铁路钢桥结构疲劳极限状态设计方法研究

The Fatigue Limit State Design Methods of Railway Steel Bridge Structural

研究目的:结合目前已经形成的城际轨道、高速铁路、客货共线、货运专线四种运输格局,计算调整铁路钢桥疲劳设计的相关参数,修正《铁路桥涵设计规范(极限状态设计法)》(2011年版)送审稿中疲劳设计相关条文,制订新形势下铁路钢桥的疲劳极限状态设计方法。研究结论:(1)采用计算机空间刚接计算得到的应力可以直接应用于疲劳设计,不需要采用构造系数进行修正,解决了目前设计人员面临的空间计算结果无法用于疲劳设计的难题;(2)通过大量调研、实测和计算,制定了新运输形势下的典型疲劳列车、桥梁疲劳荷载谱,使得疲劳设计紧密跟进目前的运输新形势;(3)研究得出了疲劳设计分项系数,确定了城际轨道、高速铁路和货运专线的疲劳承载能力极限状态设计方法,填补了城际轨道、高速铁路和货运专线疲劳设计的空白;(4)依据新形势下的疲劳设计方法对典型的钢桥进行了试设计,试设计结果表明:新形势下的疲劳设计方法的储备与现行容许应力疲劳设计方法相比略微有所提高;(5)研究成果将纳入《铁路桥涵设计规范(极限状态设计法)》,可以直接用于今后新建桥梁的设计,同时也可为既有桥梁的疲劳评估提供参考。

Research purposes： Combining the four transportation pattern that has been formed, which contains lnterclty railway ,high speed railway, passenger and freight lines and freight railway, the parameters of the fatigue design were adjusted by calculating and analyzing, and the related provisions of fatigue design in＂ railway bridge design specifications （ limit state design）＂ （2011 version） were corrected,and the fatigue limit state design methods of railway steel bridges under the new situation were developed. Research conclusions： （ 1 ） The stress calculated by computer space rigid model can be directly used to fatigue design, and need not to be corrected by structural factor. The problem faced by designer can be solved, which is that the results calculated by computer space rigid model cannot be used to fatigue design. （2） Through a lot of research, measurement and calculation, the typical operation train and fatigue load spectrum under the current transport situation are determined. It makes the fatigue design closely follow up the current transport situation. （ 3 ） Fatigue design partial coefficients are studied, and the fatigue limit state design methods of intercity railway, high speed railway and freight railway are established. It fills the blank of fatigue design in intercity railway, high speed railway and freight railway. （4） The typical steel bridge has been designed according to the fatigue design method based on the new situation, the design results show that the reserves of the fatigue design methods under the new situation compared with the existing fatigue allowable stress design method is increased slightly. Research results will be incorporated into ＂ railway bridge design specifications（ limit state design）＂, and will be directly used to design the new steel bridges in future, and can provide a reference for fatigue assessment of existing railway steel bridge.