Abstract:
The buildings developedin the seismically dynamic zone are more prone to the devastating effects of the earthquake as contrast with the structuresbuilt on sites having less seismic activity.Withurbanizationorincreasing unbalance of required area to availability or keeping the aesthetic and architecture of the structure in mind,the buildings constructed today are no more regular. It is very common now-a-days that the lift well or stair case are placed at the corner of the building or the masonry is omitted in the ground floor of the commercial structures which leads to the anomaly inthe structure causing torsional irregularity and soft storyrespectively. These irregular configurations add ontothe detrimental effectswhen subjected to seismic tremors. As the center of mass and center of rigidity of structure gets disturbed in caseof torsional irregularity and ground story becoming weak in lateral stiffness in the case of soft story, there is a dire need of givingsolutionto these susceptible structures.In view of these problems an effort to study these irregularities is done using computer program ETABS and later remedies like increasing the column size for enhancing the stiffness and provision of shear wall of various thickness and at different location is suggested keeping in mind the economicconstraints. Furthermore,a trend oftorsion irregularity coefficient with story height and no of stories is studied and conclusion is drawn that the coefficient has inverse relation with the story height and no of stories.Moreover,to stress on the provisions of ACI and UBC code a general comparison between detailing limitations of intermediate moment resisting frames and special moment resisting frames is carried out.
