摘要
铁路桥梁承受的运营动荷载很大,而且加载次数很频繁,因此,疲劳验算在铁路桥梁的设计中是很重要的部分。我国现行桥梁设计规范中,疲劳验算仍沿用国际长期采用的疲劳容许应力法。设计的假定状态和列车的运营情况脱节,设计中的作用力与抗力反映不了实际情况。根据这样规则设计出的桥梁,不能满足当前运输量日益发展的需要。为了设计方法的改革,本文主要介绍铁路钢桥疲劳可靠性的主要研究成果,其中包括疲劳荷载及标准荷载效应比频谱的制定,疲劳抗力的研究,疲劳验算方法及表达式,现有桥梁疲劳可靠度评估和新建桥梁的目标可靠度建议。采用这一新的理论进行疲劳检算不仅可以估计结构完成预定功能的概率,而且能平衡结构中每个构造细节的功能要求水平,对结构的安全与经济都有十分重要的意义。
Fatigue check is an essential task in the design of railway bridges, because railway bridges are subject to high levels of magnitude and frequency of dynamic loadings. In the fatigue check procedure according to the current Bridge Design Code in China, the allowable fatigue stress method long used in the international society still prevails. With this method, the design assumptions are divorced from the service condition of real trains. For renovating the fatigue check procedure, in this paper is given the study results on the fatigue reliability of steel railway bridges, including fatigue loading, standard loading frequency spectrum, fatigue resistance, fatigue check procedure and expressions, fatigue reliability evaluation of existing bridges and recommended target reliability for new design bridges. With this renovated philosophy introduced in the fatigue check not only the assessment of the probability of a structure realising its fatigue function can be calculated, but also a balance of fatigue reliability levels of different details in the same structure is made possible.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
1991年第2期54-64,共11页
China Railway Science
关键词
疲劳
铁路桥
可靠性
设计
fatigue reliability, railway bridges.
