EXCAVATION METHOD OF SEABED BURIED PIPELINE

摘要

PURPOSE: To make it possible to excavate under no influence of waves mounting a submarine buried pipeline to a submerged excavating machine which is buoyancy controllable by excavating partially and pushing forward the excavating machine along the buried pipeline and excavating the earth and sand around the buried pipe. ;CONSTITUTION: A submerged excavating machine 10, which is provided with a sled 13 at the lower part of a rack, is installed above a submarine buried pipeline 1 where the excavator 10 is capable of controlling buoyancy by infecting and draining water of a float by partially disgging out. Then, a reaction block 20 provided with a submerged winch 21 is fixedly installed to a seabed B in front of the advancing direction F with a specified spacing, thereby towing an excavator 10 in the advancing direction F. In this case, a hydraulic winch 21 is hydraulically driven where a hydraulic unit is mounted to the hydraulic winch 21. During the operation, the hydraulic winch 21 is laid out on a hydraulic-drive type turn table, thereby controlling the towing direction of the excavator 10 with accuracy. While advancing the excavator 10 in the direction marked with the arrow F by remote control from a work mother ship 30, the earth and sand around the buried pipeline 1 is excavated. The hydraulic winch 21 is further opened, thereby moving the reaction block 20 and continuing the excavation work.;COPYRIGHT: (C)1995,JPO