The difference between building on the deep alluvial clay of the Colorado River floodplain near downtown and on the weathered Taylor marl of the western Hill Country is not just a matter of geology—it defines the entire foundation strategy. In the floodplain, soft compressible layers extend over 15 m, while in the west, stiff clay and limestone bedrock sit much shallower. For sites where bearing capacity is borderline and total or differential settlements are the main concern, stone column design offers a proven Improvement solution that accelerates consolidation and increases shear strength. Before specifying column patterns and diameters, we always correlate results from a georradar survey to map hidden features like paleochannels or buried utilities that can alter column performance.
In Austin's expansive clays, a stone column design without site-specific shear strength profiles is a gamble on differential settlement—one we don't take.