Urban seismic resilience is shaped not only by the structural integrity of buildings but also by the socio-economic vulnerabilities of the communities they shelter. In this study, we present a novel compiled dataset that bridges these two domains by integrating socio-economic indicators with engineering-based seismic resilience metrics for neighborhoods in Istanbul, a megacity with high seismic risk and socio-spatial inequality. Our hypothesis is that socio-economic disadvantage significantly influences whether people reside in earthquake-safe structures. To test this, we compiled and merged multiple publicly available datasets released by Istanbul Metropolitan Municipality, including the number of households receiving social aid, socio-economic status (SES) scores, and structural vulnerability parameters derived from seismic risk assessments. The dataset allows for a nuanced, data-driven understanding of post-earthquake recovery capacity across Istanbul’s neighborhoods. Initial findings reveal that areas with lower SES scores correlate with higher expected recovery time and cost, suggesting a compounded vulnerability. Beyond its research value, the dataset provides practical utility for municipalities, civil protection units, and policy-makers aiming to prioritize interventions. It enables targeted resilience enhancement strategies and facilitates simulations of neighborhood-level risk under various seismic scenarios.

The assessment of the Local Seismic Response (LSR) to the expected seismic motion in a territory is the subject of seismic microzonation studies. For the estimation of the seismic action, it is necessary to define some fundamental elements: the seismic input representative of the seismic action of the seismic bedrock and an adequate geotechnical model.

Generally, at least seven accelerograms compatible with the site's target response spectrum have to be identify. Typically, such accelerograms are chosen from available databases, in order to provide the best approximation of the target spectrum, based on an appropriate range of magnitude, epicentral distance, and epsilon parameter (SMEE), i.e. the number of standard deviations by which the observed logarithmic spectral acceleration differs from the mean logarithmic spectral acceleration of a ground-motion prediction by the attenuation equation.

These choice is made irrespective to all the time-dependent features characterizing the real signals of the area subject to microzonation (e. g. duration, evolution of amplitude and energy frequency content, total energy and its distribution over time, strong motion duration, etc.).

In a recent paper (Colajanni, Pagnotta, Testa, 2020) four methods for generating fully non-stationary artificial accelerograms on the basis of a target spectrum and a set of accelerograms registered in the neighborhood of the construction site, with provide a mean response spectrum that can be different from the target one. Among these, two of them, namely (Cacciola, 2010 (CA), and Rofooei, Mobarake & Ahmadi, 2001(RMA)) have proven to be particularly efficient in reproducing the characteristics of the events expected at the site. More precisely, the CA method provides reliable results, but they are highly influenced by the selection criterion of the group of real records through which the non-stationary counterpart is defined, the RMA is able to clearly define the non-stationary characteristics of a site, but gives controversial results, due to the absence of a spectrum-compatible formulation.

In this paper, the set of accelerograms obtained with the two generating methods are used as input accelerograms for a microzonation procedure, obtained from one-dimensional linear equivalent method site response analyses implemented in AlgoShake2D software (Algoritmiqa 2024), and compared with results obtained by microzonation performed through the natural accelerogram selection procedure currently used in the professional field mentioned above (SMEE) , and with the results obtained assuming as a signal to the bedrock a set of accelerograms actually recorded at the site, which constitute the benchmark in analogy to the procedure used in (Colajanni Pagnotta, Testa, 2020).

This paper presents an experimental campaign aimed at investigating the effectiveness of reinforcing dry-joints in cold-formed steel rack structures, focusing on their down-aisle seismic behavior. Given the need of reinforcing conventional cold-formed steel storage racks during seismic events, particularly at their joints, the study evaluates practical reinforcement solutions to enhance structural resilience. A series of monotonic and cyclic tests were performed on full-scale specimens, considering both conventional and reinforced dry-joint configurations. Reinforcement methods, including the use of additional bolting, stiffening elements, and innovative connection detailing, were systematically examined. Experimental results demonstrated improvements in stiffness, ductility, and overall seismic performance of the reinforced joints compared to traditional configurations. Particular attention was given to energy dissipation capacity, deformation mechanisms, and failure modes under simulated earthquake conditions. Findings from this study contribute to a deeper understanding of seismic-resistant design for cold-formed steel racks, providing valuable insights for structural engineers aiming to improve safety and reliability of storage systems in seismic regions.

