北峪河大桥施工过程及承载能力验算分析

发布时间：2018-05-17 15:21

本文选题：刚构桥 + 有限元　；参考：《兰州交通大学》2015年硕士论文

【摘要】：随着我国交通建设的迅速发展,连续刚构桥施工技术趋于成熟,但连续刚构桥成桥后随着使用年限的增加,温度变化、地基沉降等引起的次内力以及运营过程中承受的活荷载导致连续刚构桥出现多种病害,包括“跨中挠度过大”、“混凝土开裂”等质量问题。本文对北峪河大桥施工过程及承载能力验算进行了分析,该桥是预应力混凝土连续刚构桥,对该桥建立三维空间有限元模型,通过模拟施工阶段,以及添加荷载等,对北峪河大桥主要阶段进行了全三维有限元模拟分析。结合桥梁设计与施工需要,探讨了连续刚构桥特点及受力特点,为连续刚构桥的设计和施工提供一些经验,保证工程的顺利进行。根据施工阶段的变化不断修正有限元模型参数,得出各个施工阶段各控制点位移和应力的理论数据,从施工阶段法向压应力验算、受拉区钢筋拉应力验算、使用阶段正截面压应力验算以及使用阶段斜截面主压应力验算,使现场施工监测数据有所参照。对现场施工过程实施控制点的位移监测和控制截面的应力监测,将现场实测数据与理论设计数据对比分析,得出各施工阶段满足设计要求的结论,对施工过程进行了有效的监控。此外,还对该大桥进行了主梁结构安全性验算,得出各项验算均满足设计要求的结论。在成桥后,还对北峪河大桥进行了预拱度的计算,主要计算成桥合龙阶段、运营5年和运营15年桥梁徐变挠度的区别,从控制徐变发展、避免主拉应力超标两方面着手防治跨中塌腰,分析计算合理的预拱度设置。对桥梁长期徐变引起的塌腰现象进行了分析。综上所述,通过本文对北峪河大桥的施工过程及承载能力验算分析,得出该大桥的承载能力满足设计要求,通过实际监测数据对各种有限元模拟参数进行估计和修正,用于指导和控制施工,使得各施工阶段的实际状态都最大限度地接近理想状态,确保了成桥后的内力状态和几何线型符合设计要求。
[Abstract]:With the rapid development of traffic construction in China, the construction technology of continuous rigid frame bridge tends to be mature, but the temperature of continuous rigid frame bridge changes with the increase of service life. The secondary internal force caused by the settlement of the foundation and the living load in the course of operation lead to a variety of diseases of the continuous rigid frame bridge, including "excessive deflection in the span", "cracking of concrete" and other quality problems. In this paper, the construction process and load carrying capacity of Beiyu River Bridge are analyzed. The bridge is a prestressed concrete continuous rigid frame bridge. A three-dimensional finite element model is established for the bridge. The three-dimensional finite element simulation analysis of the main stage of Beiyu River Bridge is carried out. Combined with the needs of bridge design and construction, this paper discusses the characteristics and mechanical characteristics of continuous rigid frame bridge, which provides some experience for the design and construction of continuous rigid frame bridge and ensures the smooth progress of the project. According to the change of the construction stage, the parameters of the finite element model are constantly revised, and the theoretical data of the displacement and stress of each control point in each construction stage are obtained. The normal compressive stress in the construction stage and the tensile stress in the tension zone are checked. The checking calculation of the normal section stress in the use stage and the main compressive stress of the oblique section in the use stage makes the site construction monitoring data reference. The displacement monitoring of the control point and the stress monitoring of the control section are carried out in the field construction process. The field measured data and the theoretical design data are compared and analyzed, and the conclusion is drawn that each construction stage meets the design requirements. The construction process is monitored effectively. In addition, the safety calculation of the main girder structure of the bridge is carried out, and the conclusion is drawn that all the checking calculations meet the design requirements. After the completion of the bridge, the pre-arch degree of the Beiyu River Bridge is calculated. The difference between the bridge creep deflection in the closing stage, the operation for 5 years and the operation for 15 years is mainly calculated, and the development of the bridge creep is controlled. To prevent the main tensile stress from exceeding the standard, to prevent the mid-span collapse, and to analyze and calculate the reasonable pre-arch setting. The collapse phenomenon caused by long-term creep of bridges is analyzed. To sum up, through the analysis of the construction process and load carrying capacity of Beiyu River Bridge in this paper, it is concluded that the bearing capacity of the bridge meets the design requirements, and various finite element simulation parameters are estimated and corrected by the actual monitoring data. It is used to guide and control the construction, which makes the actual state of each construction stage as close as possible to the ideal state, and ensures that the internal force state and geometric alignment after the completion of the bridge meet the design requirements.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445

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