Experimental dynamic analysis of the existing footbridge in Dobřichovice town

Abstract

The paper presents an experimental dynamic analysis of the existing footbridge across the Berounka River in Dobřichovice town, Czech Republic. The experiment was realized in two stages. The main purpose of the first one was the vibration response determination of the footbridge induced by pedestrians. At first, the natural frequencies and mode shapes of its horizontal load-bearing structure were measured and then the footbridge was loaded by different groups of pedestrians. The response was observed and dynamic behaviour of the footbridge was evaluated. In the course of the second stage of the experiment, the dynamic response of the footbridge deck to pedestrian traffic was measured by two different methods using radar interferometry and classical approach realized by piezoelectric accelerometers. Basic objectives of the second stage were to evaluate the fundamental modal characteristics of the footbridge and to verify new approach to dynamic response measurement – radar interferometry realized by two synchronized radars.