Settlement calculation method for single pile in negative friction case considering consolidation of surrounding soils

Abstract

Surcharge loading, phreatic level decline and other factors cause negative skin friction on the peripheral surface of piles, which increases engineering insecurity. Negative skin friction has been researched deeply by filed, scale and numerical test. However, few studies have considered the influences of drainage boundary conditions on pile settlement considering consolidation of surrounding soils. Based on 1D perfect elasto-plastic model, this paper demonstrates that pile-soil elastic relative displacement at the position of neutral point is zero, and derives a simplified settlement calculation method. Calculation results show that change of neutral point position makes the pile-soil relative displacement not zero. Finally, the proposed method is verified by FEM method and used to analyze the influence of different drainage cases on the pile settlement.

Comparative analysis of international codes of practice for pile foundation design considering negative skin friction effect

“…The suggested method analyzes the load transfer mechanism for defining the location of a neutral plane (NP). NP represents a location where no relative movement between pile and soil occurs [43]. The greater value of pile toe resistance causes the deeper location of NP and the greater value of drag load [14].…”