Collapse risk and earthquake-induced loss assessment of buildings with eccentrically braced frames

In this paper, earthquake-induced economic loss of buildings with the eccentrically braced frame as the lateral load resisting system is investigated. Economic loss in this paper includes collapse loss, demolition loss, and structural and nonstructural repair loss. A simplified probabilistic story-based loss estimation procedure is employed for this purpose. A thorough study is conducted on the verification of shear link response with experimental results as shear link is the main source of nonlinearity in eccentrically braced frames. Nonlinear response history analyses are conducted on four, eight and sixteen story prototype models and engineering demand parameters such as story drift ratio, peak floor acceleration, shear link rotation, and residual story drift ratios are extracted for each story in all analyses. The effect of shear tab connection in the gravity framing and various design methods, equivalent lateral force and response spectrum analysis, are also investigated on the economic loss. The results show that the buildings with eccentrically braced frames as the lateral resisting system have a superior performance during earthquakes, especially when the effect of gravity framing is included. This is in confirmation with the observations after the 2010/2011 Christchurch earthquake.