PRETENSION SOIL NAIL METHOD OF TOP-DOWN

摘要

A pretension soil nail method using top-down construction method is provided to improve shear strength of soil by vertically cutting a slope and exerting pretension to the pretension soil nail fixed by a fixing nut, thereby minimizing expected soil displacement that may occur after construction. A pretension soil nail method using top-down construction method comprises the steps of: vertically cutting a slope in top-down method, and fixing the cutting slope by performing primary soil cement injection to the cutting slope; boring a hole to which a pretension soil nail is fitted onto the cutting slope fixed by the primary soil cement job in an upward direction with respect to a horizontal plane; assembling the pretension soil nail and inserting the assembly into the hole; filling filler into an injection pipe of the pretension soil nail inserted to the hole; installing a grating plate(14) whose upper and lower parts are formed in a slant line on an upper side of the pretension soil nail, and installing a bearing plate; after the filler is cured, exerting pretension to the pretension soil nail, fixing the pretension soil nail with a fixing nut(16), for finishing by conducting secondary soil cement injection.