Grouting scope-controllable bag type micro bearing pile

The invention provides a grouting scope-controllable bag type micro bearing pile, and belongs to the technical field of structure repair. The bearing pile comprises a casing pipe, a reinforcing cage, a grouting pipe, a grout outlet, an exhaust pipe, bags and a free section, wherein the reinforcing cage, the grouting pipe, the grout outlet, the exhaust pipe, the bags and the free section are positioned in the casing pipe; the grouting pipe and the exhaust pipe are respectively positioned outside the opposite sides of the reinforcing cage; the grout outlet is positioned in the lower part of the grouting pipe; the bags are positioned at the middle part and the lower part of the bearing pile and wrap the reinforcing cage; the free section is positioned at the upper part of the bearing pile. According to the bearing pile, concrete grout liquid is injected to the bags, so that the grouting serosity is guaranteed to be filled and diffused within a determined range, the effective contact area of the pile body and a soil body is enlarged, and the bearing capacity of the pile is improved. The method adopted by the bearing pile has the advantages that the grouting quantity is controllable, the grouting scope is controllable, the serosity is effectively diffused, the grouting effect is favorable, and the grouting speed is easy to control.