SEISMIC EVALUATION OF RCMRF WITH MASONRY INFILL

Seismic vulnerability assessment and retrofitting of existing buildings is a key area in disaster resilient communities. Nature finds weaknesses left behind by mankind in structure and presents unambiguously in form of damage to such structures. Thus, Seismic damage concentrated at weak zones of structure speaks of as a report by a perfectionist ‘The Nature'. The fact is beyond any doubt that the widespread damage to structures and immense losses are not due to just natural act but due to either our negligence or our ignorance. Earthquake Engineers can contribute in the noble cause of seismic disaster mitigation by assessing seismic vulnerability of existing buildings and providing the structure safe capacities against the anticipated demands during expected ground motion. There are scores of reasons for seismic vulnerability of existing infilled RCMRF buildings. Response of having infill and its impact over the seismic performance of Reinforced Concrete Moment Resisting Frame (RCMRF) have been studied in the paper using adaptive static pushover analyses considering 2-storey, 4-storey, 6-storey, 8-storey and 12- storey buildings. The earthquake resistant philosophy being practiced all over the world accepts structure going well into inelastic zone during strong motion. A nonlinear method centered on Pushover analysis has been proposed to quantify structural response in inelastic zone in view to assess seismic vulnerability. RC MRF with masonry infill presents very different situation. Study of uniform and non-uniform distribution of masonry infill using the Pushover based method provides enough guidelines to refine and supplement our knowledge in dealing with such structures as a rational seismic vulnerability presents roadmap for appropriate retrofit strategy for the existing buildings.