Limerick sits on the banks of the Shannon at barely 10 metres above sea level, with much of the city centre built on alluvial deposits and estuarine silts that extend to depths exceeding 20 metres in places. Tunnelling through these deposits is not a matter of simply selecting a TBM and advancing. The soft, normally consolidated clays and loose silty sands beneath Henry Street, the Docklands, and out towards Raheen demand a level of geotechnical scrutiny that standard site investigations rarely provide. Our team runs the laboratory and field programmes that define the stiffness, permeability, and undrained shear strength parameters contractors need for realistic 2D and 3D numerical models. Before any cutterhead turns, you need to know how the face will behave under compressed air, whether the crown will converge excessively, and what grouting pressures the surrounding ground can accept without hydrofracture. We deliver that picture with data, not assumptions.
Limerick's alluvial silts lose up to 60% of their undrained shear strength when disturbed. Face stability predictions are only as good as the sample quality behind them.
