Model Test and Optimal Design of the Joint in a Sunflower Arch Bridge

Abstract

The sunflower arch bridge is a new type of reinforced concrete arch bridge that has been developed recently. Because of the complex constructional details, the stress distribution at the joint between the main arch and spandrel arch is very complicated. To explore the mechanical behavior of this new type of arch bridge, particularly the stress state at the joint of the arch, a 1:5-scaled model of a segment for a sunflower arch bridge was tested. The displacements and stresses at key locations of the tested model were recorded. The experimental results showed that the displacements of the main arch and spandrel arch under dead loads were notably small, which indicated that the global stiffness of the arch was sufficiently large. Moreover, the maximum tensile stress at the end of the spandrel arch subjected to dead loads was larger than the tensile strength of the concrete; therefore, the concrete in these regions is vulnerable to cracking. To avoid cracks at the end of the spandrel arch, an optimized design scheme was proposed for the joint using a steel I-beam to replace the concrete at the end of the spandrel arch. Design parameters were also suggested through a comprehensive parametric investigation based on finite-element analysis (FEA).