Mechanical properties of saline soil and stability of subgrade slope in Uzbekistan under large temperature difference

With the deepening of the "One Belt and One Road" strategy in China, the construction of transportation infrastructure in saline land areas along the Silk Road in Central Asia and other countries has increased sharply. Affected by special climatic conditions, the road construction in saline soil is prone to engineering problems such as subsidence and slope instability. Based on the Uzbekistan A380 highway project, the evolution laws of failure strength and shear strength parameters of saline soil under different freeze-thaw cycles and salt contents under large temperature difference are studied based on the freeze-thaw cycles with large temperature difference and unconsolidated undrainage triaxial shear tests. The stability of subgrade slope under different salt contents and different freeze-thaw cycles is analyzed through numerical simulation. The results show that under different freeze-thaw cycles and salt contents, with the increase of the salt content, the failure strength decreases continuously with linear attenuation characteristics, and the cohesion and internal friction angle show quadratic function attenuation characteristics. With the increase of the number of freeze-thaw cycles, the failure strength and cohesion continue to decrease, showing a logarithmic function attenuation characteristics, and the internal friction angle shows a logarithmic function growth characteristic. The safety factor of roadbed slope of saline soil decreases with the increase of the salt content and the number of freeze-thaw cycles.