PURPOSE: To equalize the bearing capacity of soft ground in waste water as well as to hasten the draining of water from the soft ground by a method in which a filter mat is laid on the soft ground, and a sand layer, a main buried net, and a gravel layer are orderly formed on the filter mat.

CONSTITUTION: A filter mat 2 pervious to water but impervious to soil particles is set on soft ground 1, and sand is laid on the mat 2 to form a sand layer 3. In this case, an auxiliary buried net 4 of a fine mesh is buried in the sand layer 3 in advance. A main buried net 5 of a coarse mesh is laid on the surface of the sand layer 3, and gravel is laid on the net 5 to form a gravel layer 6. The occurrence of blocking due to the intermixture of soil into the sand layer 3 can thus be prevented by the filter mat 2, draining of water in the soft ground 1 can be hastened, and the bearing capacity of the soft ground 1 can be equalized by the tensile resistance of the net 5.