Failure modes and ultimate bearing capacity of the isolated stone column in soft soil

Abstract

The bearing mechanism of the isolated stone column in soft soil is a complex problem involving interactions of the granular material constituting the column and the surrounding soil. The existing ultimate bearing capacity prediction formulas may be limited in extremely soft soils. A series of numerical simulations were conducted to study the isolated stone column’s failure process in soft soil during the complete loading process. The ultimate bearing capacity of an isolated stone column is controlled not only by the soil shear strength but also the soil stiffness. Based on the observations and conclusions of simulation results, a novel ultimate bearing capacity analytical solution for the isolated stone column in soft soil has been established. Numerical solutions have verified the validation of the analytical solution. The proposed solution considers the soil stiffness and the corresponding failure mode of stone columns, which is not appropriately considered by the existing theoretical methods. The influence on the ultimate bearing capacity of the isolated stone column in the soft soil from the critical parameters has been discussed.