Seismic Response and Collapse Risk of Shearwall Buildings Subjected to Long Duration Ground Motion

The damage caused by large subduction earthquakes is due in part to high number of load reversal cycles. Experimental and analytical studies indicate that shaking duration and number of cycles contribute to the damage. Currently, building codes do not include explicit design provisions for shaking duration. This paper investigates how shaking duration affects the response of tall, shearwall buildings in British Columbia, which is located in the Cascadia Subduction Zone. A suite of concrete shearwall archetype building models are analyzed with suites long and short duration ground motions. A case study of a reinforced concrete frame is presented to illustrate that long duration shaking can also affect significantly their seismic response. The results are useful for the elaboration of design provisions to account for shaking duration.