Assessment of flooding impact on thin pavement structure in Texas coastal region

Abstract

Over the recent years, transportation infrastructure in the United States have experienced numerous hurricanes or tropical storms usually accompanied with heavy rainfalls. This may lead to flooding on pavements and higher groundwater levels, causing soil erosion, slope instability, reduced pavement strength, and lowering pavement’s load-bearing capacity, subsequently shortening pavement service life or increasing rehabilitation and maintenance costs. This study focuses on the impact of flooding on thin pavement structure with surface-treated pavements in Texas coastal region, which contains 6,277 lane miles of roads. First, at a project level, a Mechanistic-Empirical pavement design tool is used to analyze pavement performance under flooding and non-flooding/normal conditions. Pavement life is estimated for different flooding timing cases. Second, simulations are run to evaluate the impact of flooding on the pavement life at a network level. Three flooding frequencies are highlighted: low, 100-year; medium, 50-year; and high, 20-year. By a comparison with non-flooding baseline, it is found that the pavement life for the entire weak pavement network in the coastal region can be reduced at varying degrees due to the flooding impact. The quantified pavement life reduction can serve to enhance pavement design practice and system management decision making in a proactive manner.