It is used to strengthen soft soils, especially clayey ones, to make the excavation safer and to prevent displacement or deformation of the excavated material. In practice, the land to be excavated is preemptively perforated over the entire section through longitudinal holes at the excavation, having lengths of up to 20 meters and a diameter of 100-200 mm. Fiberglass tubes are inserted into these holes and then cemented into the bore using special pumps. This process achieves the consolidation of the land, giving it optimal mechanical characteristics. The consolidation prevents a possible yielding of the ground inside the tunnel during the excavation phase. The ground thus consolidated can then be safely excavated like soft rock. Although the mechanical characteristics of the field have been considerably improved, the fiberglass tubes can be removed without difficulty due to the typical brittle fracture and low cutting strength.