Study on the Ultimate Bearing Capacity of Prestressed Containment Anchor Zone in New High-Strength Concrete

High-strength concrete (HPC/UHPC) provides a new way to optimize the performance of nuclear power containment, but the mechanism of its application in the bi-directional dense anchorage zone is not clear. In this paper, a three-dimensional nonlinear model was established by ABAQUS to systematically study the effects of concrete strength, cylinder thickness and other parameters on the local pressure-bearing performance of the anchorage zone. The study shows that the use of C80–C120 concrete can thin the thickness of the containment by 30–40% and significantly enhance the pre-compressive stress safety reserve. Comparison of the existing design codes (e.g., Kim’s formula, Highway Bridge Specifications and UHPC-related regulations) reveals that the prediction results have a non-conservative or over-conservative tendency, which restricts the full utilization of the material performance. This study reveals the working mechanism of bi-directional multiple anchorage zones, demonstrates the advantages of high-strength concrete containment in terms of safety and economy, and provides a theoretical basis for the design of advanced nuclear power structures.