冻胀形成的纵向裂缝和道路翻浆导致的沉陷鼓包及车辙变形是季节冻土区高速公路路基冻害的主要形式。野外调查的大量资料表明 ,地下水是导致路基冻害的最积极活跃的因素。它不仅侵袭软化路基 ,增加其冻胀 ,而且侵袭防冻砂砾层甚至底基层 ,使其失去防冻作用和辅助承载作用 ,致使道路翻浆破坏。这种水分来源不一定都是地下水由下向上的竖向迁移 ,地面水也可通过路肩边坡、失效排水沟、路面裂缝和中央分隔带等部位侵袭到路基中来 ,从而使路基土和结构层材料性能恶化 Longitudinal cracks formed by frost heave and subsidence bulge and rut deformation caused by road dumping are the main forms of frozen damage of expressway subgrade in seasonally frozen region. A large amount of data from field surveys show that groundwater is the most active and active factor leading to roadbed frost damage. It not only affects softening embankment, increasing its frost heave, but also invasion of frost-gravel layer or even the base layer, so that it lost the role of antifreeze and supporting bearing, resulting in the destruction of the road dip. This source of water is not necessarily vertical groundwater migration from bottom to top, surface water can also be through the shoulder slope, the failure of drainage ditches, pavement cracks and the central partition and other parts of the invasion into the subgrade so that the subgrade soil and structure Layer material performance deteriorated