【作者】 刘建；

【导师】 陈淮； 李杰；

【作者基本信息】 郑州大学 ， 结构工程， 2010， 硕士

【摘要】 郑州黄河公铁两用桥是石武铁路客运专线和新107国道辅道跨越黄河的特大型公铁两用桥,设计为双线客运专线、6车道公路,采用公路在上、铁路在下的公铁合建方案,其主桥钢桁梁分为两联布置,第一联为1080m的六塔斜拉连续钢桁结合梁,第二联为601.9m的连续钢桁结合梁。本文以主桥第一联为工程背景,采用桥梁有限元软件Midas/civil,对主梁钢桁梁顶推施工全过程开展了施工监控复核计算,建立了该联的空间有限元计算模型,对其施工方案进行了验算,根据现场施工监控情况,对第一联钢桁梁整个顶推施工过程进行施工监控复核计算,反馈指导施工监控工作。本文所进行的主要工作和得出的主要结论为：1.郑州黄河公铁两用桥主桥施工过程计算有限元建模研究：根据郑州黄河公铁两用桥主桥第一联的结构形式,对主桁各杆件用空间梁单元模拟,采用刚臂模拟整体节点板的影响；铁路桥面板为正交异性板,分别计算其在纵、横两个方向的面内、面外刚度,用板单元模拟,建立了桥梁有限元计算模型,为后续的桥梁施工监控复核计算服务。2.郑州黄河公铁两用桥主桥第一联采用多点顶推法架设钢主梁,施工难度大,可借鉴的经验少,本文根据该桥的多点顶推施工方案,采用有限元方法模拟施工全过程,对顶推过程中可能出现的危险工况进行详细分析,计算结果表明：在公路桥面板、主塔和斜拉索张拉施工之前,架设钢桁梁采用多点顶推法施工是可行的。3.根据郑州黄河公铁两用桥主桥第一联拼装和顶推情况,对桥梁的架设进行了全程施工监控复核计算,复核结果表明：该桥梁施工时,钢桁梁高程和应力监控实测值与监控计算值、复核计算值比较吻合,杆件及铁路桥面板的应力始终在安全范围以内,保证桥梁顺利顶推到位,主桁合拢后,桥梁线形和杆件应力满足设计要求,达到了桥梁施工监控复核的目的。更多还原

【Abstract】 The Yellow River highway-railway bridge in Zhengzhou is an extra-large one used for both Shiwu railway passenger dedicated line and the assistant highway of the new 107 national road, which has two-track passenger dedicated line and 6 lane highway and adopts the method of separately arranging the highway and railway on the upper and lower decks. The steel truss girder of main bridge is divided into two units, the first-unit of which is a continuous steel truss girder with span arrangement 1080m, and with six pylons. And the second-unit is a continuous steel truss girder with span arrangement 601.9m. Taking the first-unit of main bridge as its engineering background, this thesis uses finite element software Midas/Civil to build the space finite element calculating model and check its construction program. According to the filed construction monitoring situation, I carry out the construction monitoring recheck on the whole process of incremental launching construction of the first-unit steel truss girder and conduct the monitoring work with its feedback. The following is the major work completed in this thesis and the main conclusions:First, a study on construction calculating of the main bridge of the Yellow River highway-railway bridge in Zhengzhou based on the finite element model:According to the first-unit structure of the main bridge, we simulate each member of main truss with space beam element and adopts the rigid arm to simulate the whole gusset plate’s influence. Railway bridge panel is the orthotropic plate. With the plate element simulation, its in-plane and out-plane stiffness is calculated separately in both longitudinal and transverse directions. The finite element calculating model of the bridge is finally built, which will be beneficial to the later recheck calculation of the construction monitoring.Second, the first-unit of the Yellow River highway-railway bridge in Zhengzhou adopts the multiple-points incremental launching method to erect its main truss, which has much difficulty in the construction process. In addition, there is little relevant experience can be learned. Based on the multiple-points incremental launching method and the finite elements simulation of the whole process of construction, the present study gives a detailed analysis of potential dangers during the operating process. The calculating results indicate that it is feasible to erect the steel truss girder before the construction of highway deck, main pylon and stay-cable by using the multiple-points incremental launching method.Third, according to the assembling and incremental launching situation of the first-unit of the Yellow River highway-railway bridge in Zhengzhou, we implement a full monitoring recheck on the erection of the bridge. The rechecking results show that the monitoring measured value, the monitoring calculated value and the rechecking calculated value of the steel truss girder’elevation and stress are in consistent with each other. What’s more, the stress of bar member and railway deck is within safety range throughout the whole process, which ensures the bridge’s incremental launching in place smoothly. After the main truss folded, the linear and internal forces meet the design requirements, which also achieves the purpose of bridge construction monitoring recheck.更多还原