Based on Energy-Variational Principle Derived Moment Amplified Coefficient of Tied Arch Rib

Abstract

The arch rib, tie beam, and rod of the tied arch are considered common forces. According to the characteristics of these forces, the calculation equation of the moment augment factor of the tied arch is derived. The equation is based on the energy variational principle. The calculated results of the derived equation and the current bridge code are compared with the project example. For examples 1 and 2, the difference in calculation results between the derived practical equations and naked-arch simplified equivalent straight bar under the existing bridge specification is 12.9% to 24.3% before simplification. After simplification, the calculation results of the derived equation deviates by about 1%. The derived equation is comparatively economic and practical because the current bridge code is calculated according to the nude arch. The moment-amplified factor increases with increasing axial force and is related to the constraint and load form. The moment augment factor of the eccentric compress bar and arch rib in the arch structure exhibits substantial difference.