Tunnelling & Underpinning

McGee’s experience in large and complex underground construction includes shaft sinking and the construction of headings.

As regards segmental shaft sinking we have the capability to construct shafts from 2 to 20 metres in diameter for the underpinning technique.  Under the caisson technique we are able to construct them from 2 to 15 metres in diameter. The caisson technique is a preferred method for sinking shafts in poor ground conditions such as sand, gravel or ground with high water levels.

We also construct timber frames to secure a tunnel structure after the material has been excavated. This traditional method covers mainly short distances where open cut installation is not practical and the scheme does not warrant the use of more expensive tunnelling techniques.

We can also provide a full support and logistics suite for specialist tunnelling contractors.