Analysis of the change in the depth of frozen ground in different soils under Lithuanian conditions

Abstract

Lithuanian climatic conditions make a large influence on road design, construction and repair. Climatic conditions include amplitude and speed of temperature variation, maximum and minimum temperatures, precipitation, wind direction and speed, thickness of snow cover, depth of frozen ground. The depth of frozen ground depends on a negative temperature and its stability, thickness of snow cover and the beginning of its occurrence, vegetation, properties and composition of soils, etc. In Lithuania the ground gets frozen in the first decade of December on the average and continuous until the middle of April, sometimes until the beginning of May. The highest depth of the frozen ground is achieved at the end of winter (in February-March). In especially severe winters the depth of frozen ground reaches up to 1–1,5 m. In warm and snow-free winters the ground could not freeze at all or the frozen ground could be not deep (10 – 20 cm) and varying. The deepest frozen ground could be found in the soils of dry and dusty sand and sand loam of the South – South Eastern Lithuania and in the soils of clay in Biržai environs. The lowest depth of the frozen ground could be found in sandy and marshy soils prevailing in the Šilutė environs and in the soils of moraine sand loam and loam of Žemaičiu Highland. The action of frost changes the structure of soil, influences surface and underground water interchange, therefore, investigations and analysis of the changes in the depth of frozen ground is important from the theoretical as well as practical point of view.