Axially loaded piles in inundated collapsible soils under compression and tension forces

Abstract

The paper studies the behavior of axially loaded piles driven into inundated collapsible soils under compression and tension forces. Collapsible soils exhibit a considerable drop in the void ratio (i.e., significant changes in dry unit weight, friction angle, and shear strength) with the increase of water content. Several sandy and silty specimens of collapsible soils with different initial conditions are utilized to develop a correlation that evaluates the post-inundation soil properties and stress–strain relationship (as obtained from the conventional triaxial test). The developed model is integrated into a pile–soil model to predict the axial response of piles loaded after the inundation of the collapsible soils (i.e., no negative skin friction). The developed technique allows the assessment of the axial load transfer (t-z) and pile-head load–displacement curves. Comparisons between predicted and measured stress–strain curves of inundated collapsible soils and responses of axially loaded piles in such soils are presented for validation.