Key issues for tunnel design and construction include weak soils and fractured weak rock and mixed ground that require careful digging and support, groundwater, and surrounding infrastructure. Any tunnel project must first start with a thorough desktop study to assess likely ground conditions and aid with selection of horizontal and vertical alignments, followed by comprehensive investigation of ground conditions by boreholes and geophysical techniques as appropriate. Tunnel design also requires assessment of potential subsidence to ensure that overlying buildings and infrastructure are not adversely affected.
Asset has carried out numerous investigations associated with developments above or adjacent to existing and planned tunnels, including ground investigation to assess the subsurface conditions, and 2D and 3D FEM analysis to assess potential impacts of tunnelling. We can also undertake the geological mapping of the tunnels (where unlined) and complete condition surveys.