3D Finite Element Study of Inclined Soil-Cement Columns Adjacent to Shallow Foundations on Slopes

Dehghan Khalili, Hesam; Raisianzadeh, Javad; Namdari, Mohammad Amin

doi:10.61882/NMCE.2606.1147

3D Finite Element Study of Inclined Soil-Cement Columns Adjacent to Shallow Foundations on Slopes

Document Type : Research

Authors

Hesam Dehghan Khalili ¹

Javad Raisianzadeh ²

Mohammad Amin Namdari ³

¹ Assistant Professor, Department of Civil Engineering, Fasa University, Fasa, Iran

² Assistant Professor, Faculty of Civil Engineering, K.N. Toosi University of Technology, Tehran, Iran

³ M.Sc. Graduate, Department of Civil Engineering, Fasa University, Fasa, Iran

10.61882/NMCE.2606.1147

Abstract

The construction of shallow foundations adjacent to slopes is a complex geotechnical problem due to stress redistribution, reduced confinement, and development of plastic zones, which collectively reduce bearing capacity and slope stability. Ground improvement methods such as soil–cement columns installed by deep mixing or jet grouting have been widely adopted; however, most previous studies have focused on vertical columns, while the effects of inclined column installation on the coupled soil–foundation–slope system remain insufficiently investigated. This study evaluates the influence of soil–cement column inclination on the bearing capacity of a shallow foundation and the stability of an adjacent slope using three-dimensional numerical modeling in PLAXIS 3D. The nonlinear behavior of soil is simulated using the Hardening Soil model, and columns are modeled using embedded beam elements. Model validation is performed against available experimental data, showing good agreement in load–settlement response and failure mechanisms. A parametric analysis is conducted considering column inclination and spacing between columns. Results indicate that vertical columns maximize bearing capacity by improving load transfer to deeper soil layers, whereas inclined columns with an angle of approximately 45° provide the greatest improvement in slope stability by intersecting potential slip surfaces more effectively. Furthermore, as the column inclination angle relative to the vertical axis decreases, the bending moment in the foundation increases, highlighting the need for combined geotechnical and structural design considerations. An optimal configuration is proposed for balanced performance in bearing capacity and slope stability.

Keywords

soil-cement columns

slope stability

bearing capacity

three-dimensional finite element analysis

inclined columns

Subjects

Geotechnical Engineering

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