桥梁结构地震与温度作用效应组合研究

摘要

对于双塔斜拉桥和连续刚构等纵向约束较强的桥梁结构,纵向地震作用和温度作用会产生巨大的桥墩弯矩.作为随机性很强的地震作用和温度作用,规范中没有给出明确的温度作用效用组合系数.基于概率方法,建立了桥梁结构在纵向水平地震作用下,考虑温度作用的组合计算模型,利用Turkstra组合方法,考虑地震作用和温度作用的随机概率分布,得到了桥梁结构抗震设计中温度作用效应的组合系数.参数分析表明,温度作用效应的组合系数随组合效应概率分布分位值的增大而减小;随年最高和最低日平均气温出现的概率增大而增大;随地震与温度作用效应的比%For the bridges with strong longitudinal restraint,such as double-tower cable-stayed bridges and continuous rigid frame bridges,the longitudinal seismic action and temperature action cause large moments of piers.As the seismic and temperature actions are stochastic,the combination factor considering temperature action effects is needed in anti-seismic design of bridge,but that is not given in the codes.Based on the probability method,the model of combination of seismic action effects and temperature action effects is proposed.Using the Turkstra combination criteria and considering the stochastic probability distribution of seismic and temperature actions,the combination factors of temperature action effects are given for the seismic design of bridge.The parameters analyses show that the combination factor of temperature action effects decreases with increase of the fractile of distribution function and the ratio of seismic action effects and temperature action effects,but it increases with increase of the occurrence probability of the highest and lowest daily average temperature.When the ratio of seismic action effects and temperature action effects is higher than 6,the temperature action effects can be neglected.