| 摘要 |
PURPOSE:To easily control propulsive forces of a tube by a method in which a pressure sensor is set between a receiving ring connected to an expanding head through a connecting shaft and a buried tube to permit earth pressure only applying to the buried tube to be detected by the pressure sensor. CONSTITUTION:An annular pressure sensor 11 is set between a receiving ring 10 and a buried tube 3, by which earth pressure applying only to the tube 3 is detected. The detected value is sent through a cable 12 to a pressure sensor 13 where it is displayed. By controlling propulsive forces during the burying period in such a way as not to exceed the allowable loading force of the tube 3 of the earth pressure applying to the tube 3, the tube 3 can be buried without causing damage to it during burying period, eliminating the needs for any experienced skill in burying operation because any judgement based on experience is not needed. |
