Comparative and parametric study on codal provisions of seismic analysis of RC frame structure as per IS 1893-2016 (Part 1) and IS 1893-2002 (Part 1)

Abstract

Considerable improvement in earthquake resistant design has been observed in recent past.
The sixth revision of IS 1893 (Part 1): 2016, “Criteria for Earthquake Resistant Design of
Structures” have been published by Bureau of Indian Standards recently in December 2016.
The new code comprises changes considering standards and practices prevailing in India.
The present work aims at studying the comparison of revisions in various clauses of IS 1893
(Part 1): 2016 with IS 1893 (Part 1): 2002 and their effect on Equivalent static method and
Response spectrum method. The present work focuses on parametric study of G+3 multistory
building with varying the number of storey levels 4, 8, 12, 16 and 20 storeys using ETABS
software is performed. The effect of varying storey levels on free vibration and response
spectrum analysis is carried out. The different modes of vibrations are observed and natural
frequencies, time period are tabulated. The RC structure behave in bending for first few modes
and later torsion and then buckling. The first few modes contribute to closely spaced modes
with lateral bending, torsion. For increasing number of modes the natural frequencies of the
structure increases. The differences in storey displacements, base shear, and storey drift are
compared with both codes and the effect of variation is addressed. The base shear increases
as number of strorey increases, because of increase in seismic weight and depends upon the
value (horizontal acceleration coefficient).