| 摘要 |
A method of excavating a surface layer of soil is disclosed that uses an excavator with a grab having two bucket halves with cutting edge. In a first excavating position, the grab is held in a first orientation as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining the first orientation. While maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil. The grab is then lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible. The grab is moved towards a second excavating position and held in the first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level. While maintaining that level and the first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, the second portion being adjacent and contiguous to the first portion before excavation. The grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible. This method is repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated.
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