The invention discloses a self-expanding
pipe seam anchor rod for surrounding rock
large deformation and preparation and using methods of the self-expanding
pipe seam anchor rod. An anchor rod comprises a rod body internally provided with self-expanding explosive columns and a tray, resistance increasing seams are formed in the
pipe wall, making contact with the self-expanding explosive columns, of the rod body, ring-shaped resistance increasing grooves are formed in the pipe wall of the rod body on the rear parts of the self-expanding explosive columns, the rear end of a
threaded rod of the series-wound self-expanding explosive columns penetrates through the tray and is connected with a fastening nut, and the tray is not fixedly connected with the rod body. During using, the self-expanding explosive columns are soaked in water first, then the anchor rod is inserted into a drilling hole, the fastening nut is screwed, thus the tray and surrounding rock wall get close; radial expansion pressure is generated by using size expanding of a
hydration reaction of a self-expanding anchoring agent, and the anchoring effect is performed; when lager deformation of surrounding rocks occurs,
rock body deformation force is applied to the self-expanding explosive columns through the tray, a fastening bolt and the
threaded rod, fiction slippage occurs between the self-expanding explosive columns and the rod body when stress exceeds design resistance, in the process of slippage, constant resistance and yielding can be maintained by the resistance increasing seams and resistance increasing grooves, and the anchoring function can be continuously performed after displacement.