Abstract
We have measured the pressure at soil raise and the under soil pressure when piercers are pulled through the sandy loam and clay loam.
The results are as follows.
1) It seems that the pressure at the sandy loam raise is larger than the clay loam, but in the case of the small relative density, there is not so evident difference between the sandy loam and clay loam.
The pressure at soil raise has nothing to do with the tip angle of ball.
2) The under soil pressure near the ball is larger than that far from the ball in the case of a little soil raise, but is not so large on the whole in the case of more soil raise.
