Resumen de Installation effects of stone columns and their contribution to soil liquefaction mitigation
Raúl Antonio Cristóvão dos Santos, Abílio Nogueira, Rodney Hutchinson, Steven Roberts, Alexandre Pinto
Ground improvement using stone columns is commonly used to increase the liquefaction resistance of granular soils subjected to strong seismic events. Current design methods often consider the behavior of composite reinforced soil, allowing for the shear stress reduction provided by the columnar stiffness relative to the soil as a function of the area replacement ratio. Stone columns are also known to prevent liquefaction by providing secondary drainage and soil densification effects, specifically in soils with low fines content. With respect to static design cases, several authors have described how displacement columns have contributed an increase in the at rest earth coefficient (K0). In this study, the installation effects of stone columns in silty sand materials were assessed by numerical finite element analysis based on cylindrical cavity expansion theory, and were then compared with Seismic Dilatometer (SDMT) tests carried on site. The results reveal an important increase of the horizontal earth pressure coefficient due the stone column installation process.
This paper focuses on the additional contribution of the installation effects of vibration free displacement stone columns to reduce the risk of liquefaction, accounting for the increased at-rest earth coefficient (K0) post column installation.
