Collision damage quantification of RC pier columns coupling axial, flexural and shear effects

Reinforcement concrete (RC) pier columns are the main supporting elements of many highway bridges and city viaducts, therefore the health state of a pier column is critical to the safe operation of bridges. Vehicle-pier collision accidents, which occur increasingly frequently, often induce unexpected damage to an impacted pier column, threatening the safety of bridges. It is important to define appropriate damage indices that can be used to effectively assess the conditions of a pier column damaged by a vehicle collision in a quantitative manner. Previous researchers have proposed many types of damage indices to quantify the degree of damage to an RC column. However, the existing damage indices often suffer from limitations such as undefined upper-and lower-bound rules, ignorance of shear deformation, etc. This paper proposes a plasticity-based damage index, which uses the accumulation of plastic deformation to reflect the damage state of an impacted RC pier column. The proposed damage index ranges between 0.0 and 1.0 which can effectively couple axial, flexural and shear deformation of RC sections during vehicle collisions with detailed model validations using experimental data. A detailed parametric study is then conducted which shows that the damage index can very effectively trace the time-history and spatial distribution of damage on an RC pier column during vehicle collisions.