This study highlights the need to transition from a traditional uniform-hazard approach to a risk-targeted methodology in seismic design and assessment. Specifically, a seismic action calibration model is proposed, aiming to ensure uniform reliability across different types of constructions, both for new designs and for the assessment of existing constructions. The model is applied to the Italian territory, where seismic hazard varies from site to site.

The results offer valuable insights into the expected impact of adopting a risk-targeted approach on a national scale, emphasizing the potential benefits in terms of structural safety, economic efficiency, and code modernization.

Furthermore, a procedure is presented for deriving target reliability indexes, calibrated according to recent international research and evolving performance-based design standards.

Le strategie di riqualificazione integrata, preferibilmente di tipo olistico e applicate esternamente, si sono dimostrate efficaci nel soddisfare le molteplici esigenze degli edifici esistenti, compresi gli aspetti strutturali, energetici e architettonici. Per garantire una reale sostenibilità economica, ambientale e sociale lungo l'intero ciclo di vita di un edificio, è necessario affiancare nuovi obiettivi prestazionali - come, ad esempio, rapidità di assemblaggio, riparabilità, smontabilità e riuso - ai tradizionali requisiti di efficienza energetica e sicurezza strutturale. Studi recenti hanno evidenziato come il raggiungimento di questi nuovi obiettivi richieda lo sviluppo di tecnologie abilitanti. In questo contesto, riconsiderare il ruolo delle connessioni puntando su standardizzazione, modularità, semplicità di montaggio/smontaggio, nonché sulla possibilità di attivazione e disattivazione, si rivela una strategia fondamentale per accrescere la sostenibilità degli interventi, sia innovativi che tradizionali. Questo studio propone e analizza una connessione modulare e standardizzata tra un edificio esistente in calcestruzzo armato ed esoscheletro in acciaio. Vengono presentate le scelte progettuali e i risultati delle prove sperimentali.

The preservation of built heritage is of paramount importance for ensuring human safety, especially in the case of school buildings.

The demand for practical and non-invasive seismic strengthening solutions has led to the development of innovative techniques. For reinforced concrete buildings, one such technique involves the installation of external steel braced frames positioned adjacent to and/or perpendicular to the building façades. In addition to being highly effective, this method minimizes disruption to the building's ongoing activities.

This study presents a retrofit solution for a school building located in a high seismic risk area. The as-built structure, composed of precast concrete elements, lacks sufficient strength to meet the seismic and gravitational load requirements set by the Italian Building Code.

The proposed intervention includes the installation of external steel braced frames equipped with energy-dissipating devices. These frames increase the building's stiffness, thereby reducing displacements of structural elements. The corresponding increase in acceleration is offset by the dissipation of seismic energy through the installed devices.

The positioning of the steel frames along the building perimeter is chosen to regularize the seismic behavior by minimizing the eccentricity between the center of mass and the center of stiffness, thereby reducing the resulting torsional effects.

The reuse of structural timber plays a crucial role in promoting sustainability and circular economy principles. However, dismantling and reinstalling timber components often introduce modifications such as holes from fasteners (e.g., dowels, screws) or cavities from internal systems (e.g., piping, cabling), potentially affecting their mechanical performance. Assessing the residual load-bearing capacity of reclaimed timber is therefore essential, particularly for its application in seismic-resilient structures. This study introduces a visual grading-inspired methodology for classifying recycled timber based on hole characteristics. A stochastic numerical model is developed to simulate the bending strength reduction of beams with randomly distributed holes, generating extensive datasets for training predictive classification models. Machine learning and threshold-based classification approaches are employed to determine whether the reduction in bending strength exceeds a predefined 20% limit, which serves as a grading criterion. An experimental campaign on timber beams with controlled hole patterns supports model validation and establishes a practical classification threshold based on a single feature: the cumulative sum of hole diameters in specific beam regions. Results indicate that a simple conditional classification model achieves predictive performance comparable to machine learning techniques, yielding accuracy levels above 80% in distinguishing beams with bending strength reductions above or below 20%. This approach addresses existing gaps in current standards, providing an efficient and reliable method for assessing the viability of reclaimed structural timber, thus facilitating its safe integration into seismic-resistant construction.

