Study on Shear and Bending Envelope of a Residential Building

Structural design in reinforced concrete buildings requires a comprehensive understanding of internal forces, particularly shear and bending moments, which govern the design and detailing of structural members. The graphical representation of these internal forces through envelope diagrams provides engineers with a powerful tool to visualize the maximum and minimum demands on each structural element under different load combinations. This study focuses on the development of shear force and bending moment envelopes for a G+2 reinforced concrete residential building using ETABS software, in accordance with the provisions of IS 456:2000 and IS 1893 (Part 1):2016. The building is modeled as a moment-resisting frame subjected to gravity and seismic loads. The analysis includes the generation of load combinations considering both vertical and horizontal effects. The shear and bending moment results are extracted for beams and columns across all stories to identify the most critical members and governing load cases. The results show that maximum bending moments occur in beams at intermediate spans, while maximum shear forces are concentrated near supports and lower stories due to higher cumulative axial loads. The study highlights the significance of using envelope diagrams for safe and economical structural design by ensuring that no potential critical load case is neglected. Furthermore, it demonstrates the efficiency of ETABS in accurately predicting internal force distributions, making it an essential tool for modern structural analysis. The findings can assist practicing engineers and students in understanding structural behavior and optimizing design decisions in residential RC buildings.