【作者】 林熙；

【导师】 彭桂瀚；

【作者基本信息】 福州大学 ， 建筑与土木工程（专业学位）， 2016， 硕士

【摘要】 由于斜拉桥结构较为复杂,且桥梁在形成过程中会受到各种不利因素的影响,因此,桥梁结构内力和几何结构随着外部条件的变化而变化。为了保证斜拉桥在施工中结构的受力安全及成桥状态能满足设计需求,需对桥梁的施工过程实施施工控制。本文以漂浮体系的单向纵坡预应力混凝土斜拉桥——南平市闽江大桥为工程背景,进行了施工控制技术研究,为漂浮体系的单向纵坡预应力混凝土斜拉桥的施工监控提供了一些技术支持,也为其他类似斜拉桥的施工监控提供一定的参考依据。进行的主要工作和得到的主要结论为:(1)建立南平闽江大桥有限元计算模型,得到该桥在拉索调整后的累积主梁挠度和主梁阶段挠度(二期恒载作用、二分之一汽车荷载作用以及收缩徐变作用下),从而确定了该桥的预拱度,并对该桥各施工阶段的受力进行全面分析。同时,有限元模型的建立对施工监控过程中各个施工节点的监控起到一个基本的理论及模型的参考作用,方便施工控制的实施。(2)通过把施工监控的内容的具体分为主梁标高观测、主塔偏位观测、索力监测及应力监测等四个主要项目,对各个监测部分所使用的仪器以及测量注意事项等进行了分析研究,便于在后面实际的操作过程中能更有效地开展实施。(3)由于南平闽江大桥的结构形式为单向纵坡,且桥梁结构左右并不对称导致主梁在悬臂施工过程产生的不平衡水平力大,主跨两侧的索力不对称,所以为了平衡主梁挠度和桥塔水平位移,通过施工监控把斜拉索的索力精确合理地确定下来,以平衡主塔线形,半漂浮体系下单向纵坡的结构形式导致了主梁位移监测成为施工监控的重点。(4)通过对各主要施工阶段中的高程、应力及斜拉索索力的数据采集,并对所采集的数据与设计值及规范要求值进行分析比较结果表明:南平闽江大桥的主梁线形、主梁应力、索力等主要设计参数值与现场实测值基本吻合,满足规范要求,达到了本桥的施工监控的目的。更多还原

【Abstract】 As the cable-stayed bridge structure is more complex,and the bridge in the formation process will be subject to various unfavorable factors;therefore,the internal force and geometry of the bridge structure will change with external conditions.In order to safeguard the integrity of the cable-stayed bridge during the construction process and to ensure the bridge can meet all the design requirements upon completion,strict construction safety control needs to be implemented during the entire construction process.In this paper,the construction control technology of the NanpingMinjiang Bridge is studied,and its techniques can be used as technical references for the construction monitoring process of futuretwin-tower double-cable plane pre-stressed concrete stayed bridges.The main work and main conclusions are as follows:(1)The construction of the MinjiangBridge is based on the finite element model.The deflection of main girder and main girder phase after cable adjustment are obtained(secondary dead load action,fifty percent vehicle load action and shrinkage creep action)to determine the camber of the bridge.The force of the bridge during the construction phase is analyzed comprehensively.At the same time,the use of the finite element model plays a major role in monitoring the construction and the implementation of construction control over the various nodes.(2)By dividing the construction control monitoring into the main beam elevation observation,the main tower deviation observation,cable force monitoring and stress monitoring of the four major projects,The instrument were used in each monitoring part and the measurement precautions were analyzed and studied so as to be able to carry out the implementation more effectively in the later actual operation process.(3)As the structure of NanpingMinjiang River Bridge is a one-way longitudinal slope,and the asymmetry of the bridge structure is caused by the asymmetry of the main beam in the cantilever construction process of unbalanced horizontal force,and the cable force on both sides of the main span is asymmetric.In order to balance the deflection of the main girder and the horizontal displacement of the bridge tower,the cable force of the stay cable is precisely and rationally determined by the construction monitoring.The structural form of the one-way longitudinal slope under the full floating system has led to the displacement monitoring of the girder as the focus of construction monitoring.(4)Through the data collected during the elevation,stress and cable-stayed force in the main construction stages,the detailed analysis indicates the following conclusion:the main girder alignment,main girder stress tension and cable force,as well as other major design parameters and measured value of the site meet all specification requirements,thus achieve the purpose of the bridge construction control monitoring.更多还原