Strengthening and repairing of 5-Storey RC ductile detailed structure with open ground storey Swajit Singh GOUD 1 and Pradeep Kumar RAMANCHARLA 2 1 PhD Student, Earthquake Engineering Research Centre, International Institute of Information Technology, Hyderabad, India swajitsingh.goud@reasearch.iiit.ac.in 2 Professor and Head, Earthquake Engineering Research Centre, International Institute of Information Technology, Hyderabad, India ABSTRACT Reconnaissance reports of past earthquakes states that the open ground storey is one the most common problems, causing severe damage in the structural members of ground storey. In majority of the buildings, it was observed that even after proper ductile detailing, there is severe damage to the structure. This is mainly attributed to the presence soft storey. In this paper, a study is carried out to improve the seismic performance of a 5 storey open ground floor building with ductile detailing. The seismic performance is improved by: (a) providing wall infill in some portion, (b) increasing the moment carrying capacity of ground storey columns, and (c) combinations of the above two. The proposed methods can be used for new structures by incorporating the effect in design philosophy or can be implemented in the strengthening of existing structures. The performance of the structure is determined with the help of Non Linear Pushover analysis. The main parameters investigated are interstorey drift and lateral displacement. The study shows, with increase in design moments as per seismic codes for the columns having open ground storey will not improve the performance of the structure significantly. Also the open ground storey columns are severely damaged making their repairing difficult and costly. It is suggested that seismic performance of the structure can be improved more significantly by combination of constructing wall infill and higher design moments in columns; if damage occurs in wall only, it can be reconstructed and structure can be repaired easily. Keywords: Open ground storey, pushover analysis, retrofitting, design provision 1. INTRODUCTION Earthquake reconnaissance reports of past earthquakes shown that wall infill has significant effect on the performance of the structures. Many of the buildings which were not designed as per the seismic demand had performed satisfactorily because of infill wall. Past research done in the field of brick infill clearly shows that the stiffness and ductility of the structure increases significantly because of brick infills. On the other hand, brick infill may have negative effect introducing torsion, soft storey, weak storey and short column effects, because of irregularity in the location of brick infill