Charles D. Cameron Public Services Building Seismic Retrofit and Upgrades

OBJECTIVE / BACKGROUND

The Washington County Public Services Building was originally constructed in 1990. While the building met applicable codes at that time, it was determined in 2015 that significant damage would occur to the building during a major seismic event. Being a critical hub facility, this prompted Washington County to put forth a project to address deficient seismic force resisting systems in the structure to create a safe and resilient space for occupants and the public. The project also served to implement a much-needed solution to ongoing moisture-intrusion issues at the lower levels of the building that reside in an active water table, often referred to as the river that runs through it.

STRATEGIES & SERVICES

SERA Architects served as Architect of Record and JE Dunn Construction was the general contractor for this complex project. PRC was retained by SERA as building enclosure consultant to assist with the myriad transitions between structural “bookends” and existing building roof and cladding systems, new punched opening window systems, and the challenges associated with below-grade waterproofing systems – including the entire basement floor.

The building is a T-shape, with the south wing constructed as slab on grade, and the north wing constructed with a deep, cast-in-place concrete basement level; the two buildings joined with an expansion joint that runs the entire exterior. After review of various options, it was decided to include in the design the excavation of most of the north wing to expose basement walls and allow light into the lower level via new windows, with enhancements made for waterproofing the floor, footings, foundations, site walls, and various transitions around the building, supplemented with an active dewatering system.

During a pre-design conditions assessment phase, PRC evaluated existing exterior wall and below-grade waterproofing systems, providing recommendations that helped to refine the overall project scope of work. During subsequent stages of design, PRC provided feedback and review of design drawings and technical specifications with a focus on addressing intricate conditions formed between new building envelope and structural systems at the interface with existing systems. During construction, PRC reviewed submittals, assisted with responses to contractor questions, provided ongoing design resolution as systems and approaches were refined, and performed quality assurance inspections of the work.

OUTCOMES

Significant changes to the building required innovative solutions, and PRC’s history with the County and this building, as well as our relationship with SERA Architects, proved to be beneficial. The unique applications of interrelated building envelope and structural systems, and the wide range of challenging conditions presented, warranted intensive testing, review, and oversight efforts on PRC’s part, all leading to proper material use and function, and the overall success of the project.

Thank you to photographer, Josh Partee. www.joshpartee.com