关键词: 道路工程, 多年岛状冻土路基, 坡向性, 温度场, 位移场, 数值模拟

Abstract: There were great differences of ground temperature circumstance on both slope sides of subgrade and the underlying soil layers because of the highway direction in island-shaped permafrost areas, which caused the inhomogeneous thermal deformation of subgrade structure and brought about a series of serious subgrade diseases such as longitudinal cracking, thermal thawing, which threatened the driving safety directly. Mastering the slope-oriented difference characteristics was the premise of improving design quality and enhancing thermo-stability for permafrost subgrade. Therefore, based on the practical project, the slope-oriented thermal effect of island-shaped permafrost subgrade in high latitude and high cold regions was studied by using finite element numerical simulation method and applying different heat flux densities on both slope sides of subgrade. The research results show that the uneven change of subgrade thermal stability will become more obvious with the increasing temperature difference both of subgrade slopes. Based on the thermal response of subgrade displacement field with different heat flux conditions, the characteristics of slope-oriented thermal deformation and the possible diseases for island-shaped permafrost subgrade in different states are revealed.

Key words: highway engineering, island-shaped permafrost subgrade, slope orientation, temperature field, displacement field, numerical simulation