The sections of a super bridge with the largest span among domestic railway bridges on the China-Laos Railway was successfully joined on Tuesday after six hours of continuous operation in southwest China's Yunnan Province, laying the foundation for the subsequent construction.

Located in Pu'er City of Yunnan, the double-track super bridge crossing the Amo River is a key project of the China-Laos Railway running from the provincial capital Kunming of Yunnan to Lao capital Vientiane. Its 216-meter continuous steel girder of the main span marks the largest of its kind in China.

The 617-meter-long Amo River double-track super bridge spans the two sides of the river, supported by nine piers. More than 80 meters of the two middle piers are submerged in the water. Under such special geographical position and geological conditions, it is very challenging for the construction workers to realize the closure within the error range at a millimeter level.

"The bridge is one of the eight control projects of the whole line, as well as a typical deep-water bridge with high piers and long span. It's difficult to organize construction operations, because of the high safety risk and complicated geological conditions. During construction, we must adjust operations at any time according to the changes of water level and conduct real-time monitoring through internet of things and cloud data," said Yan Mingsai, a project manager of China Tiesiju Civil Engineering Group Co., Ltd.

The cement infilling operation started at around 01:00 on Tuesday and lasted six hours. Upon its completion, the construction workers immediately carried out measurement and data comparison to confirm that the parameters for bridge closure meet the standards.

The bridge deck has a total of 132 sections, which were assembled one by one from both sides of the river towards the middle. This construction method is of great difficulty in real operation which is like building blocks in the air. Therefore, the construction unit carried out targeted research and successively solved several technical problems.

Both ends of the bridge are connected to tunnels. Its smooth closure creates favorable conditions for the subsequent track laying operations. According to the current construction schedule, the track laying of China-Laos Railway will extend to this bridge in January next year.

The 1,000 plus-kilometer China-Laos Railway is the first international railway built mainly with Chinese investment, adopting Chinese technological standards, using Chinese equipment, and directly connected with China's railway network. It will cut travel time from Kunming City to Jinghong City of Xishuangbanna Dai Autonomous Prefecture in Yunnan to three hours, and ensure passengers to reach Vientiane in a day after it is completed and put into operation.