Minimum Concrete Filling Rate of Single Partially Concrete-Filled Steel Tubular Piers

Abstract:

Concrete-filled circular steel tubular （CFST） pier has been widely applied to urban viaducts in China due to its superior features of less road occupation， higher bearing capacity， and better energy-dissipation ability， yet the practical seismic design method is not available in earthquake prone areas. Considering the research status and deficiency of the concrete filling rate of circular CFST piers， the minimum concrete filling rates are proposed in this study based on different seismic design strategies （seismic isolation design or ductile seismic design） specified in the Bridge Seismic Design Code. In addition， corresponding practical formulas for the concrete filling rate are proposed and verified by theoretical study and numerical simulation， which provides specific design guidance for the seismic design of the circular CFST piers of urban viaducts in high earthquake-intensity areas.

Key words:urban viaduct;partially concrete-filled steel tubular pier;minimum concrete filling rate;seismic isolation design;ductile seismic design