HYBRID WALL TECHNIQUE FOR RETROFITTING SOFT-STORY RC FRAMES

In this paper, a new technique for retrofitting soft-first-story reinforced concrete (RC) frames is proposed. The proposed retrofitting technique is called Thick Hybrid Wall. In this method, the channel-shaped steel plates jacket the boundary RC columns of the open frame. The steel platesare extended to the bay of the frame through the additional steel plates connected together with the help of high-strength bolts. Then, additional concrete is cast in the provided steel formworks. To verify the efficiency of the proposed technique, one non-retrofitted specimen and three retrofitted specimens were tested under cyclic horizontal loading and constant axial forces. The experimental observed results revealed that the thick hybrid wall not only increases the lateral strength and stiffness of the frames, but also improves the lateral ductility considerably. The proposed method, in addition to obtaining superior structural performance, provides ease in construction at a building site, and minimizes the vibration, noise, and concrete dust of the retrofitting operation.

کلیدواژه ها:

Soft-story ، Pilotis ، Thick Hybrid Wall ، Seismic Retrofit ، Seismic Strengthening