| 摘要 |
PURPOSE:To enhance the safety and quickness of operations for erecting poles by a method in which a drum whose upper and bottom faces are removed is inserted into an excavated pit and excavation is made by men in the drum. CONSTITUTION:The upper and bottom faces 3 and 4 of a drum 5 are removed out. A pit 2 of a slightly larger diameter than the drum 5 is drilled in the ground where a column, e.g., pole, is to be erected and buried by means of an auger, etc. The drum 5 is inserted into the pit, and the bottom portion of the drum 5 is excavated by man in the drum 5. The drums 5 are stacked up one upon another and lowered until the excavation is made to a necessary depth. Finally, a pole, etc., is erected in the drum 5 being buried. The safety and quickness of the operations of excavation can thus be enhanced. |
