An analytical method for out-of-plane stability assessment of network arch bridges

Abstract

Network arch bridges typically feature inclined cables with a net configuration to support the bridge deck, therefore, improving the bridge's stiffness and reducing bending moments along the arch elements. Given their relatively slender cross-sections and large compression stresses, properly evaluating stability safety is crucial to the integrity of network arch bridges. However, because of the unique design of cable configuration, current design specifications mostly do not provide specific methods for such stability assessments. To address this gap, the study proposes a new analytical methodology that elucidates the mechanical relationship between basic design parameters and the stability performance of network arch bridges. A numerical example is conducted using finite element analysis to validate the performance of the proposed method. In addition, the influence of several design parameters on the stability factor and buckling length factor is investigated. This research further proposes a practical expression for the buckling length factor of arch ribs with nonlinear regression analysis. The results exhibit that the proposed method can efficiently and accurately evaluate the buckling stability performance of network arch bridges, and the established practical expression can facilitate designers in easily estimating the critical buckling load during the design process.