China, Jan. 12 -- The grandstand steel structure at the National Stadium of El Salvador has been successfully completed, marking a key construction milestone.The grandstands use a steel frame system with buckling-restrained braces (BRBs). With about 9,700 tonnes of steel, the structure is complex and required precise lifting and alignment.To ensure accuracy, the team used BIM to create high-precision 3D models and implemented a method combining ground assembly of large units, high-altitude installation, and synchronized unloading-improving both efficiency and safety.The team also addressed challenges in constructing large ground-supported intersecting trusses and a single-layer grid shell, achieving seven new technical innovations that will...