Retaining wall design in Cardiff demands a firm grasp of Eurocode 7 (EN 1997-1:2004) and BS 6031:2009, given the city's varied ground conditions. The solid geology here is largely Triassic marls and sandstones, but the surface layer alternates between glacial till from the Devensian ice sheet and soft alluvial clays along the Taff and Rhymney valleys. For walls higher than 2 m we always start with a calicata exploratoria to log the soil profile visually before any analytical work. That early look at the ground often reveals hidden gravel lenses or perched water tables that would otherwise skew the design parameters.
In Cardiff a wall that fails in the short term rarely lasts a decade — the ground water here moves faster than most models predict.