A New Concept on the Compressibility of Mixed Soils: Experimental and Numerical Approach

摘要

In this article, a new concept on the compressibility of mixed soils is proposed. Six characteristic structures of mixed soils are recognized, defined and described based on the percentage of the ground material in the mixture. The compressibility mechanism and the deformational behavior of each structure are extensively studied by both laboratory and numerical experiments. Two series of compressibility tests are initially conducted in the laboratory, using artificial mixtures of sand and clay at different ratios and subjected to typical compressibility tests using the oedometer apparatus. Then, a numerical approach is employed, based on the finite element method and Monte-Carlo simulations, in order to reproduce the conditions of the laboratory tests and to further study the compressibility of each characteristic structure. From the results obtained, it is concluded that the deformational behavior of mixed soils depends strongly on the percentage of the ground in the mixture and on the mechanical properties of the components of this mixture. Furthermore, it is shown that the estimated deformations and stress states can be highly unrealistic when the mixed soil is not properly modelled and is assumed to be governed by the properties of its weaker component.