Expanded-head anchor rod for gravel replacement and filling area

The utility model relates to an expanded-head anchor rod in a gravel replacement and filling area, which comprises a twisted steel bar, a centering support, an expanded-head section cement stone body, a variable-diameter reinforcement cage component, a first limiting nut, an axial rod, a bearing plate, a second limiting nut and two ring-shaped fixers, and a power spring is arranged between the two ring-shaped fixers. A movable mechanism is arranged below the lower ring-shaped fixer, the movable mechanism is connected with a vertical rib, the vertical rib can be unfolded when the movable mechanism is pressed, and a spiral stirrup is wound on the vertical rib; the middle section of the flexible steel wire is cushioned under the power spring, two ends of the flexible steel wire respectively penetrate into two adjacent round holes of the ring-shaped fixer and respectively fix two opposite saw-tooth-shaped clamping blocks, the two saw-tooth-shaped clamping blocks are clamped with an inverted saw-tooth-shaped clamp