Bearing Capacity of Circular Foundations on Weak Cohesive Soils Reinforced with Stone Columns

Abstract

Vertical stone columns have been employed to improve the bearing capacity of the foundations for circular oil storage tanks placed on weak clayey strata. A solid stone column was placed along the axis of the foundation along with (1) two annular rings of stone columns for a 10-m-diameter tank, and (2) four annular rings of stone columns for a 20-m-diameter tank. The tank was first placed on a thin granular pad before transferring the load to the underlying weak clayey stratum reinforced with stone columns. The bearing capacity, with and without vertical stone columns, has been determined by employing an axisymmetric finite-element limit analysis. The Mohr–Coulomb yield criterion was used for the granular pad as well as stone column materials, and the Tresca yield criterion was employed for the purely cohesive clayey stratum. The results from the analysis were compared with that reported in the literature. The employment of stone columns leads to a significant increase in the bearing capacity of the foundations on soft clay.