桥梁冲击系数测试分析研究

发布时间：2018-08-17 11:33

【摘要】：桥梁结构在运动车辆作用下的动力响应是桥梁结构动力学研究的重要内容之一。在运动车量荷载作用下，桥梁结构的变形和应力明显高于桥梁在静止车辆荷载作用下的变形和应力。随着我国经济和交通运输事业的快速发展，车辆数量、载重量都有了很大的提高，桥梁结构在重载、高速行车作用下的冲击响应问题，越来越受到桥梁研究者的关注。动载试验是分析研究桥梁承载力和桥梁动力响应的有效方法。桥梁动力参数主要包括桥梁动力特性参数和桥梁动力响应参数,其中桥梁动力特性参数主要包括：桥梁固有频率、振型和阻尼等，而桥梁动力响应参数主要包括：动应力、动应变和加速度等。以某实测大桥为分析案例，论述分析了动载试验的实验过程及注意事项，并提出了一些改进建议。无论是在桥梁设计还是桥梁承载力评估中，冲击系数都是一个很重要的参数。在桥梁承载力评估中，桥梁的动力放大效应一般以冲击系数的形式在检测报告中体现出来，分析研究冲击系数显得格外重要。利用收集到的大量简支梁桥、连续刚构桥及拱桥的动力试验报告，整理出各桥的实测频率、实测冲击系数等数据资料。对以上实测数据进行分析研究，对比分析了各个影响因素对冲击系数的影响程度及影响规律。利用统计分析软件，，拟合得到实测基频与实测冲击系数的回归包络曲线方程，并对比分析了在分段拟合、不同桥型分别拟合等情况下得出的回归包络曲线方程。将获取冲击系数包络曲线与现有规范公式进行对比分析，得出优化的冲击系数近似计算公式，以此希望能为同类桥梁的设计和承载力评估提供一定的参考。
[Abstract]:The dynamic response of bridge structure under the action of moving vehicles is one of the important contents in the research of bridge structure dynamics. Under the load of moving vehicle, the deformation and stress of the bridge structure are obviously higher than that of the bridge under the static vehicle load. With the rapid development of economy and transportation in our country, the number of vehicles and the load of vehicles have been greatly improved. The impact response of bridge structure under heavy load and high speed driving has been paid more and more attention by bridge researchers. Dynamic load test is an effective method to analyze the bearing capacity and dynamic response of bridges. The bridge dynamic parameters mainly include the bridge dynamic characteristic parameter and the bridge dynamic response parameter, in which the bridge dynamic characteristic parameter mainly includes: the bridge natural frequency, the vibration shape and the damping and so on, while the bridge dynamic response parameter mainly includes: the dynamic stress, the bridge dynamic characteristic parameter mainly includes: the bridge natural frequency, the vibration pattern and the damping, etc. Dynamic strain and acceleration etc. Taking a measured bridge as an analysis case, this paper discusses the experimental process and matters needing attention of dynamic load test, and puts forward some suggestions for improvement. The impact coefficient is an important parameter in bridge design and bridge bearing capacity assessment. In the evaluation of bridge bearing capacity, the dynamic amplification effect of bridge is generally reflected in the test report in the form of impact coefficient, so it is very important to analyze and study the impact coefficient. Based on a large number of dynamic test reports of simply supported beam bridges, continuous rigid frame bridges and arch bridges, the measured frequency and impact coefficient of each bridge are sorted out. The above measured data are analyzed, and the influence degree and law of the influence factors on the impact coefficient are compared and analyzed. By using statistical analysis software, the regression envelope curve equation of the measured fundamental frequency and the measured impact coefficient is obtained, and the regression envelope curve equation under the condition of piecewise fitting and different bridge type fitting is compared and analyzed. The obtained envelope curve of impact coefficient is compared with the existing standard formula, and the optimized approximate formula of impact coefficient is obtained. It is hoped that it can provide a certain reference for the design and bearing capacity evaluation of similar bridges.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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