Development of a Reliable Empirical Model for Lateral Resistance of Free-Head Single Piles Based on Field Data

Abstract

This study focuses on the lateral resistance capacity of free-head pile foundations subjected to horizontal loads, including earth pressure, wind, seismic, ship collision, column eccentricity, wave, and transmission tower cable loads. Previous studies have utilized finite element methods and specialized pile foundation programs to generate non-dimensional curves for estimating soil deflection and maximum bending moments. However, predictions using conventional p-y curve-based pile analysis programs often yield overly conservative results that may not reflect real-world performance. To address this limitation, we analyzed and classified 47 full-scale static lateral load test datasets from infrastructure projects across Indonesia by soil type to develop empirical load–deflection relationships. This study aims to determine the maximum lateral resistance capacity of single free-head pile foundations by considering the interaction between seismic loads and material properties. Given the structural damage caused by lateral loading during earthquakes in Java, Indonesia, this research emphasizes the importance of accurate lateral load assessment. The proposed empirical model supports the Sustainable Development Goals (SDGs) on Industry, Innovation, and Infrastructure by providing a reliable approach to predicting free-head single-pile behavior based on Indonesian field data. The results demonstrate that surface soil type significantly influences lateral pile behavior, with empirical relationships defined as δₕ = 0.0012Qₕ³ − 0.0123Qₕ² + 0.4054Qₕ − 0.0162 for cohesive soils (R² = 0.789, RMSE = 1.47 mm, MAE = 1.24 mm) and δₕ = 0.0091Qₕ³ − 0.0874Qₕ² + 0.3831Qₕ − 0.0359 for non-cohesive soils (R² = 0.993, RMSE = 0.12 mm, MAE = 0.11 mm).