University of California, Davis, West Entry Parking Structure

Davis, CA


University of California, Davis



The West Entry Parking Structure at the University of California, Davis (UC Davis), completed in 2006, features three elevator towers clad with a glass and aluminum curtain wall system.  During the replacement of a broken piece of glass along the top of the curtain wall at the south tower, an elevator engineer noticed that the intermediate horizontal mullion, directly beneath the broken lite of glass, was slightly rotated outward.  UC Davis retained SGH to investigate the curtain wall assemblies and determine if the observed damage indicated a life safety risk.  We surveyed the existing condition of the curtain wall and observed that the curtain wall was not installed in accordance with the approved shop drawings, analyzed the structural performance of the existing curtain wall mullions, and collaborated with a third-party testing agency to conduct performance testing of the in-place curtain wall assembly.  SGH determined that the installed mullions had sufficient strength to meet life safety requirements, but did not meet design requirements for strength and deflection.  We concluded that the observed deflection in combination with field modifications would affect the long-term performance of the curtain wall assembly and developed a remedial plan that included replacement of certain components with unmodified extrusions and the addition of steel reinforcement at isolated locations.