某在役高架钢箱梁桥的安全性评定及相关问题探讨

在实际桥梁工程检测中,往往因为周围环境条件的制约,不能获得原计划中的所有测试数据或是所获得数据准确性受到行车荷载的影响.针对这两个问题,以某在役钢箱梁桥的损伤检测和安全性评定为例,探讨解决这两种问题的途径.首先介绍了该钢箱梁桥跨的表现检测和无损探伤,之后对该桥进行静动载试验,以获得桥梁在试验荷载下的静动力响应.为了与试验结果对比,还用两种方法建立钢箱梁桥跨的有限元模型,在对比不同方法计算准确度的基础上获得设计以及试验荷载下桥梁静力响应以及模态参数的计算值;最后,探讨静载测试数据的扩充办法,并对试验荷载作用下的计算模型进行了修正,通过模拟试验过程中某车道行车荷载对计算结果的影响,从而成功解决了前述的两种问题,实现了该钢箱梁跨的安全评定.

SAFETY APPRAISAL OF AN IN-SERVICE STEEL BOX GIRDER VIADUCT AND DISCUSSION ON RELATIVE PROBLEMS

In actual inspecting bridge engineering, as a result of limitations of surrounding environments, the whole testing data are usually not able to be gotten or their accuracy is affected by traffic flow. With respect to these two problems, an in-service bridge inspecting engineering for its damage and safety evaluation was taken for example to discuss the approaches to solve them. Firstly the appearance investigation and NDT（Nondestructive test） of this bridge span were exhibited. In order to gain the static and dynamic response under testing load scenarios, static and dynamic loading tests were implemented on the steel bridge span. For the sake of making a favorable comparison with the testing results, finite element models of the steel span were built by two types of approaches and both static responses and mode parameters were analyzed based on comparing computational accuracy of the different approaches. Then the expansion of the static testing data was discussed and the model of the bridge under static testing loads was updated to simulate the influence of the traffic on the computing results. Herein all the inspecting and computing results were combined together to accomplish a bridge safety appraisal.