摘要 |
PROBLEM TO BE SOLVED: To provide a method for lowering the underground water level of an aquifer in the excavated ground after forming an artificial low permeable layer below the excavation bottom when no clear impervious layer exists below the excavation bottom in the case of carrying out dry work by lowering the underground water level in the excavated ground surrounded by an impervious wall, below the excavation depth. SOLUTION: At least two filling/pumping wells are installed with a specific space in the ground surrounded by the impervious wall, down to the depth reaching the formed position of the low permeable layer below the excavation bottom. One of the two filling/pumping wells is used as a filling well, and the other as a pumping well to form the low permeable layer in the ground surrounded by the impervious wall. After completing the formation of the low permeable layer, the filling/pumping wells are changed over to pumping wells functioning only in the aquifer ground above the low permeable layer, and underground water above the low permeable layer is pumped to lower the water level. COPYRIGHT: (C)2008,JPO&INPIT
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