Société du Grand Paris (SGP)
September 2014 / March 2015
The construction of the Grand Paris Express will generate around 40 million tons of excavated material, of which nearly 30 million tons will come from the red line alone.
Given the sheer quantity of the excavated materials, in order to respect both national and European environmental directives, it was necessary to develop an optimised materials management plan which limited the related environmental impacts. Two examples are: the limiting of spoil disposal (and the associated transport impact) and considering the materials not as waste, but as a mineral resource (transformation into aggregate suitable for use in concrete; use as backfill or in compacted layers for buildings and infrastructure; use in landscaping; use of clays for water-tight barriers etc.)
- Geological and geotechnical analysis of the formations encountered.
- Categorisation and identification of the optimisation possibilities: separation of the polluted soils, re-use of inert materials within the project and elsewhere.
- Specialisation in the regulatory aspects.
- Management of sulphate-containing materials.
- Development of the materials management model per excavation phase.
- Development of a number of options for the management of the excavated materials, incorporating a multi-criteria analysis.
- Optimisation of the material transport system, with a priority given to 'soft' modes of transport (river and rail transportation).