摘要
为了解决栓接U肋对接偏差引起的纵向力流传递不畅、偏差处纵肋腹板及拼接板抗疲劳性能不佳的问题,以某栓接U肋的钢箱梁斜拉桥为工程背景,进行了U肋栓接邻近区轮载应力和对接偏差影响分析,以及非栓接邻近区(相当于嵌补段焊接U肋对接处)的轮载应力分析。根据已有疲劳寿命曲线和所选取的等效损伤系数,进行了疲劳强度验算与寿命预测。根据所得上述两区域不利轮载应力与相应疲劳强度,基于提出的"应强比"指标,比较了不同连接方式下U肋的疲劳性能。研究并提出了疲劳性能不满足要求的拼接板改进方法。结果表明:栓接U肋中U肋腹板的抗疲劳性能优于嵌补段焊接连接U肋,但其常规设计的拼接板抗疲劳性能不及嵌补段U肋,即使在无对接偏差的情况下。栓接接头应力峰值集中在无填充板侧拼接板下缘各螺栓孔附近,整体上由纵向接头中点往两端递减,且在紧靠接头的第一排螺栓孔处的紧邻U肋腹板层拼接板下缘达到最大值。"当U肋对接偏差不超过3 mm时,宜采用强制矫正方式"的规范规定合理。拼接板应力随对接偏差(填充板厚度)增大而增大,偏差大于3 mm时,呈非线性急剧增加。对于背景工程,当U肋对接偏差为5~6 mm时,可将外侧拼接板由180 mm宽加至210 mm;当其为7~9 mm时,两外侧拼接板均应采用536 mm×210 mm×120 mm×12 mm的L形拼接板。
In order to solve the problems of poor transfer of longitudinal stress flow caused by connection deviation of bolted U-rib and unfavorable fatigue resistance of longitudinal rib webs and splice plates in deviation joint, on the engineering background of a steel box girder cable-stayed bridge with bolted U-ribs, the bolted U-rib stress under the wheel load near connected joint and its influence on the connection deviation are analyzed, and the stress away from the bolt connected joint(that is the welded U-rib connected joint in inserted-segment) is also analyzed. According to the existing fatigue life curve and the acquired equivalent damage coefficient, the fatigue strength checking and life prediction are carried out. On the basis of the above 2 wheel-loading stress and corresponding fatigue strengths and the proposed indicator of "the ratio of stress to strength", the fatigue properties of different connected U-ribs are compared. The improvement method of the splice plate when the fatigue performance is not satisfied with the requirement is studied and proposed. The result shows that(1) The fatigue performance of bolted U-rib webs is better than that of inserted-segmental welded U-rib, but the fatigue performance of conventional designed splice plate is lower than that of the inserted-segmental U-rib, even under the condition without connection deviation.(2) The peak stress value of bolted joint concentrates around the lower edge bolt holes of the splice plate on the side without filler plate, the stress decreases from the center of longitudinal joint to both ends, the maximum stress appears on the lower edge of the splice plate adjacent to the U-rib web close to the first row of bolt holes of the joint.(3)The stipulation of "compulsory correction scheme is necessary if the connection deviation is not more than 3 mm" in the specification is reasonable. The stress of the splice plate increases with the increase of connection deviation(the thickness of filler plate), which increases nonlinearly and sharply if the
作者
李传习
冯峥
王文强
陈卓异
柯璐
LI Chuan-xi;FENG Zheng;WANG Wen-qiang;CHEN Zhuo-yi;KE Lu(Key Laboratory of Safety Control for Bridge Engineering of Ministry of Education,Changsha University of Science&Technology,Changsha Hunan 410004,China;Foshan Road&Bridge Construction Co.,Ltd.,Foshan Guangdong 528303,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2020年第3期49-58,共10页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51778069,51708047)
湖南省研究生科研创新项目(CX2018B522)
973计划项目(2015CB057702)
桥梁工程领域省部级重点实验室开放基金项目(18KE04)。
关键词
桥梁工程
栓接U肋疲劳性能
有限元方法
正交异性桥面板
对接偏差
bridge engineering
fatigue performance of bolted U-rib
finite element method
orthotropic bridge deck
connection deviation
