摘要
人行悬索桥吊索断裂不但会使局部桥面坍塌,还会由于剩余构件应力重分布程度过大而引发吊索连续断裂。采用数值模拟方法对单根吊索断裂和相邻2根吊索断裂后人行悬索桥的动力响应进行分析,并通过静力重分布系数SRF、动力重分布系数DRF、振荡系数OF和动力放大系数DAF对冲击效应进行综合评估。结果表明,单根吊索瞬断后同侧相邻吊索及断索区域纵梁的静、动力重分布程度明显,但对主缆及对侧吊索产生影响较小;同侧相邻2根吊索断裂比对侧断裂对剩余吊索和断索区主梁的影响更大;除边吊索和跨中吊索外,其他剩余吊索的SRF均在50%左右,DRF均在100%左右;接近跨中区域剩余吊索的DAF均为2.0左右,但边吊索的DAF较跨中区域增大25%左右,DAF采用2.0对于边吊索偏于不安全。单根吊索断裂后其下方相应位置处纵梁弯矩的DAF值均在1.20~1.40之间。
The breakage of hangers in suspension footbridges not only causes local collapse in bridge deck,but also leads to continuous breakage in hangers due to excessive stress redistribution in remaining components.The structural dynamic response of a suspension footbridge was analyzed using numerical simulation methods under the breakage of a single hanger and two adjacent hangers.The impact effect of the breakage of hangers was comprehensively evaluated through static redistribution factor(SRF),dynamic redistribution factor(DRF),oscillation factor(OF),and dynamic amplification factor(DAF).The results show that after a single hanger fractures suddenly,the static and dynamic redistribution degree of adjacent remainder hangers on the same side and the longitudinal girder under the broken hanger is obvious,but the impact on the main cable and hanger on the opposite side is relatively small;For the remaining hangers and the longitudinal girder under the broken hangers,the breakage of two adjacent hangers on the same side has a greater impact than that of the two adjacent hangers on the same side;Except for the edge hanger and mid-span hanger,the SRF and DRF of all remaining hangers are around 50%and 100%,respectively;The DAF values of the remaining hangers near the mid-span area are all around 2.0,but the DAF of the edge hanger is increased by about 25%compared to that of the mid-span area.Using a DAF of 2.0 for the edge hanger is not safe.The DAF values of the bending moment of the longitudinal girder below the broken single hanger are all between 1.20 and 1.40.
作者
李运生
王帅
侯屹峰
李璇
张彦玲
LI Yunsheng;WANG Shuai;HOU Yifeng;LI Xuan;ZHANG Yanling(Key Laboratory of the Ministry of Education for Road and Railway Engineering Safety Assurance,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)
出处
《石家庄铁道大学学报（自然科学版）》
2024年第4期1-10,44,共11页
Journal of Shijiazhuang Tiedao University(Natural Science Edition)
基金
国家自然科学基金(51778377)
河北省自然科学基金(E2018210149)
中央引导地方科技发展资金项目(246Z5409G)。
关键词
桥梁
人行悬索桥
吊索断裂
动力响应
冲击效应
bridge
suspension footbridge
breakage of hanger
dynamic response
impact effect
