Constructing the arncliffe ventilation connection - A case study from the westconnex new M5 project
The WestConnex New M5 provides a duplication of the M5 East corridor through the design and construction of twin motorway tunnels, nine kilometers long, from Kingsgrove to St Peters. The Arncliffe ventilation connection, located midway along the alignment, comprises of a complex series of ventilation adits, 4 overhead shafts, and 6 large span tunnel junctions each with unique geometry and construction sequencing. Furthermore, unfavorable geology, including a 40 m deep palaeochannel and the intersection of the inferred Woolloomooloo fault zone placed further constraints on construction. These aspects compound with an ambitious construction sequence which has resulted in a challenging scope of works for the construction team to deliver. The design of the Arncliffe ventilation connection was previously presented by the author. This paper provides an update on the construction phase, highlighting the progress, challenges, and lessons learnt during this phase of the project.