A hybrid interaction-improved numerical model for pile–soil interaction with varying pile lengths
Dalya S. Mahdi1 and Reem Siham Tawfeeq2
Department of Civil Engineering,Al-Iraqia University, Baghdad,Iraq2
Corresponding Author : Reem Siham Tawfeeq
Recieved : 16-October-2025; Revised : 14-April-2026; Accepted : 15-April-2026
Abstract
Pile group combined foundation systems with varying pile lengths involve the use of different pile lengths within the same foundation to optimize load distribution and settlement, particularly in challenging and dense soil conditions. In this article, a novel hybrid interaction-improved model (HIIM) is proposed to enhance the performance and design of pile group combined foundations with varying pile lengths. Unlike the traditional Fast Lagrangian Analysis of Continua in 3 Dimensions (FLAC3D), HIIM integrates a semi-systematic support–friction mobilization approach with comprehensive numerical analysis to effectively capture both local shaft resistance and group pile interaction effects. Seven different pile lengths, ranging from 3.5 m to 33.4 m, are evaluated under progressively increasing loads. Based on the HIIM framework, up to a 25% reduction in settlement is achieved compared to traditional models when pile lengths exceed the critical length (𝐿crit). The results demonstrate that HIIM not only improves prediction accuracy, with a root mean square error (RMSE) of less than 5 mm, but also reduces computational time by approximately 30%. The proposed model provides practitioners with a significant tool for efficient, reliable, and systematic foundation design, offering clear guidelines for selecting optimal pile lengths and their positioning.
Keywords
Pile group foundations, Varying pile lengths, Hybrid interaction-improved model (HIIM), Settlement reduction, Numerical model, Pile–soil interaction.
Cite this article
Mahdi DS, Tawfeeq RS. A hybrid interaction-improved numerical model for pile–soil interaction with varying pile lengths. International Journal of Advanced Technology and Engineering Exploration. 2026;13(137):447-460. DOI : 10.19101/IJATEE.2025.121221386
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