Seismic Evaluation and Simplified Analysis of an Existing High rise Steel Building Retrofitted with Seismic Energy Dissipated Devices

Abstract:

Buckling restrained braces (BRBs), eccentrically braced frames and moment connections retrofitted using two side plates were incorporated into the seismic retrofitting design of a 34 story hotel tower in Kaohsiung, Taiwan. This paper discusses the analytical models for simulating the experimental responses of the BRB members, shear link beams of the eccentrically braced frames(EBFs), and the welded moment connections before and after being retrofitted by side plates. Nonlinear response history analyses (NLRHA) indicate that the peak total beam end flexural rotation demand reaches 0.01 rad, the BRB peak core strain demand is about 1.25% and the link beam total shear rotation demand reaches 0.065 rad under the maximum earthquakes, which are less than those found in the seismic building codes or laboratory tests.

Key words:high rise buildings; nonlinear analysis; seismic demand; seismic performance evaluation