Seismic retrofitting and upgrading reinforced concrete moment resisting frames by using expanded metal shear panels

peer reviewedExpanded Metal is a second product made from metal sheet by first cuttings, cold-drawing, and finally by being flattened. A research is under way at University of Liege with the aims at determining the mechanical properties of this type of material under seismic excitations. In view of their application to building seismic retrofitting and upgrading, three approaches: analytical models, numerical simulations and experimental investigations, have been used to characterize the mechanic behavior of expanded metal sheets which are monotonically and cyclically loaded in shear. Nonlinear numerical simulations and experimental tests are used to determine the hysteretic behavior of expanded metal shear panels (EMSP), and an analytical model is then proposed, with the aims of using that to study the influence of such EMSP when they are used to retrofit and upgrade reinforced concrete moment resisting frames (RC-MRF). Many RC-MRF are then designed in two cases: (1) in accordance with only Eurocode 2 and (2) in accordance with both Eurocode 2 and Eurocode 8. Capacities of such designed structures are evaluated by using nonlinear static analysis (Pushover) and nonlinear time history analysis under different types of soils and ground motions. The efficiency of using EMSP is evaluated in terms of strength, stiffness and energy dissipation. Additionally, with the presence of EMSP, some unfavorable behavior of RC-MRF under seismic action such as soft story mechanism can be prevented