SEISMIC PERFORMANCE EVALUATION OF DIFFERENT COMPOSITE SHEAR WALLS AS ALTERNATIVES TO CONVENTIONAL RC SHEAR WALLS

Abstract

Nepal is location in the subduction zone of the Indian and Eurasian plates renders it highly vulnerable to seismic activity, with devastating earthquakes posing a significant threat to life and infrastructure. The 2015 Gorkha earthquake (M7.8) highlighted this vulnerability, underscoring the urgent need for resilient structural systems in earthquake-prone areas. This study investigates the seismic performance of multistory buildings with different types of shear wall systems: ordinary reinforced concrete (RC) shear walls (Type 1), composite shear walls with embedded steel sections (Type 2), and composite shear walls with encased steel plates (Type 3). Using pushover analysis, the study evaluates these systems in terms of capacity curves, performance points, ductility, displacement profiles, plastic hinge patterns and performance level across low-rise (5-story), medium-rise (8-story), and high-rise (10-story) building configurations. Results reveal that composite shear walls (Types 2 and Type 3) significantly outperform ordinary RC shear walls in base shear capacity, ductility, and energy dissipation, with composite shear wall (Type 3) walls exhibiting the best overall performance, particularly for higher structures. Additionally, the controlled hinge formation observed in composite walls enhances safety and reliability under seismic loading. The findings highlight the potential of composite shear walls to improve structural resilience in seismically active regions like Nepal. The study recommends the adoption of these systems in seismic design to mitigate future risks and enhance building performance in vulnerable areas, offering valuable insights for engineers and policymakers.