Experimental Research on the Aerodynamic Characteristics of Typical Pipeline Suspension Bridge Girders

Wind-resistant performance is a major concern in the design and operation of pipeline suspension bridges. The mean aerodynamic force coefficients (MAFCs) are essential parameters for quantifying the wind loads on a bridge. However, a systematic investigation of the MAFCs of typical pipeline suspension bridge girders is unavailable. Specifically, the effects of design parameters (perforation rate of grate plates, horizontal spacing between pipelines, vertical spacing between pipelines, pipeline number, pipeline diameter, and pipeline surface roughness) and Reynolds number on MAFCs remain to be investigated. This study systematically investigated the MAFCs of three typical pipeline suspension bridge girders in wind tunnel experiments. The galloping stabilities of these girders were examined based on the quasi-steady galloping theory. The experimental results show that the effect of pipeline surface roughness on the Reynolds number effect of drag force coefficient is similar to that on the Reynolds number effect of a circular cylinder. Closing the grate plates may deteriorate the galloping performance of a bridge girder, whereas increasing the pipeline surface roughness may strengthen the galloping performance of a bridge girder. Unlike parallel circular cylinders, the horizontal spacing between pipelines slightly affects the MAFCs. Optimizing the vertical spacing between the pipelines can significantly reduce the MAFCs. In addition, optimizing the shape and roughness of the pipeline can reduce the lift force and pitching moment, and optimizing the shape of guardrails and truss stiffening girder can reduce the drag force. These research results can provide a basis for quantifying the aerodynamic loads and a reference for the wind-resistant design of pipeline suspension bridges with similar bridge girders.