P.X. WANG (1), G. MILANI (1), S.C. LI (2), (3)
(1) Politecnico di Milano, Department of Architecture Built Environment and Construction Engineering, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
(2) School of Architectural Science and Engineering, Yangzhou University, 225127, China.
(3) Jiangsu Huajian Construction Co., LTD, 225002, China.
Relevant damage to historical masonry structures mainly comes from earthquakes. This paper focuses on the prediction of the seismic behaviour of a masonry pagoda in China using non-linear static and dynamic analyses, whose results are then compared with a more straightforward procedure, represented by a limit analysis with pre-assigned failure mechanisms. Pushover and non-linear dynamic numerical simulations are carried out in Abaqus which can satisfactorily predict the generation and development of earthquake-induced damage in masonry structures. At the same time, manual limit analysis is an important tool for common practitioners to assess seismic vulnerability quickly and effectively. Together they represent, therefore, an excellent protocol to follow. This research applies the above methods to an ancient iconic Chinese masonry pagoda – namely the Zhongjiang South Pagoda, located in the Sichuan province PRC. It has an octagonal cross-section containing a central room and a staircase that spirals upwards in a clockwise direction. After the 2008 Wenchuan Earthquake, Zhongjiang South Pagoda suffered serious damage. Surveys have shown that seismic loads caused a bottom-up crack in the middle part of the pagoda and almost activated the collapse by rocking on an inclined plane through the bottom 2-3 floors. The numerical results obtained are in general agreement with what occurred in reality and provide positive recommendations for the protection and repair of ancient masonry pagodas and towers in general.
KEYWORDS: seismic vulnerability; masonry pagoda; numerical simulations; limit analysis; collapse mechanism