The Leaf at Assiniboine Park | Blackwell Structural Engineers

Category
Public Facilities and Institutions
Fabric Structures
Specialty Structures
Completed
2022
Location
Winnipeg, MB
Area
84400 square feet
Architect
KPMB as Design Architect in association with Architecture 49

Program

The Leaf: Canada’s Diversity Gardens is part of the Assiniboine Park revitalization project in Winnipeg, Manitoba. This project aims to celebrate culture and botanical diversity and will welcome visitors to one of Canada’s largest year-round biodiversity gardens. The 84,000 square foot facility features several zones exhibiting different climates and environments, including indoor spaces like the Tropical, Mediterranean, and Butterfly biomes, and outdoor spaces like the Cultural Mosaic Gardens and the Indigenous Peoples’ Gardens. The proposed article will explore the most prominent structural features of the facility.

The desire for long spans and a transparent envelope for the biome spaces led to the selection of a tensioned cable net roof, clad with an array of ethylene-tetrafluoroethylene (ETFE) pillows. The flexibility of this cladding system allows for a very light weight roof structure, despite spans of up to 150 feet. The cable net follows a spiral pattern, selected to maintain a relatively constant span for the ETFE cushions. At its centre, the roof is supported on a 100-foot tall steel diagrid tower. The tower is constructed of round HSS and pipe elements framing between cast steel nodes. Due to the long cable spans, the cable forces are immense. The structure, which is almost entirely exposed, has been conceived to address these large forces gracefully.

Public Facilities and Institutions