Abstract
Just after work, the foot print of the semi-legged vehicle was about 50cm in width, about 60cm in length, about 30cm in depth and at interval of about 3m on the flat ground. The values of cone index on the foot print were similar to those on the undisturbed soil. Therefore, the foot prints were marked by the slip of the foot, but soil compaction scarcely occurred. One year later, the depth of the foot prints were reduced by about 10cm, and surface landslides didn't occur. The values of cone index did not vary change. Just after work, the tracks by the tracked vehicle were about 5cm to 10cm in depth. The dug tracks by skidder were the maximum of 43cm in depth. The tracks did not so vary change in four years. Four years later, the values of cone index on the tracks by harvester were similar to those on the undisturbed soil. The dry bulk density on tracks against the undisturbed soil was reduced. But the content of organic matter on tracks was constant and lower than that on the undisturbed soil.
