PURPOSE: To prevent an early ageing of a water reservoir or a processing site owing to the solar beams by covering a recessed ground surface with a water permeable shade sheet layer.
CONSTITUTION: The inner surface of a recessed ground is rammed, and a waterproof sheet 5 is laid along the bottom surface 2, the face of slope 3, and the ground surface 4 around the recessed ground. In this case, instead of the waterproof sheet 5, a sheet made by weaving simply a twisted long size HDPE may be used, or a sheet of a flexible plate form in which plural holes are engraved may be also used. Then, the whole surface of the sheet 5 is covered with a net-form shade sheet 7 to cut off the solar beams. As a result, the radiant heat is cut off as well as the water permeation to the ground surface is prevented, and the expansion and contraction by the heat are reduced, the ageing is prevented, and the weatherproof property can be improved.
IMAMURA SHIYOUSUKE
WATANABE TADAMICHI
