Fatigue life assessment of steel connectors in the adjustable column-base connection for high-speed rail

Abstract

High-speed rail (HSR) systems provide numerous benefits, including reduced travel time, increased transport capacity, and lower environmental impact compared to conventional rail networks. Recent experience in Poland has confirmed that the design of high-speed rail lines requires the development of new, dedicated structural solutions. One such example is the need to assess the load-bearing capacity of the column-to-foundation connection, which in Poland is designed as a connection with a spacing between the column base plate and the top part of the pile foundation – an uncommon solution in HSR applications. The study included the development of a fatigue damage spectrum in the high-cycle range, taking into account stress variability caused by pressure fluctuations from passing trains. The results establish a relationship between the number of load cycles and pressure values, enabling a simplified estimation of the fatigue strength of the examined connection. Wind effects are influenced by several factors, including train speed, aerodynamic shape, and the angle of load application. The study highlights the sensitivity of the system to boundary conditions and recommends design improvements to enhance fatigue resistance. The novelty of the work lies in identifying critical failure modes specific to distance-type connections and emphasizing the need for full-scale experimental validation in the context of HSR development in Poland.