Cherry Lane Foundation Underpinning
This 3 story apartment building had undergone significant settlement over the years due to being founded on poor soils.
Subsurface conditions consisted of fill up to 8 feet deep over a peat layer roughly 2 feet thick over 2 feet of silty sand over 12 feet of sandy clayey till with cobbles and boulders over granite bedrock.
A foundation underpinning systems was conceived using Injection-Bore Micro-Pile (IBO) technology. The IBOs were used to penetrate the cobble and boulder filled soils and reach the granite bedrock to prevent the structure from any further settlement. Eight IBOs were installed with limited access and equipped with underpinning brackets. The underpinning brackets cradle the underside of the foundation wall where a hydraulic jack transferred the load to the IBOs to stabilize the foundation.