Seismic Strengthening of Reinforced Concrete Framed Structures : Using Steel Caging and Aluminium Shear Yielding Dampers

Reinforced concrete (RC) framed buildings with open-ground-storey and masonry-infilled upper stories introduces severe stiffness- and strength-type of discontinuities, which together causes significant strength and inelastic deformation demand on ground-storey columns during ground shaking leading to partial or complete collapse of the buildings as observed in several past earthquakes around the world. Hence, it is necessary to develop a simple and efficient technique to enhance the lateral strength, stiffness, and energy dissipation potential of such non-ductile RC frames. A strengthening technique consisting of steel caging to increase the lateral strength of deficient ground-storey columns and aluminium shear-yielding dampers (Al SYD) to improve the overall energy dissipation potential and lateral stiffness is proposed to enhance seismic performance of non-ductile open-ground-storey RC frames. A performance-based design method was developed with the objective that the structure should develop sufficient flexural strength and inelastic rotation at a target yield mechanism to withstand the probable seismic demand.