Horn mouth type tunnel portal structure

The utility model provides a horn mouth type tunnel portal structure. The horn mouth type tunnel portal structure comprises a lining structure on a tunnel portal section. The horn mouth type tunnel portal structure is characterized in that a portal is arranged on the outer side of the lining structure in a smooth butt joint mode, the portal stretches outwards, and the area of the cross section of an inner cavity of the portal becomes larger gradually towards the periphery to form a horn mouth. According to the horn mouth type tunnel portal structure, the horn mouth type tunnel portal can meet aerodynamics requirements in railway tunnel specifications, the pressure peak of a micro-pressure wave can be reduced by 20-35%, an extra special buffer structure is not needed, extra square brushing of the wall of the tunnel portal is not needed, the square brushing amount on the portal is small, the structure is simple, and the occupied space is small. In addition, due to the fact that the structure is simple and the l