Shaking table test on a full-scale unreinforced clay masonry building with flexible diaphragms

This paper presents the results of an experimental campaign which is part of a wider research project, aimed at assessing the vulnerability of buildings in the Groningen region of the Netherlands. This area, historically not prone to tectonic ground motions, has been subjected to seismic events induced by gas extraction during the last two decades. As part of this project, a unidirectional shaking table test was performed on a single-story, full-scale, unreinforced masonry building. The specimen represented a detached pre-1940’s house, consisting of clay unreinforced masonry walls, without any specific seismic detailing. The building was designed to include large openings and a reentrant corner, causing a discontinuity in one of the perimeter walls. The first floor was made of timber beams and planks, resulting in a flexible diaphragm. The roof, characterized by a very steep pitch, consisted of a series of timber trusses connected by wood purlins and boards. The two façades perpendicular to the shaking direction were designed in order to represent two typical gable geometries. An incremental dynamic test was performed up to the near-collapse condition of the specimen, using input ground motions selected to reproduce a realistic scenario of seismic events in the examined region. This paper summarizes the main characteristics of the specimen and the shaking table experimental results, illustrating the dynamic response of the structure and the evolution of the damage mechanisms.