Consolidation of high replacement ratio stone column-reinforced ground: Analytical solutions incorporating clogging effect

Abstract

The utilization of stone columns has emerged as a popular ground improvement strategy, whereas the drainage performance can be adversely hampered by clogging effect. Despite the ample progress of calculation methods for the consolidation of stone column-improved ground, theoretical investigations into the clogging effect have not been thoroughly explored. Furthermore, it is imperative to involve the column consolidation deformation to mitigate computational error on the consolidation of composite ground with high replacement ratios. In this context, an analytical model accounting for the initial clogging and coupled time and depth-dependent clogging of stone columns is established. Then, the resulting governing equations and analytical solutions are obtained under a new flow continuity relationship to incorporate column consolidation deformation. The accuracy and reliability of the proposed model are illustrated by degradation analysis and case studies with good agreements. Subsequently, the computed results of the current study are juxtaposed against the existing models, and an in-depth assessment of the impacts of several crucial parameters on the consolidation behavior is conducted. The results reveal that ignoring column consolidation deformation leads to an overestimate of the consolidation rate, with maximum error reaching up to 16% as the replacement ratio increases. Furthermore, the initial clogging also has a significant influence on the consolidation performance. Additionally, the increment of depth and time-clogging factors a and b will induce a noticeable retardation of the consolidation process, particularly in the later stage.

Keywords

• Consolidation
• Composite ground
• Stone column
• Clogging effect
• Ground improvement
• Analytical model