One of the main challenges in framed Reinforced Concrete (RC) structures under seismic loads is the behavior of beam-column joints, as these elements experience high stresses during seismic events, which can lead to unexpected collapses due to brittle failure mechanisms. In Italy, many RC buildings constructed before the mid-1970s exhibit significant structural vulnerabilities, having been designed solely for gravity loads. Key deficiencies include the use of plain reinforcing bars, inadequate anchorage details, and the absence of horizontal reinforcement in the joints. Specifically, the use of plain bars for RC structures was prohibited only with the introduction of the 2008 Building Code.

This study provides an overview of the seismic performance of exterior beam-column joints reinforced with plain bars, based on experimental results from cyclic load tests found in the literature. The reviewed tests examine key parameters that influence joint behavior, such as the amount of horizontal reinforcement, column axial load, and anchorage details. The overview provides a comprehensive framework for understanding the behavior of exterior joints reinforced with plain bars and their failure mechanisms.

The study highlights the shortcomings of specific reinforcement arrangements and details in the tested joints. It provides a critical discussion on the damage patterns and failure mechanisms observed, focusing on the effects of reinforcement details and the influence of key parameters, such as the impact of column axial load on joint shear stress at failure. Given the lack of similar studies in the literature, this analysis establishes a foundation for a thorough understanding of the behavior of joints with plain bars. This knowledge is crucial for upgrading these joints and developing effective retrofit solutions for buildings constructed before 2008.

Current seismic codes facilitate force-based design and safety assessment of buildings under the assumption that they remain indefinitely within the linear elastic range. However, to account for their inelastic deformation capacity, design seismic forces can be reduced using the seismic behavior factor (q). When plastic analysis is employed, dissipative members are intentionally designed to undergo plastic deformations, enabling energy dissipation. This design approach should consider the associated expected annual loss, which includes damage costs and expenses related to the replacement or retrofitting of dissipative members.

This paper presents a framework, formulated through closed-form equations, to quantify the cost required for a dissipative building, designed according to the capacity design approach, to achieve economic competitiveness compared to a low-dissipative counterpart that remains within the elastic range.

Parametric analyses are conducted to evaluate the impact of key factors on the target cost, including the seismic behavior factor, the replacement cost of dissipative members, the nominal life of the building, and the tolerable probability of failure for earthquake-resistant structures. The proposed methodology is then applied to a case study to demonstrate the robustness of the framework and support its integration into common practice.

Fiber‑reinforced strengthening systems, whether based on fiber‑reinforced polymer (FRP) composites or on fabric‑reinforced cementitious matrices (FRCM/TRM), are widely adopted to enhance the load‑carrying capacity and ductility of concrete and masonry elements. Within the SAFER‑REBUILT project (“Sustainable Approaches for Earthquake‑Resistant Rehabilitation Solutions for the Built Environment”), funded by the University of Bari Aldo Moro, this paper presents preliminary experimental and numerical results on bond deterioration and the sustainable recycling of FRP applied to masonry and concrete specimens. The experimental program and accompanying finite‑element analyses investigate the cyclic bond behavior and assess an innovative bio‑leaching and anaerobic‑digestion process for eco‑efficient recycling of strengthening systems once they are removed at end‑of‑life.

Structural resilience against seismic events is a critical challenge in modern engineering. This study introduces an innovative concept of smart bracing beams, which are designed to dynamically alter their structural behavior in response to earthquake forces. Unlike conventional beams, these smart elements function as moment-resisting members under normal conditions but transform into bracing elements during seismic activity to enhance lateral stiffness and stability. The transition mechanism is governed by adaptive control systems, integrating advanced sensor networks, machine learning algorithms, and actuator-based interventions.

A comprehensive numerical simulation is conducted to evaluate the performance of smart bracing beams under various seismic scenarios. The results demonstrate significant improvements in energy dissipation, lateral displacement control, and post-earthquake recoverability compared to traditional structural systems. Furthermore, the potential for automated post-event reconfiguration minimizes downtime and structural repair needs.

This research paves the way for next-generation seismic-resistant structures by combining structural engineering principles with cutting-edge artificial intelligence and smart materials. Future developments include experimental validation and the integration of real-time adaptive control systems for large-scale applications.

