Abstract: Seasonal freeze-thaw cycles degrades the strength of loess structures in northwest and north China, giving rise to many problems. In this research, indoor freeze-thaw cycle test was carried out on loess solidified by the new polymer curing agent SH to examine the impact of freeze-thaw cycles on the compressive and shear strength of the solidified loess. Results unveiled that curing agent SH significantly improved the compressive strength of loess. The higher the SH content, the higher the strength of loess, the lower the loss rate after freeze-thaw cycle, the lower the mass loss rate, and the better integrity of solidified loess samples. The shear strength of solidified loess decreased with the increase of the number of freeze-thaw cycles. Freeze-thaw cycle also has an evident impact on cohesion. The cohesive force and internal friction angle of the solidified loess decreased the most after 3-4 freeze-thaw cycles; such decline attenuated and gradually stabilized after 5 times of freeze-thaw cycles. The research findings offer reference for the promotion and application of curing agent SH in the frozen-melt zone of loess, and provide some theoretical basis for the treatment of frozen-melt zone of loess.

Key words: loess, freeze-thaw cycle, SH curing agent: compressive strength, shear strength, cohesion, internal friction angle