The Chinese metropolis of Guangzhou was investing in the expansion of the gas-pipeline infrastructure in order to reduce its dependency on coal and oil. During the construction of the pipeline, the Pearl River, which flows through the city, had to be underpassed. The geology was characterized by heterogeneous ground conditions. Layers with high rock strength (up to 160MPa) had to be passed as well as clay and sand formations. Two tunnel sections were driven from both sides of the river meeting in the target shaft located on an island in the Pearl River.
Two almost identical AVND3080AHs drove protective and service tunnels for the gas pipeline below the riverbed. The tunnel was segmentally lined. Cutting wheel access for cutter change is provided via a lock. The first TBM started tunnelling in October 2005 and reached the target shaft after 540 meters in April 2006. Between November 2005 and October 2006, the second Mixshield was on duty. The longer, 1,500-meter section was driven from the opposite side of the river.