PURPOSE: To easily insert a water-barrier material by recessively providing a water- passing groove for water passing in the longitudinal direction and installing a water- absorptive material in the state to cover the water passing groove on an impermeable linear body.
CONSTITUTION: A water-barrier material 1 is formed of an impermeable linear body 11 provided with a large number of water passing grooves 13 in the longitudinal direction and a water-absorptive filter layer 12 installed in the state to cover the grooves 13. Drilling mud 21 is sucked up through the grooves 13 by way of inserting the water-barrier material 1 by several meters in the longitudinal direction on the upper part of a trench 2 filled with the drilling mud 21 and giving negative pressure on the head end of the grooves 13. Then, the water surface of the drilling mud 21 inside of the grooves 13 becomes higher than the water surface inside of the trench 2 by Δh by a suction force of the negative pressure and increases the apparent weight, and the water-barrier material 1 is inserted in the trench 2 by the dead weight. Thereafter, soil particle part contained in the drilling mud 21 and others is absorbed toward the outside of the filter layer 12 through the filter layer 12 and a soil particle layer is constituted, and it displays its function as a protective layer for the water-barrier material 1 and resists against deformation and damage after insertion.
KODERA HIDENORI
SHIMIZU JUNJI
