Unit-23.docVIP

Unit 23 The Bridge Testing Technology 桥梁测试技术 内容概要 本文以一座斜拉桥为例介绍了在瑞士进行荷载动力试验的一般步骤和获得的结果。介绍了动力试验的主要目的以及结构的主要动力指标。阐述了在试验中如何对桥梁进行激励以使其产生振动。同时将试验获得的结果以图形的形式表示出来。讨论了桥面受到破坏对动力性能的影响，并将动力试验与静力试验的结果进行了比较。 A. Text Dynamic Load Testing of A Cable-Stayed Bridges The article presents results obtained using a simple dynamic testing procedure frequently used in Switzerland for highway bridges. Typical results are shown and tendencies observed in the dynamic behavior of highway bridges are presented. For a deteriorated pavement, the dynamic impact of heavy vehicles is shown to be larger at lower truck speeds. Some correlation is shown between the dynamic properties of the bridge and its stiffness, as measured in a static load test. 1. Introduction Dynamic load testing is an important part of the acceptance process for new bridges in Switzerland. As a complement to static load tests, dynamic tests yield useful information about the actual behavior of the bridge under traffic. This information is usually difficult to obtain analytically, because of the complexity of the actual structure. The effect of pavement deterioration on the dynamic response of the bridge is of particular importance for the management of the structure. This information can be easily and realistically obtained from a dynamic test, and thereafter used by the highway authorities to organize the pavement maintenance. Drawing on the large number of tests performed by IBAP over the past twenty years, the paper describes the general dynamic characteristics of highway bridges. Some correlation is shown between the stiffness obtained in a static load test and the measured eigenfrequencies. The influence of the speed of a vehicle crossing the bridge is discussed. In particular, the effect of an artificial damage in the pavement on the dynamic behavior is presented. 2. Dynamic Load Testing The purpose of the dynamic load test is to determine the controlling parameters of the dynamic behavior of the bridges. The