Postgraduate research students

Research Title: Experimental investigation into the particle-scale mechanisms controlling the anisotropic behaviour of fine-grained geomaterials

In classical soil mechanics, soils are treated as continuous media, enabling the use of continuum-based constitutive models for geotechnical design. While this simplifies analysis, soil is a collection of discrete particles with complex interparticle interactions and pore spaces filled with fluids. As such, its macroscopic behaviour stems from the mechanisms occurring at smaller scales, that continuum models cannot always fully capture. One notable limitation is the prediction of anisotropic behaviour, where material properties vary with direction. In soils, anisotropy may arise from the directional distribution of contact forces, particle orientations (notably in elongated particles like clays), and the size, geometry and distribution of pores. These particle-scale features evolve under loading and are neglected in continuum-based constitutive models, leading to inaccurate predictions of deformations (e.g., vertical settlements and lateral displacements). This has critical implications for the design of excavations and retaining structures.

This PhD project aims to experimentally investigate the anisotropic behaviour of fine-grained, coarse-grained, and mixed-grained soils to: (1) explore the anisotropic character of soils subject to different mechanical and environmental loading conditions using conventional and advanced laboratory techniques; (2) correlate the observed anisotropic behaviour at the macroscale with microstructural experimental evidence; and (3) integrate these insights to improve the fundamental understanding of soil behaviour, potentially informing the development of micro-inspired constitutive models. The research will involve standard geotechnical testing (e.g., triaxial testing with bender elements) and microstructural characterization methods such as Mercury Intrusion Porosimetry (MIP) and 2D/3D imaging techniques to bridge microscale features and macroscopic response under loading.

• Dr Arianna Gea Pagano
• Dr Roisin Buckley

• Nithy, R.K., Shire, T., Wheeler, S., Shang, J. (2021 December). Effect of Non- Plastic Fraction on Desiccation Cracking. Research presented at the 18th UK Travelling Workshop: GeoMechanics: from Micro to Macro (GM3).
• Nithy, R.K., Akhter, S.H., Wilson, C.A. (2020 December). A GIS Based Hazard Susceptibility Analysis in Coastal Belt of Bangladesh Using MCE Technique. Paper presented at the 5^th International Conference on Advances in Civil Engineering, Bangladesh.
• Mamun, M.A., Nithy, R.K., Shahsuja, M.J. (2020, January). Development of Eco-friendly and Sustainable Non-fired Geopolymer Brick Using Local Geo-resources. Paper presented at the International Conference on Earth and Environmental Sciences and Technology, Dhaka, Bangladesh.

Demonstrator, Tutor & Marker

• ENG2047 Soil Mechanics 2
• ENG2080 Geology for Civil Engineers 2
• ENG4072 Rock Mechanics and Engineering