梁拱组合体系桥梁断索效应及安全评价  

Cable Breakage Effect and Safety Evaluation of Beam Arch Combination System Bridge

作　　者：闫磊[1] 惠启祥 闵林涛 祁山白 沈旭 YAN Lei;HUI Qi-xiang;MIN Lin-tao;QI Shan-bai;SHEN Xu(Key Laboratory of Bridge Detection Reinforcement Technology Ministry of Communication,Highway College,Chang'an University,Xi'an 710064,China;SCEGC Mechanized Construction Group Company Ltd.,Xi'an 710032,China;Shaanxi Construction Project Management Co.,Ltd.,Xi'an 710016,China)

机构地区：[1]长安大学公路学院,旧桥检测与加固技术交通行业重点实验室,西安710064 [2]陕西建工机械施工集团有限公司,西安710032 [3]陕西建工投资项目管理有限公司,西安710016

出　　处：《科学技术与工程》2024年第32期13960-13968,共9页Science Technology and Engineering

基　　金：陕西省交通运输厅2021年度交通科研项目(21-63K)。

摘　　要：为了分析梁拱组合体系桥梁发生断索效应对结构安全性的影响,依托陕西省某在建梁拱组合桥梁,采用有限元数值模拟,对运营期间多种“吊杆突然断裂”的状况进行动力响应分析以及安全性评价。结果表明:受梁-拱组合结构“墩-梁-拱”三者结合作用,断索跨的断索冲击效应显著并对相邻跨有一定的影响,但对其余跨几乎无影响;不同数量的断索发生后结构振动在5 s时间内基本趋于稳定,断索后3种情景下主梁响应幅度相对较小,拱肋相对较大,拱肋动力放大系数(dynamic amplification factor,DAF)最大达到10.5,动力作用下吊杆的需求能力比(demand capacity ratio,DCR)有大幅提高。依托工程在发生断索后短时间内吊杆内力会有数倍的增加,各情景下吊杆动力DCR最大值为40.3%,结构安全储备大幅下降,表明桥梁在断索振动的过程中有吊杆连续断裂的危险,运营过程中应特别注意此类安全事故发生。To investigate the structural safety implications of cable rupture on the arch bridge system,based on an under-construction arch bridge in Shaanxi Province,finite element numerical simulations was adopted.Various scenarios of“sudden cable rupture”during operation were subjected to dynamic response analysis and safety assessment.Results demonstrate that the combined effects of the pier-beam-arch structure significantly impact adjacent spans while minimally affecting others.Structural vibrations stabilize within 5's post-rupture,with main beam responses exhibiting minor amplitudes compared to larger ones in the arch rib.The maximum dynamic amplification factor(DAF)for the arch rib reaches 10.5,and the demand-capacity ratio(DCR)of hangers substantially increases under dynamic loading.Hanger forces experience a several-fold increase shortly after cable rupture,with a maximum DCR of 40.3%,indicating a significant reduction in structural safety reserves.The potential for consecutive hanger ruptures during cable vibration highlights the necessity for heightened safety vigilance during bridge operation.

关 键 词：梁拱组合体系 断索效应 数值模拟 动力放大系数(DAF) 安全性 

分 类 号：TU398.7[建筑科学—结构工程]