Seismic Behavior Enhancement of Reinforced Concrete Structures in Hilly Terrains Using Shear Walls and Friction Dampers

Abstract

This dissertation presents a comprehensive comparative study on the seismic performance of reinforced concrete (RC) structures located in hilly terrains, focusing on three distinct design approaches: (i) a bare frame structure without supplemental elements, (ii) a frame structure incorporating shear walls, and (iii) a frame structure equipped with friction dampers. The primary objective of the research is to evaluate and enhance the earthquake resistance of RC buildings using advanced modeling and analysis techniques tailored for topographically irregular sites. Special emphasis is placed on two common structural configurations used in hilly regions: Step-back (SB) and Split-foundation (SF) buildings. These configurations present unique challenges due to geometric irregularities, varying foundation levels, and eccentric mass distributions, which tend to amplify seismic vulnerabilities. The study models both SB and SF buildings under each of the three design schemes to accurately reflect real-world construction practices in hilly areas. Initially, linear static and response spectrum analyses were conducted to understand the fundamental seismic behavior of each model. The analysis revealed that the introduction of shear walls significantly improves the lateral strength and stiffness of both SB and SF buildings, reducing displacements, drifts, and base shear compared to bare frame configurations. However, to better capture the nonlinear dynamic response and energy dissipation capacity, nonlinear time history analysis was employed using real earthquake records. The incorporation of friction dampers provided further performance enhancement, particularly for splitfoundation structures, which are inherently more susceptible to torsional irregularities. Friction dampers effectively minimized story drifts and displacements by dissipating seismic energy, outperforming both bare frame and shear wall models across key response parameters. The results indicate that while shear walls provide substantial improvement over bare frame structures, friction dampers offer superior control over seismic response, especially in irregular hill buildings like SB and SF configurations. This research underscores the necessity of integrating modern damping technologies alongside traditional reinforcement techniques to achieve resilient and earthquake-resistant structures in seismically active hilly terrains.