Consolidation behavior and load transfer efficiency in a comparative study between stiffer and drained elements in soft clay

Abstract

In response to the growing demand for infrastructure development, utilizing ground improvement techniques on soft soils has become imperative. This study concentrates on enhancing soft soil, primarily via stiffer elements (stone columns) and drained members (sand drains, prefabricated vertical drains). The research entails a case study of an embankment on soft clay in Finland, evaluating both unimproved and improved (PVDs) sections. Verification of the Haarajoki embankment case study precedes parametric analyses probing stiffness's effect on consolidation behavior. Outcomes highlight stone columns' superior settlement reduction and consolidation rate compared to sand drains and PVDs. Examination of axial stiffness ratios and settlement improvement factors between stiffer and drained elements, resultant insights culminate in a design chart for embankments over soft soil, incorporating embankment geometry, clay properties, and improved column parameters to ascertain settlement improvements and global safety factors.

Keywords

• Soil improvement
• Soft clay
• Stone columns
• Sand drains
• Prefabricated vertical drains (PVDs)
• Plaxis 3D