摘要
为了解柔梁密索体系矮塔斜拉桥结构静力特性,以主跨380 m的双索面柔梁密索体系混合梁矮塔斜拉桥——潮惠高速榕江大桥为背景,利用MIDAS Civil有限元软件建立柔梁密索体系矮塔斜拉桥和常规斜拉桥2种方案桥梁模型,对主梁内力和斜拉索索力进行对比分析。结果表明:柔梁密索体系矮塔斜拉桥的力学行为与常规斜拉桥基本相似,可通过调整斜拉索索力达到“梁平塔直”的合理成桥状态,主梁弯矩较小,但主梁轴力和斜拉索索力比常规斜拉桥大;正常使用阶段主梁活载内力较常规斜拉桥大,斜拉索活载应力幅值与常规斜拉桥相当,斜拉索的安全系数应按2.5进行控制;运营阶段柔梁密索体系矮塔斜拉桥主梁应力明显高于常规斜拉桥主梁应力,但均满足规范要求。
The Rongjiang River Bridge of Chaozhou-Huilai Expressway,which is a hybrid girder extradosed bridge featuring the 380 m-long main span and dense double-plane stay cables,is used as a case to study the static performance of the bridge of similar type.The finite element models of the extradosed bridge with flexible girder and dense stay cables as well as the common cable-stayed bridge were developed by MIDAS Civil to analyze and compare the internal forces and stay cable forces.The analysis indicates that the mechanical behavior of the extradosed bridge with flexible girder and dense stay cables is similar to that of the common cable-stayed bridge.The as-built geometries of the bridge,namely“straight girder and vertical pylon”,are able to be realized via adjusting the stay cable forces.Although the bending moment of main girder is small,the axial force and stay cable forces of the extradosed bridge with flexible girder and dense stay cables are greater than those of the common cable-stayed bridge.At the normal service stage,the internal forces of the main girder under live loads are greater than those of the common cable-stayed bridge,the stress amplitudes of stay cables under live loads are similar to those of the common cable-stayed bridge,and the safety factor of the stay cables should be 2.5.At operation stage,the stresses in main girder of the extradosed bridge with flexible girder and dense stay cables are remarkably higher than the common cable-stayed bridge,but all meet the code requirements.
作者
蔡小杨
王雷
韩金豹
刘淦彬
CAI Xiao-yang;WANG Lei;HAN Jin-bao;LIU Gan-bin(Guangdong Communications Planning & Design Institute Group Co. ,Ltd. ,Guangzhou 510507,China)
出处
《世界桥梁》
北大核心
2022年第2期99-104,共6页
World Bridges
关键词
矮塔斜拉桥
柔梁密索体系
混合梁
静力分析
有限元法
extradosed bridge
flexible girder and dense stay cables system
hybrid girder
static analysis
finite element method