Influence of difference in deformation modulus between asphalt concrete core and transition layer on core behavior and difference threshold determination

Abstract

Asphalt concrete core is the main impermeable structure of asphalt concrete core dams (ACCDs). The deformation modulus difference between the core and transition layer is directly related to the core behavior, especially the arch effect. This paper mainly studies the threshold of the deformation modulus difference between the transition and asphalt concrete core and the core arc safety. A database of 54 ACCD cases from domestic and abroad is collected. The thickness and material characteristics of the transition and core are statistically analyzed, and the range of deformation modulus ratio η between them is determined. A numerical model is established, and the impact of different interface models on the core behavior is compared and analyzed. By comparing measured data and numerical calculation results, an appropriate interface simulation method is selected to study the influence of deformation modulus ratio η on the core performance. On this basis, the threshold ηmax is determined using a cusp catastrophe model. A new valley shape characterization parameter δ is proposed, and the arch safety area under different δ is studied based on ηmax for reference in ACCDs design and construction. Finally, engineering measures to enhance the arch safety of the core are discussed.