Abstract: The laying of a vegetation mat in close contact with a clad surface is achieved. The vegetation mat has a net, which prevents freezing or flow-away of vegetation material without the need for stretching a separate net. The mat comprises a layer of vegetation material selected from the group consisting of soil improvement material, fertilizer, organic material, vegetation seeds and combinations thereof, a front and back sheet, which are capable of being at least partly decomposed and are coupled together to wrap the vegetation material. A net having a mesh size permitting the budding and growth of the vegetation seeds, is provided on the front surface of the front sheet.

Abstract: A hydrophobic material used in the construction of a culver for improving the drainage of the culvert. The hydrophobic material comprises a textile or knit fabric, preferably biodegradable, having large and small mesh portions. A soil-aggregating agent is adhered to the small mesh portions of the textile or knit fabric. The hydrophobic material can be coated with a water soluble film to prevent the soil-aggregating agent from being removed during construction or handling.The hydrophobic material used for the drainage of a culvert is capable of keeping the water-penetrating property of the culvert for a long time.

Abstract: A soil, which has been regulated in particle-diameter, is blended with a hydraulic material and water or an aqueous solution of synthetic resin emulsion, so that a moisture content may be 1.2 to 1.5 times an optimum soil compacting moisture content, and then stirred and followed by subjecting to a rolled fill which is followed by watering or spreading an aqueous solution of a soil-agglomerating agent on the mixture, which was subjected to the rolled fill, at least one time within 1 to 5 days after the completion of the rolled fill and further watering at least one time within 7 to 21 days after the completion of the rolled fill respectively, whereby an ideal sportssurface and the like showing not only a water-permeability but also a preferable compression strength and bending strength and showing no frost heaving is obtained.