• Mahesh N. Koli
• Prof N.P. Phadatare

The thesis involves analysis of buildings with vertical mass irregularity in horizontal plan regular and irregular configuration, to evaluate performance of the building during earthquake forces. In this project an attempt will be made to see variation in design forces due to different mass distributions along the height of the multistoried structures. All seismic codes give different limits of irregularities. IS 1893:2002, prescribe a single storey of building should be mass irregular, if its mass exceeds 200 % more than adjacent storey. When a single storey considered and its stiffness is less than its adjacent by 70% or less than 80 % average lateral stiffness of three storey’s above, then the storey is known as “soft storey”. In Seismic analysis and design, calculation of fundamental time period of vibration is a critical, because its gives global seismic demands of the structure. The period of structure depends upon properties as stiffness, mass, seismic forces, cracking, height and no of storey. Basically the structure has always forms structural irregular and cracks which leads to change in stiffness and strength of structure. These things has been ignored in code while calculation of empirical expressions of fundamental time period of structure. Due to this, calculated expressions are not suitable for calculation of actual seismic demands of structure. So, there is a need to change codal fundamental time period. Previously Eigen value analysis used for calculating fundamental time period. This research work proposed modified equations of fundamental time period calculation to overcome on codal limitations in terms of mass irregularity in vertical and horizontal plan regular and irregular configuration. Analysis of building carried out using computer program ETABS Software.

Mass irregularity, Multi-story building, Seismic responses, Seismic demand, ETAB

"The Seismic Performance of Multi storied RC Building with Mass Irregularity", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.7, Issue 8, page no.253-257, August-2020, Available :http://www.jetir.org/papers/JETIR2008337.pdf

"The Seismic Performance of Multi storied RC Building with Mass Irregularity", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.7, Issue 8, page no. pp253-257, August-2020, Available at : http://www.jetir.org/papers/JETIR2008337.pdf