Imperial College London

Dr Fernando Patino-Ramirez

Faculty of EngineeringDepartment of Civil and Environmental Engineering

Research Associate
 
 
 
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Contact

 

l.patino-ramirez CV

 
 
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Location

 

Skempton BuildingSouth Kensington Campus

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Summary

 

Overview

Fernando's early research work focused on the physical modeling of foundation systems, soil improvement, and the development of instrumentation tools for slope stability.

Between 2016 and 2020 Fernando was a doctoral student in the geosystems group at the Georgia Institute of Technology in the US, where he studied the design and optimisation of underground networks through bio-inspiration and novel computational algorithms.

In 2018, he became a visiting researcher in the Lab 3SR at the Universite Grenoble Alpes (France), where he studied the expansion of horizontal, shallow cavities using computer tomography (CT-scanning) and image analysis using digital image correlation (DIC).

In 2021 he joined the geotechnics section at Imperial College, working with Prof. Catherine O'Sullivan in the development of a burrowing robot capable of measuring the mechanical and chemical properties of the surrounding soil.

Terra-Dynamics of underground exploration

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Underground exploration makes possible the construction of tunnel networks, utility systems, resources withdrawal and storage, and soil characterisation. Recent advances in robotics, data science, and soil mechanics motivate the development of new devices capable of burrowing autonomously underground.

Dr. Patino-Ramirez works in the development of such a device, namely the BRISS (Burrowing Robot with Integrated Sensing). He uses the discrete element method, heuristic algorithms, and soil mechanics to understand the dynamics of underground penetration and optimise the design of the underground burrower.

Bio-inspired design of transportation networks

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Transportation networks connect a set of points in space (e.g. tube stations or homes in the utility grid) in the most efficient way possible, and under a set of economic and physical constraints. In a very similar way, nature has developed efficient strategies to solve similar problems. Ants optimise the path from their nest to food sources, leaf venations improve redundancy by creating hierarchical interconnected netwokrs, and slime molds prioritise exploration or survival according to environmental conditions.

Dr. Patino-Ramirez has studied the similes between biological and engineered networks and has proposed bio-inspired algorithms for different applications with different optimisation goals to create better human systems borrowing inspiration from nature.

Engineered Granular Mixtures (EGM): Towards sustainable earth structures

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Infrastructure makes cities possible, making up the roads, utility systems, and buildings needed to fulfil the needs of their population. Granular aggregates (i.e., sand and gravel) are the main component of concrete, pavements, and earth structures, and due to the growing need for infrastructure, they have become the most mined material in the world. The frantic extraction of aggregates carries a heavy environmental toll, destroying forests, changing the course of rivers, and threatening the species that live in them.

Meanwhile, the production of plastics has grown exponentially over the last 40+ years. And due to the limitations of recycling and the absence of large-scale alternatives to dispose of plastic waste, the majority (>80%) of all the plastic ever produced rests in landfills or the environment.

EGM, a new infrastructure construction material comprised of aggregates and shredded non-recyclable plastic, will reduce the demand for mined aggregates while creating a long-term disposal alternative for plastic waste. Our recent findings have shown that when granular materials are loaded, the load is not evenly distributed among their particles. Instead, relatively few particles carry most of the load, while the rest mostly fill the space between load-carrying particles providing lateral support. EGMs will exploit this behaviour, with the aggregate fraction carrying most of the load, while the plastic portion densifies and stabilises the material. EGMs will be designed for specific applications, including fills, pavements, and embankments.

Evolution of the micro-structure of granular media to shear deformation

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We have developed a framework to analyse the response of granular materials to shear deformation at the scales of the entire system (macro), the underlying contact sub-networks (meso), and the individual force chains (micro). The new framework is demonstrated considering data from discrete element method simulations of a ribbed wall moving against a granular sample.
Statistical analyses using cross-correlation functions and Granger causality are used to develop an energy-flow model in the system at the macro-scale. Results show that the work done by the moving wall is directly correlated to the increase in strain energy and kinetic energy in the system, while the release of strain energy is the main driver of frictional dissipation. The meso-scale considers the contact network and uses network analysis to identify two complementary contact networks: a percolating network made of larger particles, which reorientates in response to the wall movement and transmits 85%- 95% of the stress in the sample, and a supporting network that carries the rest of the load. The micro-scale analysis uses a new algorithm that divides the percolating network into individual force chains. This micro-scale reveals the contribution of force chains in the network to be highly centralized, composed of a small set of strong and long-lived force chains, plus a large set of weak and short-lived force chains.