TRANSFER PIPE INSIDE WATER BACKFLOW PREVENTIVE DEVICE IN IMPROVED EARTH PLACING DEVICE

摘要

PROBLEM TO BE SOLVED: To effectively restrain separation of sediment in improved earth until the improved earth descending in a transfer pipe reaches the water bottom by preventing a backflow of water in the transfer pipe in an improved earth placing device for placing the fluidity improved earth keaded by adding a solidifying material to the sediment at the water bottom by transferring the improved earth downward to the water bottom from above a placing ship through the transfer pipe. SOLUTION: The transfer pipe 12 is attached with an opening-closing valve V capable of opening-closing an outlet 12o of the pipe 12. An energizing means F is connected to this opening-closing valve V for applying valve closing directional energizing force for holding this valve in a valve closing position Va. The opening-closing valve V is opened against the energizing force of the energizing means F according to an increase in valve opening force applied to the opening-closing valve V by weight of the improved earth S in the transfer pipe 12.