A Study on the Behaviour of Single Piles and Pile Groups in Consolidating Ground from Coupled Consolidation Analyses

Title & Authors
A Study on the Behaviour of Single Piles and Pile Groups in Consolidating Ground from Coupled Consolidation Analyses
Kim, Sung-Hee; Jeon, Young-Jin; Lee, Cheol-Ju;

Abstract
In the present work, a number of advanced three-dimensional (3D) parametric finite element numerical analyses have been conducted to study the behaviour of single piles and pile groups in consolidating ground from coupled consolidation analyses. Single piles, $\small{4{\times}4}$ and $\small{6{\times}6}$ piles inside groups with a spacing of 2.5D were considered, where D is the pile diameter. It has been found that dragload and downdrag on the piles developed rather quickly at the early stage of consolidation. However, when the degree of consolidation was more than 50~75%, only little increases of dragload and downdrag were induced on the pile. Negative Skin Friction (NSF) on the pile in the fill layer was mobilised quickly and remained constant throughout further consolidation. The development of NSF is influenced both by the relative shear displacements at the pile-soil interface and the vertical effective soil stresses during consolidation. The former governed the early stage of consolidation and the latter affected the later stage of consolidation. The vertical effective soil stresses adjacent to the piles were reduced due to the shear stress transfer at the pile-soil interface, in particular for piles inside the pile groups. The range of NSF influence zone concerning the reductions of the effective vertical soil stresses was about 20D measured from the piles in the horizontal direction. On the contrary, the effective horizontal soil stresses acting on the piles were similar to those at the far field.
Keywords
Coupled analysis;Negative skin friction;Numerical modelling and analysis;Piles;Pile groups;
Language
Korean
Cited by
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