基于车桥耦合动力作用的高速铁路桥梁状态评估方法研究

发布时间：2018-01-14 21:20

本文关键词：基于车桥耦合动力作用的高速铁路桥梁状态评估方法研究　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：高速铁路桥梁作为高速铁路的重要组成部分，在高速铁路不断提速和荷载不断增大的情况下，其在长期服役过程中的运营状态倍受关注。在高铁桥梁结构正常运营过程中，很容易发生由多级变幅疲劳荷载作用、钢筋锈蚀、混凝土碳化、盐离子侵蚀以及预应力筋应力腐蚀等原因引起的梁的刚度退化现象，这些因素虽不能显著地造成桥梁结构的强度破坏，但其对桥梁结构长期性能，尤其对高速列车的运营安全有着至关重要的影响。本文基于以上考虑，针对高速铁路桥梁结构的特点，从分析桥梁的动力响应数据入手，提出了一套基于桥梁健康监测系统的针对中小跨径高速铁路桥梁的状态评估方法。首先，本文对所用的列车-轨道-桥梁动力学理论进行阐述和分析，利用其力学相互作用关系建立了高速列车-轨道-桥梁动力耦合仿真模型。当列车在桥梁上的行驶时，利用在桥跨上布置的传感器对桥梁进行监测，即可获得用来对桥梁进行状态评估的原始应变响应数据。其次，在获得桥梁的应变响应数据后，即可推算桥梁的状态评估指标。本文共确定两个状态评估指标，分别为自振频率和竖向挠度值，其中，自振频率可利用傅里叶变换等数学方法对应变响应数据进行分析得到，竖向挠度值可由本文推导的应变与位移之间的关系经换算得到。若桥梁的评估指标大于设计规范的规定值，则桥梁结构处于不安全状态，需马上进行人工检测维修和深度分析，若小于规定值，则暂时处于安全状态，需对响应数据进行常规分析。最后，对处于安全状态的桥梁进行的常规分析，其本质为分析桥梁的刚度退化情况，针对此分析，本文提出了应变差法来定位刚度退化位置，结合了频率分解法和应变模态的无模型识别法来确定识别指纹，识别其刚度退化程度。为验证本文的定位和识别方法的有效性，本文共模拟了十二种不同工况进行分析，分析结果与模拟情况基本相同。本文提出的基于健康监测系统的高速铁路桥梁状态评估方法，针对中小跨径梁式桥，具有简单、经济、快速、准确和有效等特点，若要应用在实际工程中，不同的桥梁需根据实际情况具体分析。
[Abstract]:As an important part of high-speed railway, high-speed railway bridge is under the condition of increasing speed and increasing load. In the normal operation of high-speed railway bridge structure, it is easy to take place by multi-stage variable amplitude fatigue load, steel corrosion, concrete carbonization. The degradation of beam stiffness caused by salt ion erosion and stress corrosion of prestressed tendons, which can not significantly cause the strength damage of bridge structure, but the long-term performance of bridge structure. Especially for the operation safety of high-speed train has a vital impact. Based on the above considerations, this paper analyzes the dynamic response data of the bridge in view of the characteristics of the high-speed railway bridge structure. This paper presents a method of state evaluation for medium and small span high speed railway bridges based on bridge health monitoring system. First of all, the theory of train, track and bridge dynamics used in this paper is expounded and analyzed. The dynamic coupling simulation model of high-speed train, track and bridge is established by using its mechanical interaction relationship. When the train is traveling on the bridge, the sensors arranged on the bridge are used to monitor the bridge. The original strain response data used to evaluate the state of the bridge can be obtained. Secondly, after obtaining the strain response data of the bridge, the state evaluation index of the bridge can be calculated. In this paper, two state evaluation indexes are determined, which are the natural vibration frequency and the vertical deflection. The natural frequency can be obtained by using Fourier transform and other mathematical methods to analyze the strain response data. The vertical deflection value can be obtained from the relationship between strain and displacement derived in this paper. If the evaluation index of the bridge is larger than the specified value of the design code, the bridge structure is in an unsafe state. Manual inspection and maintenance and depth analysis are needed immediately. If it is less than the specified value, it is in a safe state for the time being, and the response data should be routinely analyzed. Finally, the essence of the conventional analysis of the bridge in the safe state is to analyze the stiffness degradation of the bridge. In view of this analysis, the strain difference method is proposed to locate the location of the stiffness degradation. The frequency decomposition method and the model-free identification method of strain mode are combined to determine the fingerprint identification and identify the degree of stiffness degradation. In order to verify the effectiveness of the localization and identification method in this paper. In this paper, 12 different working conditions are simulated and the results are basically the same as the simulation results. The state evaluation method of high-speed railway bridges based on health monitoring system is presented in this paper. It is simple, economical, rapid, accurate and effective for small and medium span beam bridges. Different bridges should be analyzed according to the actual situation.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.13;U441.3

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