Alea — Layer of the clay withdrawal-inflating hazard in Lorraine

As part of the departmental mapping program for clay withdrawal-swelling conducted by the BRGM from 1997 to 2010, the baseline data used is that of geological maps drawn up and published by BRGM at a scale of 1:50,000. Their analysis made it possible to identify the clay formations (in the broad sense), outcropping or sub-outcropping, and to establish a numerical map, homogeneous at the departmental level. The preventive provisions generally prescribed for building on clay soil subject to the phenomenon of shrink-inflating follow the following principles, knowing that their application can be carried out using several different techniques, the choice of which remains the responsibility of the manufacturer. In municipalities with a Natural Risk Prevention Plan (PPR), which specifically takes into account the phenomenon of clay removal and swelling, the measures to be followed in each of the restricted areas are those defined by the PPR Regulation.