Construction equipment dumping earth (France, 2008).
© Girodjl - Fotolia
Bouygues Travaux Publics and the BRGM will present their Immoterre partnership on sustainable management of excavated earths at the Pollutec Trade Fair 2018.
Underground workings for the Grand Paris Express metro line will produce some 43 million tonnes of excavated earth, including a substantial proportion of non-inert material, as defined for inert waste storage facilities, because they contain high natural concentrations of trace elements (selenium and molybdenum in particular).
The Immoterre project was developed in response to this issue. Bouygues Travaux Publics and the BRGM set up a partnership to work on the reuse of this surplus earth and optimised management of their environmentally sound removal from Grand Paris worksites.
Characterising and stabilising contaminants in excavated earths to optimise their management
Conducted through the BRGM Carnot Institute, which encourages scientific research under public-private partnerships, the Immoterre project is focusing on two lines of work: characterisation and stabilisation of contaminants. It aims to put forward two solutions.
- One is for rapid analysis of trace elements found in excavated earth to ensure their appropriate disposal or reuse. This innovation will drastically reduce the time and costs of characterising materials and thus limit the need for temporary storage facilities.
- The other is a solution to stabilise these trace elements and reduce their mobility and thus lower the costs of removing these materials with the option of transfer to inert waste disposal facilities.