PURPOSE: To settle down a pipeline at a low cost as well as make burying work of pipes easier by a method in which a settled layer of soluble solids is formed of a plurality of soluble solid matters on the bottom of an excavated trench, a solving liquid is spread from pipes in the settled layer to dissolve the solids or the solids are dissolved by ground water.
CONSTITUTION: A settled layer 4 consists of soluble spherical solids which are composed of an oil soluble substance or water-insoluble substance such as sand as nucleus 9a and a water-soluble substance as the covering substance 9a of the nucleus 9a. After completion of burying work, a solving liquid such as water is supplied from a storage tank through pipes 3 set in the layer 4 to the layer 4 to dissolve the substance 9b of the solids 9 forming the layer 4. Soil on the layer 4 and the pipeline 6 set on the layer 4 are made to collapse so that the pipeline 6 is settled down and at the same time settling displacement is allowed to occur.
NAKAJIMA YOSHIKAZU
SUZUKI NOBUHISA
