Setting up the double-packer assembly inside a flushed borehole, our technicians rely on a calibrated pressure gauge and flow meter to capture the precise injection rate that defines the Lugeon pattern. In Ipswich, where the shallow strata alternate between Kesgrave Sands, London Clay outcrops, and Gipping Valley alluvium, packer seating depth becomes the critical variable — a misjudged seal in a sandy lens renders the test invalid. We run the five-pressure-step cycle while continuously logging flow versus time, because the transient response often reveals hydraulic fracturing thresholds that a single-stage falling-head test would miss. For deeper boreholes, the Lefranc method with an uncased pocket provides point measurements in soil, and we often complement the readings with a grain-size analysis on recovered cuttings to cross-check the permeability range deduced from Hazen’s correlation.
A five-step Lugeon test reveals hydraulic fracturing pressure — critical data for grouting design in Ipswich's variable glacial till.
