The invention discloses a tunnel
segment structure and a construction method, the tunnel
segment structure comprises a segment and a fixed
pile foundation, the segment is buried in surrounding rock soil, and a grouting layer is arranged between the segment and the surrounding rock soil; the fixed
pile foundation is arranged in the grouting layer, the fixed
pile foundation comprises a bag device and a grouting
pipe communicating with the bag device, grouting is conducted in the bag device through the grouting
pipe to form the fixed pile foundation, one side of the fixed pile foundation abuts against the surrounding rock soil, and the other side of the fixed pile foundation abuts against the segment. According to the tunnel
segment structure, the wrapping characteristic of the bag device isutilized; the
slurry in the bag device can be prevented from being dispersed and diluted; the duct piece and the surrounding rock soil form a
whole body; the constraint force of the surrounding rock soil is used for effectively controlling the segment to float upwards, so that the segment is stably arranged in the surrounding rock soil in time, the situations of segment staggering, crack damage and even axis deviation caused by floating upwards after the segment is separated from the shield
tail are avoided, the waterproof performance of a tunnel is guaranteed, and the safety of the tunnel isimproved.