Seismic Analysis of Stiffness Irregular Struc...

Seismic Analysis of Stiffness Irregular Structures

Author Name : Syed Abubakar Siddik, P. V. Hari Krishna

ABSTRACT The Indian Standard code IS- 1893:2002 (Part-I) defines a number of structural irregularities and suggests different approach criteria for analysis of such structures. Stiffness Irregularity, both soft storey and extreme soft storey and extreme soft storey is a form of vertical irregularities and is dependent upon the ratios of lateral stiffness of a relative storey to above that as described in table 5 of the code. Soft story irregularity is one of the main for building damage during Past Earth Quakes and has been mentioned in almost all reconnaissance reports. Social, aesthetics and functional needs such as parking, lobbies, service floors etc, makes it compelling to provide soft storeys in high rise buildings primarily due to increased storey heights, however Soft storeys can also he formed as a direct consequence of earthquake induced vibrations which causes abrupt changes in amount of infill Walls between storeys in sudden changes in the stiffness.