Seismic Retrofitting of Low-Rise RC Frame Structures with Wing Walls

Seismic damage investigations and previous studies show that adding wing walls on both sides of frame columns is an economical and practical enhancement measure to improve the seismic performance of reinforced concrete (RC) frames. Quasi-static tests of three 1/3 scale specimens were carried out to study the seismic performance of two schemes, i.e., wing walls mainly bearing lateral load named as functional separation structure, wing walls both bearing lateral and vertical load named as functional integration structure. The damage development, hysteresis behavior, stiffness degradation, energy dissipation capacity, and other seismic behaviors of the specimens were investigated. The obtained results showed that wing walls improved the structural stiffness, bearing capacity and energy dissipation, but reduced the structural ductility. For the two schemes of will walls, the functional integration structure had a higher load-bearing capacity, while the functional separation structure had a better ductility. There was no obvious difference between the seismic performance of the two schemes overall. Furthermore, seven different retrofitting structures were designed, the seismic collapse resistance of the structural systems is evaluated by the increment dynamic analysis (IDA) method, and design suggestions were given.