Structural Behavior of Inferior-Deck Spatial Arch Bridges with Imposed Curvature

Abstract

Spatial arch bridges have significant out-of-plane behavior that must be controlled even under vertical loads. In some designs, the centerline of the arch may not lie within a plane. This study focuses on the structural behavior and the effect of the geometrical configurations of inferior-deck arch bridges with imposed curvature. In this type of spatial arch bridge, the arch and the deck centroid lines are both contained in the same vertical cylinder. The aim of this study is to propose the most appropriate design for controlling the out-of-plane response. A simple analytical model representing the stiffness of the arch, the deck, and a hanger allowed us to determine the main variables that control the behavior of the system. We also analyzed a series of linear three-dimensional-frame finite-element models of the complete bridge. This study demonstrates that nonplanar arches can be approximated by inclined planar arches. These parametric analyses have led to a set of recommended relevant design criteria for such bridges.