铁路钢桁梁桥疲劳检算三线系数

Trilinear Coefficient for Fatigue Computation of Railway Steel Truss Bridge

我国铁路正准备修建三线桥甚至四线桥,现行规范及研究只涉及到两线桥的疲劳检算。将三线铁路桥梁列车相遇的复杂随机过程问题简化为较简单的概率问题,推导出铁路三线钢桁梁桥列车两两相遇概率及相遇次数、三线相遇概率及相遇次数,通过模型处理和简化,推导出三线钢桁梁桥疲劳检算三线系数的近似计算式。算例说明,应用近似计算式将使三线钢桁梁桥的疲劳检算变得简单、方便。该研究思路和方法也为四线钢桁梁桥及更多线钢桁梁桥的疲劳检算多线系数研究提供依据。

China is planning to build three-line and four-line railway bridges. The current criteria and researches only deal with the fatigue check and computation of double-line bridge. The complicated random process problems of train encountering on three-line railway bridge are simplified into more ordinary probability problem. Two-two encountering probability of trains and number of times, trilinear encounter probability and number of times are deduced for three-line steel truss bridge. The approximate formula of the trilinear coefficient for fatigue check and computation of steel truss bridge is deduced by processing and simplifying the model. Calculation example shows that fatigue check and computation of steel truss bridge becomes simpler and more convenient by employing approximate formula. The research ideas as well as approaches have provided useful reference of multiple-line coefficient for fatigue check and computation of four-line and multiple-line steel truss bridge.