Ambient vibration test on an existing prestressed concrete bridge

Abstract

The dynamic test in situ of existing bridges is a very promising solution for assessing a reliable model, since it is more convenient than a load test requiring to organize the trucks and close the use of the infrastructure for a longer time. However its effectiveness depends on the test technique, the number, type and location of the sensors, but also on the numerical model that have to allow the introduction of the real boundary conditions. Cleary the dynamic identification of the structural behavior can be also the first step of a monitoring process to check the health of the construction during the time, therefore its effectiveness is fundamental. In this paper the first results of the structural identification based on an ambient vibration test of an existing prestressed concrete bridge are presented. The selected case study is a bridge designed by Riccardo Morandi in 1952-1955 with the emerging technique of Prestressed Concrete (PC). An important step of the process is the developing of the model though a survey and a wide investigation campaign, but also the role of the knowledge of the original design is highlighted due the complexity of the structure.