2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Dr. Shahria Alam, University of British Columbia
Concentric Braced Frames (CBFs) are commonly used all over the world to resist seismic forces in buildings. Buckling, however, is a major concern for CBFs where they lose their strength and stiffness when subjected to load reversals during earthquakes. To tackle this problem, a novel easy-to-fabricate low-cost Spring Based Piston Bracing (SBPB) system will be developed with single and double friction spring configurations. In this system, a brace member can carry a large magnitude of tension and compression forces where a special spring is employed in the piston cylinder. Stable and self-centering hysteresis behavior can be achieved when the system is subjected to qualifying quasi-static loading. Strain rate effect will be assessed, and comparable results will be studied to investigate any performance degradation. Numerical simulation will be conducted to accurately capture the behaviour of the system and match it with the test results. Two four story braced steel building will be designed: a) utilizing Buckling Restrained Braces (BRBs) and b) SBPB, and their performances will be compared in terms of interstory drift and residual drift. The proposed system is expected to experience zero residual deformations compared to BRBs.