To provide a boring method and equipment capable of drilling earth smoothly in a short time by using boring equipment with a size the same as that of a conventional one even when a scheduled drilling depth is great.
A double casing comprising an inner casing 12 formed by connecting a plurality of hollow rods 12a, 12b... and an outer casing 13 formed by connecting a plurality of short pipes 13a, 13b... armoring the inner casing are fixed to a drilling chuck 11 in such a manner that a passage space 14 between both casings 12, 13 is clogged inside. This inner casing 12 is rotated by a rotation drive equipment and, as a result, the double casing is rotated and the ground is drilled. In this case, water for slime mudding is introduced from the end portion of the inner casing 12 to water filling device, the amount of mud flowing out from the opening through the passage space 14 between both casings 12, 13 is controlled and part of or whole the mud is passed through the space between the casing and bore hole inner wall and drained above the ground surface by switching.
IMASAKA SHIGEFUMI
UCHIDA YOSHIHIRO
