Load Rating of Cast-in-Place Reinforced Concrete Box Culverts: State-of-the-Art Review

Abstract

Cast-in-place (CIP) reinforced concrete (RC) box culverts are the most common type of culvert in the United States. As buried structures, the structural behavior of CIP RC box culverts under earth loads and vehicular live loads is not fully understood, and accurate load rating remains challenging. Relevant communities have conducted research and developed codes to achieve more realistic load ratings. This paper provides a comprehensive review of current guidelines, practices, and state-of-the-art research on load rating CIP RC box culverts. The review encompasses national standards, state procedures, standard plans, and publications from agencies and institutes. Additionally, commonly used structural analysis and rating software for culverts is introduced. The paper identifies and discusses key parameters and assumptions that affect load rating, and examines various analysis techniques, including 2-D analysis, 3-D analysis, and soil-structure interaction modeling. Using single-cell and multicell culvert examples, this paper conducts a study to quantify the influence of identified key parameters and analysis techniques, validating results from existing literature. The conclusion summarizes the findings, offers suggestions for load rating practices, and identifies areas requiring further investigation in future research.