Keywords: Smart Bracing Beams, Seismic Resilience, Adaptive Structures, AI in Structural Engineering, Earthquake-resistant Design, Structural Control

The use of base-isolation systems represents one of the most effective solutions for the seismic protection of medical facilities, aiming to ensure resilient structural performances as well as to avoid downtime. Nevertheless, traditional base-isolation systems may amplify the vertical seismic response similarly to fixed-base structure inducing significant structural and nonstructural damage, especially in a near-fault area where large vertical spectral accelerations are expected. Aim of the present work is to investigate the effectiveness of a double seismic isolation system for the vertical isolation against near-fault ground motions. An in-series vertical assembly of a high-damping rubber bearing (HDRB) and high-damping rubber layers (HDRLs) is considered, the latter independent of the horizontal and vertical (in tension) responses of the HDRB. A five-storey pavilion of the hospital campus in Avellino, Campania (Italy), is retrofitted with the double base-isolation system in line with the current Italian seismic code. A homemade code is implemented for the nonlinear seismic analysis of the test structure, including a lumped plasticity model of RC frame members and shear, compression and tension nonlinear modelling of the double elastomeric isolation system. In-plane and out-of-plane nonlinear modelling of masonry infills arranged along the interior bays of the perimeter is also considered, while a homemade code is implemented for the wavelet analysis. Nonlinear seismic analysis of the test structure is carried out assuming a set of fifteen near-fault earthquakes extracted from the PEER database, with and without accounting for the vertical seismic component.

The majority of bridges in Amsterdam’s historic city centre are founded on timber foundation piles, typically 12 to 15 meters in length, which function as end-bearing elements reaching the underlying stiff sand layer. Currently, many timber foundations have been in service for up to 300 years, raising concerns about their remaining load-bearing capacity and the overall safety of the bridges they support. The timber piles beneath the bridges remain fully submerged, where their outer cross-section is exposed to slow bacterial decay in anaerobic conditions, leading to a reduction in the sound load-bearing core of the piles. Despite decay, the piles maintain their structural capacity for many years, although their load-bearing capacity gradually decreases over time. The two primary risks are attributed to the applied loads exceeding the load-bearing capacity of the timber piles, and progressive damage accumulation over time due to sustained loading, ultimately leading to large settlements or failure. In this context, 201 pile segments were extracted from two bridges in Amsterdam and mechanically characterised, with respect to their amount of biological decay and service durations ranging from 100 to 300 years. Large-scale compression tests were carried out to determine the remaining saturated short-term compressive strength of the piles. Micro-drilling measurements were conducted to assess the amount of bacterial decay, validated with Computed Tomography (CT) scanning. Finally, this study investigated the load history and current loads acting on the timber foundation ofbridge 30 (De Isa van Eeghenbrug) in Amsterdam, to assess the remaining load-bearing capacity of the piles, considering mechanical damage and decay.

The safety assessment of existing structures constitutes a quantitative process aimed at evaluating a structure's load-bearing capacity while ensuring compliance with current regulatory safety standards. Enhancing structural safety typically requires targeted interventions, ranging from localized modifications to comprehensive system upgrades.In the case of protected historical buildings serving social or strategic functions, this assessment was conducted through a systematic approach involving three key phases: first, a detailed geometric survey of all structural elements; second, comprehensive material investigations to characterize construction properties; and third, numerical modeling to evaluate seismic vulnerability and identify necessary performance improvements.This rigorous methodology generates substantial technical data requiring careful analysis and integration, often resulting in intervention strategies that demand extended planning and implementation periods due to the complex nature of historical structures.

