Limit Analysis of Reinforced Concrete Arch Bridges

The analysis of limit load and deformations of arch bridges can be cast as linear programming problems by idealizing them as plane structures that consaist of discretized elastic elements connected by plastic hinges and by assuming elastic-plastic models for both steel and concrete before the ultimate concrete strain is reached. For the case of holonomic behavior, the internal forces and displacements can be determined at any level of loading up to collapse by using a general matrix formulation of the equilibrium, compatibility, and constitutive law equations along with the appropriate computer programs. Theoretical formulations of the limit load analysis under static loadings and the historical elastic-plastic analysis are presented. Their applications to reinforced concrete bridges are then examined and results are compared with experimental and numerical data of an arch bridge tested in Italy.