The Wharfside Building at China Basin is a waterfront six-story 540,000 square foot structure originally constructed in 1922.
Olson Steel was contracted by Hathaway Dinwiddie Construction Company to detail, fabricate, and install five buttress towers in the property’s elevated courtyard, each one six stories tall and weighing 225 tons. These buttress towers required 72 steel collector plates, 60 buckling-restrained braces, and substantial interior steel framing as a part of Voluntary Seismic Upgrades.
Olson obtained as-built survey dimensions inside the existing building utilizing the latest manufacturing and construction technology. Collector plates were detailed with a scribe line installed in the shop. This line matched the field layout and provided control to precisely align each point. As a result, Olson and Co. Steel was able to successfully install all interior collector plates and extend these plates through the face of the building in advance of fabricating and installing the buttresses. A 3D scan was performed prior to the installation, confirming no final adjustments were required. Throughout the entire process, Olson ensured the interior of the building had minimal disruption to occupied tenant spaces, while allowing for follow-up trades to complete their scope ahead of schedule. Olson Steel used a 90T crane with less than 6 inches of clearance to install the buttresses in the courtyard section. As a full-service contractor, a high level of collaboration was maintained alongside other trade partners to plan and communicate each process step, ensuring a safe execution of work, given the project’s challenging constraints. At each tower installation, collector plates, BRB gusset plates and column splices were welded to the buttresses. Each unit required a 4-week welding process, consuming over 1,200 pounds of welding material. Olson Steel’s track record of being able to complete a complex and logistically challenging scope safely, on time and within budget was key in being selected as the steel trade partner to Hathaway Dinwiddie Construction and McCarthy-Cook.