This contribution illustrates the preliminary research findings of an ongoing structural health monitoring (SHM) campaign on prestressed concrete (PC) beams with artificially damaged prestressing strands. The specimens have been designed to be representative of a scaled bridge girder belonging to a 4-girder grillage scheme, with the transverse diaphragm here simulated by means of a transversal steel profile crossing the main girder at its mid-span. The SHM tests are aimed at analyzing both serviceability and ultimate load conditions of these PC girders under different damage scenarios by means of modal identification techniques based on operational modal analysis (OMA). Indeed, the specimens have been manufactured with small holes in their bottom face, thus enabling the execution of some cuts of prestressing strands to artificially simulate damage in the prestressing system at different locations. A network of piezoelectric and MEMS acceleometric sensors are deployed along the beam to capture the main vibration frequencies and mode shapes in the various phases of the experimental campaign. The experimental campaign includes progressively increasing load levels and different damage scenarios (in terms of locations and amounts of strands’ cuts). The experimental tests have been complemented by a finite element model (FEM) of the beams, incorporating nonlinear behavior through fiber hinges and staged construction to reproduce the various phases of the experimental campaign. This finite element modeling strategy has been preliminarily validated by comparison with previously tested PC beams with two different prestressing levels and is also corroborated by a good match with ongoing experimental results of the present experimental campaign in terms of natural frequencies and mode shapes.

Beam-column joints represent critical components in reinforced concrete structures. In recent years, the use of post-installed reinforcing bars has become increasingly widespread for such connections, both in the retrofit of existing structures and in new constructions. Several commercial adhesives exhibit bond strengths significantly higher than typical steel-to-concrete bond capacities, potentially allowing for a reduction in the required anchorage lengths. This study presents experimental results from full-scale tests on two beam-column joints employing post-installed bars, comparing the performance of two adhesives with distinct mechanical properties. The results are also compared against current design formulations to evaluate their adequacy in predicting the behavior of such connections.

Le costruzioni sono progettate, al giorno d’oggi e in un contesto di rapido cambiamento climatico, tenendo in considerazione combinazioni di scenari possibili che comprendono rischi naturali e antropici. Nonostante ciò, non ci sono sufficienti dati sulle prestazioni degli edifici in corrispondenza di eventi critici, e questo a causa dell'assenza di una prassi consolidata per l'installazione e la gestione di sensori dedicati al monitoraggio delle performance strutturali. Questo rende estremamente difficili le indagini sul campo post-evento e la mappatura di eventuali danni, portando ad un allungamento dei tempi di intervento, con riversamenti negativi sulla resilienza dell'intero patrimonio edilizio. Manini Connect è un sistema innovativo brevettato che fornisce una risposta a questo problema attraverso il monitoraggio integrato delle strutture prefabbricate. Attraverso un insieme di sensori interconnessi, il sistema monitora il comportamento statico e dinamico delle strutture durante eventi critici, come terremoti, forti venti e piogge intense. Inoltre, può essere abbinato a sensori dedicati al monitoraggio della qualità dell'aria all'interno dell'edificio, alla produzione e al consumo locale di energia e ai consumi in termini di acqua, gas e rifiuti. Per le strutture di nuova costruzione, in fase di produzione sono posizionate delle predisposizioni all’interno dei pilastri mentre esternamente viene posizionata una stazione meteo per il monitoraggio dei parametri ambientali. I dati vengono ricevuti in tempo reale dal centro di controllo interno dell’azienda Manini Prefabbricati SpA da cui si ricevono gli alert dei superamenti soglia dei parametri, rivelando il verificarsi di un evento eccezionale, da cui vengono effettuati i controlli in tempo reale. L'utente ha accesso costante ai dati tramite una piattaforma dedicata accessibile da PC e altri dispositivi. Ciò permette di pianificare interventi di retrofit e manutenzione predittiva in risposta ad anomalie o danni rilevati dal sistema, basandosi sui parametri di progetto strutturale di ogni singolo edificio.

Il degrado del cemento armato per effetto della corrosione delle barre di armatura dovuto all’attacco di cloruri o di carbonatazione del calcestruzzo può influenzare negativamente la capacità prestazionali delle pile da ponte. In questo studio si è analizzato il comportamento di una pila a fusto unico rettangolare cava. Lo studio prevede un’analisi temporale per individuare i parametri salienti che influenzano la prestazione della pila. Si analizza la sezione a diversi istanti temporali che comportano perdite di massa delle armature differenti e conseguenti prestazioni dei materiali diverse. Vengono analizzate differenti estensioni di degrado in altezza e diverse configurazioni di degrado sul fusto per una fissata estensione. Il comportamento meccanico della pila è stato valutato, in forma parametrica al variare di parametri salienti, con analisi pushover in termini di resistenza laterale e spostamento al collasso. Le prestazioni sismiche della pila sono valutate attraverso analisi statistiche non lineari su modelli a fibre con plasticità concentrata.

