A recent mixed-use project along the Dock Road hit a snag at six meters: saturated silty sand that trembled under the rig. The developer needed a clear go/no-go for the foundation design, and fast. Limerick’s low-lying ground, shaped by the Shannon estuary and its tributaries, holds pockets of loose alluvium that can lose strength during a seismic event. Our team ran a targeted soil liquefaction analysis to map the susceptible layers and deliver a factor of safety against liquefaction (FSL) for every critical stratum. Before the boreholes were even backfilled, we had the answers the structural engineer needed. For deeper profiling, we often pair the investigation with a CPT test where access allows, since the continuous tip resistance and sleeve friction clarify transitions between dense and loose zones that SPT alone can miss. In tighter urban lots, a MASW survey provides the shear-wave velocity (Vs) profile needed to calculate the cyclic stress ratio (CSR) without extensive drilling, which proved essential behind the old Cleeve's factory site last spring.
Limerick's estuarine silts can transition from stable to liquefied with a shift in pore pressure of just a few kilopascals — the margin is that narrow.
