Photo taken on November 12, 2016 shows the Ganhaizi Bridge, the world's longest concrete tubular bridge. Built to stand 2,500 meters above sea level, the bridge is 1,811 meters long, 24.5 meters wide and has 36 bridge spans. The huge "roller coaster" boasts the world's highest steel pipe concrete lattice pier, composite pier and hybrid bridge pier. It is the first bridge to use steel fiber concrete as structural material. It makes an important part of China's first high speed "double helix tunnel" through the mountainous Yaxi expressway of Ya'an City, southwest China's Sichuan Province. [Photo: Chinanews.com]

Photo taken on November 12, 2016 shows the Ganhaizi Bridge, the world's longest concrete tubular bridge. Built to stand 2,500 meters above sea level, the bridge is 1,811 meters long, 24.5 meters wide and has 36 bridge spans. The huge "roller coaster" boasts the world's highest steel pipe concrete lattice pier, composite pier and hybrid bridge pier. It is the first bridge to use steel fiber concrete as structural material. It makes an important part of China's first high speed "double helix tunnel" through the mountainous Yaxi expressway of Ya'an City, southwest China's Sichuan Province. [Photo: Chinanews.com]

Photo taken on November 12, 2016 shows the Ganhaizi Bridge, the world's longest concrete tubular bridge. Built to stand 2,500 meters above sea level, the bridge is 1,811 meters long, 24.5 meters wide and has 36 bridge spans. The huge "roller coaster" boasts the world's highest steel pipe concrete lattice pier, composite pier and hybrid bridge pier. It is the first bridge to use steel fiber concrete as structural material. It makes an important part of China's first high speed "double helix tunnel" through the mountainous Yaxi expressway of Ya'an City, southwest China's Sichuan Province. [Photo: Chinanews.com]