INNOVATION May-June 2017

School becomes the first base-isolated building in Canada Vancouver’s Lord Strathcona Elementary School is one of British Columbia’s oldest, continuously operating schools. Three heritage buildings, to continue to be used as school buildings in the future, were assessed as having high seismic risk. Ausenco was contracted to design the seismic upgrades. Two buildings were upgraded using conventional upgrading methods—one externally, one internally. The third building— a load-bearing, unreinforced brick and stone building built in

APEGBC members, Ausenco: John Sherstobitoff, P.Eng., Sebastian Guerrero, P.Eng., Ramin Latifi-Naeini, P.Eng., Danny Yu, P.Eng., Struct.Eng., Reza Mousavi-Jarrahi, P.Eng., Aref Arefnia, P. Eng.,  Amir Afrasiabi Garekani, EIT, Miguel Fraino-Gonzalez, EIT

1897—was upgraded using base-isolation technology. This is the first time base isolation has been applied to a building in Canada. The upgrade completely separates the structure above the isolation plane ( yellow line in photo ) from that below, with the school’s upper floors now connected to the basement walls and columns by only 30 isolators, devices that ‘soften’ the response and dissipate energy during earthquakes. Perimeter load-bearing stone walls were saw cut, and flat-jacks were used to transfer the vertical load to the isolators. The work conserved the building’s exterior heritage aspects and will enable the building to be used immediately after an earthquake. Projects elsewhere in the world have typically used below-grade, below-foundation isolation planes in buildings. This project shows applying an above-ground, mid-structure isolation plane is cost-effective.

Shoring supported three storeys of walls without touching main floor aDB Engineering provided temporary structure engineering during restoration of the Vancouver School Board’s Lord Strathcona Elementary School. The team designed custom shoring to support three storeys of brick walls so that the main floor could be removed and a new slab could be poured. To accomplish this, the team designed a system to hold up the second and attic floors and the roof loads without touching the main floor for support. Custom hollow structural section (HSS)

both the brick wall and the lattice work of support members. The main support system was laterally supported by using horizontal and diagonal struts anchored into the new footings. APEGBC members, Sean Dingley, P.Eng., Andrew Boettcher, P.Eng., Struct.Eng., Arben Gashi, P.Eng. v

shoring posts that bore on specific concrete footings were used to support the second floor. The attic floor was shored using regular reusable, rentable items from an equipment supplier. Wall uniformity was ensured by bolting horizontal and vertical members to the existing brace walls, thereby supporting

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