Numerical Simulation of the CBR test for subgrades in the city of Bogotá

The CBR test is widely implemented in road infrastructure projects. The test result is presumed to be correlated with the dynamic modulus. This contradicts the conceptual background of the test which was identified from the beginning as a bearing capacity test. In those times, pavements were designed based on resistance criteria, so that, in the origins of modern pavement engineering, there was no such contradiction. Today, with the implementation of mechanistic models, it became necessary to modify the concept of bearing capacity per resilient modulus, and the most widely used test was correlated with the stiffness of geomaterials. This work shows the results of numerical modeling of a CBR test under axisymmetric conditions using the PLAXIS 2D finite element software. Through a parametric analysis it is shown that the load criterion at 0.1 and 0.2 inches is invariant over a wide range of modules. elastic but very sensitive to resistance parameters. These results are highly relevant and support the abandonment of CBR as a method for estimating the dynamic modulus for pavement engineering.