Subgrade subsidence led to intermittent foundation settlement and related damage over a 20 year period to a three-story apartment complex. Initial evaluation involved installation of emergency shoring and temporary stabilization of exterior masonry facade.  A system of helical screw anchors was developed to be threaded through approximately 12 feet of organic fill and tree roots to support new mat foundations, grade beams and slabs.  Portions of the facade and interior bearing walls were sequentially removed and replaced after installation of foundation system.

Location: Philadelphia, PA