Abstract: The ballastless track structure, reknown for its superior geometric stability assurance capability, has significantly contributed to the rise and development of high-speed railway technology. It is a key factor in ensuring the safety and smooth operation of high-speed railway. However, its limited adjustment capacity imposes stringent requirements on the deformation control of the underlying foundation. In recent years, some sites have experienced track upheaval deformation, which disrupt normal high-speed railway operations and present a new technical challenge. Therefore, investigating the heaving of ballastless tracks on high-speed railway subgrades holds important engineering significance. This study begins by systematically summarizing the mechanisms behind subgrade heaving in ballastless tracks, identifying three major contributing factors: foundation lithology, subgrade fill characteristics, and environmental conditions. Next, techniques including rail fastener adjustment and track gradient adjustment methods, are thoroughly reviewed, with their advantages, disadvantages, and applicable conditions outlined. Countermeasures and suggestions for effective prevention of upward deformation in the stages of railway surveying, design, construction, and operation are proposed. Finally, combining with a typical project case of a high-speed railway, the causes of its upheaval deformation; and remediation maintenance strategies are analyzed. The results can provide technical support for the prevention and remediation of upheaval deformation; diseases of high-speed railway subgrades.

Key words: high-speed railway, ballastless track, subgrade, upheaval deformation, reason, countermeasure