Ground anchor of which stress can be self-diagnosed, and construction method therefor

An existing stress self-diagnosis ground anchor comprising:

• a bond length part positioned at a predetermined depth of a boring hole excavated from a target surface of a ground;
• a head portion positioned around the target surface;
• a tensile material configured to connect the bond length part and the head portion in a state of receiving tension and installed to transfer bonding force of the bond length part to a structure;
• a displacement measurement member having one end fixed at a predetermined position of the bond length part and the other end positioned in a form of a free end on the head portion and installed to recognize a relative displacement of the head portion with respect to the bond length part;
• and
• a comparison marker formed to compare a reference position of the head portion and a position of the other end of the displacement measurement member,
• wherein the comparison marker includes:
• a cap configured to surround the other end of the displacement measurement member and attached to the head portion, and
• a detachable portion formed to be detachable from the head portion via force generated while the other end of the displacement measurement member contacts and pushes the detachable portion.