Pore size distribution of Brasilia tropical soil in 3 different initial states

Camilla Rodrigues Borges,Bruna De Carvalho Faria Lima Lopes,Manoel Porfírio Cordão Neto,A Tarantino,E Ibraim

doi:10.1051/e3sconf/20199201009

Camilla Rodrigues Borges, Bruna De Carvalho Faria Lima Lopes + Show 3 more

Open Access

https://doi.org/10.1051/e3sconf/20199201009

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Abstract

In the last decades there was an evolution in the analysis of the soil structure, most importantly, there was an improvement in the evaluation and in the ways of determining the mentioned structure and how it relates to the hydro-mechanical behaviour of soils. Due to the necessity of understanding the behaviour of tropical soils under different structures (natural, compacted and slurry) this study was developed by means of the Mercury Intrusion Porosimetry (MIP), enabling the analysis of the structural characteristics of these samples. The main objective of this work is to evaluate how the different structures are affected by external loading and how the changes in the pore sizes influences the hydro-mechanical behaviour of the soil in both, saturated and unsaturated conditions. It has been observed that the results regarding the influence of the structure showed a bimodal behaviour. The structural modification of the soil under study, due to the mechanical and / or hydraulic loading, leads to changes in the structure of the macropores and does not affect the micropores. With this, it is noticed that even fixing the parameters related to the microstructure it is possible to make a good adjustment of the macro. This is justified by the fact that the microstructure of all samples are very similar.

Highlights

The future of engineering practice is to incorporate aspects of the microstructure into the macroscopic characteristics of soils in order to simplify and make the geotechnical analysis more realistic
Despite advances achieved over the years regarding soil structure, a very small fraction of the studies published internationally involves tropical soils. To fill this gap, this study investigates the structure of Brasilia (Brazil) tropical soil at different states, by means of the Mercury Intrusion Porosimetry (MIP) tests
There are several techniques used for the microstructural analysis of the soil, among them are: particle size distribution, soil water retention curve, reflectometry, infrared measurements, tomography, microstructural intrusion, Environmental Scanning Electron Microscopy (ESEM) and Mercury Intrusion Porosimetry (MIP)

Summary

Introduction

The future of engineering practice is to incorporate aspects of the microstructure into the macroscopic characteristics of soils in order to simplify and make the geotechnical analysis more realistic. Amongst the techniques used to investigate the soil microstructure, the Mercury Intrusion Porosimetry test is one of the most used. The technique of Mercury Intrusion Porosimetry is widely recognised as an experimental technique in determining the distribution and structure of porous soils [5,6,7,8,9,10,11,12,13,14,15]. The results obtained from this technique of soil microstructure analysis allow a better understanding of the soil’s mechanical behaviour, since it separates the response of the micro and macrostructure [16, 17].

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