Abstract:

This research study addresses the transformation from 3D systems into a 2D plane model to examine the effectiveness
of simplified modeling approaches for stone columns in soft soil dam foundation using PLAXIS 2D. Three discrete
modeling techniques were evaluated and compared with an untreated foundation, a homogenized model, and a unit cell
model. The analyses included sequential plastic-consolidation calculations and full construction simulations, incorporating
installation-induced soil stiffening. The results revealed that each approach enhances stress distribution and reduces
settlement; however, they impact the performance differently. The homogeneous model is the most effective in reducing
displacement, but it eliminates stress concentration effects and differential displacements. The elasticity adjustment
method provides the most realistic load-transfer mechanism, balancing stress concentration and settlement. The spacing
and diameter adjustment models show localized stress peaks and less settlement reduction. Incorporating installation
effects significantly changes both stress and settlement responses, as increasing the stiffness of the surrounding soil redistributes
vertical stress from columns into the matrix and reduces total settlements. The findings confirm the agreement
between simulations and field settlement measurements, confirming that the stiffness increase in the surrounding soil plays
a critical role in the overall system response. despite the limitation of 2D modeling in capturing the full 3D confinement
behavior, it can reliably predict the field-scale performance of stone columns reinforced foundations, offering a practical
and computationally efficient alternative to 3D simulations for large-scale geotechnical projects. However, the design
parameters must be carefully tuned.