Swansea’s coastal geology catches out contractors who treat the whole city as uniform ground. The estuarine alluvium along the Tawe corridor behaves nothing like the glacial till draping the slopes toward Kilvey Hill, and we see the consequences in cracked jointed concrete when the subgrade wasn't properly profiled. Rigid pavement design here has to start with a real understanding of what lies beneath the formation level, not just a desk study assumption. We run the site investigation, test the CBR values with in-situ plate loads where the formation is marginal, and feed those numbers directly into the Westergaard-based thickness calculations. The result is a concrete pavement section that handles Swansea’s wet winters and the daily pounding from HGV traffic without premature faulting at the joints.
A rigid pavement is only as good as the subgrade it sits on. In Swansea, that subgrade can change completely within 50 metres along the same alignment.
