SHAFT RESISTANCE OF PILES IN CLAY

A new method is proposed for elucidating, formulating, and predicting the axial capacity of friction piles in moderately overconsolidated clays (1 ≤ OCR ≤ 4) within a systematic and rational framework. The paper focuses on single, vertical, rigid, and cylindrical piles driven in deep deposits which exhibit normalized behavior. The normalized limiting skin friction, [Formula Presents], during rapid monotonic undrained axial loading is written as the product of a lateral earth-pressure coefficient, [Formula Presents] at the end of soil consolidation, which follows pile installation, and a skin-friction ratio, [Formula Presents] Important factors affecting Kc are shown to include the overconsolidation ratio (OCR) of the clay and its sensitivity. The friction ratio, p, is not sensitive to the in situ OCR of the deposit and corresponds to the normalized peak-strength ratio, [Formula Presents] in undrained direct simple shearing of the clay at an OCR = 1.2 (±0.1). © ASCE.