REPAIR AND RETROFITTING OF RC WALLS USING SELECTIVE TECHNIQUES

In the context of capacity design philosophy, where a desired failure mode exhibiting adequate levels of energy absorption capacity is envisaged, control must be exercised on the member behaviour to safeguard the achievement of the target overall response. Therefore, local repair and retrofitting methods that result in unquantifiable effects on seismic response characteristics should be re-assessed. In contrast, techniques to affect, in a controlled and easy-to-monitor fashion, individual design response parameters, i.e. stiffness, strength and ductility, may provide a new framework for repair and retrofitting earthquake-damaged structures to mirror 'capacity design' principles used for new structures. Such an approach is discussed in this paper and possible scenarios where selective intervention may be required are identified. A number of tests on RC walls are also reviewed to confirm the feasibility of the proposed intervention techniques. Finally, extensive parametric studies are carried out, using verified analytical models, leading to the derivation of selective re-design expressions and guidelines.