铁路高桩承台承载力分析与加固技术

发布时间：2018-11-18 07:18

【摘要】：套箱为承台施工阶段的临时设施,由于混凝土套箱体积较大,阻水面积大,在主河槽位置导致冲刷加剧。套箱下部损坏及与河床进一步分开后,使桥墩所受荷载增大。在河流动力作用下,套箱破损及逐步下沉、歪斜,将直接桥梁的安全性。因此,需要对铁路高桩承台的承载能力进行分析,使用合适的方案进行加固,满足桥梁在使用过程中的安全性及耐久性要求。本文在总结目前关于承台传力模式、承载能力评估和桥梁下部结构加固方法研究成果的基础上,以某特大桥为工程背景,对既有铁路桥梁的状态检测、承台承载能力评定、加固方法及加固后的承载能力进行了分析,主要研究内容如下:根据该实例工程的结构及构造特点,对桥跨及桥墩进行振动测试,利用过路客、货列车,实测桥跨跨中的最大横向振幅及最大横、竖向加速度以及墩顶横向振幅,了解桥梁结构的工作状态。在此基础上,建立并调整midas FEA有限元模型,依据新旧规范规定,在不同荷载组合下,分析连续梁部分承台承载力,并依据相关规范要求,综合评价铁路高桩承台的承载能力。通过对15#~20#承台承载力的分析,比较新旧规范关于抗震设防标准之间的差异。在总结桥梁常用的下部结构加固方法的基础上,针对桥梁下部结构的实际特点,对抗震能力不满足相关规范要求的16#、17#承台进行加固处理。依据加固后结构的特点,重新建立有限元分析模型,以分析加固后16#、17#承台在主力和地震作用下的承载能力,进而评定承台的加固效果以及加固后的承载能力。
[Abstract]:The jacket box is a temporary facility in the construction stage of the cap. Because of the large volume of the concrete jacket box and the large area of water blocking, the scour is aggravated in the main channel position. The damage of the lower part of the box and the further separation from the riverbed will increase the load on the pier. Under the action of river power, the casing is damaged and gradually sinking, askew, which will be the safety of direct bridge. Therefore, it is necessary to analyze the bearing capacity of railway high pile cap and reinforce it with appropriate scheme to meet the requirements of safety and durability of the bridge in the process of operation. On the basis of summing up the current research results on the load transfer mode of the cap, the assessment of the bearing capacity and the reinforcement method of the understructure of the bridge, this paper, taking a large bridge as the engineering background, tests the state of the existing railway bridge and evaluates the bearing capacity of the cap. The method of strengthening and the bearing capacity after reinforcement are analyzed. The main research contents are as follows: according to the structure and structural characteristics of the practical engineering, the vibration test of bridge span and pier is carried out, and the passengers and freight trains are used. The maximum transverse amplitude, the maximum transverse and vertical acceleration and the transverse amplitude at the top of the pier are measured in order to understand the working state of the bridge structure. On this basis, the midas FEA finite element model is established and adjusted. According to the new and old code, under different load combinations, the bearing capacity of part of continuous beam cap is analyzed, and the bearing capacity of railway high pile cap is comprehensively evaluated according to the requirements of relevant codes. Based on the analysis of the bearing capacity of the 15 #Li 20 # cap, the difference between the new and old codes on seismic fortification standards is compared. On the basis of summing up the common methods of strengthening the substructure of the bridge, according to the actual characteristics of the substructure of the bridge, the reinforcement treatment of the 16#17# cap which does not meet the requirements of the relevant code is carried out in the light of the actual characteristics of the substructure of the bridge. According to the characteristics of the reinforced structure, the finite element analysis model is established to analyze the bearing capacity of the reinforced 16#C17# cap under the main force and earthquake action, and then to evaluate the reinforcement effect and the bearing capacity of the strengthened cap.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U443.25;U445.72

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