Uso dos ensaios de cone de penetração dinâmica e light weight deflectometer na previsão do módulo de resiliência de solos.

Abstract

The Modulus of Resilience (𝑀𝑅) is a fundamental parameter for the characterization of the mechanical behavior of soils and aggregates that make up the pavement structure in the face of dynamic traffic actions. However, its standard method of determination, through the triaxial test of repeated loading, is a considerably expensive procedure and difficult to perform. In this scenario, the use of in situ tests of Cone of Dynamic Penetration (CPD) and Light Weight Deflectometer (LWD) for the estimation of 𝑀𝑅 has shown promise, in view of the portable aspect of these equipment, the speed and simplicity of the methods used. , in addition to its possibility of application throughout the course of a work, from the preliminary investigation to the quality control stage. Thus, this work studied the resilient behavior of eight sandy soils from subgrades and subbases of urban pavements in the city of Campina Grande-PB, with the objective of developing statistical correlations between the 𝑀𝑅 and the indices obtained from the CPD and LWD The experimental research was divided into two stages, with the field phase corresponding to the performance of the CPD and LWD tests, together with the determination of the humidity and specific mass of the materials and the collection of samples. In the laboratory, the characterization of the materials and the determination of 𝑀𝑅 were carried out through triaxial tests under different humidity conditions, so that the values ​​corresponding to the in situ state of the materials could be estimated. The test results of 𝑀𝑅 were fitted based on eight constitutive models that established the relationship between this parameter and stress state variables. Employing an approach where the parameters 𝑘1, 𝑘2 and 𝑘3 of the best performing model were correlated with the indices of the CPD and LWD tests through regression analyses, a set of equations capable of estimating the 𝑀𝑅 of soils was obtained studied under different stress levels. Among the equations obtained, those based on the LWD presented a better performance in the estimation of 𝑀𝑅, which was associated with the greater similarity of this method with the mechanical conditions of the triaxial tests. Finally, it was concluded that the proposed equations are limited to a context of local soils and with similar characteristics, so that their application must be restricted to such particular conditions.