Comparative Seismic Performance of High-Rise RCC Buildings with Outrigger-Belt Truss Systems

Based on the results obtained from Response Spectrum Analysis and Wind Load Analysis of the G+30 reinforced concrete building with four different lateral load-resisting systems, the following conclusions are drawn: 1. The Combined Outrigger and Perimeter Belt Truss System (M4) demonstrates the BEST overall structural performance among all four models, with the lowest storey displacement and drift under both seismic and wind loading. 2. Compared to the conventional core shear wall system (M1), Model M4 reduces RSA roof displacement by 10.83% in the X-direction and 9.67% in the Y-direction. Under wind loading, the reduction is even more significant at 24.02% in the X-direction and 20.96% in the Y-direction. 3. The incorporation of outrigger and belt truss systems significantly increases lateral stiffness. M2 and M4 attract higher base shear under RSA, confirming that stiffer structures engage more seismic mass but provide better resistance against lateral forces. 4. The overturning moment is maximum for Model M4 (Combined system), indicating its superior ability to resist the "toppling" effect induced by lateral loads. 5. Storey drift values for all four models are well within the permissible limit of 12 mm specified by IS 1893 (Part 1): 2016. However, Model M4 exhibits the minimum drift, ensuring superior serviceability and reduced non-structural damage during earthquakes. 6. The combined action of radial outriggers and perimeter belt trusses in Model M4 effectively distributes lateral forces to the exterior columns, reduces core rotation, and enhances the global stiffness of the structure. 7. Based on the overall evaluation, the performance ranking of the structural systems is: M4 > M2 > M3 > M1. 8. For high-rise reinforced concrete buildings (G+30 and above) located in Seismic Zone IV, the Combined Outrigger and Perimeter Belt Truss System (M4) is highly recommended as the most efficient lateral load-resisting system for ensuring safety, stability, and serviceability.

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