side of the turnpike.
The new Park and Ride, which has 130 parking spaces with five handicapped spaces, is replacing an existing Park and Ride on Route 202, early in 2016.
The old facility, which had 75 parking spaces with three handicapped spaces, was very successful and routinely filled to full or near capacity, but it needed to be replaced because it is located within the new interchange layout. When phase 2 is underway, it will be used as a contractor laydown area.
The pre-load area was constructed with eight settlement platforms—steel pipes mounted vertically on 1” thick pieces of plywood and protected by sections of PVC sewer pipe. Before placing the pre-load material, crews laid down the plywood sections on a prepared subgrade, and attached the pipes. As the fills increased in elevation the crew screwed on new sections of pipe and added sections of PVC to ensure that the pipe would move freely as the weight of the pre-load material compresses the soil underneath and pushes the plywood sheets down.
The crews will survey the top of the pipe until April and take readings to determine how much compression has taken place. The MTA has estimated that the pre-load will compress the underlying soil by 15”.
Work on the project started the first week in July. The pre-load work was on a very fast track and was completed August 30, one day before the pre-load deadline of August 31 (a certain amount of time is needed for consolidation before phase 2 can be put out to bid).
Operations manager Colby Currier said 12 to 15 trucks were used to haul the borrow, the majority of which came from the MTA borrow pit on Bennett Road in New Gloucester, along with material from the Chandler pit, also on Bennett Road.
Colby said getting the 64,000 cubic yards of borrow to the project within the deadline was a challenge.
He said the borrow was a granular material, which had to be placed in lifts, and it required quite a bit of water to get compaction.
“It was challenging to get the trucks in and out, working on a sandy, mealy material,” Colby said. “We needed a fair number of trucks because of the length of the haul coming down from New Gloucester, and in the middle of summer, sometimes trucks are hard to come by. But the crew worked some long days, did a good job, and met the deadline, so the Turnpike Authority is happy.”
Troy Harvey was the superintendent for Sargent, Glenn Adams was project manager, and Pat Dubay was the estimator. Paul Gervais was the foreman and did the layout.
Jeff Nadeau was the resident engineer for the MTA, and Jody Dyke was the on-site inspector.
Subcontractors included P&B Paving, Gray; A&D Electric, Monmouth; P. A. Lyford, Hermon and Gorham, seeding and landscaping; Fineline Striping, Hermon; and Douglas W. Jones Inc., Bethel, stumping and grinding.