At 9 a.m. on November 12, the final batch of concrete-filled steel tubes was jacked into place for the No. 9 lattice pier of the Nanxi River Grand Bridge on the Wenshan–Mengzi Railway in Yunnan, marking its successful completion. This represents the first use of a lattice pier structure in a domestic railway project and constitutes a major technical breakthrough in high-pier bridge construction in China's mountainous regions. The bridge spans 789.71 meters in total length, with a maximum height difference of 118 meters between the deck and the ground, making it the tallest bridge on the entire line. The concrete-filled steel tube lattice pier adopted for this project features steel tubes and I-beams assembled into a trapezoidal pier body—wider at the base and narrower at the top—with high-strength concrete poured inside. This design saves 30% to 50% of concrete and steel, while the prefabricated assembly process reduces on-site pollution and construction risks and enhances seismic capacity and geological adaptability.