Cardiff grew fast during the 19th century, transforming from a small market town into one of the world's busiest coal ports. That boom left a legacy of made ground, old dock basins, and variable alluvial soils along the Taff and Rhymney valleys. When we work on settlement analysis in Cardiff, we always start by mapping the historical land use. A site near the old Bute Docks might sit on several metres of uncontrolled fill, while a Victorian terrace in Roath Park could be founded on stiff glacial till. Understanding that urban stratigraphy is essential before we calculate anything. We routinely cross-reference borehole logs with the British Geological Survey's 1:50,000 mapping for Cardiff. For projects on reclaimed land, we also run a corte directo to measure shear strength parameters directly, which gives us reliable input for the settlement models.
A two-storey extension on tidal flat deposits can settle 40 mm in five years if compressible layers are not identified and treated.