DEVELOPMENT OF PERMEANT SOIL IMPROVEMENT SYSTEM SUITABLE FOR HORIZONTAL DIRECTIONAL DRILLING

To apply to soil improving method using horizontal directional drilling (HDD), smaller grouting pipes are desirable for installing into curving boring hole. In this study, the self-packers are newly equipped on grout pipes, that is more simplified than conventional packer system. Feasibility of the new systems were examined through field tests. The grout pipes were installed into the ground successfully and its applicability to HDD was found satisfactory. Furthermore the improved soil bodies were directly observed and effectiveness of grouting were confirmed through compressive strength tests.