Ricerc@Sapienza

Between August 2016 and January 2017 nine shallow events with moment magnitude between 5.0 and 6.5 occurred in Central Italy, with largest magnitude being the most severe in Italy since 1980. Several thousands of heritage buildings have been affected to a different degree by the ground motion shaking, highlighting some specific behaviours in the most stricken areas. In and around Amatrice extensive masonry fragmentation, cracking of large walls without openings, as well as survival of tall towers and slender bell gables have been observed.

The seismic sequence which started on August 24th, 2016, caused hundreds of casualties, damage and collapses in four regions of Central Italy (Lazio, Umbria, Abruzzo and Marche). The strongest event, which occurred on October 30th (Mw6.5), was forerun by four earthquakes with magnitude between 5.4 and 6.0. So far, a total of nine events with magnitude greater than or equal to 5.0 have taken place in the affected area. The earthquakes were caused by normal faults, all of them having NW–SE or NNW–SSE strike, approximately along the spine of the Apennine Mountains.

Between August 2016 and January 2017 nine shallow earthquakes ranging from 5.0 and 6.5 of moment magnitude affected Central Italy, involving several municipalities wherein unreinforced masonry buildings are more than three quarters of all constructions. Damage state has been very severe, with sixteen settlements belonging to the municipalities of Amatrice, Arquata del Tronto, Accumoli, Castelsantangelo sul Nera and Norcia experiencing a cumulative European macroseismic scale intensity larger than IX.

The 2009 L’Aquila earthquake in southern Italy affected a rather large number of buildings, which experienced macroseismic intensities between V and IX on the Mercalli–Cancani–Sieberg scale. Almost sixty thousand unreinforced masonry constructions were officially inspected and almost half of them ended up losing their usability status temporarily, partially or completely, where the term usability refers to the suitability of a building for habitation or occupancy after a seismic event.

A widespread approach for the prediction of the structural response as function of the ground motion intensity is based on the Cloud Analysis: once a set of points representing the engineering demand parameter (EDP) values is obtained as function of the selected seismic intensity measure (IM) for a collection of unscaled earthquake records, a regression analysis is performed by assuming a specific functional form to correlate these variables.

This study focuses on the conceptual development, analytical modeling and experimental wind tunnel testing of a high efficiency energy harvesting (EH) device, based on piezoelectric materials, with an application for the sustainability of smart buildings.

This paper describes the blind prediction carried out to simulate the response of a thin reinforced concrete wall tested under uni-directional (in-plane) quasi-static reverse cyclic loading. The specimen was a singly reinforced T-shaped wall panel with a shear-span ratio of 3.7. The response of the test specimen was simulated prior to the release of test results using a finite element model which had already been verified for its capabilities in capturing different failure patterns of rectangular walls, particularly out-of-plane instability.

This paper focuses on the development of energy dissipaters for rocking precast systems. The energy dissipaters developed in this work are to be used externally, having the advantages of being easy to inspect and replace after an earthquake. The main parameters to take into account for the development of the energy dissipaters are the cyclic behavior, the strength, and the ductility. The cyclic behavior has to be stable from cycle to cycle. The developed dissipater has to respond with adequate strength.

An experimental investigation was conducted to evaluate both residual capacity and the damage of the concrete material in previously damaged RC columns. Three circular columns, each caged to provide low, medium, and high level of confinement, were axially loaded to failure. All damaged columns were then cut into three pieces, and two cored cylinders were taken from each piece. The first core was prepared and instrumented for compression, whereas the second was sliced into a number of 25-mm disks for permeability testing.

Instability failure (also referred to as out-of-plane instability) has been observed in several experimental studies conducted on seismic performance of rectangular structural walls under in-plane loading. Observation of this failure pattern in some well-confined modern walls during the 2010 Chile and the 2011 Christchurch earthquakes has raised concerns about the reliability of current design code provisions.