International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 11 Issue: 05 | May 2024
www.irjet.net
p-ISSN: 2395-0072
Comprehensive Analysis of Modifications in the Draft Code IS1893 (WC) 2023 for RC Buildings Dr. Dhara Shah1 1Sr. Assistant Professor, F
aculty of Technology, CEPT University, Ahmedabad-09 ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - The latest draft of the building code IS 1893 (WC) Part1 & Part 2, issued by the Bureau of Indian Standards (BIS) in
April 2023, introduces significant alterations and provisions necessitating careful scrutiny before enforcement. Key changes include the transition from Deterministic Seismic Hazard Assessment (DSHA) to Probabilistic Earthquake Hazard Assessment (PEHA) methodology for seismic zone factor determination, leading to substantial increase in peak ground accelerations and distinct seismic zone factors for strength design and serviceability checks within the same structure. This exodus hints a substantial shift towards performance-based seismic design practices. Moreover, adjustments to the horizontal response spectrum curve, expansion of soil site classification based on shear wave velocity, and modifications in load combinations, minimum design horizontal base shear force, lateral storey drift limits, and allowable structural systems in reinforced concrete (RC) buildings have been implemented. Furthermore, the draft code introduces novel criteria for assessing building irregularities, with a specific focus on torsion, and mandates consideration of soil flexibility in structural analysis. It also incorporates provisions for analyzing Architectural Elements and Utilities (AEU), addresses small residential structure design, and delineates torsional analysis criteria for rectangular regular buildings. While these revisions aim to enhance seismic design methodologies, challenges such as comprehending return periods and adapting to new methodologies may arise. Therefore, the provision of clear explanations within the code and educational resources is imperative to facilitate understanding and implementation. This research paper conducts a comprehensive analysis of the revisions introduced in the draft code, particularly focusing on their implications for RC buildings. Key Words: Draft building code IS 1893 (WC) part 1 & part 2, peak ground accelerations, Probabilistic Earthquake Hazard Assessment, shear wave velocity
1. INTRODUCTION The latest draft of the building code IS 1893 (WC) Part1 & Part 2 released by BIS in April 2023 [1] [2] have brought substantial changes and provisions that warrant thorough review. While the final version of the revision is anticipated to closely resemble this draft, it's essential to acknowledge the possibility of modifications in values or specifications before its implementation. It's worth noting that the imminent release of IS 1893 Parts 3 to 11, which encompass topics ranging from tanks to tunnels and more, is anticipated in the near future. Part 1: General provisions Part 2: Buildings Part 3: Liquid retaining tanks Part 4: Bridges and retaining walls Part 5: Industrial structures Part 6: Base isolated buildings Part 7: Pipelines Part 8: Dams and embankments (to be formulated) Part 9: Coastal structures (to be formulated) Part 10: Steel towers (to be formulated) Part 11: Tunnels (to be formulated) Some noteworthy changes outlined in the draft of the building code IS 1893 (WC) Part1 & Part 2 are presented here.
1.1 Interpreting part 1 & part 2 together The existing IS 1893-2016 Part 1 encompasses general provisions and guidelines for seismic design of buildings, while IS 1893 (WC) Part 1 and Part 2 serve as complementary sections to be interpreted together. Part 1 typically addresses general provisions, while Part 2 specifically focuses on seismic design considerations for buildings. It could potentially introduce confusion or make the code less user-friendly if essential provisions for seismic design are spread across multiple parts. Consolidating all pertinent information into Part 1 of the code would likely streamline the design process and facilitate easier
© 2024, IRJET
|
Impact Factor value: 8.226
|
ISO 9001:2008 Certified Journal
|
Page 663