A Frequency-sensitive Energy-based Method for Evaluating Liquefaction Range during Vibratory Pile Driving in Saturated Sandy Soils

Abstract

High-frequency vibratory pile driving in saturated non-cohesive soils can induce excess pore pressure and localized instability, posing liquefaction risks to foundation. In this study, we propose a computational framework to assess the liquefaction potential and its spatial impact range by quantifying the energy dynamics between transmitted vibration energy during pile driving and the soil's liquefaction resistance. Model-scale experiments reveal that excess pore pressure accumulation and stress redistribution occur near the pile, indicating the onset of localized instability under high-frequency excitation. The proposed method incorporates a frequency-dependent soil attenuation coefficient, α(f), to capture the critical role of vibration frequency in energy transmission and liquefaction behavior.
The framework iteratively evaluates the liquefaction energy demand (N_ED) and liquefaction energy capacity (N_EC), enabling precise estimation of the liquefaction range. Shear modulus reduction and damping ratio curves derived from typical sandy soils are integrated into the analysis to reflect strain-dependent soil behavior. Case studies validate the method's ability to provide early liquefaction risk assessments, with practical implications for optimizing pile driving operations. Although assumptions such as neglecting pore pressure dissipation may overestimate liquefaction extent in shallow layers, the framework bridges theoretical modeling and engineering practice, offering a frequency-sensitive basis for foundation design in complex ground conditions.