Abstract: A lateral hole boring method whereby a lateral hole of a desired length is formed underground by repeatedly performing the following steps. A vertical hole is prepared, and a lateral hole boring apparatus equipped with a leading auger of a smaller length than the diameter of the vertical hole is lowered into the vertical hole to a predetermined position. The apparatus is manipulated from the ground level to advance and rotate the leading auger to bore a lateral hole. When the lateral hole has reached a predetermined length commensurate with the length of the leading auger, the advance movement of the leading auger is stopped, and the lateral hole boring apparatus is manipulated from the ground level to detach the leading auger therefrom, and is lifted above the vertical hole while leaving the leading auger in the lateral hole.

Abstract: A clamping device for connecting a branchpipe to a main pipe buried underground, has a main body with a lower side having a curved surface for engaging the main pipe and, at the same time, is provided with a connection port for a branched coupling. Arms are supported by sections of the body on both sides of the connection port cand on the upper side of the main body. These arms are extended downwardly so as to hold the main pipe and move for free rotation with respect to the support sections. Arm retainers are idly supported at the centers by bolts which are screwed into threaded holes provided on a midplane of the support sections of the main body. The retainers have pushing sections formed on both their ends for pushing the arms from above, at external sides of the support sections. Only a small working hole must be excavated for connecting the branched pipe to the main pipe since the clamping device can be positioned and tightened from ground level.