| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water barrier device for a water collecting borehole that can surely collect ground water in a water collecting pipe on a semi permanent basis and that can also reinforce an easily collapsing section or a severely leaking portion in the water collecting borehole. <P>SOLUTION: Impervious member 5 having a water-absorption swelling property is attached at a prescribed position of water collecting pipe 4 to be inserted into water collecting borehole 3. The impervious member 5 comprises a pair of fixing flanges 5a attached on the upstream and downstream sides, a pair of impervious rubber materials 5b1 and 5b2 having a water-absorption swelling property placed between the opposite faces of the fixing flanges 5a, and impervious cementitious material 5c having a water-absorption swelling property placed between the impervious rubber materials 5b1 and 5b2 that retains the expansion volume for a long time on a semi permanent basis after water absorption/swelling. The expansion rate of the impervious rubber materials 5b1 and 5b2 having a water-absorption swelling property is set higher than that of the impervious cementitious material 5c having a water-absorption swelling property. The expansion rate of the impervious rubber material 5b1 having a water-absorption swelling property on the downstream side is set higher than that of the impervious rubber material 5b2 having a water-absorption swelling property on the upstream side. <P>COPYRIGHT: (C)2012,JPO&INPIT |
