Future developments for ground models

• Published in: Quarterly journal of engineering geology and hydrogeology 2021-05, Vol.54 (2)
• Main Author: de Freitas, Michael H
• Format: Article
• Language: English
• Subjects: case studies; clastic sediments; clay; cone penetration tests; Consultancies; Descriptions; development; Drilling; earthworks; Engineering; Engineering geology; engineering properties; England; Europe; feasibility studies; Fibers; Geologists; Glass fibers; Great Britain; Ground motion; hydrology; Instrumentation; Laboratories; Laboratory tests; London England; penetration tests; prediction; Predictions; rock mechanics; sediments; site exploration; Soil; soil mechanics; Testing; Training; United Kingdom; Western Europe
• ISSN: 1470-9236; 2041-4803
• DOI: 10.1144/qjegh2020-034

A Ground Model is now an accepted part of any ground engineering that requires a prediction to be made of how the ground on and around a site will respond to the engineering changes caused by construction. However, until now it has not been possible to quantify how predictions of such responses can be improved by developing the Ground Model. Thanks to the instrumentation provided by glass fibres that can be inserted into the ground, a stream of factual evidence of ground response to engineering change has been provided from measuring the brillouin spectra of fibres as they deform. Thus, it is both possible and timely to research the ways in which a Ground Model can be improved to assist the quantitative prediction of ground response to engineering change. This paper outlines and summarises key areas where further work is needed. The fundamental need is to enable a Ground Model to be a quantitative source for predicting ground response; ways for achieving this, through the development of field and laboratory testing, are described. Augmenting the presently accepted descriptions of rocks and soils will also be needed as these are biased towards describing what earth materials "are" when what is also needed are descriptions of what earth materials "do"; i.e. how they respond to change. Such descriptions include all scales of observation from the "mass" to the "material", however there are inherent problems with quantifications that cross scales. A Ground Model will contain information that crosses many scales from 1:1 to 1:50,000 and a better understanding is required of what a mix of scales does to the data generated from such models. Attention must also be paid to the inputs made from non-geologists and how they can be incorporated into a Ground Model, especially those from drillers and laboratory staff. These are the people who probably see more of the ground than most consultants and designers, and how it responds to drilling and testing; i.e. to engineering change - the very topic that needs to be strengthened in ground models. Such practitioners will need appropriate teaching and training for them to make these contributions. The research for such advances is ideal material for those in academia who wish to collaborate with industry; it is technically possible and timely. Thematic collection: This article is part of the Ground models in engineering geology and hydrogeology collection available at: https://www.lyellcollection.org/cc/Ground-models-in-engi