Chinese builders completed construction on the 832.2-meter-long Yuanjiang Super Railway Bridge, spanning the V-shaped Honghe River Canyon in Southwest China's Yunnan province.

It is the highest and longest span railway bridge pier of its kind in the world, and showcases the smooth progress of the Chinese section of the 925.5-kilometer China-Laos railway, a major project in the Belt and Road Initiative.

The bridge was perfectly joined on Wednesday by builders from China Tiesiju Civil Engineering Group (CTCE) after a construction period of more than four years.

The dual-track bridge, located in Yuanjiang, Yuxi city, is one of 134 bridges to be built on the 508.5-km Chinese section of the railway, that will link Yuxi and the Lao capital Vientiane when fully operational in December 2021, said Kang Ning, publicity chief at CTCE Fifth Engineering Co Ltd.

The main span of the Yuanjiang bridge, with six piers in total, is 249 meters long while its No 3 pier is 154 meters high-about the height of a 54-story high-rise, said Liu Wei, deputy chief engineer at the First Civil Engineering Design and Research Institute under China Railway Eryuan Engineering Group.

The foundation of the No 3 pier reaches 78 meters underground, and took 22 months to build before official construction of the aboveground portion broke ground on Aug 20, 2018, Liu said.

Construction of the No 3 pier, which can withstand a maximum wind speed of more than 40 meters-per-second, was an engineering challenge and will help maintain safety and security going forward, he said.

"After many demonstrations, a construction scheme was proposed consisting of two reinforced concrete hollow piers to be connected horizontally by the pier top beam and the middle X-shaped steel structure. This first innovation mode of its kind in the country provides a Chinese plan for the construction of similar bridges with similar geological conditions in the future," Liu said.