A system dynamics framework for mechanistic analysis of flexible pavement systems under moisture variations

Abstract

The infiltration of water in pavement layers due to heavy precipitation, snow melting, surface water flow, or ground water fluctuation can lead to a substantial change in pavement performance under traffic loading. The extent of this change depends on several complex and interdependent factors such as climatic and mechanical stressors, hydro-geological material properties, and traffic loads. Due to a very large number of variables and their interdependencies, a system dynamics approach can holistically capture all significant variables and provide a tool to study and visualize governing factors and their effects on pavement response under variable initial and boundary conditions. The objective of this study is to develop and program a system dynamics model (SDM) to study the performance of pavement systems under extreme moisture variations in real time. The application of the model is illustrated by evaluating surface deflection of a conventional flexible pavement system with hypothetical material and precipitation conditions. A parametric study was also conducted to illustrate the capability of the proposed SDM to simulate moisture movement in subsurface and estimate pavement performance at variable initial conditions in real time. Results demonstrated that the pavements weakened through water infiltration may suffer a considerably high surface deflection. This indicated that the proposed SDM can be potentially used for load restriction decision making which results in provision of safe traffic passage as well as preservation of pavements’ structure during extreme climatic events.