Fill with underlying glacial till
Sheet piles, tiebacks, micropiles
On 58 acres in the tiny town of Sharon, Pennsylvania, Ellwood Crankshaft Group (ECG), a manufacturer of complex steel crankshafts used for locomotives and marine engines, initiated the construction of a new form press in an existing warehouse.
The construction required a 24-foot deep excavation to complete the concrete pour and post-tensioning of the slab. To limit water ingress and support the excavation, Nicholson provided the design and construction for a cement-bentonite diaphragm wall with interlocking sheet piles. The shoring extended 27 feet below grade and formed a uniquely-shaped, 16 sided, continuous wall. The panels were dug under a cement-bentonite mix. The mix was designed to sustain 24 hours before setting to allow sheet installation on the following shift and to reduce water penetration through the panels. Nicholson was able to interlock the last sheet with the first upon completing the continuous wall.
Working inside of an existing structure presented many challenges, including low headroom for large diaphragm wall equipment, tight work spaces near columns and under girders, and pre-planned work sequences. The team rose to the challenge, finding creative ways to fit the Liebherr 855 in the building and under the girders and working around the various constraints for a successful project.