Yunwu Bridge on the Duyan Expressway in Guizhou: Green Construction Paving the Way Through Mountains and Waters

The Yunyun Bridge on the Guizhou Du'an Expressway has recently become a model for green transportation development. This cablestayed bridge, located among karst mountains, spans through clouds and mist, complementing the surrounding landscapes while serving the full opening of the Du'an Expressway and improvements to regional transportation. According to the report, Yunyun Bridge is a key control project on the Du'an Expressway. With a main span of 480 meters and a main tower 300 meters high, it is also the first superlarge highway bridge in Guizhou to be completed and opened during the 14th FiveYear Plan period. The entire expressway features 56 steelstructure bridges, promoting structures such as steelconcrete composite girders and steel box girders to improve earthquake and wind resistance as well as the recycling rate of materials. During construction and maintenance, the project team emphasized ecological protection and lowcarbon construction. The painting of the bridge steel girders was completed in the factory to reduce dust pollution on site. When the route passes through areas with ancient forests, measures such as cofferdams to protect old trees, root reinforcement, route adjustments to avoid them, topsoil recovery, and land reclamation and revegetation were used to minimize impacts on the native ecosystem. In the operational phase, maintenance technologies such as hightoughness, highelasticity modified asphalt were also introduced to reduce material consumption and carbon emissions and extend the service life of the pavement.