【作者】 曹飒飒；

【导师】 黄平明； 梅葵花；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 以阅海大桥(三肋五跨中承式系杆拱桥,拱肋为哑铃形截面)为工程背景,采用大型有限元计算软件MIDAS建立桥梁结构空间三维模型,对阅海大桥空钢管阶段、浇筑钢管混凝土阶段、挂横梁阶段、铺槽形板阶段、成桥阶段的静力、动力、稳定性进行仿真计算,通过线形和应力理论值与实测值的对比,表明仿真计算是成功的,可以有效的指导施工控制。在建立模型过程中,拱肋采用MIDAS中的施工阶段联合截面法进行模拟,该方法的理论为换算截面法,将哑铃形截面分为钢管框架、上下拱肋内混凝土、缀板内混凝土四个部分,将各个单独的混凝土截面换算为钢截面,随着实际施工阶段的进行,不断进行叠加,直至钢管混凝土浇筑完之后完成叠加。在各个施工阶段中,该桥中肋各控制截面的挠度基本为边肋的两倍,中肋各控制截面的应力为边肋的1.5倍左右。对阅海大桥线形、应力的理论计算结果与实测结果进行对比,理论计算结果与实测值较为吻合。对阅海大桥各个施工阶段稳定性进行了屈曲分析,稳定系数均远远大于4,该桥在各个施工阶段的稳定性较高,失稳模式均为面内失稳,说明其面外刚度较大,失稳控制应以面内控制为主。采用子空间迭代法,求解了该桥的前30阶振型,采用反应谱理论分析了该桥在8级地震作用下的响应。计算结果表明该桥柔性较好,地震对该桥的中肋和边肋的影响是相同的。计算结果可以为该桥进行动力评估提供依据。各个施工阶段的线形与应力均在控制范围内,施工控制良好。更多还原

【Abstract】 Based on Yue Hai Bridge (a five-span tied arch bridge with three dumbbell-shaped arch ribs), the three-dimensional space model of the bridge is built by MIDAS finite element software. The simulation analysis of the static,dynamic,stability performance of the bridge in hollow tube stage,pouring concrete into the tube stage,hanging beams stage,the lay channel board stage and the completed bridge stage is carried out. Through contrasting the theory values with the measure ones of lineshape and stress, the consistency of the structure simulation analysis is verified .In the process of building model , the arch rib section is simulated by the MIDAS’s combined-section of construction phase. The method of it is conversion of the section.The rib is made up of four parts: dumbbell-shaped steel tube frame, top concrete section, middle concrete section and bottom concrete section.The sections of the concrete are converted into the steel sections. With construction stage going on, the sections are combined one by one. The combination of the sections will be completed untill the steel tube is filled by the concrete actually.In every stages of the construction, the displacement of the middle arch rib on the bridge control section is almost twice of the side ribs’s; the stress of the middle ribs on the control section is about 1.5 times of the side ribs’s. The lineshape and stress of theoretical results were compared with the measured results and it indicates that the theoretical results and measured are anastomosis.The stability of the buckling through all the bridge construction stages is analyzed. The stability factors are far greater than 4 which indacates that the bridge is very stable in every construction stage. All instability models are in plane of the bridge. It shows that it is very strong in outface. The major control of stability should be in its plane.The sub-space method is used to extract its first 30 vibration models. The response spectrum theory is used to analyze the bridge’s reflection in eight degree of the earthquake. The results show that the bridge flexible better. The effects of earthquake in the middle rib and side rib are the same. The results can be used for the bridge’s dynamic evaluate.The lineshape and the stress are controlled in an ideal limitation. Construction control is successful.更多还原