| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the intrusion of roots into a pipe by laying water-repellent soil grains provided with water-repellent layers on the soil grain surfaces at the prescribed thickness to cover the periphery of the pipe buried in the ground. SOLUTION: Surfaces of normal soil grains are covered with water-repellent coating layers made of silicone to form water-repellent soil grains having the grain size 0.5 mm or below, preferably 0.3 mm or below, for small grains and the grain size from 2 mm to about several mm for large grains. At the time of execution, two pipes 1 are connected via a cylindrical union joint 2. The periphery of the union joint 2 and the pipes 1 near it is buried in the water- repellent soil 3 made of the water-repellent soil grains, and the pipes 1 located apart from the union joint 2 are buried in the normal soil 4. Since the water- repellent soil 3 forms a dry layer containing no moisture, roots of plants do not intrude into the water-repellent soil 3, thereby roots can be prevented from intruding into the pipes 1 from the joint portions of the pipes 1.</p> |
