Analysis of Stress Transfer and Distribution of an Embankment on Unreinforced and Stone Column-Reinforced Soft Soils

Abstract

The technology of stone column-reinforced soft soil (SCRS) has become widespread use in infrastructure projects including embankments, dikes, and dams, as well as industrial and civil constructions, with a particular presence in Western countries and North America. Compared to traditional reinforcement methods, SCRS offers numerous benefits which are the substantial enhancement of ground load-bearing capacity, the considerable decrease in building time, the increase in soil liquefaction resistance, and the utilization of locally sourced materials. The study establishes 3D numerical models of a four-meter high embankment on unreinforced and stone column-reinforced soft soils to investigate the stress transfer and distribution within the systems. The geological condition was derived from the project involving the approach road to the Ganh Hao bridge in Bac Lieu province, Vietnam. The soils, embankment, and stone columns were modeled using the linear elastic, perfectly plastic model. The stresses acting on the column head and soft soil, the stress concentration ratio, and the stress along column depth were described. The numerical results show the appearance of an arching effect for stress transfer within the embankment, characterized by a stress concentration ratio exceeding 3. Moreover, the assessment of negative skin friction around the column shaft points to the presence of an equilibrium plane for negative skin friction located at a depth of approximately 17 to 18 meters.