Civil Insight: A Technical Magazine Volume 2 | Page 17

CIVIL INSIGHT 2018
TEACHERS’ SECTION
17
Figure 5: Base and Story shear distribution in Y-direction in 200% mass irregular case
Figure 6: Base and Story shear distribution in Y-direction in 200% mass irregular case
Regular building has fewer shears than that of bare frame. Top story shear is very larger value when irregularity
is in top part of the building in both 200% and 300% irregular cases. Increase in 5 th and 6 th story force when
irregularity is in 5 th and 6 th story in 200% mass case is 13% and 63% in X-directions and 52% and 145% in
Y-directions. In 300% mass when in 5th and 6th story, in X-directions 68% and 184% is increased in lateral
story force and 82% and 193% in Y-directions respectively.
CONCLUSION
Regular buildings having regular distribution of mass, bare (no infi ll in any story) and irregular frames (having
one specifi c mass irregular story) were analysed using linear time history method for the comparison of base/
story shear to conclude the effect of infi ll, location and magnitude of mass irregularity in special moment
resisting RC frames.
From the analysis results following conclusions can be made:
•
Presence of brick infi ll wall in the RC frames enhances the lateral stiffness of the buildings.