季节冻土区高速公路路基含水状况与冻害调查

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。

Investigation on Frost Damage and Water-Bearing Condition of Expressway Subgrade in Seasonally Frozen Soil Region

The lengthwise cracks caused by frost heave,and settlem ent, bulge, rut caused by spring thaw are the main forms of frost damage of roa ds in seasonally frozen soil region. The vast amount of field investigation data prove that gr oundwater is the most active and live factor causing roads to be frost damage. It not onl y attacks subgrade and aggravates its frost heaving, but also attacks frost-pro o f sand-gravel layer even subbase, and makes them lose the frost-proof function and the auxiliary bearing capacity, so that the frost boiling and damage of the roa ds ar ise in spring. The source of moisture is not just from vertical migration of gro undwater but also including the surface water supply from slopes of shoulders, d is abled drain ditches, cracks in pavements, median strips and so on, thus deterior ating the performance of subgrade and structural material.