The Salk Institute

The Salk Institute

Dr. Jonas Salk commissioned Louis Kahn to design the Salk Institute of Biological Research near La Jolla, California. Salk believes that medical research should not be confined to science alone. In response to Salk's view, Kahn saw the possibility of uniting art and architecture with the functional aspect of the design. He agrees with Salk that someone with a mind in art, like himself, could contribute in creating a mental environment of scientific research. Kahn's pursue of this vision is apparent in his design process.

The earliest massing strategy was to place a linear group of vertical towers parallel to the face of the cliff (diagram 1a). In the second version, a year later, the towers were replaced by four rectilinear, two-storey blocks set perpendicular to the sea (diagram 1b). In this version, the four blocks of laboratories were made up of clear span spaces, made possible by five box girders running across each rectangle, with a 'V'-shaped folded plate system perpendicular to the girders, spanning between them. Later, Kahn simplified the configuration of the laboratories, from four rectangular blocks to two, upon Salk's request (diagram 1c).

In the process, Kahn kept he basic idea of the scheme, which was to place scientists' studies away from the laboratories in the central garden and to place auxiliary spaces in vertical towers on their external walls. However, he increased the number of floors to three, including the basement, and replaced the 'V'-shaped folded plates above each of the three floors with concrete Vierendeel beams.

Stringent seismic criteria related to construction in the San Diego area made it difficult for Kahn's structural engineer to convince local building officials, who wanted him to use steel frame, that concrete, Vierendeel truss system would have the required flexibility. They agreed only after a 400 page report of undoubtedly integrated deflection computations that shows how post-tensioned columns would provide the main resistance to lateral seismic forces. These columns absorb both dead and live load compression plus vertical post-tensioning forces. They were also designed to maintain zero tension if subjected to lateral movements by earthquake. The trusses are 9 ft deep, spaced 20 ft on center and have a clear span of 65 ft (diagram 2). He made use of the 9 ft high resultant space as service area, allowing pipe chases to be dropped to the 65x 245 ft floor below with more latitude than before.