Published in the June 27, 2019 edition.
By MARK SARDELLA
WAKEFIELD — The settling problem with the slab underneath the five-year-old Galvin Middle School will be corrected at no cost to the town and will not occur again, according to the chairman of the Permanent Building Committee and the chief operating officer of BOND, the construction and general contracting company that built the school.
Chairman Joseph Bertrand of the Permanent Building Committee and Frank Hayes, COO of BOND and president of the firm’s building division, appeared before the Town Council this week to discuss the issue.
Bertrand said that the slab settling has been monitored for the last few years but in the past year it has reached beyond design tolerance. Bertrand introduced Hayes for a more detailed explanation on what happened and how it was being addressed.
Hayes said that early in the construction process, BOND had hired a firm called Helical to install a soil stabilization technology known as rammed aggregate piers (RAPs). He explained that there are two RAP types: grouted and ungrouted. Grouted RAPs were installed under major structural elements, such as footings and columns. There have been no issues to date in those areas.
In between major structural elements, ungrouted RAPs were used. Hayes said that it’s a very proven technology and has been widely used in the industry as a soil stabilization and slab support system, particularly in soils like those encountered at the Galvin site.
Hayes reviewed a timeline of the slab settlement issue.
He said that in April of 2015, before a certificate of occupancy was issued, some cracking was noticed, but it was within design tolerance. Cosmetic repairs were completed by BOND to various areas of the building. In August of 2015, BOND performed a laser scan to establish a baseline for the slab. Four more scans done from that time through March 2017 indicated that the settling seemed to have stopped.
In the summer of 2017, extensive cosmetic repairs and leveling of the floors were completed by BOND, and the slab was resurveyed to establish a new baseline.
But in December of 2017, the town noticed that sealants and grouting had separated in some areas and in September of 2018 the town notified BOND that additional settling had occurred.
Hayes said that Helical was put on notice that there were additional problems and they had to solve them permanently. The only way to do that, Hayes said, was to go into the slab and install a series of grouted piers to support the slab. He said that approximately half of the piers will be installed this summer and the remainder will be done the following summer. BOND will also re-level the floors and reset the door frames.
Hayes expressed confidence that the system will work to stop the settling. He said that the work will be going on a 10-hours-a-day, six days-a-week schedule this summer.
Bertrand assured the Town Council that the building remains structurally sound and safe. He said that Helical has no idea why the settling is happening and had never before experienced a problem with the system used.
Hayes said that there are only guesses as to why the settling happened.
“It doesn’t matter what the cause is,” Hayes said, “It needed to be fixed.”
Town Councilor Ann Santos said that it appeared that best practices were followed and no negligence was involved. Something unexpected happened and it is now being taken care of, she observed, the building is structurally sound and the fix will not cost the town anything.
Town Council Chairman Edward Dombroski asked about the possibility of the problem recurring or happening in another part of the building.
Hayes assured the board that the planned fix would stop the problem from recurring and in the unlikely event that it does recur, BOND would be “on the hook” for correcting it.
It was noted that, with the exception if summer school being moved to a different location, the planned work will not involve any disruptions.