BACK-FILL FILLING METHOD AND DEVICE IN SHIELD CONSTRUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To prevent a filling pipe from being blocked due to hardening of back-filling material remaining and adhering in a filling pipe during the cessation of excavation by cooling the filling pipe in a back-fill filling device for a shield machine. ;SOLUTION: A cooling pipe 6 is spirally wound around the peripheral part of a filling pipe 1, and liquid nitrogen is used as a cooling medium. The flow of the liquid nitrogen circulated in the cooling pipe 6 is regulated by a temperature sensor 8. When excavation is started, a hydraulic jack 3 is contracted to retreat a change-over valve 4, and the filling pipe 1 is communicated with a tail void T through a guide pipe 5 to fill back-filling material. When excavation is suspended, the liquid nitrogen is made flow through the cooling pipe 6 so as to cool the residual back-filling material in the filling pipe 1. The manifestation of initial hardening strength of the back-filling material is thereby delayed to prevent the blocking of the filling pipe 1. In the case of suspending excavation for many hours, the hydraulic jack 3 is elongated to advance the change-over valve 4 so as to communicate the filling pipe 1 with a cleaning pipeline 2, and the inside of the filling pipe 1 is cleaned with wash water.;COPYRIGHT: (C)1997,JPO