Efficiency Above All

The Richard C. Blum Hall at UC Berkeley was more than a project, it was a model of multi-tasking. The project consisted of three core areas of work: historic renovation, new construction, and architectural concrete.  Additionally, the project fell under the jurisdiction of the California Office of Historic Preservation, the California State Fire Marshal, UC Berkeley Capital Projects, and required review by nine different entities for approval.  Hathaway Dinwiddie was able to draw on a depth of self-performed construction experience few other general contractors in the industry can equal and deliver a project that exceeded the requirements and expectations of all involved.

The project required renovation of the existing building and installation of a completely new foundation beneath it.  The project also required integrating the existing building into the old to allow for collaboration between the two.  It was clear that excavation would be required to place the new foundation, so Hathaway Dinwiddie proposed digging a bit deeper and creating a new basement level that would tie both buildings together. Drawing on in-house engineering, BIM modeling, unrivaled carpentry expertise, and unique project understanding, Hathaway Dinwiddie was able to conceptualize and realize a system for supporting the entire wood-framed structure in place, allowing for excavation below.

Once peer review of the proposed building support system was complete, Hathaway Dinwiddie acted on the plan. The support system consisted of very simple and common elements. Soldier piles were drilled along the length of each side of the building, and needle beams were threaded through the structure and secured to the tops of the piles. The needle beams were thread through the structure above the floor and all-thread hangers were thread through the floor to support the existing floor joists using standard tube steel. Once all components were in place, the hangers on each beam were jacked, one beam at a time, until the structure was softly lifted from the foundation. The process was closely measured and meticulously executed to ensure that the historic structure did not suffer any racking.

Once each needle beam was sufficiently supported, locking collars were engaged and the jacks were removed and used on the next beam. The system required only five jacks to complete the entire effort, so equipment rental costs were kept to a minimum, and through the use of standard materials, material cost was also low. Through Proactive Partnership involving many in the subcontracting community, as well as the design team, Hathaway Dinwiddie developed and implemented a system that increased the efficiency and reduced the cost of the foundation construction. By hanging the floor joists rather than supporting them, the new concrete foundation walls were poured without the typical blockouts. Additionally, the hanging system provided almost three additional feet of headroom, allowing for more efficient excavation with larger equipment.