Supporting structure and construction method for shallowly-buried unsymmetrical pressure tunnel entering hole

The invention provides a supporting structure and a construction method for shallow-buried unsymmetrical-pressure tunnel hole entering construction. The supporting structure comprises a mountain slope protection structure arranged on the unsymmetrical-pressure side of a to-be-built tunnel, a protective retaining wall and a protective arch. The protective retaining wall comprises a foundation, a first wall body and a second wall body. The first wall body is arranged at the top of the foundation, the second wall body is arranged at the top of the first wall body, and a supporting end is arranged between the top end of the first wall body and the inner side face of the second wall body; one end of the protection arch is supported on the supporting end, and the other end of the protection arch is supported on the mountain slope protection structure; the protective arch is fixedly connected with a mountain through a plurality of anchoring structures; the inner side face of the first wall body and the bottom face o