基于梁轨相互作用的铁路桥梁徐变上拱限值

Limit Value of Creep Camber in Railway Bridges Considering Track-bridge Interaction

摘要:

为研究铁路桥梁徐变上拱对于梁轨相互作用的影响，分别建立了三跨连续梁桥及简支梁桥的梁轨相互作用有限元模型，分析了徐变上拱对桥上无缝线路的钢轨附加应力、扣件上拔力、扣件剪切力以及列车走行性的影响.结果表明：徐变上拱值主要影响扣件上拔力和行车舒适度，而对钢轨附加应力的影响可以忽略；徐变拱跨比相同的梁桥所导致的钢轨应力、扣件上拔力及扣件剪切力峰值基本一致；对于该研究的主跨125 m的连续梁桥和跨径30 m的简支梁桥而言，徐变拱跨比的建议限值分别为1/2 500和1/2 000.

关键词:铁路桥梁; 梁轨相互作用; 徐变上拱值; 无缝线路纵向力; 扣件上拔力; 列车走行性

Abstract:

In this paper, track-bridge interaction finite element models of both a three-span continuous beam bridge and a simply supported beam bridge were established in order to study the influence of creep camber on the track-bridge interaction in railway bridges. The effects of creep camber on additional rail stresses (ARSs), the uplift and shearing force of fasteners, and the train running performance of continuous welded rail (CWR) on bridges were analyzed. The results show that for the limit value of creep arch based on beam-rail interaction, the uplift force of fasteners and driving comfort play a controlling role, while the effect of ARSs is relatively insignificant. For beam bridges with the same arch-span ratio, the peak values of ARSs, uplift force and shearing force of fasteners induced by creep camber are basically the same. For the continuous beam bridge with a main span of 125 m and the simply supported beam bridge with a span of 30 m in this paper, the reasonable limit value of the archspan ratio of creep camber should be 1/2 500 and 1/2 000 respectively.

Key words:railway bridges; track-bridge interaction; creep camber; continuous welded rail longitudinal force; uplift force of fasteners; train running performance