Live Load Radial Moment Distribution for Horizontally Curved Bridges

Abstract

This study is designed to determine the effect of major parameters on maximum total bending moments of curved girders, establish the relationship between key parameters and girder distribution factors (GDFs), and develop new approximate distribution factor equations. A level of analysis study using 3 numerical models was performed to establish an appropriate numerical modeling method on the basis of field test results. 81, 2-traffic lane curved bridges were analyzed under HL-93 loading. Two approximate GDF equations were developed based on the data obtained in this study: 1) a single GDF based on total girder normal stress; and 2) a combined GDF treating bending and warping normal stress separately. The 2 equations were developed based on both an averaged coefficient method and regression analysis. A goodness-of-fit test revealed that the combined GDF model developed by regression analysis best predicted GDFs. This research study demonstrated that radius, span length, cross frame spacing, and girder spacing most significantly affect GDFs. The proposed GDF equations are expected to provide a more refined live load analysis for preliminary design.