Rockfall prevention structure for tunnel portal

The invention discloses a rockfall prevention structure for a tunnel portal. The rockfall prevention structure for the tunnel portal aims to substantially reduce the amount of moving rocks at the tunnel portal, lower the construction cost of a rockfall prevention project and reduce the construction difficulty. The rockfall prevention structure for the tunnel portal comprises a tunnel portal structure and a rockfall happening area located on a slope face above the tunnel portal structure. A falling rock induction groove is formed in the portion, between the tunnel portal structure and the rockfall happening area, of the slope face. The falling rock induction groove is provided with an arc top segment, a left side segment and a right side segment, wherein the arc top segment is close to the rockfall happening area, and the left side segment and the right side segment extend downwards along the original slope face to the portions outside the tunnel portal structure and the line.