Seismic Response of Nuclear-Reinforced Concrete Shear Walls with High-Strength Materials

Recent research studies have investigated the use of high-strength materials in nuclear power plants to enhance the constructability of their massive squat-reinforced concrete shear walls. Despite the advantages of these high-strength materials, the dynamic response of such walls has not yet been fully investigated at the different damage states. To address this, the current study focuses on developing fragility functions for squat-reinforced concrete shear walls with high-strength materials to evaluate their seismic response compared to their counterparts with normal-strength materials. In this respect, a numerical OpenSees model, validated using previous experimental programs that have been conducted on reinforced concrete shear walls (i.e., with different aspect ratios, vertical and horizontal web reinforcement ratios, yield/ultimate strengths of reinforcement, and concrete compressive strengths), is used in the current study. Incremental dynamic analyses, using the 44 far-field ground motion records recommended by the FEMA P695 methodology, are then performed to develop fragility functions for reinforced concrete shear walls with normal- and high-strength materials at different damage states. These damage states are characterized by several performance indicators including cracking and crushing of concrete, residual displacements due to sliding, and reinforcement buckling/fracturing, following the FEMA P-58 guidelines. Finally, design recommendations are presented to enhance the seismic performance of squat-reinforced concrete shear walls when high-strength materials are adopted in nuclear construction practice.