The cone penetrometer rig arrives on a flatbed and within an hour it’s pushing a 36 mm diameter rod into the Ashford subsoil at a steady 2 cm/s. We’re not just logging tip resistance; we’re measuring pore pressure dissipation in real time because that’s what tells you whether the loose alluvial sands beneath the Great Stour floodplain will turn to slurry during a tremor. Ashford sits on a variable drift geology—Weald Clay to the north, river gravels through the centre—and the combination of shallow groundwater and historical channel deposits creates exactly the conditions where CPT testing paired with laboratory cyclic triaxial becomes non-negotiable. Without it, a perfectly designed foundation can lose 90% of its bearing capacity in less than 20 seconds.
A sand that looks competent on SPT blow count alone can liquefy at just 0.15g if fines content exceeds 15%.
