CALCULATION AND STUDY OF LONGITUDINAL FORCES OF CONTINUOUS WELDED RAIL TRACK ON DECK ARCH BRIDGE

摘要

In order to study the characteristics of longitudinal forces of continuous welded rail track (hereinafter short for CWR) on deck arch bridge, according to the finite element theory, a rail-bridge-pier coupling system calculating model was established based on principles of track-bridge interaction,which can be used to calculate forces due to the thermal expansion of the deck, forces due to the deck bending under vertical traffic loads(hereinafter short for bending forces), forces acting on the bridge due to braking of trains, etc. Taking the deck arch bridge on certain single-line railway as an example, the influences of some main factors, including constraint of arch foot, bending stiffness of arch ring, temperature change of arch ring, loading manners, on longitudinal forces of CWR were analyzed. The calculation results show that results of model with arch foot centre constrained are similar to that of model with arch foot edge constrained, so model with arch foot edge constrained can be selected for modeling expediently. The results of calculating model using equivalent section method to simplify arch ring are more accurate; Temperature change of arch ring has a large impact upon longitudinal forces of CWR, in the example, when the temperature change of arch ring considered, the largest force due to the thermal expansion of the deck increases by 3.7 times; Under the effect of train loads, the rapid relative displacement between track and bridge will be largest when trains brake on the full-span, usually, half-span loading can be selected to calculate bending forces.