Ground Improvement in Loose Sandy Soils through Dynamic Replacement

Abstract

The challenge of maintaining the stability and longevity of structures in areas with high fines content soils necessitates effective ground improvement strategies. One such strategy, dynamic replacement, has been successfully implemented in the developing city site of Jaber Al Ahmed, around 25 km west of Kuwait City. The site's soil profile features extensive sand deposits varying from very loose to medium, silty, and clayey, reaching a depth of roughly 10 m. Areas characterized by fines content exceeding 30% were earmarked for improvement. The dynamic replacement technique involves the creation of a crater by dropping a heavy weight, subsequently filled with imported granular material, forming a stiff granular column within the soil. This reduces soil compressibility and settlement significantly while increasing bearing capacity under applied foundation loads. Through an extensive laboratory and field-testing program encompassing an area of 36,000 m², soil conditions were assessed using boring and sampling, Standard Penetration Tests, Cone Penetration Tests, and Pressuremeter Tests, both before and after the dynamic replacement. The results were marked improvements in ground conditions, satisfying the specified acceptance criteria with a minimum allowable soil pressure of 300 kN/m² for the foundation design of the housing project's structures. This study highlights the impact of dynamic replacement as a ground improvement strategy in terrains rich in fines, establishing a paradigm shift towards resilient, sustainable, and economically viable construction methodologies, with a significant potential to revolutionize infrastructure development in similar geological settings worldwide.