Comparatıve Study Of Old And New Indıan Seısmıc And Wınd Codes For Analysıs Of Exıstıng Hıgh Rıse Structure

Abstract

The sixth revision of IS 1893 (Part 1): 2016, “Criteria for Earthquake Resistant Design of Structures” have beenpublished by Bureau of Indian Standards recently in 2016 and the 3rd revision of IS 875 (part 3): 2015, “Design loads (other than earthquake) for buildings and structures (part 3 –wind loads)” have been published by Bureau of Indian Standards in 2015.  In these new codes many changes have been included considering standards and practices prevailing in India.Recently modern architecture deals with something regularity and irregularity in geometry. This work aims at studying revisions in various clauses of new IS 1893 (Part 1): 2016 with respect to old IS 1893 (Part 1): 2002 and IS 875(PART 3):1987 and IS 875(PART 3):2015 and their effects especially, on an existing structure with the help of ETABS software.Results of existing building were compared as per old and new IS-Codes.Old IS-1893- 2002 has given one response spectra for Equivalent Static Method and Response Spectrum method for 4.0s periods. Expressions are given for calculating design acceleration coefficient (Sa/g), for rocky/hard soils, medium soils and soft soils. New IS 1893- 2016 gives response spectra for Equivalent Static Method and Response Spectrum method separately for 6.0 s periods. Expressions are given for calculating design acceleration coefficient (Sa/g), for Equivalent Static Method and Response Spectrum method separately for Rocky/hard soils, medium soils and soft soils. The Sa/g valueswill be changed. Definition of soft storey and weak storey, change in definition of mass, torsion and vertical irregularities has been modified. Importance factor of 1.2 has been specified in new code for residential buildings, in old code residential buildings were assigned importance factor of 1.0.New gust factor have been introduced in wind code IS 875(PART 3):2015 and as new formulations are introduced in revised codes.In this study, clauses of all the IS codes were compared and building was analyzed as per the old and new IS codes.ETABS results showed that building design is safe as per the new IS codes.