This paper was presented at the 16th World Conference on Earthquake Engineering (16WCEE) in Santiago, Chile, January 9th-13th, 2017. The paper is a result of research into the use of Extreme Loading for Structures in seismic assessment and retrofitting historic masonry structures performed in cooperation between Applied Science International (ASI) and the University of L’Aquila.
Abstract: During the 2009 L’Aquila earthquake, the tower of Santo Stefano di Sessanio, the town’s iconic symbol, collapsed to the ground. The tower was believed to have been rendered vulnerable to collapse because of 20th-century renovations to the tower’s observation platform, which replaced a wooden deck with one made of reinforced concrete, thus making the tower top-heavy. In the current study, a numerical analysis was used for investigating the collapse behavior of the tower. Doing an initial elastic model of the tower did not allow any realistic prediction of the anomalous seismic behavior showed by the tower; the reason why only a stump of structure actually survived the earthquake remained unexplained.
Key Words: Heritage Masonry Structure; 3-D Applied Element Model; Nonlinear Dynamic Analysis.
Authors: Salem, A. Gregori, H. Helmy, K. Fassieh, H. Tagel-Din
Margharita Palace
Damaged structure with scaffolds and jacks supporting it
Laser Scan
Laser Scanning of Damage
ELS Model
ELS Model of the Palace
Seismic Wave
Time history seismic wave applied to the model
All 3 Floors
Displacement Contour of Damage at .9 Seconds
Bottom 2 Floors
Displacement Contour of Damage at .9 Seconds
First Floor
Displacement Contour of Damage at .9 Seconds
Collapsed Historic Structure
Displacement Contour of Damage at 14 Seconds