Abstract: The design method based on failure approach index was proposed to optimize the pavement structure. Three-dimensional model were built according to typical pavement structure of the grade road and loads. Based on Abaqus numerical analysis method, the distance, the stress, the strain and the plastic analysis of pavement structure layers with vehicle loads were put forth. Failure approach index was calculated for each layer of the pavement and treatment layer of the subgrade. Comparison and analysis among the failure approach index, the predicted fatigue life and the modular ratio of different layers were done. The result demonstrated that the failure approach index could represent the balance property of the pavement structure layers.

Key words: failure approach index, pavement structure balance, fatigue life, layer modular ratio