PROJECT SPOTLIGHT

form the needed seismic retrofit work. To accommodate the changes being

made to the building’s internal struc- ture and to meet current standards, the building required a seismic upgrade that involved drilling more than 27,000 holes into the interior concrete walls and floor. Dowels were epoxied into the holes, rebar was added, and then a new layer of shot- crete (12 - 24 inches, depending on the location), was applied for greater support. The team had to creatively figure out

how to approach the drilling in the saf- est manner possible (i.e. finding an er- gonomic solution and eliminating silica dust exposure). McCarthy brainstormed a solution working with engineers from UC Berkeley that involved the use of 10 large drilling rigs set up on cranks with a HEPA vacuum attachment, which cleanly drilled the thousands of dowels without the typi- cal dust storm created by more traditional methods. “We really helped refine a design and

prototype for these drill rigs that (UC Berkeley) had started,” Sinha said. “It be- came a somewhat effortless task to drill the dowels. Had we not had those drill rigs, all of the workers would have had to wear res- pirators. That was a significant part of our work program and our safety efforts here.”

Rendering of the interior of the renovated South of Market building. The design and construction team includes lead architect Perkins+Will, interior architect/design firm TEF Design, and general contractor McCarthy Building Companies.

provided cost savings, but also more design, functionality, and future lease opportunities,” Sinha said.

Complex Atrium Design and Con- struction. The inclusion of a dra- matic, light infusing atrium as a key feature in the building was always on the table, but hammering out the de- sign and construction approaches was a major challenge – particularly with the presence of an existing tenant at the same time that major demolition work to create the atrium needed to be done. Recently the canopy that had been covering that atrium was removed, a key project milestone. “It was very exciting because we had still been working in the dark in the center of the building until then,” Sinha said. “It gave everybody a renewed sense of purpose when that temporary roof structure came off.”

Working with Existing Structural www.AGC-CA.org

Elements. Designing and building new interior spaces while working with extensive numbers of existing structural elements was another key challenge uncovered during the initial soft demolition phase, according to Sinha. “There were several different structural elements that had to be addressed,” he commented. “We were challenged with the number of vertical chases that had perimeter beams around them. When you work within an existing structure there are always many challenges created by it. We always had a saying here: ‘The building will win.’ You just have to work around it.”

Challenges Spur Innovation Some of the challenges on this project

drove the team to seek innovative solutions that also ultimately improved the work environment. Case in point: McCarthy’s search for a cleaner and safer way to per-

Technologies’ Key Role In addition to putting in place the pro-

totype drill rigs, the McCarthy team em- ployed various other technologies on the project. Of major benefit was laser scan- ning all areas to model existing conditions, something Sinha described as a “signifi- cant undertaking by the team that allowed for better decision making for the project overall.” 4D BIM played a major role as well. All

building commissioning of the building will be performed in BIM 360 to deliver a complete model for building maintenance after this project is complete. In just a few short months, December

of 2015, the team is slated to turn over a project that looks and feels nothing like the structure it was three years ago – a light-infused, modern showcase space for BAHA and other office and retail tenants. “It has been completely transformed,

inside and out,” Sinha concluded. “This should be a really nice place to work.”

Associated General Contractors of California 17