The study of soil mechanical capability of different mines for using in forest road pavement

The use of appropriate building materials for forest road pavement has the important role in deceasing the forest road repair and maintenance. According to the role of forest mines for procurement of building material, awareness of their mechanical properties has a crucial importance. For this purpose, the soil mechanical properties of mixed four forest mines used for forest road pavement were investigated in Nav district in 7TH watershed in northern forest of Iran. Gradation, broken face, plastic properties, durability, and sand equivalent of mixed soil were analyzed. The gradation of mixed mines and soil classification were performed by dry sieving and unified method, respectively. The mean values of the investigated variables were compared with standard values. Final result indicated that soils of mines number 1, 3, 4 are gravel and poor graded (GP) but the soil of mine number 2 was sandy well graded (SW). The best curvature and uniformity coefficient belonged to the mine number 2 with 22.5 and 4.44, respectively. Percentages of fractured particles in four mines were 71.7, 72.4, 74.8 and 72.6, respectively which was consistent with the standard values. Coefficient of friction values for selected mines was consistent with the standard values with 38.55, 42.20, 39.47, and 43.87, respectively. The mean values of sand equivalent for four mines were higher than 0.5. Therefore the soil of mine number 2 is more preferable for use in permanent way while, the soil gradation of other mines should be corrected for using as a pavement material.