Langley Memorial Hospital South Tower Seismic Upgrade

For this seismic upgrade project, Bush Bohlman provided prime consulting services, including structural design and construction administration.

To bring the current structure up to modern standards, the retrofit was designed using the BC Seismic Retrofit Guidelines (SRG); this performance-based method combines the seismic resistance of existing non-ductile seismic systems with new retrofit ductile systems. A 3D model of the building was analyzed using ETABS with seismic demands provided by SRG. The design features multiple external concrete shearwalls with foundations restrained by Dywidag soil anchors. Instead of traditional cast-in-place concrete, the exterior shearwalls were constructed out of shotcrete, which shortened the schedule and significantly reduced the formwork compared to other conventional methods. Additionally, several columns were wrapped with carbon fibre reinforced polymers (CFRP) to increase their ductility.

Almost all of this critical upgrade work was completed on the building’s exterior, allowing the Langley Memorial Hospital’s South Tower to remain occupied throughout the construction process and continue to serve its community—as it will continue to do well into the future.