Study on Mechanical Characteristics and Durability of Prestressed Anchorage Structure of Rock and Soil under Fatigue-Corrosion Coupling Action

This paper presents a comprehensive approach encompassing indoor experiments, theoretical analysis, and numerical simulations to investigate the durability of prestressed anchorage structures subjected to fatigue loads and corrosion. The study addresses the critical issue of gradual aging and damage caused by cumulative loads and corrosion, which ultimately leads to a decrement in structural durability. Through a rigorous analysis of the effects of fatigue load and corrosion on the performance of steel bars, numerical simulations were conducted to elucidate the failure mechanisms and variation patterns within the internal anchoring section. After subjecting steel bars to fatigue and corrosion tests for a defined duration, they were systematically categorized and exposed to varying fatigue tensile cycles in diverse acidic and alkaline environments. Employing the PFC2D program, a numerical model of the prestressed anchorage structure under the coupled effects of fatigue load, corrosion, and fatigue load was developed. This model allowed for a comparative analysis of the evolution of shear stress, axial stress, and displacement fields at the bolt-grout interface under two distinct conditions. The findings reveal the microscopic mechanisms underlying bond degradation at the bolt-grout interface under the synergistic impact of fatigue load and corrosion. The proposed methodology and experimental results demonstrate that geotechnical anchoring technology can effectively reinforce up to 70% of geotechnical structures, significantly reducing soil loss by approximately 80%. This research provides valuable insights into the durability of prestressed anchorage structures, paving the way for future improvements and optimizations.