Prefabrication experiments - 179 - Geometries - 10 - Pier Luigi Nervi and elucidating structures

Geometry underlies any architectural composition. Since antiquity the compass, straight edges and strings were used to set out building foundations relying on the rigorous organization of lines and curves. Shaping architectural form, proportioning construction elements, and regulating architectural space can all be related to arithmetical constructions. Modernity not only continued using geometry as a designing device but celebrated geometry as a way of reforming architectural language from classic geometries to industrial production based geometries. Modules and standardized spans replaced golden sections or daisy wheel compositions. Geometry became the basis of celebrating structural form for architects and engineers. Pier Luigi Nervi’s designs reveal a fascination for showcasing structural behaviour through geometric shapes. His Palazzo Del Lavoro designed in collaboration with Italian architect Gio Ponti inaugurated in 1961 for the Turin Worker exhibit celebrated 100 years of Italian unity. The flagship building exposed Italian industry and would later be converted into a technical school.  

Spectacularly modular, its 16 square topped mushroom columns are juxtaposed to produce a great exhibition space. Each 25 m tall monumental and tapered reinforced concrete columns are fluted to showcase load transfer from top to bottom. The cruciform columns have a 6 m x 1m wide base section. Each column supports a 40 m square plane head composed of steel radiating beams also tapered from their center to their edges to explain the increasing stresses toward the center mast.  Each element was prefabricated and the structure was completed in just 18 months. The square mushroom columns are juxtaposed to construct a 160 m square canopy. Each mushroom head is separated from its adjacent slab by a 2m skylight reinforcing both the modular geometry and the sensation of being underneath a colossal covering. Mezzanine galleries lace the interior space and reveal geometric ceilings using the same type of isostatic rib slab employed by Nervi at the Gatti wool factory which employed geometric patterns as ribs to minimize bending moments in a two-way slab system. The building’s all glass envelope frames the basic overhead plane supported by equally spaced columns each celebrating the basic geometry of a square layered with radial sectors pointing to the central column. 

Column Elevation