Static and Dynamic Investigation of the Taro Masonry Bridge in Parma, Italy

The Taro bridge has a very long history since was built by Antonio Cocconcelli in 1820. The bridge is composed of 20 arch spans and is arranged in the shape of three center Perronet arches with flood holes in the piers. The road over the bridge has two lanes and is set for the highest truck loading category. After the second World War has been used intensively for road transportation and due to some intrinsic features of the structure, in recent times many brick and stone detachments occurred. Recently, in order to assess the health of the bridge, static and dynamic testing was carried out, by using a set of 8 trucks filled with sand. A Finite Element Model was worked out for the data interpretation, and the parameters of the model were identified on the basis of the vibration frequencies. In order to test the effectiveness of the model, a comparison is made with the static load testing, finding a very good agreement. The main identified parameter are the compliance of the foundation blocks, and the elastic modulus of the fill. The analysis shows that models with different number of spans are all capable to identify the main frequencies of the bridge, if the correct value of the main parameters is introduced.