HANOVER — When officials learned last month that a massive crater dug to accommodate parking for a major campus expansion was off its intended mark by over 10 feet, Dartmouth College faced a decision.
Would the college have contractors redig the hole so that a new center for engineering and computer science occupied its intended footprint, or would the building be built over the hole as dug, slightly to the south of where project planners envisioned?
An application filed last week with the town indicates the college has come to a decision: the hole is going to remain as is; no further excavation is planned. The application is necessary because moving the building several feet is a significant enough departure from the what the town previously had approved that the college needs another vote by the Planning Board.
Allowing work to continue would save time and money, as well as prevent harm to surrounding buildings, college officials said.
“After careful evaluation of our options, we are proposing to move the building to fit within the excavated site,” John Scherding, the college’s associate vice president of planning, construction and design, wrote in a July 2 letter to the Hanover Planning Board.
Work on the 160,000-square-foot structure began this winter but was halted last month after crews found the hole was about 10 feet south of its intended layout.
Preparations for the building’s north wall required the installation of 231 anchors, some of which extend 60 feet deep, beneath the neighboring MacLean Engineering Sciences Center building, Scherding said.
Although it’s possible to shift that wall 10 feet north as originally planned, he added, removing the anchors could cause settling at both MacLean and the future engineering/computer science building.
However, building in-place also could add to construction costs, Town Manager Julia Griffin noted on Monday. A pedestrian bridge was planned to connect the MacLean and new buildings, which would need to be extended if Dartmouth’s application is approved, she said.
Lighting along nearby pathways also will have to be shifted, according to a letter submitted to the town by Boston-based HLB Lighting Design. The college is “taking appropriate steps” to ensure its financial exposure is minimized, spokeswoman Diana Lawrence said in an emailed statement on Monday.
“In the coming weeks, we expect to have a better understanding of how this development could affect the College financially as well as the effect on the overall project schedule,” she wrote.
While officials are still working to determine the exact cause of the excavating error, the problem appears to have originated with the project’s baseline survey, where surveyors measure the distance between fixed points on the site, according to Meaghan Hooper-Berdik, vice president and general manager of Turner Construction Co., a national firm with offices in Boston.
“This baseline control was provided by a licensed surveyor who has experience on the Dartmouth College campus,” she wrote in an email. “Turner Construction and its subcontractors, along with the design consultants, are working with Dartmouth College to determine the best path forward.”
Griffin characterized the mistake as a “data-driven snafu,” caused by surveyors who entered incorrect information into engineering software.
Contractors then took that data and began work on the building, which includes a 340-vehicle underground parking garage, she said.
The mistake was discovered last month when Turner prepared to install a construction crane at the worksite.
“I’m sure that this is not the first project in history that’s had this issue, but this is Dartmouth’s project to have to deal with,” Griffin said.
The six-member Planning Board is expected to take up Dartmouth’s application sometime this month, she said.
Meanwhile, roadwork tied to the west end expansion is continuing. The town’s Fire Department asked that Dartmouth move forward with its news system of roads so that a ladder truck could maintain access to campus in an emergency, Griffin said.
Tim Camerato can be reached at tcamerato@vnews.com or 603-727-3223.