Compression Membrane Arching Analysis of Reinforced Concrete

An analytical procedure was developed to generate the load-deformation characteristics of laterally restrained reinforced concrete members, a phenomenon commonly referred to as compression membrane arching action. The lateral restraint provided by adjacent structural members generates large internal compressive forces resulting in an overall increase in strength and stiffness characteristics. The procedure assumes that flexure and arching calculations are uncoupled, and that the arching force component will follow a simply supported mode shape with lateral axial restraint. A pure flexure analysis is used to determine the degree of contact between the beam-end and lateral support. The arching contribution to member strength capacity is calculated based on the contact force arising from the projection of the beam-end into the lateral support. The total strength due to arching is the superposition of pure flexure and arching strength components. The methodology can handle supports with both rigid and non-rigid lateral restraint and varying degrees of rotational fixity. The numerical procedure has been verified extensively against static experimental data found in the literature and can be used to model arching action under static conditions, or for inelastic dynamic analysis of structures subjected to blast and impact.