随机车流下钢-UHPC组合正交异性桥面疲劳性能研究

发布时间：2018-07-18 15:10

【摘要】：为获得钢-UHPC组合铺装正交异性桥面板构造细节轮载作用下的响应特征,准确评价随机车流下其疲劳敏感构造细节的疲劳性能,以佛陈扩建西幅桥为例,开展了钢-UHPC组合铺装正交异性钢桥面板全部构造细节的应力监测试验。利用7d连续记录的应力时程和雨流计数法获得了构造细节的应力谱;基于Miner疲劳损伤等效原则计算得到了最大应力幅、等效应力幅及疲劳加载次数。结果表明:当构造细节位于轮载正下方时,通行货车每个车轴将在面板上的构造细节中产生1个应力循环,但其他构造细节只能由每个轴组产生1个应力循环;钢-UHPC组合铺装虽并未改变正交异性钢桥面板构造细节轮载作用下明显的局部效应特征,但增大了正交异性钢桥面板的刚度,使得横隔板弧形切口的面外应力减小;其显著降低了面板上构造细节的应力幅,使得纵肋-面板焊缝构造细节和面板对接焊缝构造细节所记录到的最大应力幅均小于常幅疲劳极限;基于AASHTO规范开展的疲劳评价表明,在当前交通流下,佛陈扩建西幅桥钢-UHPC组合铺装正交异性钢桥面板全部构造细节具有足够的疲劳强度。
[Abstract]:In order to obtain the response characteristics of the structural details of steel UHPC composite pavement under the wheel load, and to accurately evaluate the fatigue performance of the fatigue sensitive structure details under random traffic flow, a case study of Fochen extension of Xifeng Bridge is presented. Stress monitoring tests on all structural details of orthotropic steel bridge panels for steel-UHPC composite pavement were carried out. The stress spectrum of the structural details is obtained by the counting method of stress time and rain flow recorded continuously for 7 days, and the maximum stress amplitude, equivalent stress amplitude and fatigue loading times are calculated based on the Miner fatigue damage equivalent principle. The results show that when the structural details are located directly below the wheel load, one stress cycle will be produced in the structural details of each axle of the passing truck, but only one stress cycle can be generated by each shaft group in the other structural details. Although the steel-UHPC composite pavement does not change the obvious local effect characteristics of orthotropic steel bridge panel under the action of detail wheel load, it increases the stiffness of orthotropic steel bridge panel and reduces the out-of-plane stress of the transverse diaphragm arc notch. The stress amplitude of the structural details on the face plate is significantly reduced, so that the maximum stress amplitude recorded in the longitudinal rib-face plate weld structure details and the panel butt weld construction details is smaller than the constant fatigue limit, and the fatigue evaluation based on the AASHTO code shows that the maximum stress amplitude of the longitudinal rib-face welding seam structure details is less than that of the constant amplitude fatigue limit. Under the current traffic flow, all the structural details of the orthotropic steel bridge face slab of the Xichang Bridge combined with UHPC for Fochen extension have sufficient fatigue strength.
【作者单位】：湖南大学土木工程学院;湖南大学风工程与桥梁工程湖南省重点实验室;
【基金】：国家重点基础研究发展计划(“九七三”计划)项目(2015CB057701) 国家自然科学基金项目(51278191) 湖南省交通科技项目(201522)
【分类号】：U441.4

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