LOAD DISTRIBUTION IN SKEWED BRIDGES TREATED IN SPACE

Four simply-supported skewed railway bridges of the same span, but with various angles of skew, were studied. The bridges were composed of two main girders connected together by two end transverse bracings and an upper and a lower wind bracing. Maximum bending moments in the main girder, and reactions and forces in the bracings were obtained for a vertical load moving along the center line of the bridge by using the ordinary planar method of calculation, and by treating them as space structures. The maximum bending moments decrease significantly with the decrease in the angle of skew, as do the reactions at the acute end, while at the obtuse ends, a considerable increase in reaction occurs. The values of the bending moments and reactions are presented in tables as a function of the skew. The end transverse bracings and wind bracings are subject to enormous horizontal forces due to vertical loading. The calculation of these forces is possible only by treating the bridges as space structures, and they are plotted as a function of the angle of skew.