季冻区高速铁路路基改良填料冻融性能研究

针对季冻区高速铁路路基填料冻融性能问题，将水泥和水泥粉煤灰掺入级配碎石作为改良措施。为了研究水泥和水泥粉煤灰改良碎石填料的抗冻融耐久性能，对填料的水稳定性、冻融变形特性和冻融耐久性进行试验，分析改良剂的种类、掺量以及养护龄期等因素的对路基填料性能的影响规律。研究结果表明：水泥改良填料相较于水泥粉煤灰改良填料有较高的无侧限抗压强度；填料单向冻胀量随着水泥掺量的增加而降低，掺入粉煤灰后会提高填料的冻胀率；水泥粉煤灰改良填料在28 d养护后水稳定性性能较水泥改良填料更佳优异，抗冻融性能则会低于水泥改良填料。

Study on Freeze Thaw Durability of Improved Filling Materials for High Speed Railway Subgrade in Seasonal Frozen Regions

According to the freeze-thaw performance of high-speed railway subgrade filler in a seasonal freezing area, graded crushed stone mixed with cement and fly ash is used as improvement measures. In order to study the anti-freeze-thaw durability of cement and cement fly-ash improved filler, the water stability, freeze-thaw deformation characteristics, and freeze-thaw durability of the filler are tested. The influence of the modifier's type, dosage, and curing age on the performance of subgrade filler is analyzed. The results show that the cement-modified filler has higher unconfined compressive strength than the cement fly-ash-modified filler. The unidirectional frost heaving of filler decreases with increasing cement content, and the frost heaving rate of filler increases with the addition of fly ash. After 28 days of curing, the water stability of cement fly ash-modified filler is better than that of cement-modified filler, and the freeze-thaw resistance is lower than that of cement-modified filler.