Francesco Graziotti

This study describes a dataset from an experimental campaign investigating the quasi‐static cyclic lateral response of two full‐scale, two‐storey, two‐bay reinforced concrete (RC) frames with masonry infills representative of mid‐20th century European construction practice. The nominally identical specimens were tested in both as‐built and retrofitted configurations. The dataset aims to provide new experimental evidence on the investigation of the effectiveness of a cross‐laminated timber (CLT)‐based retrofit system, in which the external masonry wythe is replaced by a CLT panel connected to the RC frame through a glulam subframe and dissipative fasteners, while the internal wythe is retained to ensure compatibility with finishing layers. The campaign comprises snap‐back tests to characterize initial dynamic properties and quasi‐static cyclic tests conducted up to near‐collapse conditions. The dataset includes actuator forces and displacements, local deformations of masonry infills and CLT panels, relative slip at connections and material characterization tests. The work presented aims at contributing to the calibration and validation of numerical/analytical models and, possibly, to the development of guidelines for integrated seismic and energy renovation of existing infilled RC framed buildings.

This article presents a dataset from an experimental campaign investigating the out-of-plane (OOP) seismic response of unreinforced masonry (URM) gables in existing buildings. Addressing a critical gap in published research, the dataset provides novel experimental data on the incremental dynamic OOP behavior of three URM gables tested under seismic loading until full collapse. All three gables were nominally identical but differed in their interaction with the supporting roof structure. This interaction was experimentally reproduced by imposing differential motions at the top of the gables, which were either linearly amplified or both amplified and phase-shifted relative to the motion at the base. This approach ensured idealized and numerically replicable boundary conditions, making the dataset an ideal benchmark for refining existing and developing new modeling approaches for URM structures. The dataset includes measured and calculated acceleration, displacement, and force time histories. Beyond supporting the validation and development of numerical models, it can also contribute to improving guidelines for the out-of-plane seismic assessment of URM gables and is openly available for further research and engineering applications.

Timber, with strength-to-weight and modulus-to-strength ratios comparable to steel, is increasingly utilized in seismic retrofitting due to its versatility, sustainability, and rapid installation potential. However, concerns exist regarding its capacity to respond effectively to seismic events, particularly the risk of delayed activation compared to existing structural damage. Timber retrofits high deformability, largely attributed to the ductility of metal connections, enables significant displacements without compromising stability. Nonetheless, challenges arise when timber systems interact with brittle materials, such as in retrofits of reinforced concrete (RC) and masonry buildings, questioning the conventional ultimate limit state. This study examines the application of cross-laminated timber (CLT) panels for retrofitting RC buildings, as part of the Sustainable Timber Retrofit Of reinforced coNcrete buildinGs (STRONG) project conducted at STRULAB, University of Patras, within the ERIES framework. A two-storey RC frame with masonry infill, representative of 1950–1970 Mediterranean construction practice, was retrofitted using a CLT-based technique (RC-TP) and tested under lateral cyclic loading up to ultimate conditions. The intervention prioritized life safety and global stability over damage containment during high-intensity events. This paper outlines the design criteria and experimental results, highlighting the potential of CLT panels to enhance seismic performance while ensuring structural stability.

This article presents a numerical investigation into the influence of vertical ground motion on the global seismic response of unreinforced brick-masonry buildings. Vertical accelerations of significant intensity can cause variations in gravity-induced loads, affecting the in-plane lateral capacity of masonry piers. This study employs a suite of numerical structural models to explore the damage potential of vertical accelerations on a masonry building through earthquake simulations. The building features piers with varying aspect ratios, axial loads, and shear resistance. The models are developed using the equivalent-frame modeling approach and nonlinear macroelement within the TREMURI software. Initially, the study demonstrates the capability of the numerical models to replicate dynamic responses under combined horizontal and vertical seismic inputs. The predictive accuracy is validated through simulations of multidirectional shake-table tests on full-scale structures under near-source ground motions. Subsequently, the validated models undergo cloud analysis using unscaled three-component ground motions from earthquakes with moment magnitudes 5–7 and short epicentral distances (below 30 km). The findings indicate that vertical accelerations do not cause considerable differences in global seismic behavior. Any effect on maximum displacement demands for walls with varying geometric and mechanical properties appears random and negligible. Vertical accelerations may only become relevant under certain synchronization scenarios between horizontal and vertical motions, which are rarely encountered in natural settings. This study underscores the importance of considering vertical earthquake motion in seismic analysis yet highlights its generally limited effects on regular masonry structures.

This paper discusses the results of an experimental study aimed at evaluating the influence of the vertical ground motion component on the seismic performance of unreinforced brick‐masonry buildings. The research was motivated by post‐earthquake observations of significant structural damage in the vicinity of the fault, where horizontal and vertical ground motions are often strong and synchronized. Vertical accelerations can fluctuate gravity loads, which control the in‐plane lateral load capacity of masonry piers and affect the out‐of‐plane overturning stability of thin walls. Such phenomena seem not to be sufficiently explained in existing literature, while experimental evidence is undoubtedly missing. Here, the damage potential of vertical accelerations was investigated through a series of multidirectional shake‐table tests on full‐scale structures under simulated near‐source ground motions of increasing intensity. The experiments comprised three nominally identical building specimens subjected to the principal horizontal component alone, the horizontal component combined with the vertical one, and the full three‐component ground motion. The buildings included structural/nonstructural elements (e.g., gables, chimneys, and parapets) sensitive to gravity load variations due to their low axial loads. Two different sets of three‐component earthquake records were employed to assess the effects of both tectonic and induced seismicity scenarios. Overall, the vertical earthquake motion did not cause appreciable differences in the behavior of the buildings. Any influence on the strength and peak response of structural/nonstructural walls was marginal and non‐systematic. Data and observations from these experiments add substantially to our understanding of the vertical acceleration effects on masonry structures.