大跨度连续箱型公路桥梁承载力评估方法研究

发布时间：2019-04-21 13:16

【摘要】：由于连续梁桥的结构刚度大,变形小,与简支梁桥相比,大大减少了桥梁的伸缩缝的数量;且行车平稳,抗震性能好,因此连续梁桥这种桥型广泛应用于公路桥。但近年来超载现象频频出现,且愈演愈重,超载给桥梁造成了诸多不利影响,由于振动冲击过大导致裂缝迅速开展,长此以往,累积的损伤会大大减小桥梁结构的承载力,缩短正常使用寿命,易造成交通事故的发生。因此,对桥梁的承载力进行快速准确的评估是十分必要的。本文以某大跨度连续箱梁桥为研究背景,分析比较在役桥梁承载力评估方法。首先结合外观检测和规范评定方法,计算桥梁实际承载力;建立建立Midas Civil模型,根据静载试验结果对模型进行修正,计算修正后的桥梁承载力,并推定剩余承载力;对比分析基于桥梁检查和规范计算的承载力评定结果与基于荷载试验的承载力评定结果;根据动载试验结果,结合模型分析动力响应和模态参数(频率和振型)对桥梁承载力进行评定。最后对桥梁进行健康监测,结合有限元分析结果,提供安全报警值,并根据健康监测数据进行承载能力评估。研究结果表明:综合在役桥梁承载力评估方法对该大跨度连续箱梁桥进行比较分析,其结果是可行的,并评定了该桥受力性能(包括刚度和承载能力),评定结果满足规范要求,为类似桥梁工程提供参考依据,有推广应用价值。
[Abstract]:The continuous beam bridge is widely used in highway bridges because of its large structural stiffness and small deformation, which greatly reduces the number of expansion joints compared with the simple beam bridge, and the smooth driving and good seismic performance of the continuous beam bridge. However, in recent years, the phenomenon of overloading frequently occurs and becomes more and more serious, overloading has caused many adverse effects on bridges. Because of excessive vibration and impact, cracks develop rapidly. In the long run, cumulative damage will greatly reduce the bearing capacity of bridge structures. Shorten the normal service life, easy to cause the occurrence of the traffic accident. Therefore, it is necessary to evaluate the bearing capacity of bridges quickly and accurately. Based on the research background of a long-span continuous box girder bridge, this paper analyzes and compares the evaluation methods of the bearing capacity of a long-span continuous box girder bridge. Firstly, the actual bearing capacity of the bridge is calculated with the method of appearance inspection and criterion evaluation, and the Midas Civil model is established to modify the model according to the results of static load test, to calculate the modified bearing capacity of the bridge, and to deduce the residual bearing capacity. The results of bearing capacity evaluation based on bridge inspection and code calculation are compared with those based on load test. According to the test results of dynamic load, the dynamic response and modal parameters (frequency and mode shape) of the bridge are analyzed and the bearing capacity of the bridge is evaluated. Finally, the bridge health monitoring is carried out, combined with the results of finite element analysis, the safety alarm value is provided, and the carrying capacity of the bridge is evaluated according to the health monitoring data. The results show that it is feasible to compare and analyze the long-span continuous box girder bridge based on the comprehensive evaluation method of the bearing capacity of the bridge in service, and the mechanical performance (including stiffness and bearing capacity) of the bridge is evaluated. The evaluation results meet the requirements of the code and provide reference basis for similar bridge engineering, which has the value of popularization and application.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U446

【相似文献】