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International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 12 Issue: 06 | Jun 2025

p-ISSN: 2395-0072

www.irjet.net

PERFORMANCE BASED ANALYSIS OF TALL BUILDING WITH OUTRIGGER STRUCTURAL SYSTEM IN HIGH SEISMIC ZONES Sevanthi S1, L. Govindaraju2, 1Post Graduate Student Department of Civil Engineering, UVCE College (University), Banalore 2Professor, Department of Civil Engineering, UVCE College (University), Karnataka, India 560056

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Abstract - This study presents a performance based

inter-storey drift and reduces the overall deformation of the structure during seismic events. This paper explores the performance of various outrigger configurations and evaluates their effectiveness using computational modeling and real seismic data. Additionally, the study incorporates the impact of Soil-Structure Interaction (SSI), acknowledging that foundation flexibility can alter the dynamic response of tall buildings. By addressing these factors, the research aims to provide valuable insights into optimizing structural design for earthquake resilience, ultimately contributing to the development of safer and more sustainable urban infrastructure.

analysis of a 40-storey high-rise building with and without outrigger systems, focusing on its seismic performance in Zones IV and V as per IS 1893 (Part 1): 2016. The objective is to evaluate the effectiveness of outriggers in reducing lateral displacement and inter-storey drift under seismic loading conditions. The building is modeled and analyzed using ETABS and SAP2000 software, considering irregular plan configurations. Key parameters such as storey displacement and drift are compared for models with and without outriggers using the Equivalent Static Method and Response Spectrum Method. Further, advanced seismic analysis techniques such as Pushover Analysis and Time History Analysis are performed to understand the building's nonlinear behavior and dynamic response to actual earthquake records. The influence of Soil-Structure Interaction (SSI) is also incorporated to assess how different soil conditions affect structural performance. The results indicate a significant reduction in both displacement and drift when outriggers are used, especially in Zone V. The addition of outriggers greatly enhances the lateral stiffness and stability of the structure. The study concludes that outriggers are a highly effective structural solution for improving the seismic performance of tall buildings in highrisk seismic zones.

2. LITERATURE REVIEW

Key Words: Outrigger System, High-Rise Building, Seismic Analysis, Story Drift, ETABS, SAP2000, SoilStructure Interaction, Performance-Based Design.

Numerous studies have underscored the benefits of outrigger systems in tall structures. Fawzia & Fatima (2010) demonstrated substantial reductions in lateral deflection with multi-level outriggers. Chang et al. (2013) introduced semi-active damped outriggers using MR dampers, showing enhanced seismic control. Chopra (2017) emphasized the role of pushover analysis in capturing non-linear behavior. Other researchers, such as Kogilgeri & Shanthapriya (2015), examined the effect of varying outrigger depths and concluded that full-height outriggers provide optimal performance. Despite these findings, research gaps remain in understanding virtual outriggers, soil-structure interaction, and the response of irregular building geometries under actual seismic conditions.

1. INTRODUCTION

3. OBJECTIVES AND METHODOLOGY

Tall buildings are increasingly common in urban areas due to the growing demand for vertical expansion in densely populated regions. These structures face substantial lateral forces generated by wind and seismic activity, necessitating advanced structural systems to ensure safety and stability. The outrigger structural system has emerged as a prominent solution, effectively linking a building's central core to its perimeter columns to distribute lateral loads more efficiently. This configuration significantly improves the building's lateral stiffness and minimizes sway, enhancing occupant comfort and structural integrity.

2.1 Objectives Of The Study The primary objective of this study is to evaluate the seismic performance of tall building with and without outrigger 1. 2. 3.

In high seismic zones, where the risk of ground motion is considerable, such reinforcement becomes even more critical. The integration of outrigger systems helps control

Impact Factor value: 8.315

To compare the lateral displacements (story displacement) and story drifts of a building structure with and without an outrigger system. To analyze the behavior and performance of the structure when subjected to seismic forces, particularly in high seismic zones To evaluate the overall performance of the structure, focusing on how the outrigger system enhances the building’s ability to resist lateral forces.

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