Geotechnics section
Supervised by: Prof Catherine O’Sullivan (Department of Civil and Environmental Engineering), Dr Stefano Angioletti – Uberti (Department of Materials) and Dr Paul Tangney (Department of Materials and Department of Physics)

Prior to starting her PhD, Sara completed an MEng in Civil Engineering (Structures) at the University of Pavia (Italy).

Sara was awarded with a Leverhulme Trust Scholarship to undertake her PhD studies at Imperial College.

Why did you decide to do a PhD in the Department of Civil and Environmental engineering?

Although I obtained an MEng in structural engineering, the topic of my dissertation focussed on geotechnics, I developed an interest in this subject. After having completed my studies in Italy I felt the need to deepen my knowledge in the field by undertaking research into the fundamental behaviour of soils. I chose the Department of Civil and Environmental Engineering at Imperial College as its Geotechnics Section has a remarkable history within this research field, with some of the major contributors having studied, taught or are still teaching here.

Tell us about your PhD research

Clay is the most abundant type of soil on the Earth’s surface. According to the British Geological Survey (2016), clay minerals constitute an estimated 16% of the total volume of soil. Unlike cohesionless materials (e.g. sand), clay is challenging to study because the influence of the structure (i.e. particle arrangement and inter-particle forces) on its behaviour cannot be neglected. Although the importance of structure has been highlighted by several authors in the literature, particle scale simulations of clay, which have the potential to explain structure effects in a fundamental way, are very limited. This research aims to improve the understanding of the response of clay to applied loads and deformations by explicitly simulating the interactions between three-dimensional clay particles using the Molecular Dynamics (MD) technique.

What impact do you hope your research will have/what do you hope your research will lead on to?

I hope my research will improve the understanding of particle-scale simulations of clayey materials in the geotechnics field and will define a simulation protocol for further studies on clay. As my research is very fundamental, the results obtained will not be immediately employed in practice. They will be used to inform other research work to gain a better understanding of clay’s behaviour in order to improve the existing constitutive models, which are employed in FE (Finite Element) analyses to simulate the behaviour of geotechnical structures (e.g. foundations, retaining walls, piles, etc.) founded or embedded in clay.

Does your research involve working with collaborators outside the Department? If so, who and why?

Yes. My research is co-supervised by Dr Stefano Angioletti – Uberti, a Lecturer in Theory and Simulation of Materials in the Department of Materials (Imperial College London) and by Dr Paul Tangney, a Senior Lecturer in the Departments of Materials and Physics (Imperial College London). Since the main objective of my research is to simulate clay using numerical techniques usually employed in material science, their knowledge in material modelling helps me to set up the simulations and to understand the results, which are expressed in a way I was not familiar with at the beginning of my PhD (since the scale employed is not the scale usually civil engineers work with).

What is a typical week like for you?

My work mainly focuses on performing simulations using the High Performance Computing (HPC) facilities at Imperial, but often I need to develop tools to analyse data obtained from the simulations, review previous work published in the literature or write reports to document my progress. I regularly meet with my supervisors, both in one-to-one meetings or in group meetings and even with other students in my research group to share my problems and show the achievements. During term time I work a few hours per week as a Graduate Teaching Assistant (GTA) for some of the lecturers within the Geotechnics section helping them with tutorials, exam invigilation or coursework marking. Throughout the year, I also attend conferences/workshops where I have the possibility to present my findings and learn from other researchers’ work.

How have your skill developed, both professional and personal?

During my time at Imperial I had the opportunity to interact and network with a lot of experts in my field and learn from their work and their attitude towards research. The first months of literature review and close work with my supervisors helped me to improve my critical thought and to move across different fields (i.e. geotechnics and material science). The attendance of numerous conferences and the opportunity of presenting my work in front of different audiences enhanced my communication skills using the appropriate terminology and led to numerous interactions with other academics, some of which resulted in active collaborations.

What do you enjoy most about being a PhD in the Department?

The Department is an international environment in which the network between peers is promoted through several activities (e.g. breakfast, 2nd year PhD seminar series, Christmas party). I also really appreciate all the support given to assure the well-being of PhD students (e.g. Yoga sessions, pastoral care). Lastly, I enjoy my research, which could have not progressed as far without the continuous support of my supervisors.