Road pavement design using the finite element method

The purpose of the work is to calculate the stress-strain state of the III-type road, as well as to determine the load factor for road pavement and roadbed. A model of non-rigid road pavement consisting of 4 layers is considered: dense-graded asphalt concrete, open-graded asphalt concrete, gravel roadbed, ground roadbed (silt sandy loam). A numerical code is developed for calculating the principal physical and mechanical parameters of road pavement. C++ is used as a programming language. A method of evaluating the shear resistance of roadbed is proposed. To calculate the load factor of roadbed, the Drucker-Prager strength criterion is used without the term responsible for the intensity of tangential stress. A T-90 tank fitted with special rubber track pads is considered to be a static load. The computations reveal the maximum vertical deflection, equal to 0.004 m, in the contact area of the tracks. In the same area, the load factor of road pavement is 9 ÷ 10, which indicates a high bearing capacity of dense-graded asphalt concrete. The analysis of shear resistance shows the presence of irreversible deformations in gravel roadbed in the contact area of the tracks, while the load factor of silt sandy loam is 3 ÷ 10.