大跨度钢管混凝土系杆拱桥拱肋受力特性研究

发布时间：2018-03-31 18:21

本文选题：钢管混凝土　切入点：系杆拱桥　出处：《兰州交通大学》2014年硕士论文

【摘要】：在钢管混凝土结构中，钢管对混凝土的约束效应使钢材和混凝土弥补了彼此缺点，从而充分发挥各自的优点。近些年来，钢管混凝土在我国桥梁建设中得到广泛应用，修建了大量钢管混凝土拱桥。钢管混凝土系杆拱桥中，吊杆将荷载传递给拱肋，最终拱肋将荷载传递给支座，绝大部分荷载是通过拱肋传递到支座的。拱肋安全直接影响桥梁结构的工作性能，所以研究拱肋结构的受力非常重要。本文以兰新二线乌鲁木齐河特大桥为工程背景，对下承式钢管混凝土系杆拱桥拱肋受力性能进行了研究，主要完成以下工作：介绍了大桥施工工艺以及钢管混凝土轴心受压构件的工作性能，详细阐述了哑铃型钢管混凝土拱肋在施工过程中的受力特点。利用有限元软件Midas/Civil建立了全桥模型，对拱肋在各施工阶段、成桥阶段以及运营阶段的受力进行研究，总结了拱肋受力规律。在成桥阶段，，拱肋应力范围为-(65~106)MPa，拱肋钢管承担拱肋总内力中的56%～58%，下弦管混凝土承担20%～25%，上弦管混凝土承担19%～22%。运营阶段，拱肋钢管应力范围为-(112~190)MPa。比较分析了理论分析值与现场实测值的差异，得出钢管应力产生偏差的原因是流动性良好的泵送混凝土存在较大的流体压力。分析了不同拱肋混凝土灌注顺序对拱肋受力的影响，当灌注顺序不同时，拱肋同一截面内力不变，但应力不同。如果以拱肋应力作为评价灌注顺序优劣的标准，先灌注上弦管混凝土，后灌注下弦管混凝土的施工顺序是比较合理的。分析了拱肋支架拆除时间不同对拱肋受力的影响，得出先灌注后拆拱肋支架的顺序是比较合理的，其钢管应力降低10%~19%，上、下弦管混凝土应力增大12%~30%，拱肋钢管承担拱肋总内力的46%～48%，下弦管承担24%～27%，上弦管承担25%～28%。
[Abstract]:In concrete filled steel tube (CFST) structures, the restraint effect of steel tube on concrete makes steel and concrete make up for each other's shortcomings, thus giving full play to their respective advantages. In recent years, CFST has been widely used in the construction of bridges in China. A large number of concrete-filled steel tubular arch bridges have been built. In the concrete-filled steel tubular tied arch bridge, the suspender transfers the load to the arch rib, and finally the arch rib transfers the load to the support. Most of the loads are transferred to the support through the arch rib. The safety of the arch rib directly affects the performance of the bridge structure, so it is very important to study the force of the arch rib structure. In this paper, based on the engineering background of Lanxin No. 2 Urumqi River Bridge, the mechanical behavior of arch rib of through concrete-filled steel tubular tied arch bridge is studied. The main work is as follows:. This paper introduces the construction technology of the bridge and the working performance of the concrete filled steel tube (CFST) members under axial compression. The stress characteristics of the dumbbell-shaped concrete-filled steel tube arch ribs during the construction process are described in detail. The full-bridge model is established by using the finite element software Midas/Civil. The stress of arch rib in construction stage, bridge stage and operation stage is studied, and the force law of arch rib is summarized. The stress range of arch rib is-65 / 106 MPA, the steel pipe of arch rib bears 56 / 58 of the total internal force of arch rib, the concrete of lower chord tube bears 20 / 25, and the concrete of upper chord pipe bears 1922. In the operation stage, the stress range of arch rib steel pipe is -112m / 190MPa. The difference between the theoretical analysis value and the field measured value is compared and analyzed. It is concluded that the deviation of steel tube stress is due to the large fluid pressure of pumping concrete with good fluidity. The influence of different pouring order of arch rib concrete on the stress of arch rib is analyzed. When the sequence of pouring is different, the internal force of the same section of arch rib is unchanged, but the stress is different. If the stress of arch rib is taken as the criterion to evaluate the order of pouring, It is reasonable to pour the upper chord concrete first and the lower chord concrete later. This paper analyzes the influence of different time of removing arch rib support on the stress of arch rib, and concludes that the order of removing arch rib support after pouring first is reasonable, and the stress of steel tube is reduced by 10% and 19%. The concrete stress of the lower chord tube is increased by 12% and 30%, the arch rib steel pipe bears 46% of the total internal force of the arch rib, the lower chord assumes 24% 27 and the upper string bears 25% and 28% of the total internal force of the arch rib.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.225

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