Modélisation sous macrogravité d’une paroi clouée respectant le phasage de construction | Revue Française de Géotechnique

Modélisation sous macrogravité d’une paroi clouée respectant le phasage de construction | Revue Française de Géotechnique - Macrogravity modeling of a soil-nailed wall respecting the construction phasing

Soil nailing was developed in the 1970’s in France and is a technique for the stabilisation of slopes and walls realised by soil excavation. Subhorizontal inclusions ensure the stability of the structure through friction with the soil. The questions raised within the committee for the current revision of the French standard NF P 94-270, pertaining to the design of reinforced soil slopes and walls, pointed a lack of knowledge regarding the facing solicitations and the importance of the construction steps. In order to contribute to improving the design of soil nailed wall facings, reduced scale models have been constructed and tested using the geotechnical centrifuge facility of the Gustave Eiffel University, campus of Nantes. A specific experimental protocol was developed to realise the excavation in flight. The tensile forces along the nails were monitored during the whole test using optic fibers equipped of Bragg networks. The displacements in the soil were monitored through an Image-based technique called GeoPIV, since the models were prepared in a container with a side window. It was found that the slenderness of the wall (the ratio of the height of the wall over the length of the nails) has a significant influence on the behaviour and the loading distribution on the facing. In addition, the GeoPIV technique allowed to describe the failure mechanisms in the different tested soil-nailed retaining walls.