Gabriele Guerrini1, Ilaria Senaldi1, Francesca Di Santo1, Umberto Tomassetti1,
Francesco Graziotti1,2, Guido Magenes1,2, Katrin Beyer3, and Andrea Penna1,2
1)  Dept. of Civil Engineering and Architecture, University of Pavia,
via Ferrata 3, 27100 Pavia, Italy.,,,,,
2)  European Centre for Training and Research in Earthquake Engineering,
via Ferrata 1, 27100 Pavia, Italy.
3)  École Polytechnique Fédérale de Lausanne,
Bâtiment CE 3316, Station 1, CH – 1015 Lausanne (Switzerland)

Keywords: Historical building aggregates, natural stone masonry, flexible diaphragms, scaled shaking-table test, damage limit states

Abstract. The seismic performance of a half-scale model of a natural stone masonry building aggregate has been assessed via unidirectional shake-table testing. This test is part of an experimental and numerical research project, jointly carried by the University of Pavia and École Polytechnique Fédérale de Lausanne, aimed at investigating the seismic behavior of historical buildings in the city of Basel, Switzerland.
The scaled prototype reproduces architectonic features and construction details of existing masonry building aggregates typical of the historical center of Basel. The three-story-high specimen consists of two weakly connected structural units, each built with double-leaf undressed stone masonry walls with a limited percentage of pebble stones. The floor timber diaphragms are flexible and simply supported by the transverse walls. The roofs of the two units, characterized by different pitches and side-gable walls of different heights, are supported by timber trusses.
This paper summarizes the main structural characteristics of the specimen and describes its hysteretic response at various stages of the incremental dynamic test, performed with input ground motions representative of local seismic scenarios. The evolution of the structural dynamic properties and its correlation with the exhibited damage level is also discussed.