基于静动载试验吉安赣江公路大桥承载力评定

发布时间：2018-01-07 10:35

本文关键词：基于静动载试验吉安赣江公路大桥承载力评定　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：桥梁工程是关乎国计民生的重要基础设施,其承载能力和通行能力是保持交通线路畅通的关键。随着时间的推移,越来越多既有桥梁因各种原因发生损伤,导致结构功能不足,桥梁承载力下降,从而影响桥梁的正常使用,需要对既有桥梁的状况进行评估。承载力评定是桥梁评估的关键内容,本文以吉安赣江公路大桥主桥为工程背景,进行了基于静动载试验桥梁承载力评定。首先进行了外观调查和无损检测,并对桥梁承载力作出初步的定性分析。随后进行了静载试验、环境振动试验和车辆激励试验,识别出了动力特性和冲击系数,对桥梁承载力进行定性评估。根据原始设计资料,建立了吉安赣江公路大桥主桥的初始有限元模型,进行参数的频率敏感性分析,选出对频率影响敏感的结构参数,以环境振动试验实测的动力特性结果为基础,合理调整初始有限元的参数,使得有限元模型计算结果与实测结果尽可能地吻合,得到反映桥梁的实际工作状态的有限元模型。最后基于调整后有限元模型对该桥的承载力进行了更详细的评定和预测。本文建立的既有桥梁承载力评定方法和流程,可供其它既有桥梁承载力评定参考。论文的主要工作如下:1.对吉安赣江公路大桥主桥进行了外观检测,统计了该桥的主要病害情况,并进行了混凝土强度检测、混凝土碳化深度检测、钢筋保护层厚度检测、钢筋锈蚀检测等无损检测。依据相关评定规程,对桥梁各构件分别评分后进行加权求和综合评定,获得了该桥的技术状况等级和总体评价结果,为进一步评估桥梁的承载力做准备。2.根据吉安赣江公路大桥主桥原始设计资料,建立了该桥的初始有限元模型,先后进行了静力验算和模态分析。静力验算主要进行了影响线计算和基于影响线的活载计算,静力验算的目的在于获取静载试验测试控制截面的具体位置和保证静载试验加载效率。而模态分析是为动载试验中环境振动试验做理论计算和提供测点参考位置。3.对吉安赣江公路大桥主桥首先进行了静载试验,获得了桥梁的应变、挠度等数据,结合静力数值加载结果,对该桥的承载力进行初步评定。然后进行了环境振动试验和车辆激励试验,获得桥梁的动应变、加速度等数据,实测得到了桥梁的冲击系数。利用实测的环境振动加速度响应,分别采用频域峰值法和时域随机子空间识别相互校验的方式,识别出了该桥的模态参数,并与初始有限元结果进行了比较。对初始有限元模型的材料、几何参数进行频率的敏感性分析,调整初始有限元模型参数,使有限元模型计算与环境振动试验实测结果吻合,修正后的有限元模型更能够反映桥梁的实际工作状态。4.采用修正后的有限元模型对吉安赣江公路大桥主桥承载力进行更详细的评估和预测。针对目前交通量增大和公路桥梁设计规范中汽车荷载的变化,计算了新规范下该桥汽车荷载在静载试验控制截面的内力,并与旧规范进行了比较。最后通过有限元模型结构参数退化模拟结构损伤,使用修正后的有限元模型计算静载试验加载工况,采用等效检验系数方法,对吉安赣江公路大桥主桥未来的承载力进行评估,这也是基于修正后有限元模型进行既有桥梁承载力评估的优越性所在。
[Abstract]:Bridge engineering is an important infrastructure for its carrying capacity and beneficial to the people's livelihood, capacity is the key to keep the traffic line smooth. With the passage of time, more and more bridges damage due to various reasons, resulting in insufficient bearing capacity of structure and function, thus affecting the normal use of the bridge fell, the bridge, the need to assess the existing bridge situation. Carrying capacity evaluation is the key content of bridge evaluation, in this paper, the main bridge of Ji'an Ganjiang highway bridge as the engineering background, the dynamic and static load test of bridge bearing capacity evaluation based on the external view. First, investigation and nondestructive testing, and make a preliminary qualitative analysis of bridge bearing capacity. Then the static load test. Environmental vibration test and vehicle test to identify the excitation, dynamic characteristics and impact factor, qualitative evaluation on the bearing capacity of the bridge. According to the original design, the establishment of Kyrgyzstan The initial finite element model of the bridge safety Ganjiang highway bridge, the frequency analysis of sensitivity parameters of the selected structural parameters sensitive effect on the frequency, to the dynamic characteristics of the measured environmental vibration test results as the basis, reasonable adjustment of initial parameters of finite element, the finite element model calculation results and the test results as much as possible with finite element model of the actual working conditions reflect the bridge. Finally adjusted based on the finite element model of bearing capacity of the bridge is evaluated and predicted more detailed. The existing bearing capacity evaluation method and process for other bridges, bridges carrying capacity assessment. The main contents are as follows: 1. the main bridge of Ji'an Ganjiang highway bridge of visual inspection, statistics of the main diseases of the bridge, and the strength test of concrete, concrete carbonation depth detection, reinforced protective layer The thickness of steel corrosion detection, detection of nondestructive testing. According to the relevant evaluation rules, respectively score for every member of the bridge after the weighted sum of the comprehensive evaluation, obtained the bridge the technical grade and overall evaluation results, to prepare.2. according to the original design of the main bridge of Ji'an Ganjiang Highway Bridge data for further evaluation of the bearing capacity of the bridge, set up the initial finite element model of the bridge, has analyzed the static checking and static checking mode. Mainly the influence of the line calculation and influence line based on live load calculation, static checking is to ensure access to the specific location and static load test control section of the static load test. The loading efficiency and modal analysis for dynamic load environmental vibration test tested the theoretical calculation and measurement for the reference point position.3. on the main bridge of Ji'an Ganjiang highway bridge was the first bridge static load test should be obtained Change, deflection data, combined with static loading numerical results, preliminary assessment of the carrying capacity of the bridge. Then the vibration environment test and vehicle excitation test, strain bridge, acceleration data, obtained the impact coefficient of the bridge. By the measured vibration acceleration response, respectively by frequency peak method the time domain and the stochastic subspace identification between parity means, to identify the modal parameters of the bridge, and compared with the initial finite element results. The finite element model of initial material, sensitivity analysis of geometric parameters of frequency, adjust the initial parameters of finite element model, the finite element model with the results of calculation and vibration test the measured and actual working condition of.4. modified finite element model can better reflect the bridge using the modified finite element model of the main bridge of Ji'an Ganjiang highway bridge bearing capacity Evaluate and forecast more detail. Aiming at the automobile load design specification for increased traffic and road bridge changes under the new standard of the bridge vehicle load in internal force static load test control section were calculated and compared with the old standard. Finally, the finite element model of structure parameter degradation simulation of structural damage calculation. The static load test of loading conditions using the modified finite element model, the test coefficient equivalent method to evaluate the bearing capacity of the future of Ganjiang highway bridge in Ji'an, this superiority is also based on the finite element model was modified after the evaluation of existing bridge bearing capacity.

【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441

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