Blockuppfrysning: Observationer vid Uppgraevning i Vaeg E4, 518 och 571, AC-Laen, 1983 (Boulder Heave in Roads: Observations from Excavations in Road E4, 518 and 571, AC-County, 1983)

摘要

Bumps on roads are generated by up-ward migrating boulders, caused by frost action in a frost susceptible and boulder enclosing subgrade. VTI has within its budget of R and D followed the Road Administration's excavation of boulders in road E4, initiated by occurring bumps on the road surface, the route Nordmaling-Hornefors, AC-county, and the adjoining roads 518 and 571. When considering the position of the boulders in the road and the adjacent soil type the following can be mentioned: Excavation was performed in several places where the subgrade consisted of till and even in places where boulders were not expected. Slope cuts are considered to be particularily risky referring to boulder migration. A compilation of such slope cuts where boulder migration can be expected, shows that excavation was necessary in 50% of the cases.