Abstract:Due to insufficient research on the interaction mechanism between freeze-thaw soil and anchor, the influence of freeze-thaw of soil on the internal force of anchor cannot be fully considered in engineering practice. Therefore, building an empirical relationship of collapsible loess cohesion considering the influence of freeze-thaw cycles based on the triaxial shear test of freeze-thaw cycles of seasonal freeze-thaw collapsible loess in Xining City. Based on the deformation coordination relationship between the anchor body and the surrounding soil layer, the analytical formula of the axial force and shear stress of the anchorage section of the frame prestressed anchor under freeze-thaw conditions is deduced, and the results of the theoretical calculation are compared with the results of the field tests, and the influence of freeze-thaw cycles on the axial force and shear stress of the anchorage section is analyzed. The results show that the cohesion of the soil decreases exponentially with the increase of freeze-thaw cycles, and the axial force and shear stress of the anchorage section increase sharply in the first 3 freeze-thaw cycles, and then tend towards stable after 7 freeze-thaw cycles. The axial force at the beginning of the anchorage section is more influenced by freeze-thaw cycles than the axial force at the end of the anchorage section, however, the variation law of shear stress from the beginning to the end of the anchorage section with freeze-thaw cycles is same. Results of the field tests proved the rationality of the calculation method, which can provide a reference for the design and calculation of frame supporting structure in such areas.