PURPOSE: To determine soil quality continuously and readily, by excavating excavation water via pilot holes under the same excavating conditions and by judging the soil quality from an excavated form obtained by the survey.
CONSTITUTION: Pilot holes 3 are excavated into ground 2 to be explored with excavating pipes 5 at a given depth. Then, high-pressure water 6 from nozzles 7 provided on the excavating pipes 5 is horizontally rotated to be jetted toward the circumferential ground 2, and the ground 2 is gradually excavated. The excavated forms SHP of excavated ground is explored with ultrasonic rangefinders 9 provided on the excavating pipes 5, by surveying the distance between the excavating pipes 5 and the excavated ground wall surface. As the result, the slight change of soil can be easily judged and the safety factor for suitable value on the work can be also determined.
NAKAMURA SHINOBU
IMANISHI HAJIME
NIT CO LTD