EFFECTS OF IRREGULARITIES ON REINFORCED CEMENT CONCRETE FRAMED BUILDINGS

Abstract

In this report twelve buildings have been analysed.The first building is regular building and remaining buildings are having two kinds of irregularities. Those are plan and vertical irregularities.These irregular buildings incorporated with different conditions for irregularities.These kind of deficiencies arises due to poor design practices and due to lack of symmetry and continuity.When these irregular buildings subjected to earthquake will produce high forces and moments in members which some times leads to collapse of building. STAAD.PRO software has been used for analysis and design of all regular and irregular buildings. All analysis and design results are compared and discussed. The quantitative assessment of analysis and design results of regular and various irregular buildings will used to estimate magnitude of damage. The qualitative assessment of results of regular and various irregular buildings will helpful to predict which irregularity is total damage,moderate,slight or none.In plan irregularities the kind of damage occurred to out of plane offsets building is total damage and slight damage to diaphragm discontinuity building. In vertical irregularities the kind of damage occurred to vertical geometric irregularity building is destruction and moderate damage to discontinuity in capacity building and soft storey But the regular building subjected to slight damage. From the above results it is clear that plan irregularities are and more severe than vertical irregularities . This is due to high torsion and sway compared to vertical irregularities. The above analysis and design results,and classification of damage are helpful in vulnerability assessment.From the above results weak members can be identified and retrofitted.The retrofitting principle adopted for these irregular buildings are (i) completion of load path (ii)removal of irregularities.The same results can also applied for important buildings,this can be done by multiplying above results by importantance factors. The present study will be of use in developing standards for assessment of safety of existing buildings.