Two halves of the Quanzhou Bay cross-sea bridge — built simultaneously from both sides — were joined together on Aug 6 in coastal Fujian province. It is the world's first bridge for high-speed trains over a sea body and will support speeds up to 350 kilometers per hour.

The 20.29-km bridge, with a cross-sea segment spanning about 9 km, is a cable-stayed bridge that was chosen for its strength.

Yan Aiguo, the bridge's chief designer from China Railway Siyuan Survey and Design Group Co, said that repeated trials found that the combination of a concrete deck slab and steel girders would meet all engineering requirements.

Wind tunnel tests and related research conducted at Southwest Jiaotong University, showed that the bridge will be able to resist typhoons of up to Grade 12, and that trains are virtually vibration-free at 350 km/h.

The bridge is an integral part of the 277-km Fuzhou-Xiamen high-speed railway, China's first cross-sea high-speed line. The railway, which connects Fuzhou with Xiamen, Fujian, is expected to be completed next year.