To provide a casing driver capable of preventing pulling out of a casing from becoming difficult in a pull-out process.
This casing driver grips a casing C, lowers it while rotating and driving it, and pushes it into the ground to dig a shaft. In this case, a depth of pushing in of the casing C is measured by a band grip detection means 10 detecting the grip motion of a band for gripping casing 7, a travel amount detection means 11 of a lifting frame 3, a push-in amount computing element 21 of the casing C, and an integrator 22, a pull-out force for pulling out the casing C in the ground is measured by pressure detection means 12a, 12b of thrust cylinders 4a to 4d a pull-out force computing element 23 of the casing C, an estimated value of pull-out force in a pull-out process is computed a processor 30 based on pull-out forces and depths at a plurality of points measured in a push-in process, and the estimated value is compared with a pull-out capability of the casing driver to display the results of the comparison on an output means 50.
TAMURA KATSUMI
ODA HISAKAZU
KUSUMI HIROSHI
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