Novel Quasi‐Static Testing of Shear Walls With Embedded Parts: Experimental Insights and Interaction Mechanisms

ABSTRACT In nuclear power plant (NPP) structures, equipment and pipelines are all anchored to shear walls using embedded parts. The shear walls with embedded parts may suffer cracks and potential structural damage under earthquakes due to stress concentrations. The individual mechanics of the embedded part or the shear wall had been investigated worldwide; however, comprehensive research on their coupled interaction has never been found. To address this deficiency, this study investigates the impact of suspended equipment on shear walls by integrating embedded parts and applying predetermined stresses. A novel quasi‐static loading system and experimental procedure with out‐of‐plane localized loading are proposed to meet the experimental requirements. The system integrates multi‐actuator coordinated control and a follow‐up device that ensures real‐time alignment of prestress direction, effectively addressing the challenges posed by combined in‐plane and out‐of‐plane loading. A three‐phase loading protocol is developed to simulate the dynamic interaction between the shear wall and anchored equipment during earthquakes. Experimental investigations of distribution analysis are conducted on five squat reinforced concrete (RC) shear walls with embedded parts, focusing on the combined effects of loading forms, position, and prestress of embedded parts on seismic performance. The results reveal that the placement of embedded parts exacerbates crack distribution and disrupts the hysteresis symmetry. As Embedded Part's Prestress (EPP) increases, the stiffness and strength of the shear walls decrease, leading to significant stress concentrations around the embedded parts and reinforcement yielding. Furthermore, wall damage significantly influences the performance of the embedded parts, and load‐displacement analysis was conducted to quantitatively assess this damage. Additionally, shear stress application significantly influences reinforcement strain evolution, and appropriate embedded reinforcement stress can effectively modify the shear transfer mechanism. This study provides valuable insights into the design and regulation of NPP structures.