地震下拉索损伤对矮塔斜拉桥索力的影响  

Influence of cable damage on cable force of short tower cable-stayed bridge under earthquakes

作　　者：王尧 陈建兵[1] 刘晨光 方雨 Wang Yao;Chen Jian-bing;Liu Chen-guang;Fang Yu(School of Civil Engineering,Suzhou University of Science and Technology,Suzhou 215011,China)

机构地区：[1]苏州科技大学土木工程学院,江苏苏州215011

出　　处：《工程抗震与加固改造》2024年第4期69-76,共8页Earthquake Resistant Engineering and Retrofitting

基　　金：国家自然科学基金(52208189);江苏省研究生科研创新计划资助项目(KYCX20-2773)。

摘　　要：为研究拉索损伤和地震双重作用下矮塔斜拉桥索力变化规律,以某矮塔斜拉桥为工程背景,采用Midas Civil软件建立有限元梁格模型,研究不同数量、不同位置拉索损伤对桥梁动力特性的影响,并深入分析地震和拉索损伤双重作用时拉索索力的变化规律。结果表明:边跨外侧及中跨索塔中部的拉索损伤对结构的自振频率影响较大,随着拉索损伤程度的增大,结构的自振频率变化率也在不断增大,且二者之间基本呈线性变化;地震下单索断裂会对矮塔斜拉桥剩余拉索索力产生规律性的影响,索力变化率的最大值一般出现在与断索相邻的拉索中,且距离断索越远,索力变化率越小,但索力变化率基本保持在10%以内;在拉索损伤程度不断增大的过程中,存在一个极值,使得剩余拉索的索力变化率在该极值两侧随拉索损伤程度的变化而基本呈线性变化。In order to study the variation law of cable forces of a low-pylon cable-stayed bridge under the double action of cable damage and earthquake,the finite element beam lattice model of a low-pylon cable-stayed bridge was established by using software Midas Civil.The influence of cable damage in different quantities and positions on the dynamic characteristics of the bridge was studied,and the variation law of cable forces under the double action of earthquake and cable damage was further analyzed.The results show that the damage of the outer side span and the middle part of the middle span cable tower has a great influence on the natural vibration frequency of the structure.With the increase of the damage degree of the cable,the change rate of the natural frequency of the structure is also increasing,and the change between them is basically linear;Single cable breakage will have a regular impact on the cable force of the remaining cables of the low tower cable-stayed bridge.The maximum value of the cable force change rate generally appears in the cable adjacent to the broken cable,and the farther from the broken cable,the smaller the cable force change rate,but the cable force change rate is basically kept within 10%;In the process of increasing cable damage,there is an extreme value,which makes the change rate of residual cable force on both sides of the extreme value change linearly with the change of cable damage.

关 键 词：矮塔斜拉桥 有限元分析 拉索损伤 自振频率 地震作用 索力变化规律 

分 类 号：U488.27[交通运输工程—载运工具运用工程]