Structural test at the laboratory scale for the utilization of stabilized fine-grained soils in the subgrades of High Speed Rail infrastructures: Experimental aspects

Abstract The use of in situ fine-grained soils stabilized with lime and/or hydraulic binders as subgrade is common for civil engineering infrastructures. This process allows the sustainable upgrading of natural materials with low mechanical performances. But, the global lack of knowledge on the mechanical fatigue behavior of these materials has purely and solely led to them not being used in High Speed Rails (HSR) infrastructures. However, recent numerical and analytical studies have shown that those materials are relevant for a use in HSR projects. Thus, a specific test, the Biaxial Flexural Test (BFT) was proposed. At the laboratory scale, it allows, by considering the materials behavior in the field, the study of the long-term mechanical fatigue performances of stabilized soils in the structures. In this paper, this test is experimentally validated. Fatigue performances under biaxial flexion are determined for two stabilized soils. Based on numerical modeling of the HSR structure, results confirm the relevance for a use in HSR capping layers. Moreover, they open new perspectives for scientific and technologic explorations in order to rationalize the costs of the structures.