Investigation of Rubble-Masonry Wall Construction Practice in Latium, Central Italy

Abstract

The 2016-2017 Central Italy seismic sequence severely affected existing unreinforced-masonry constructions in four regions. Those in Latium region proved the most prone to fragmentation because of an unfortunate combination of undressed natural stone units and very low lime content in mortar. Within the framework of a research project funded by the regional government, shake table tests are planned to investigate masonry disintegration as well as possible intervention techniques, as described in a companion paper. All specimens will have natural stone units retrieved from the debris in Collespada, a settlement of the municipality of Accumoli, one of the most affected by the seismic sequence. To push further the representativeness of the specimens with respect to field conditions, wall geometry, masonry

Low-impact techniques for seismic strengthening fair faced masonry walls

“…The walls (Figure 1) were about 500 mm thick, which is close to the average thickness surveyed in the historical centres of Central Italy [12] and 1630 mm wide. Since the out of plane response was under investigation, the width was not crucial and was defined to obtain a significant wall surface for the installation of the strengthening systems while limiting the forces requested upon the shake table and the construction costs.…”

“…The aforementioned projects SISMI and SICURA included shake table tests on three masonry walls, which were built using the compact marlstone units and lime mortar typical of the built heritage of the historical centres of Central Italy struck by the 2016-2017 earthquake. Professional bricklayers took care of their manufacturing according to construction practice (stone size and shape, bond pattern) typical of the area [12]. The accurate representation of the masonry types surveyed in the field is acknowledged as essential to investigate their behaviour, replicate their failure modes and assess the effectiveness of strengthening strategies [13].…”

“…Since the out of plane response was under investigation, the width was not crucial and was defined to obtain a significant wall surface for the installation of the strengthening systems while limiting the forces requested upon the shake table and the construction costs. The height of the walls was 3730 mm, thus delivering a height/thickness ratio of about 7.5, which is common in the area [12]. The investigation of natural scale specimens made it possible to build the walls and apply the seismic inputs without scale effects.…”