IMPACT OF GEOSYNTHETIC IN SOFT SOIL REINFORCED BY RIGID INCLUSIONS

The rigid inclusions technique consists in reinforcing a soft soil by rigid vertical inclusions and in installing a granular mattress on it. To improve this technique, a geosynthetic sheet can be added between the reinforced soil and the granular mattress. A centrifuge model, based on the mobile tray, has been tested at 20xg. This device simulates the settlement of a fictive soft soil by the vertical downwards movement of the tray. This experimental study shows that a thick mattress, a dense inclusion network and a geosynthetic allow decreasing both the stress on the soft soil (i.e. on the tray) and the differential settlement. These results are completed by a finite element analysis with a 2D axisymmetric model.