Too many foundation designs in Swindon still treat the ground as if it were a uniform, competent bearing stratum. The reality across much of the town is a sequence of Kimmeridge Clay overlain by variable made ground, particularly on the former railway lands and post-war industrial estates. When a standard pad or raft comes back with excessive differential settlement, the knee-jerk reaction is often an expensive deep pile grid. A properly engineered stone column design can cut project costs significantly—sometimes by a third or more—while delivering the same settlement performance. The key is understanding when vibro-replacement works and when it doesn't, and that judgement comes from interpreting the right ground investigation data. In the Swindon area, where soft alluvium lenses sit within the clay profile, we typically combine findings from CPT testing with laboratory classification to define the undrained shear strength envelope before committing to column spacing and diameter.
In Swindon's Kimmeridge Clay, a well-designed stone column grid can reduce total settlement by half compared to untreated ground, often making shallow foundations viable on sites that would otherwise demand piling.
