Improvement in Bognor Regis addresses the engineering challenges posed by the local geology, which is dominated by the Brickearth and Raised Beach deposits of the Quaternary period overlying the London Clay Formation and the Chalk Group. These superficial Brickearth deposits are weakly cemented silts and sandy silts, often exhibiting metastable structure and susceptibility to collapse upon wetting or loading. Effective ground treatment is therefore critical to mitigate settlement and ensure long-term performance of structures. A comprehensive investigation programme, incorporating Cone Penetration Test (CPT) profiling, is essential to delineate the extent of these problematic soils and to design an appropriate improvement strategy in accordance with the recommendations of BS EN 1997-2:2007 and the forthcoming BSI Flex 260 for sustainable ground treatment.
Our methodology for Improvement in the UK adheres to the rigorous standards set by the Institution of Civil Engineers (ICE) and the British Drilling Association (BDA). The selection of a suitable technique, whether it be deep vibro compaction, controlled modulus columns, or dynamic replacement, is driven by the data obtained from detailed In-Situ and laboratory analysis. For fine-grained soils typical of the Bognor Regis area, we perform index testing to determine Atterberg limits and grain size analysis via sieving and sedimentation (hydrometer method) as per BS EN ISO 17892-4:2016 and BS EN ISO 17892-12:2018, respectively. This classification is critical for predicting soil behaviour under dynamic or static treatment energy. For fills and granular layers, we execute field density tests using the sand cone method to verify achieved compaction against the method specification, ensuring compliance with the end-product requirements of the Manual of Contract Documents for Highway Works (MCHW) Series 600.
Typical projects in Bognor Regis where Improvement becomes a prerequisite range from coastal residential developments on the Selsey Peninsula to commercial builds near the town centre. The variable thickness and composition of the Raised Beach and Brickearth frequently necessitate treatment to support traditional shallow foundations, thereby avoiding the higher costs and carbon footprint associated with deep piling. For instance, a recent development of terraced housing on a site underlain by collapsible Brickearth required a programme of deep vibratory probing to pre-collapse the soil structure and achieve a minimum bearing capacity. This approach was validated by post-treatment CPT verification testing, demonstrating a significant increase in cone resistance and conformity with the performance criteria defined in BS EN 1997-1:2004+A1:2013.
The process begins with a targeted ground investigation and a thorough geotechnical review to develop a ground model and select the most viable treatment method. We then produce a detailed method statement and execute the improvement works under full-time supervision, generating comprehensive field records. The final deliverables include a validation report that integrates pre- and post-treatment in-situ test data, laboratory test results on treated material, and as-built records, providing your project with a fully verifiable compliance package. This complete, integrated service, from initial site characterisation to final validation, offers a single point of technical responsibility, delivering a treated ground mass with predictable engineering properties, de-risked construction, and a robust foundation for your asset.