| 摘要 |
PROBLEM TO BE SOLVED: To suppress ground subsidence in a peripheral area separated from an excavation area while sufficiently lowering a groundwater level in the excavation area.SOLUTION: A system 1 for lowering a groundwater level includes a well pipe 5, a vacuum pump 7 which decompresses an internal space 6 of the well pipe 5, a submersible pump 8 which is installed in the vicinity of the bottom of the well pipe 5, and a lifting pipe 9 which is connected to the submersible pump 8. An air introduction pipe 12 is arranged in the ground 2 so that the upper end thereof communicates with the atmosphere and the lower end thereof communicates with an artesian aquifer 3 and that the air introduction pipe 12 penetrates an impermeable layer 4 located directly on the artesian aquifer 3. When the groundwater level in the air introduction pipe 12 is below the top surface of the artesian aquifer 3, air flows spontaneously into the artesian aquifer 3 through the air introduction pipe 12. |
