Frost-resistant assembled initial support structure of tunnel and construction method thereof

A construction method based on a frost-resistant assembled initial support structure of a tunnel comprising a bearing layer, an elastic compressible structure and an inflatable airbag;

• wherein, a gap space is formed between the bearing layer and the surrounding rock, and the inflatable airbag and the elastic compressible structure are provided in the gap space;
• and the inflatable airbag after being inflated and the elastic compressible structure jointly fill up the gap space;
• wherein the construction method comprises the following steps:
• providing the bearing layer in the tunnel, and forming the gap space between the bearing layer and the surrounding rock;
• providing the inflatable airbag and the elastic compressible structure in the gap space;
• and
• inflating the inflatable airbag and filling up the gap space with the inflatable airbag and the elastic compressible structure;
• wherein,
• the bearing layer comprises a plurality of assembly units jointed to each other;
• and the plurality of assembly units are encircled to form a closed annular structure.