{"id":125238,"date":"2019-06-06T14:03:26","date_gmt":"2019-06-06T18:03:26","guid":{"rendered":"https:\/\/www.bates.edu\/news\/?p=125238"},"modified":"2019-06-07T12:28:00","modified_gmt":"2019-06-07T16:28:00","slug":"campus-construction-update-june-7-2019","status":"publish","type":"post","link":"https:\/\/www.bates.edu\/news\/2019\/06\/06\/campus-construction-update-june-7-2019\/","title":{"rendered":"Campus Construction Update: June 7, 2019"},"content":{"rendered":"

The next big objective in the construction of Bates\u2019 new Bonney Science Center will be the driving of piles, dozens or hundreds of them, to support the building\u2019s foundation. That work could begin as soon as the week of June 10.<\/p>\n

This does not mean piles as in \u201cheaps.\u201d Instead, these piles will consist of steel pipes driven 40 or 50 feet deep into the bottom of the building\u2019s foundation hole, and then filled with concrete.<\/p>\n

Nor should these pipe<\/em> piles be confused with the sheet<\/em> piles that subcontractor H.B. Fleming has been sinking for more than a month. Those interlocking metal sheets are shoring up the sides of the foundation hole, whereas the pipe piles will stabilize the soil beneath the hole and eventually beneath the building. They\u2019ll be capped with steel plates that underlie the foundation.<\/p>\n

Between the two systems, all that pesky earth will have no choice but to keep still and behave.<\/p>\n\t\n\t

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The construction site is quiet at mid-morning on June 7, the Friday of Reunion 2019. Note the tops of the sheet piles barely visible around the rectangle in the foundation hole: That spot will be dug down another eight feet or so. (Doug Hubley\/Bates College)<\/p><\/div>\n\t\t

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It's full-tilt action in the science building foundation hole on June 4. Suspended from the Fleming Inc. crane, the red vibro hammer is driving a sheet pile at a secondary excavation. Meanwhile, the yellow power shovel is removing clay that it will dump in a heap, not to be confused with a pile, for a second machine to load into a truck. (Doug Hubley\/Bates College)<\/p><\/div>\n\t\t

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Consigli Construction opened Gate B, on Nichols Street near the former location of the Bates Communications Office, at the Bonney Science Center construction site in late May. (Doug Hubley\/Bates College)<\/p><\/div>\n\t\t

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Maintaining this ramp down into the foundation hole goes on constantly. Here's the June 3, 2019, edition. (Doug Hubley\/Bates College)<\/p><\/div>\n\t\t

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Two H.B. Fleming employees guide the vibro hammer into position atop the sheet pile at left. They're pulling hoses that connect the hammer to its power unit. (Doug Hubley\/Bates College)<\/p><\/div>\n\t\t

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Columnar piles like the pipes are often driven down to bedrock so as to transfer a structure\u2019s weight to something really solid. But the pipe piles likely won\u2019t go that deep, explains Chris Streifel, who\u2019s managing the science building project for Bates Facility Services.<\/p>\n

\u201cIt doesn’t necessarily have to go to bedrock,\u201d he says. Instead, the piles will improve the site\u2019s weight-bearing capacity by displacing the soil, effectively stiffening and reinforcing it.<\/p>\n

Compared to other systems, the pipe piles allow for greater monitoring and control during the driving process, he says. The pile-driver is equipped to transmit \u201creal-time information about the condition of the support that\u2019s being driven,\u201d as well as the soil it\u2019s penetrating, Streifel explains. \u201cEvery time the hammer strikes the pile, you get a sense of the stiffness [from resistance] and the anchorage that it\u2019s providing.\u201d<\/p>\n

Water is also a factor favoring the pipe piles. A different choice for soil reinforcement would be so-called rigid intrusions, which involve injecting concrete directly into the ground. But \u201cwater and concrete aren\u2019t the best of friends, and the ratio between the two is very important,\u201d explains Stacey Harris, project superintendent for Consigli Contruction, the firm overseeing the science-building job.<\/p>\n

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Let’s take a drive: two minutes of sheet-pile driving condensed into a nine-second time lapse. (Jay Burns\/Bates College).<\/em><\/span>
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