Durable comb plate type bridge expansion device

The invention belongs to the technical field of bridges, and particularly relates to a durable comb plate type bridge expansion device which comprises a bridge abutment, a bridge body and an embedded steel bar structure, a fixed end anchoring plate is arranged above the bridge abutment, a fixed end comb plate is fixedly connected to the fixed end anchoring plate, and a fixed end supporting body is arranged between fixed end comb teeth and the fixed end anchoring plate. A movable end anchoring plate is arranged above a bridge body, a movable end comb plate is fixedly connected to the movable end anchoring plate, a movable end supporting body is arranged between the movable end comb plate and the movable end anchoring plate, and concrete structures are poured between a fixed plate comb plate and a bridge abutment and between the movable end comb plate and the bridge body. The fixed end supporting body and the movable end supporting body are located on the lower sides of the tooth roots of the fixed end comb pla