Dredging and methods for dredging pollution prevention caisson

摘要

PROBLEM TO BE SOLVED: To move with avoidance of a contact to the bottom of the water for preventing a damage by filling water in a hollow side wall part to sink a metallic caison body and draining it to make its floating up possible through a water supply and drain means. ;SOLUTION: A front earth A in the first pollution preventing caison 1 is excavated by a bucket on a dredger and loaded in a burge, and the earth and sand in the lower layer of the front earth A are therefore exposed. Next the front earth A loaded in the burge is disposed, and the earth and sand are excavated and loaded in the burge, and the second caison 1 is sunk adjacently to the first caison. In addition, the front earth A in the second caison 1 is excavated to backfill the excavated spot of the first caison 1, and the exposed earth and sand in the second caison 1 are excavated and gathered in the burge. While the earth and sand in the second caison are excavated, the polluted matter of water in the first caison settles down, and the water turns into a pure state. After that, the first caison is moved to an adjacent position opposite to the second caison 1. Thus the damage of the caison 1 can be prevented and easily moved.;COPYRIGHT: (C)1998,JPO