Shaking Table Test of 1/30 Scale Model of Palasport in Bologna with Timber Shell Roof Structure

Abstract

The dynamic stability of a timber shell roof structure of the Palasport located in Bologna, has been investigated by means of reduced 1/30 scale model tested on seismic shaking table at Dynamic Testing Laboratory of IZIIS, Skopje, Macedonia. The model was physically modeled according to similitude lows and Buckingham's theorem as an artificial mass simulation model, using the same material as for the prototype structure. The supporting structure of the model was constructed by 26 micro-concrete foundations, 52 micro-concrete columns and 52 steel braces. The roof structure made of wooden lamellar beams forming triangles. The roof consists of a central cylindrical part and 2 lateral spherical parts. The connection between the beams was made by steel rings. The total number of the wooden beams was 550 forming 203 internal and external joints. The model was tested in vertical and horizontal direction considering various loading conditions: symmetrical and non-symmetrical. After definition of dynamic characteristics of the model, it was subjected to seismic excitation of Ancona, as well as Montenegro earthquakes. It was found out that the cylindrical part is more flexible than the spherical one. The largest amplitudes during the tests were obtained in vertical direction. The highest stress concentration was at the cylindrical central arches. The asymmetric load produced more unfavorable behavior than the symmetric one.