【摘要】 铁路桥梁结构的疲劳寿命主要取决于桥梁结构构造细节、活载作用效应特征和活载作用次数。从列车上桥时刻的随机分布特征及列车相遇对桥梁损伤的累积作用出发,分析三线铁路桥梁结构疲劳检算中三线系数的影响因素。分析结果表明,三线系数只与各线列车的最大作用效应、列车运营密度(发车时间间隔)以及在桥上的持续时间有关。基于遭遇概率理论,推导三线系数的计算公式。采用该公式计算的三线系数与现场调查分析法所得结果基本一致。更多还原

【Abstract】 The fatigue life of railway bridge mostly lies on the constructional details of the bridge structure,characteristics of live load action effect,and times of live load actions.Taking account of the random distribution characteristics at the moment when trains running on bridges,and based on the accumulative effect of the damage the encountering trains brought to the bridges,the influence factors of trilinear coefficients in fatigue check computation of triline railway bridges are analyzed.Analysis results show that trilinear coefficients only have something to do with the maximal action effect of trains on each line,train traffic density(time interval between departure trains),and the duration on the bridges.Based on the theory of encounter probability,the formula for calculating trilinear coefficients is deduced.The trilinear coefficients derived from this calculation formula basically agree well with those obtained from field survey method.更多还原