Analytical and experimental studies on seismic behavior of double-layer barrel vault systems with different open angles

This paper presents the seismic behavior of double-layer barrel vault systems with different open angles through analytical and experimental studies with modeling of thin-walled steel tubes. For the analytical study, different six open angles and four fundamental frequencies were incorporated into the barrel vault analysis models and analyzed. A total of 24 double-layer structures were developed using the MIDAS computer analysis program and these structures were subjected to three different ground motions with a 5% damping ratio. The characteristics of the dynamic responses for the X, Y, and Z directions of the analytical model, subjected to both horizontal and vertical earthquakes, were investigated. In addition to the analytical study, an experimental study using scaled down thin-walled steel tube models was undertaken using a shaking table test. Comparing the analytical and experimental studies, the dynamic behaviors were very similar in terms of the distributions of the acceleration responses. Both the analytical and experimental models had maximum values at the 1/4 and 3/4 nodes, while having relatively smaller responses at the center node from horizontal earthquakes. It is believed that the barrel vault model with an open angle of 90 degrees has the most advantageous shape of the analytical barrel vault models used in this study.