International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 12 Issue: 11 | Nov 2025
p-ISSN: 2395-0072
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P-DELTA ANALYSIS OF MULTI-STOREY BUILDING USING E-TABS SOFTWARE Jayshri S. Sirsat1, Prof. D. M. Pandit2 1M-TECH student, Department of Civil Engineering, CSMSS Chh. Shahu College of Engineering, Chhatrapati
Sambhajinagar.431005, MAHARASHTRA, INDIA
2Assistant Professor, Department of Civil Engineering, CSMSS Chh. Shahu College of Engineering, Chhatrapati
Sambhajinagar.431005, MAHARASHTRA, INDIA ---------------------------------------------------------------------***--------------------------------------------------------------------these second-order effects, potentially leading to inaccurate Abstract - The stability of tall and slender reinforced prediction of drift, stiffness degradation, and internal forces in tall structures.
concrete buildings is strongly influenced by second-order effects, particularly the P–Delta phenomenon arising from the interaction of gravity loads and lateral displacements. Neglecting these geometric nonlinearities can lead to underestimated structural responses and unsafe design decisions, especially under seismic and wind loading. This study investigates the influence of P–Delta effects on a multistory RC building and evaluates the effectiveness of shear walls in mitigating associated instabilities. A G+24 building model was developed in ETABS and analyzed under identical loading conditions using linear static analysis and nonlinear P–Delta analysis, both with and without shear walls. Key response parameters story displacement, drift, base shear, and overturning moments were examined to quantify the amplification induced by second-order behavior. The results indicate a significant increase in lateral deflection and drift when P–Delta effects are considered, emphasizing their relevance for high-rise structures. Incorporating shear walls markedly improved stiffness and reduced adverse P–Delta impacts, demonstrating their effectiveness as a lateral loadresisting system. The findings highlight the necessity of incorporating geometric nonlinearity in the analysis of tall buildings and optimizing shear wall placement to enhance seismic performance and structural safety.
Advanced numerical tools such as ETABS allow engineers to simulate both first-order and second-order behaviors, enabling a more realistic evaluation of tall structures under lateral loads. Additionally, the use of lateral load-resisting systems—particularly reinforced concrete shear walls—has proven highly effective in reducing deformation and improving the overall stiffness and stability of RC structures. Integrating shear walls within structural frames can help counteract the detrimental effects of P–Delta actions, especially in slender buildings subjected to seismic forces. Given the limitations of linear analysis and the increasing emphasis on performance-based design, a systematic investigation of the P–Delta effect becomes essential, particularly for buildings with and without shear walls. This research aims to evaluate the significance of P–Delta effects in multi-storey buildings and assess the contribution of shear walls in mitigating instability under seismic conditions.
1.1 Problem Statement Tall and slender RC buildings are highly susceptible to second-order geometric nonlinearities. However, in routine practice, the P–Delta effect is often ignored or inadequately accounted for, leading to underestimation of displacement, drift, bending moments, and shear forces. This simplification can compromise structural safety during strong ground motion or lateral loading. Moreover, the effectiveness of shear walls in reducing P–Delta-induced amplification remains inadequately quantified for buildings of intermediate to high rise.
Key Words: P–Delta effect, geometric nonlinearity, shear wall, ETABS, storey drift, seismic response, second-order analysis.
1.INTRODUCTION The rapid increase in urbanization has led to a growing demand for high-rise reinforced concrete (RC) buildings, where structural stability under dynamic and lateral loads is a critical design consideration. As building height increases, the influence of geometric nonlinearity becomes more pronounced, particularly the P–Delta effect, which results from the interaction between axial gravity loads (P) and lateral displacements (Δ). This interaction generates secondary moments that magnify structural deformation and may compromise stability during seismic or wind actions. While linear static analysis is widely used in conventional design practice due to its simplicity, it neglects
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Therefore, the problem addressed in this study is: “To determine how P–Delta effects influence the seismic response of a multi-storey RC building and to evaluate the extent to which shear walls can mitigate these second-order effects when analyzed using ETABS.”
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