Abstract: Two reinforced concrete arches,which have been in service for 28 years,were removed from an old bridge to the laboratory.Failure experiments were performed.Combining the elastic damage theory with the finite element method proposed by the first author,a numerical method and a computer program are developed to simulate the failure process of the RC arch structures.The theoretical results of the failure mode,displacements and strains of the arch structure are in good agreement with the experimental observations.The concrete damage parameters are obtained.Numerical results reveal the complicated behavior of concrete in a damaging process.The reinforced concrete structures exhibit pronounced nonlinearity at large loading levels.The elastic damage theory is valid to describe the damage and fracture behavior of concrete.