Black Street and Coronation Drive relief drainage
This project involved construction of a 404m tunnel using a long single drive 3.5m diameter manned steerable tunnel boring machine. The tunnel outlet exited into the Brisbane River which necessitated construction of a coffer dam at the outlet to protect the works from sea water inundation. The tunnel bore alignment travelled directly below two major high rise buildings and two major roadways and the shafts were constructed in a highly congested urban environment. Tunnel excavation soil type consisted of a clay and marine mud.