| 摘要 |
PROBLEM TO BE SOLVED: To reliably prevent groundwater in a lower permeable layer from being contaminated by a pollutant contained in an upper permeable layer during and after construction of a foundation pile in a foundation pile construction method to construct the same by inner excavation method.SOLUTION: A foundation pile construction method, to install a precast pile 5 by inner excavation method to sink the same while excavating the ground having a first layer 103, a water stop layer 105 below the first layer 103 and a second later 111 below the water stop layer 105, comprises: an enlarged diameter water stop section construction process to form in a vertical hole 113 an enlarged diameter excavation section 115 with a diameter thereof enlarged so that at least either an upper edge or a lower edge thereof is positioned in the water stop layer 105 and to construct an enlarge diameter water stop section 117 by injecting cement milk into the enlarged diameter excavation section 115; and a foot protection section construction process to excavate the vertical hole 113 in the second layer 111 below the enlarged diameter water stop section 117 and to construct a foot protection section 119 at the lower edge of the vertical hole 113. |