In this study, a new quantitative index for multi-hazard risk assessment, the GEological-geotechnical Index (GETI), is applied to a selected case study to determine its effectiveness. The GETI aims to address the limitations of existing methods by accounting for the cascading effects of a primary hazard and providing a quantitative assessment tool for decision-makers.

The workflow is composed by two stages: first, a thorough literature review is performed to establish the geological context, followed by an evaluation of morphological, stratigraphic, and tectonic features, including field investigations, to determine potential instability conditions. This stage includes remote analysis, such as utilizing high-resolution Digital Terrain Models (DTM) derived from LiDAR data, to identify ground deformations and factors that predispose an area to seismic hazards.

The second stage involves developing a geological and geotechnical model using on-site and laboratory geotechnical evaluations, along with non-invasive geophysical techniques. This process facilitates the identification of natural hazards, which are then quantified using both simplified and advanced methods documented in existing literature.

Thus, the effects of the occurrence of hazards on the subsoil were quantified, and used as input parameters to calculate the probability of damage for each event and the total probability of damage using fragility curves.

The index primarily concentrates on earthquake-related risks and their secondary effects, such as ground motion amplification, soil liquefaction, and landslides or rockfalls. This method uses conditional probability to mathematically represent the concept of cascading effects. The GETI is designed as the total probability of damage from an earthquake, considering a range of damage intensities from minor to severe.

The limited availability of construction land in mountainous regions, such as Yunnan Province where 94% of the area is categorized as mountainous or semi-mountainous has increased hillside construction. However, buildings constructed on slopes exhibit unique vulnerabilities to seismic activity due to vertical irregularities, which make them prone to torsional forces during earthquakes. This study explores the effectiveness of base isolation technology designed explicitly for hillside structures, focusing on step-terrace buildings. The research uses a combination of theoretical analysis, finite element simulations, and shaking table tests to evaluate how isolation systems can reduce torsional responses and enhance seismic resilience. Shaking table tests conducted on isolated step-terrace models subjected to various seismic scenarios showed a significant 20% reduction in torsional dynamic response when the eccentricity of the isolation layers was maintained below 5%, thereby adhering to structural safety standards. Furthermore, isolated hillside models demonstrated an overall improvement of approximately 15% in torsional stability compared to their non-isolated counterparts. A subsequent parametric analysis underscored the critical impact of isolation layer positioning, slope inclination, and seismic input direction on the torsional stability of hillside buildings. A customized envelope design method for step-terrace structures was proposed and validated through finite element simulations and experimental testing, optimizing seismic resistance and overall structural performance. These findings provide a quantitative foundation for applying isolation technology in hillside construction, yielding practical insights for improving torsional control and overturning resistance. This approach promotes seismic safety and supports efficient land use in mountainous regions, contributing to the development of resilient and sustainable hillside infrastructure. This research substantially contributes to the safe and sustainable advancement of infrastructure in seismically active areas by refining base isolation techniques for hillside structures.

Anti-seismic devices are designed to meet performance criteria at the Life-Safety limit state and to resist earthquakes of higher intensity associated with the Non-Collapse limit state. To this end, current Seismic Codes prescribe γ-factors to amplify the design effect of the seismic action, ensuring adequate reliability margins. However, these factors vary across different Codes, and their effectiveness in guaranteeing structural reliability remains insufficiently investigated.

This study examines the design of hysteretic dampers for the seismic retrofit of two reinforced concrete buildings (3 and 6 stories) following the provisions of the Italian Building Code for a return period of 475 years. A range of ductility levels is considered to reflect the diversity of hysteretic dampers available on the market. The seismic performance and the structural reliability of the retrofitted structures are evaluated under high intensity earthquakes by checking the absence of structural collapse and failure of the damper system. The time-history analyses consider seismic events with return periods of 975 and 1950 years.

Findings reveal that the γ-factors prescribed in current Seismic Codes tend to be overly unconservative. Moreover, the results highlight a direct correlation between the reliability of retrofitted structures and the ductility of the damped braces.