确定系杆拱桥合理吊杆索力的方法及其应用

发布时间：2018-02-10 03:08

本文关键词： 系杆拱桥吊杆索力未知系数法振动频率法　出处：《浙江大学》2014年硕士论文　论文类型：学位论文

【摘要】：系杆拱桥一种是外部静定、内部超静定的梁拱组合结构,主要受力构件是拱肋、系梁和吊杆。系梁直接承受桥面荷载,通过吊杆将大部分荷载传递给拱肋,再由拱肋和系梁的结合部传递到支座和下部结构。可见吊杆是连接系梁和拱肋的主要传力构件。吊杆索力分布是否合理,将直接影响到系杆拱桥结构的线形及内力分布的均匀性,严重时,还会关系到桥梁能否正常运营,甚至影响结构的寿命。因此,如何确定合理吊杆索力,如何在施工过程中将吊杆张拉至设计目标状态,是系杆拱桥设计和施工过程中的关键问题之一。本文在以现有确定合理吊杆索力方法为基础,结合实际工程,运用MIDAS软件中的未知系数法确定了玉带桥施工阶段的合理吊杆索力。通过正装迭代法,对玉带桥施工阶段的张拉吊杆索力进行了计算,确定了三种张拉顺续及其相应的张拉力,无论采用哪一种方法,均能一次张拉到位,为施工提供了方便。在已建计算模型基础上,分析了端横梁的局部约束对靠近拱脚处的吊杆索力的影响。论文还采用影响矩阵计算施调向量的方法,对东风大桥更换吊杆后二次调索的吊杆索力和顺序进行了计算,并应用于现场监控,经与现场监测数据对比,验证了本方法的正确性。最后,基于拉索振动频率理论解和有限元方法,对影响吊杆振动频率的主要因素进行了分析,可作为振动频率法检测吊杆索力的参考。
[Abstract]:A beam-arch composite structure with external statically indeterminate and indeterminate interior. The main force members are arch ribs, girders and suspenders. The girders bear the bridge deck loads directly and transfer most of the loads to the arch ribs through the suspenders. Then it is transferred from the joint of arch rib and tie beam to the support and substructure. It can be seen that the suspender is the main force transfer member connecting the tie beam and the arch rib. It will directly affect the uniformity of the linear shape and internal force distribution of the tied arch bridge structure. When serious, it will also affect the normal operation of the bridge and even the life of the structure. Therefore, how to determine the rational cable force of the suspension rod, It is one of the key problems in the design and construction of tied arch bridge that how to stretch the suspenders to the design target state during the construction process. Based on the existing methods for determining the rational cable force of the suspenders and combining with the actual engineering, this paper uses the unknown coefficient method in the MIDAS software to determine the rational cable force of the suspenders in the construction stage of the jade belt bridge. In this paper, the cable force of the tension suspenders in the construction stage of the jade belt bridge is calculated, and the three kinds of tensioning continuation and the corresponding tensile forces are determined. No matter which method is adopted, the tension can be put in place at one time. On the basis of the established calculation model, the influence of the local constraint of the end beam on the cable force of the suspender near the arch foot is analyzed. The method of calculating the adjusting vector by the influence matrix is also used in this paper. This paper calculates the cable force and sequence of the secondary adjusting cable of Dongfeng Bridge after replacing the suspension rod, and applies it to the field monitoring. The correctness of the method is verified by comparing with the monitoring data on the spot. Finally, based on the theoretical solution of cable vibration frequency and finite element method, the main factors affecting the vibration frequency of suspension rod are analyzed, which can be used as a reference for measuring the cable force of suspension rod by vibration frequency method.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.225

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