New centrepiece museum entrance, with glass-fronted and glass-topped cantilever system that can withstand high snow, wind and seismic forces.

AIA St. Louis Honor Award 2018

Eero Saarinen’s emblematic 1950s museum beneath the St Louis Arch commemorates the Louisiana Purchase and the foundation of the modern United States. It’s new centrepiece west entrance expands the museum, and merges iconic historical architecture with modern technology.

The existing building, which is largely underground, is now supplemented with a curved glass facade entrance. Three-hundred feet long, the structure uses custom blast-engineered structural glass panels.

Eckersley O’Callaghan developed an innovative pre-stressed structure with preloading tendons hidden within the glass joints. This allows the cantilever glass canopy to be achieved with minimal stainless steel framing to realise the architect’s brief for maximum transparency.

The cantilever and rod system uses 24-inch bolts to hold the cantilever in place and the structure is tuned for optimal blast performance using ductile plastic hinge failure mechanisms, designed to absorb the dynamic shockwaves in this seismic zone.

St Louis, MO

City Arch River 2015

James Carpenter Design Associates