Existing tunnel repairing structure and construction method

The invention provides an existing tunnel repairing structure and a construction method. The existing tunnel repairing structure comprises a corrugated plate assembly, ground feet, rail penetrating battens and a reinforcing layer. The corrugated plate assembly is formed by splicing stainless steel corrugated plates in the annular direction of the existing tunnel, and inner flanges are arranged on the two sides of each stainless steel corrugated plate. According to the split mounting type corrugated steel assembly, the split mounting type corrugated steel assembly is connected with a ballast bed into an integral annular structure through the ground feet and the rail penetrating battens, and then the split mounting type corrugated steel assembly and an existing tunnel are fixed into a whole through the fasteners; micro-expansion high-strength cement mortar is poured into a space formed between the assembly structure and the inner wall of the existing tunnel, and a reinforcing layer formed after solidification i