Numerical Simulation of Seasonal Variations of Base Course Resilient Modulus in Pavement Structures in Nonfrost Regions

The seasonal variation of unbound material properties is often significant, and water within a pavement structure is a principal cause of pavement deterioration. A small water content increment will result in a significant reduction in soil resilient moduli and a tremendous increment in permanent deformation. Unfortunately, the resilient modulus determined by falling weight deflectometer tests may not be representative, and the conventional enhanced integrated climatic model has its own limitations. This paper aims at numerically simulating the seasonal variations of the resilient behavior of a base course under saturated/unsaturated conditions with the influence of localized climatic conditions. A coupled hydromechanical model with considerations of climatic effect was proposed and calibrated. Then, three case studies were conducted to evaluate the dynamic resilient behavior of the base course under different climatic and working conditions. The suction, water content, and resilient modulus distributions were presented to demonstrate the dynamic resilient behavior of the base course, and the advantages of the proposed model against the enhanced integrated climatic model (EICM) in terms of simulating the moisture migration within pavement structures are discussed.