Limerick sits on the banks of the Shannon, where the city’s 100,000 residents live above a complex basin of carboniferous limestone overlaid by estuarine alluvium. The last notable seismic event to stir the mid-west was the 1984 Llŷn Peninsula earthquake, a modest M5.4 whose waves still reached the Treaty City. While Ireland is classed as a low-seismicity region, EN 1998-1 requires any structure above consequence class CC2 to account for peak ground acceleration. Base isolation seismic design decouples the superstructure from ground motion, and in Limerick’s soft alluvial pockets along the Dock Road or Corbally, that decoupling makes the difference between a building that weathers a rare event and one that cracks at the slab. We pair the isolation parameters with site-specific MASW profiles, because Vs30 on estuary mud can drop below 180 m/s, and that changes the spectral ordinates the isolators need to handle.
Base isolation in Limerick is not about surviving the Big One; it’s about controlling drift on estuary clay so the hospital stays operational after a 475-year event.
