基于交通量调查的大跨PC箱梁跨中区段疲劳应力谱  

Analysis on Fatigue Stress Spectrum for Mid-Span Segments of Long Span PC Box Girders Based on Traffic Volume Survey

作　　者：刘杰[1,2] 叶见曙[3] 陈娟娟[1,2] 

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [2]三峡大学土木与建筑学院,湖北宜昌443002 [3]东南大学交通学院,江苏南京210096

出　　处：《应用基础与工程科学学报》2015年第2期273-284,共12页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(11472160);宜昌市自然基础科学研究与应用专项项目(A14-302-a02);三峡大学科学基金项目(KJ20130047)

摘　　要：为分析大跨径预应力混凝土(简称PC)箱梁跨中区段在车辆荷载作用下的疲劳累积损伤,以某PC连续刚构桥为例,对车辆荷载产生的疲劳应力谱进行了研究.首先,运用实桥交通量调查数据,计算得到了等效标准疲劳车的总轴重,据此从相关设计规范中选取了标准疲劳车模型.其次,运用Newmark法进行了动力时程分析,得到了标准疲劳车通过全桥时跨中截面的内力历程,并运用雨流计数法对内力历程进行了计数处理.然后,根据实桥交通量调查数据,分析了桥梁设计基准期内疲劳荷载的循环次数.最后,依据Miner线性累积损伤理论以及桥梁实际受力状况,分别确定了200万次室内疲劳试验的等效疲劳应力幅和疲劳平均应力,由此得到了由车辆荷载产生的疲劳应力谱.In order to study the fatigue accumulated damage for mid-span segments of long span Prestressed Concrete（PC）box girders, the fatigue stress spectrum produced by vehicle load was analyzed by taking a PC continuous rigid frame bridge as a example. First, a total axle load of equivalent standard fatigue vehicle was obtained, according to actual traffic data.And a standard fatigue vehicle model was chosen from design codes concerned. After that, dynamic time-history analysis was done using Newmark method, and so internal force history of mid-span section was derived. And the internal force history was counted utilizing rain-flow counting method.Then, cycle times of fatigue load in bridge design reference period were studied based on actual traffic data.Furthermore, equivalent fatigue stress amplitude and fatigue average stress of 2million times indoor fatigue test were determined, according to Miner linear accumulated damage theory and bridge actual stress state, respectively. In doing so, the fatigue stress spectrum produced by vehicle load was gotten.

关 键 词：预应力混凝土箱梁 疲劳荷载 疲劳累积损伤理论 交通量调查 下挠 

分 类 号：U448.383[建筑科学—桥梁与隧道工程]