ABSTRACT
The impact of aerodynamic forces generated by passing high-speed trains on support structures of overhead contact lines is increasingly significant, as these forces grow with the square of train speed. This effect is critical in the design of support structures for high-speed rail systems. This paper focuses on the exposed column-base connection without grout, a common solution in Poland for attaching columns to foundations. The study investigates how variable-direction wind pulses, caused by passing trains, influence the fatigue life of these connections. Using numerical analyses, it highlights the complexity of accurately assessing the load magnitude and direction. Preliminary results indicate a high sensitivity of fatigue performance to load variations, especially at speeds around 350 km/h. Due to the lack of field measurements, assumptions based on standard aerodynamic loads may not fully represent actual conditions. The paper proposes accounting for time-varying load directions to improve fatigue life predictions and calls for further experimental studies to validate these findings and support safer design practices.
