Ground Improvement Techniques for Seabed Consolidation: An Evaluation of Stone Columns and Soil Mixing based on Settlement Performance

This thesis investigates the consolidation behavior of a test embankment constructed on compressible soils at the site of Augusta, Sicily, Italy. Upon my experience of three months, directly on-site, extensive field monitoring of settlement and piezometric had been conducted over six months to evaluate the effectiveness of two ground improvement techniques: stone columns and soil mixing. Standard methods for calculating overpressure using sensor readings were found to be unreliable due to the influence of the construction activities required highlighting the need for alternative approaches. This study illustrates that the settlement measurements offer a more reliable and direct method for assessing embankment performance. By analyzing the collected data, this report compares the consolidation efficiency of stone columns and soil mixing, considering factors such as settlement rate, time required for consolidation, and potential cost implications. The findings provide valuable insights into the selection of appropriate ground improvement techniques for achieving optimal embankment stability and consolidation, particularly in challenging soil conditions. The research contributes to the field of geotechnical engineering by offering practical recommendations for embankment design and construction, informed by real-world data, analysis, and an understanding of stone column theory and its practical application. This thesis also highlights the value of on-site observation and data collection in understanding complex geotechnical processes.