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.

隔离石柱在软土中的承载机理是一个复杂的问题，涉及构成柱的粒状材料与周围土壤的相互作用。现有的极限承载力预测公式可能仅限于极软的土壤。进行了一系列数值模拟，以研究软岩在完整加载过程中碎石柱的破坏过程。隔离石柱的极限承载力不仅受土壤抗剪强度的控制，还受土壤刚度的控制。根据模拟结果的观察和结论，建立了软土地基中孤立石柱极限承载力分析的新方法。数值解已经验证了解析解的有效性。所提出的解决方案考虑了土的刚度和相应的石柱破坏模式，而现有的理论方法并未适当考虑。讨论了关键参数对软土中孤立石柱极限承载力的影响。