Method and device for reinforcing the ground using fibrous additives

A method for reinforcing materials already in place in the ground, comprising the steps of:

• depositing onto the surface of the materials to be reinforced an even layer of fibrous additives, and
• mixing together the materials to be reinforced and the fibrous additives,
• wherein said fibrous additives are selected from the group consisting of glass fibers in the form of bundles having a length of from 3 to 500 mm, glass fibers obtained by centrifuging and packaging in the form of nodules by passing through a holed plate, and rock fibers obtained by centrifuging and packaging in the form of nodules by passing through a holed plate.