Uncertainties of Experimental Tests on Cyclic Liquefaction Potential of Unsaturated Soils

Day after day, soil liquefaction took the attention of the researchers due to its huge and dangerous impact on its surroundings. Generally, soil liquefaction is related to saturated soils; however, recent studies showed that it is possible for unsaturated soils. Laboratory tests are done using dynamic triaxial test on unsaturated Hostun sand RF. As all experimental tests, uncertainties are unavoidable due to many factors affecting these tests from the sample preparation, the considered approximations (the stopping conditions of each phase of the test) and the heterogeneity of the material. Dynamic triaxial experiments were done on Hostun Sand RF samples with relative density of 50% in undrained conditions. This paper presents the possibilities of the repetitions of our experimental tests showing the statistical error (standard deviation and coefficient of variation) occurring between the same tests performed, focusing on the different parameters that might cause these uncertainties. The experimental tests carried out showed that it is impossible to be 100% repeatable and perfect, but the statistical errors and the uncertainties must be minimal compared to the complexity of the experimental test. To reduce these uncertainties, it is necessary to perform more replicated tests; however, in geotechnical field, it costs additional time and expenses.