TANGENTIAL FROST HEAVING FORCES OF CLAY AND SANDY SOILS ACTING ALONG THE METAL SURFACE
A.G. Alekseev1,2
1Gersevanov NIIOSP, JSC "Construction", 2nd Institutskaya str. 6, Moscow, 109428, Russia
2Moscow State University of Civil Engineering, Yaroslavskoye sh. 26, Moscow, 129337, Russia
Keywords: tangential frost heaving forces of soils, stable resistance to the shift of frozen soil along the foundation surface, laboratory studies
Abstract
The results of experimental studies of the tangential frost heaving forces of clay and sandy soils in laboratory conditions on three installations with different single-plane shear rates at constant normal load are presented. The installations made it possible to perform conditionally instantaneous shift, long-term tests with the application of a stepwise shifting load and a shift at a constant speed. As a result of complex studies, the dependences of shear resistance or equivalent tangential forces of frost heaving of sand and loam on water content (from 10 to 28 %) and temperature (from 0 to -10 °C) on the metal surface have been established. An increase in soil water content and a decrease in soil temperature leads to an increase in the resistance to soil shear. The shear resistance of sand is up to 2 times higher than similar values for loam under identical shear conditions, temperature and water content. An increase in soil moisture leads to an increase in the contact area of soil particles through ice layers with a metal foundation and to an increase in the bonds between the particles as a result of an increase in the volume of ice. It is established that the resistance to conditionally instantaneous shear is up to 3 times higher than the values of extremely long-term shear resistance and shear at a constant speed under similar thermal humidity conditions.
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