To investigate the freeze-thaw resistance of hydroxypropyl methylcellulose (HPMC)-modified loess, the study analyzed the effects of HPMC dosage and the number of freeze-thaw cycles on the shear strength of modified loess through triaxial shear tests. The results indicated that the peak stress of modified loess exhibited a tendency to increase and then decrease with the increase of the dosage. The optimal dosage of HPMC was 0.5 %. When the confining pressure were 100kPa and 200kPa, the stress-strain relationship curves of modified loess with optimal dosage after freeze-thaw cycles exhibited a weak hardening behavior; at confining pressures of 300kPa and 400kPa, the stress-strain curves exhibited weak softening behavior. As the number of freeze-thaw cycles increased, the peak stress and shear strength indices of the optimal dosage of modified loess exhibited fluctuations. with the lowest values observed after five freeze-thaw cycles. Based on the peak stress, an anti-freezethaw modification effect parameter was proposed, which exhibited a positive correlation with the number of freeze-thaw cycles. The anti-freeze-thaw modification effect parameters for modified loess with optimal dosage were all greater than 1, indicating that the addition of HPMC significantly enhances the freeze-thaw resistance of seasonally frozen soil. HPMC functions both within the soil and at the air-water interface, forming hydrogen bonds, three-dimensional network structures, and flocculated agglomerates, thereby enhancing the strength and freeze-thaw resistance of the soil.

来源平台：CONSTRUCTION AND BUILDING MATERIALS