Without seamless lines, it would be impossible to achieve high-speed and safe train operation. High-speed railway seamless lines are an extremely complex technical system, facing three major technical challenges:
(1) Adaptability to complex climatic conditions. my country spans different climatic zones, with an annual rail temperature difference of up to 110°C, and there are extreme climates such as sudden cooling and heating, and continuous high or low temperatures. The temperature stress of high-speed railway rails is huge (209t/110°C) and unevenly distributed, which can easily cause geometric shape to be difficult to maintain, rail expansion, rail breakage, etc. High-speed seamless turnouts with more complex structures are more sensitive to complex climates;
(2) Coordination of complex line foundations. my country has a complex geological environment, with many mountainous rivers, and a large number of long bridges and elevated stations have been built (the proportion of bridges on some lines exceeds 80%). The deformation of beams and piers will directly lead to stress damage and excessive deformation of seamless lines;
(3) Controllability of safe service status. High-speed railways have high speeds, high density, and short maintenance time. The application of traditional observation piles and nighttime manual testing methods has poor accuracy and long cycles, and cannot provide timely warnings of seamless line status. The existence of the above three problems will directly affect the safety of high-speed railway operations.
