Coventry’s subsurface is shaped by its glacial legacy and post-industrial fill. Much of the city sits on river terrace sands and gravels over Mercia Mudstone, but shallow layers often contain loose made ground from decades of coal mining and manufacturing. In the city centre, old cellars and buried foundations add further variability. For sites where deep compaction is needed before footing construction, we apply vibrocompaction design tailored to the actual grading and density of the fill. Typical depths reach 4–8 m, and the process relies on controlled vibration to densify cohesionless soils. Before specifying the grid pattern we always correlate with a density test using the sand-cone method to confirm baseline compaction levels.
In loose granular fills below the Coventry water table, vibrocompaction can raise relative density from 30 % to over 70 % in a single pass.