TY JOUR TI Justification requirements granulometric composition material drainage layer of logging roads KW size KW soil subgrade KW the load unit JO Actual directions of scientific researches of the XXI century: theory and practice AU Sushkov, S.I. AU Burmistrova, O.N. PY 2014 IS 2 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov