Torsional behavior of curved concrete box beam with small radius

Abstract

Curved concrete box beams are commonly used for their superior integrality performance and greater torsional stiffness. This paper investigates the torsional behavior of these beams using both experimental and finite element analyses. The experiment is based on a 1:6 scale model of a three-span curved girder bridge with a small radius. The study examines six different load cases, including central vertical and eccentric vertical loads. The study reports the detailed reaction forces of the supports, as well as the displacements and strains of the mid-span section. Finite element models are established to analyze the warping behavior of the curved concrete box beams. Based on the experimental and FEM analysis, the following conclusions are noted. Firstly, in the central load case, the strain of the curved concrete box girder is close to a straight line, so the curved concrete box girders follows the plane-section assumption. Besides, the warping normal stress is produced in curved concrete box girder in eccentric load cases. Moreover, the ratio of warping normal stress to bending normal stress is smaller and smoother in the section with diaphragms than that without diaphragms. And this ratio decreases with an increase in the curvature radius and diaphragm number. This study contributes to the theoretical and numerical modeling of a large span curved girder bridge with a small radius.