One Washington Square, a historic high-rise building in downtown Philadelphia, needed a permanent solution to stop water infiltration that had been occurring for years in its basement. This ongoing issue lead to extensive damage of structural steel beams as well as the surrounding slab. High voltage switch gears and transformers that supplied power to the entire building were also located close to the area of concern, making this repair project necessary to avoid a potentially catastrophic event.

PULLMAN, a licensee of STRUCTURAL TECHNOLOGIES’ products and technical support services, formed a design-build team with an engineer partner, Wiss, Janey, Elstner Associates (WJE), to provide the most effective means of solving the structure’s issues. There were numerous penetrations in the slab varying in size, including two four-foot diameter openings. To address this damage, the penetrations were filled with hydraulic cement and then waterproofed.

An interior investigation also discovered corrosion on three structural beams that supported the façade above. This required the design and installation of a needle beam shoring system to support the façade during the structural repairs.

Access to the structural beams in the basement was challenging, requiring a custom decking system to be erected over the switch gears and transformers to allow for a safe working environment. Once all structural repairs were completed, below grade waterproofing was successfully installed to prevent any further water infiltration.

Through value-engineering, creative thinking and teamwork, the renovations made to the One Washington Square basement were completed on time. The team’s collaborative approach beginning with the investigation and unique ability to perform numerous specialty construction and restoration services led to the successful completion of this project.