Colliers Engineering & Design provided geotechnical engineering, geophysical services, and construction special inspections in support of the design and construction of this mixed-use development in Philadelphia. The new development included the partial demolition and vertical expansion of the existing structure. Our geotechnical engineering services included a test boring program comprised of exterior perimeter test borings in the limited available space surrounding the existing structure; interior borings using specialty low-clearance drilling equipment; and hand-excavated test pits to expose and evaluate the existing foundation system. Recommendations for foundations included a combination of newly constructed spread footing foundations, micro-piles and pile caps, and the existing structure foundations.

Geophysical services were performed to assist the geotechnical engineering and structural design efforts, including existing foundation element mapping at targeted column locations; identification of reinforcing steel dimension and layout at select beam and girder locations; and identifying subsurface features and confirming utility clearance at the test boring locations. Special inspections services were performed during construction of the new foundations (spread footings and micro-piles) and related below-grade construction elements.