| 摘要 |
PROBLEM TO BE SOLVED: To provide a ground improvement method that allows a construction condition of a perforated steel pipe to be set to suit a ground to be worked, the perforated steel pipe offering both a drainage function and a ground constraining function, and the selected steel pipe to be worked for certain on an artificial ground or a natural ground of any type of soil, including a viscous soil, a sandy soil, a gravel-mixed soil, or a combination of any of these.SOLUTION: A ground improvement method uses a perforated steel pipe with a blade having a spiral blade and a drain hole for discharging moisture in the ground formed on an outer periphery of a steel pipe body, and includes the following steps for: setting a ground constant for the ground to be worked; setting a current safety ratio and a planned safety ratio; calculating a necessary deterrent from the planned safety ratio, for both a normal condition and an earthquake disaster condition; calculating an installation length and an installation density of the perforated steel pipe with a blade; calculating a necessary tensile force and an allowable tensile force per perforated steel pipe with a blade; and driving the perforated steel pipe with a blade having the derived installation length into the ground at the installation density.SELECTED DRAWING: Figure 1 |
