| 摘要 |
The pin has a upper flange formed at its top and a lower driving spike, and is driven into a pre-formed hole (2) in the ground. The hole tapers downwards, where the upper region (4) is larger than the cross section of the pin and the lower region (3) is smaller. The diameter of the lower region is determined so that the lower end of the pin is held so tight that before the pin is driven in, its top end can rotate with respect to the vertical. The pin is then driven into the ground until the lower edge (19) of the flange comes to rest at the ground surface (8). The pin is then aligned with the vertical and driven in until the top surface of the pin is in line with the ground surface. |
