The SPT rig we mobilise in Hull is a track-mounted Dando 2000, compact enough to access the tight streets around the Marina and Hessle Road. It delivers a 63.5 kg hammer dropping 760 mm, measuring N-values every 300 mm in the borehole. For projects on the Humber estuary floodplain, where soft alluvial clays and peat layers are common, the Standard Penetration Test provides the raw data for bearing capacity calculations and liquefaction screening under Eurocode 7. We typically extend the bore to 15–20 m depth to reach the chalk bedrock that underlies much of Hull.
In Hull's soft alluvial clays, an SPT N-value of 6 can mean the difference between a shallow strip footing and a piled foundation.