独柱型钢索塔施工阶段稳定性分析  

Stability Analysis on Single-column Steel Cable Pylon during Construction

作　　者：周畅 尹梦祥 丁磊 李亮 魏祎 ZHOU Chang;YIN Meng-xiang;DING Lei;LI Liang;WEI Yi(Nanjing Public Project Construction Center,Nanjing Jiangsu 210019,China;China Design Group Co.,Ltd.,Nanjing Jiangsu 210014,China;College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]南京市公共工程建设中心,江苏南京210019 [2]华设设计集团股份有限公司,江苏南京210014 [3]同济大学土木工程学院,上海200092

出　　处：《公路交通科技》2024年第1期98-104,共7页Journal of Highway and Transportation Research and Development

基　　金：江苏省交通运输科技项目(2020QD29)。

摘　　要：为探明并验证斜拉桥独柱型钢索塔在施工阶段的结构稳定及极限承载性能,指导设计和施工,以上坝夹江大桥钢索塔为工程背景,基于有限元方法,研究主桥在施工阶段的弹性与弹塑性稳定性能。采用杆系模型对结构整体稳定进行分析,采用多尺度模型对结构局部稳定进行分析并验证整体稳定,对裸塔工况、最大双悬臂工况和最大单悬臂工况进行分析。通过弹性稳定分析得到结构主要失稳模态,通过弹塑性稳定分析,得到结构塑性铰连续形成历程,明确结构极限承载力以及破坏位置。结果表明:对比分析恒载和风荷载对独柱型钢索塔稳定性的影响程度,表明恒载是决定稳定系数的最主要因素,风荷载对钢索塔施工阶段弹性稳定系数影响很小,对弹塑性稳定系数影响较大;随着施工进展,结构整体的弹性稳定性和弹塑性稳定性逐渐下降,弹性稳定系数由18.5降至16.3,弹塑性稳定系数由3.03降至2.57;独柱型钢索塔的最终破坏形态为主塔中下塔柱区域范围大面积达到屈服强度,形成塑性铰,索塔的承载能力急剧下降,结构已失去承载能力,可能破坏的位置为中下塔柱位置;本研究独柱型钢索塔在施工阶段的弹性稳定系数最小为16.34,弹塑性稳定系数最小为2.57,均满足稳定性要求。In order to find out and verify the structural stability and ultimate bearing capacity performance of the single-column steel pylon of cable-stayed bridge during construction,and to guide the design and construction,taking the steel cable pylon of Shangba Jiajiang Bridge as the engineering background,based on the finite element method,the study is conducted on the elastic and elastic-plastic stability performance of the main bridge during construction.The structural overall stability is analyzed by using a frame model,and the structural local stability is analyzed and verified by using a multi-scale model.The free-standing pylon working condition,maximum double cantilever working condition and maximum single cantilever working condition are analyzed.The main instability modes of the structure are obtained through elastic stability analysis,the continuous formation process of the structural plastic hinge is obtained through elastic-plastic stability analysis,and the structural ultimate bearing capacity and failure location are clarified.The result shows that(1)dead load is the main factor determining the stability coefficient by comparing the influence of dead load and wind load on the stability of single-column steel pylon,and wind load has a small impact on the elastic stability coefficient of the steel pylon during the construction stage,but has a large impact on the elastic-plastic stability coefficient;(2)with the process of construction,the overall elastic stability and elastic-plastic stability of structure gradually decrease,with the elastic stability coefficient decreasing from 18.5 to 16.3,and the elastic-plastic stability coefficient decreasing from 3.03 to 2.57;(3)the final failure mode of the single-column steel pylon is that the large area of the middle and lower pylon region reaches the yield strength,forming a plastic hinge,the bearing capacity of the pylon rapidly decreases,the structure loses its bearing capacity,and the possible failure locations are probably the middle and lower pylon region;(4

关 键 词：桥梁工程 稳定性分析 数值模拟 独柱型钢塔 施工阶段 

分 类 号：U441.5[建筑科学—桥梁与隧道工程]