The de Young Museum Revisited
THE TOWER
View of tower under construction. Copyright: 2004 Rutherford and Chekene
The 144-foot high tower located at the northeast corner of the site is the climactic moment of the whole composition. Combining a dramatic form visible from afar with the transparency the museum lacks, the tower is one of the “bold strokes” that Director Harry Parker said were what distinguished Herzog’s and de Meuron’s initial design concept and survived the myriad decisions made over the course of five years of construction.
The 360-degree view from the observation floor is an unrivaled visitor attraction that benefits greatly from overlooking the park’s natural setting rather than the concrete streetscape of the city proper. The use of low-iron glass in the openings increases their transparency, making them appear almost permeable.
From this vantage point visitors can also see the roof of the museum and the three fingers widening at the knuckles that define the main interior spaces. The skylights above the light-boxes are visible, and the drains for carrying off rainwater are fortunately hidden in raised ribs that run east-west across the roof.
Since the tower is a fixed base structure and consequently could not be connected to the base-isolated museum building, Fong and & Chan Architects, the principal architects, designed a so-called “seismic cab,” in essence a passageway that can move between communicating openings in the two structuress during and after a seismic event. The concrete elevator core provides stiffening to counteract seismic movement.
The tower under construction taken when the installation of supports is in progress.
Copyright: 2004 Rutherford and Chekene
The tower’s first four levels are stacked in a rectangular concrete box. Its long axis shares the museum’s NW/SE orientation for the first three levels. At the fourth level the floor plates begin to rotate clockwise, changing from rectangles to parallelograms and twisting 30 degrees by the ninth-level observation floor to approximate the alignment of the NE/SW city street grid. This twist caused the north and south end walls to tilt 16 degrees from vertical. To counterbalance this unusual tilt, Bret Lizundia, the project structural engineer for Rutherford and Chekene, designed a vertical system of post-tensioning cables housed in five ducts embedded in the north and south concrete end walls. The post-tensioning in the tilting walls balances the gravity overturning moment so that the walls ‘feel’ balanced. Lizundia said that, to his knowledge, this solution had never been used before for this type of application.
The view of the twisting tower from across the music concourse, the John F.Kennedy Memorial Drive, and other distant vantage points is one of the visual treats that makes the new de Young Museum unforgettable.
