Study on the Effect of Non-Linear Ventilation Pipe Composite Measures on the Slope Permafrost Subgrade

In the alpine mountain area, stability of steep-slope permafrost subgrade is mainly affected by temperature variation in frozen soil layer at base road. Under conditions climate warming and engineering-related disturbance, cooling an urgent problem to be solved field construction. this paper, numerical calculation method, combined with data monitored situ, used study effects several measures, which non-linear ventilation pipe rubble are combined. The results show following: (1) clearly different lateral terms—after 20 years operation, maximum difference melting depth between left shoulder center 3 m; (2) gravel 3.85 m, while 2.3 (3) effect composite measures noteworthy, a −2.2 °C freezing area appears under subgrade.