Greenfield Rd Reconstruction features an important retaining wall

by Joe Parzych

Baltazar Contractors, Inc., of Ludlow, MA is involved in a $5.2 million roadway project that consists of reconstructing slightly less than 2 miles of Greenfield Road in Montague, MA. Soil conditions in that area are tough. Wet running sand overlaying wet clay on top of extremely hard re-cemented silica-rich shale, makes supervisor, Robert Macauley’s project a challenging one. Nevertheless, the job has gone well and it is on schedule, according to Macauley.

On portions of the job, despite drought-like conditions, wet running sand mixed with silt and clay, slumped off the slopes. On the flat sections, depending on the amount of ground water, Baltazar’s crew installed ABS corrugated sub-drain ranging from 8” to 18” in diameter. Baltazar’s crew bedded the sub-drain with crushed trap rock.

On the hill where the bedrock was thought to be basalt, the rock formation had stymied efforts by the company’s excavator held hydraulic hammer, which could only create a little dust. Local geologist, Steven Winter later identified the bedrock as “re-cemented silica rich shale.” He explained that this shale had shattered into fragments eons ago possibly by earthquakes. After that, it re-cemented itself back together according to Winter. Ironically, this blasted re-cemented shale will be used once again to build a 600-foot long retaining wall, 22 feet high in places. It will be concreted into place, sporting a concrete cap on top. This work is to be done by sub-contractor Varandas & Sons also of Ludlow, MA.

Baltazar is well-equipped to do this job. A Komatsu PC 300 LC excavator, a Cat 345B excavator, a Volvo EW170 excavator, a Samsung SE 130 LC-2 excavator, a Bob Cat S590 loader, and a Freightliner tandem dump truck maneuver about the jobsite which is approximately one eighth of a mile long. In addition, a crew from Chicopee Concrete Service of Chicopee MA was on site to pour concrete into footing forms that will support the mortared boulder retaining wall.

It was fascinating to watch Baltazar operator, Enrique Tyson, walked a BMP 8500 Economode sheep’s foot vibratory roller down the road using the roller’s remote control. As he guided the unit between the heavy equipment, it looked as if he were walking a dog on an invisible leash. The remote controlled roller is especially useful when backfilling trenches after digging shields are removed. This handy tool helps eliminate the risk of a worker being buried in the trench.

In the early stages of the project, Baltazar’s crew performed a great deal of preliminary work. That included clearing trees, stumping , and installing of sub drains in wet areas with a high water table. As the job progresses, they will have more sub drains and road culverts to install.

As the retaining wall begins to take shape, Varandas & Sons, subcontractors to Baltazar, plan to use huge boulders blasted from the bedrock onsite as their primary source of material for the wall. They also use additional boulders from Mitchell’s quarry in Northfield, MA. The wall is backed up with gravel borrow with 4” ABS weep pipes installed through the wall to carry off any ground water that accumulates. A sub-drain at the base of the wall, at the road’s edge, collects ground water along with the water from the weep pipes.

Owner Gus Varandas, a real hands-on CEO, was at the controls of the company’s Volvo EW170 Excavator hoisting boulders into place on wall. It will be some 22 feet high in places. As we concluded our time at the jobsite, we watched Guss’ son, Richy, darting about the project like a water bug, as he operated a JD 320 skid steer loader to do some important grading while supplying sand and gravel for the wall.  Gus’s son Bruno said his family is proud of how nice the concrete cap and finished portions of the wall appear. It is assuring to know that pride in workmanship still exists. For more information on Baltazar Contractors, Inc. visit their website at www.baltazarcontractors.com or give them a call at 413 583-6160. Varandas and Sons Contractors can be reached at 413 589-8773.