Cofferdams/Subaqueous Pipeline: Merrimack River Water Intake Structure

Owner: Pennichuck Water Service Corporation Partner: Kingsbury Companies Type: Infrastructure Support Location: Merrimack, New Hampshire Project Description: For this project, H.B. Fleming installed three cofferdams on land for junction structure, as well as interconnected piping and a wet well. In the water we installed a trestle for crane access to the river and a 200-foot-long…

Cofferdams/Excavation Support: Dartmouth College

Owner: Dartmouth College Partner: Turner Construction Type: Institutional Construction Location: Hanover, New Hampshire Project Description: H.B. Fleming installed 1,000 feet of shoring to support construction of a parking garage three stories below grade, with an engineering and science hall to be built on top. The project entailed driving 70-foot-long sections of sheet pile around the…

Drilling: York Toll Plaza

Owner: Maine Turnpike Authority Partner: Reed & Reed Type: Highway Construction Location: York, Maine Project Description: H.B. Fleming is constructing 28 rock-socketed, drilled-shaft foundations to support the new toll gantries and overhead signage. Challenge: The project requires drilling hard rock at multiple locations in multiple phases.  Solution: To minimize drilling durations at each location and…

Ground Improvement: Maine Veterans Homes

Owner: Maine Veterans Homes Partner: Cianbro/VJS Construction Services Type: Commercial Building Location: Augusta, Maine Project Description: H.B. Fleming provided foundation engineering for the construction of new memory care, long-term care, and assisted living facilities, and a new community center. Challenge: Design-build a deep foundation installation as a more cost-effective alternative to pile driving.  Solution: We installed…

I-89 – Georgia, VT

Owner: Vermont Agency of Transportation Partner: J.A. MacDonald, Inc. Location: Georgia, Vermont Project Description: Designed and installed a cofferdam to allow for the replacement of a culvert under I-89. It was replaced by J.A. MacDonald, utilizing the sequential excavation method.

Hydro-Kennebec Upstream Fish Passage

Owner: Brookfield Renewable Partners Partner: Bancroft Contracting Corp. Location: Waterville, Maine Project Overview: Designed and Installed a cellular cofferdam to assist the construction of a new fish passage. The cofferdam consisted of five major cells with a diameter of 29’ and four minor cells with a diameter of 21’. All nine cells were backfilled with +/- 5500 cu.yds…

Portsmouth Wastewater Treatment Plant

Owner: City of Portsmouth Partner: Methuen Construction Location: Portsmouth, New Hampshire Project Description: Designed and installed a cofferdam to support an excavation depth of 26’ feet, which included a 12’ cut in bedrock. The cofferdam was supported with soil anchors, tie-rods/deadman, and drilled pin pile to support the sheet pile tips.

Falmouth Pump Station

Owner: Town of Falmouth Partner: Apex Construction Location: Falmouth, Maine Project Overview: Designed and installed a cofferdam to support an excavation depth of +/- 24’, which included +/- 15’ in bedrock.  The cofferdam supported the excavation with internal bracing and pin pile drilled into ledge.