Difficult projects are their strong point, that according to D’Allessandro Corp. Project Manager Peter Piantedosi. The company has garnered a reputation for a contractor that can take on the hardest projects and see them through to completion. The company, based in Avon, Mass., recently bolstered that reputation on a difficult access pipe bursting project in the City of Quincy, Mass.
Piantedosi said, “Most of our work comes to us as challenging. It’s the difficult jobs that no one else can handle. That’s the way we’re geared. The harder, more difficult, detailed work is kind of our niche. The company is grown from a 2-crew company 25 years ago to 12-crews equipped to take on any challenge. There isn’t a job that we haven’t finished.”
For the project in Quincy, a section of vitrified clay pipe (VCP) sanitary sewer main near Quincy Bay had collapsed and needed to be replaced. The existing main ran along the banks of the Black’s Creek and feeds the Massachusetts Water Resources Authority MWRE Nut Island Headworks treatment facility. Black’s Creek is a tidal waterway, affected by the ocean tides. Every 6 hours the depth of the creek changes. A lock system controls the flow of tidal water. During the project, the city of Quincy closed the lock to keep the tide out while crews were working.
In order to burst and replace the failing 15-inch clay sewer main with 16-inch High Density Polyethylene Pipe (HDPE), D’Allessandro Corp. used a Grundoburst 1250 G static pipe bursting system from trenchless equipment manufacturer TT Technologies, Aurora, Ill.
TT Technologies pipe bursting specialist Ric Micelota said, “D’Allessandro Corp has a lot of pipe bursting experience. They’ve been in these challenging projects before and always come through. The Black’s Creek project did present some distinct challenges, but D’Allessandro always finds a way to over come difficult conditions.
Jon D’Allessandro founded D’Allessandro Corp. over twenty-five years ago. The multi-facetted utility contractor services customers in the municipal, commercial, and private sector throughout the greater Boston area and beyond.
Safety is a top priority at D’Allessandro Corp. The company employs the services of an on-call, full-time safety auditing service that visits each one of the crews every other week on a revolving schedule. The company inspects, audits and provides a safety evaluation report to the main office.
Piantedosi said, “It’s all about safety. Everyone is expected to work safely. We encourage our team to take initiative, be responsible and go the extra step to make certain our clients are satisfied. All of our operations are carried out with OSHA safety and health regulations. Training is ongoing according to OSHA standards. Every level of the business strives for excellence in providing a safe and healthy work environment.”
The company conducts annual safety meetings and has a safety committee that meets once a month to review issues and provide recommendations on improvement strategies. In addition the company conducts foreman’s meetings to review crew safety and holds daily “toolbox talk” meetings before work begins on any project.
With a significant service offering including water, sewer, drain, conduit installation, as well as above ground work such as road building, curbing, sidewalk, fencing and guardrail installation, D’Allessandro Corp. employs anywhere between 85-100 people depending on the season. In addition to traditional construction methods, the company has been utilizing trenchless pipe bursting for almost 20 years and is recognized as one of the most capable bursting contractors on the East Coast.
Micelota said, “Static pipe bursting continues to evolve. The method started gaining a lot of attention early on because the potential to burst and replace ductile iron and steel pipe. That was a significant accomplishment. The ability of static pipe bursting to facilitate the installation of various product pipe materials is also a big step. In the case of D’Allessandro’s project, static pipe bursting was used because the pipe was collapsed and rodding the existing pipe was a challenge. It would have been difficult to get a winch cable through the pipe for pneumatic bursting. So, the bursting rods of the static machine were a better option in this case.”
Road Building & Static Bursting
In order to gain access to the collapsed sewer main, D’Allessandro crews first had to construct a road. Piantedosi said, “The site was extremely difficult to access. One manhole, which we needed to replace, was located next to a wooded area, along a 30- to 40-foot slope. But the challenge was getting the equipment we needed to the actual job site area. There were no roads or even access points to bring equipment in. So we had to build a road along a narrow easement to get to the site. The road was built out of a dense graded stone product, 2- to 4-inch minus stone. We put that stone down and stabilized the slope along the roadway to accommodate the excavator, loader, pipe and bursting equipment.”
D’Allessandro crews also installed a silt fence on site, as well as straw wattle to prevent any potential washout long the road. The grade change was about 20 feet from one end of the job to the other. D’Allessandro crews planned to burst the pipe from the shallow pit into the deeper pit. The layout of the job resulted in the launch pit being approximately 6 feet deep, while the machine or exit pit was approximately 18 feet deep. An 18-foot shoring box with 8-foot spreaders was used to secure the exit pit.
Crews then set up a dewatering system with a 3-inch pump for the launch and exit pits, as well as a 6-inch bypass sewer line, which ran for the duration of the project. Once all the equipment was in place, crews were ready to begin the bursting process.
Piantedosi said, “The 15-inch clay host pipe was broken, probably crushed, about 25 feet away from the manhole at the top. We were able to get the rods through which was one of the biggest concerns because of the collapsed pipe. The soil was decent for bursting, a boney gravel, because we were so close to the creek.”
Micelotta said, “The Quicklock style rods are securely linked not screwed together. This system provides the optimum in terms of strength of connection and elimination of rod torque. This style of rod also speeds installation and breakdown because the rods are easily and quickly removed at the exit pit as bursting is in operation. There’s no time wasted screwing and unscrewing rods or having to deal with a potentially dangerous high torsion situation.”
After rodding the bursting rods through the host to the launch pit crews were able to attach the bladed rollers, expander and fused HDPE product and began pullback.
During the static bursting process the bladed rollers are pulled through the host pipe by a hydraulically powered bursting unit. As the bladed rollers are pulled through, they split the host pipe. The expander forces the fragmented pipe into the surrounding soil while simultaneously pulling in the new pipe.
While total prep time took around 4 days to create the access needed to facilitate the project and another day to put in the proper environmental protection features, actual bursting time took approximately 45 minutes. Once the new section of pipe was tied into the main and put back into service, site restoration took another 4 to 5 days to complete.
Micelota said, “This project again shows why D’Allessandro is the go to contractor for the toughest jobs. This highly skilled crew with the right equipment can get it done. They did a nice job on Black’s Creek.”