Innovative and sustainable precast arch solution for High Speed 2 Green Tunnels

EKFB-JV will build the Cut and Cover ‘Green Tunnels’ (GTs) as part of the High Speed 2 C2 & C3. The design of the GTs was undertaken by ASC-JV. This Paper presents the significant benefits of GTs, in terms of savings in cost, time, waste, reduced safety risk profile and improved sustainability. The design of GTs has a key objective to minimize the maintenance requirements over their total length of 6.6km. This type of construction was selected after a rigorous options assessment. It is efficient and innovative, as this is the first time that has been adopted in the UK for high-speed rail in high overburden (up to 16m). The Paper discusses the benefits that this solution offers covering buildability through reduced complexity in interfaces with other operations and increased level of safety. Other environmental considerations related to construction activities are also presented and discussed.