Qualifying soils for low volume roads based on soil and pavement mechanics

摘要

Due to their paramount importance in unsurfaced or thinly surfaced roads, it seems worthwhileto qualify soils based on both Pavement and Soil Mechanics principles. Such an approach is used in this article todiscuss the mechanical behavior of a residual soil found in Southern Brazil. The experimental program includedtests traditionally used in Pavement Engineering, such as grain size distribution, Atterberg Limits, compaction,CBR, resilient modulus and permanent deformation under repeated loading. The influence of water content andcompaction degree on soil strength and stiffness was quantified. Besides, direct shear tests were carried out todefine strength parameters, used to verify the layer safety against shear failure. Water retention curves relatingsoil suction to saturation degree were used to analyze permanent deformation evolution under repeated loads.The interpretation of test results confirmed the suitability of the approach here suggested with the purpose ofqualifying soils for roads construction.