In March 2024, the Search for Hidden Particles (SHiP) experiment and its associated Beam Dump Facility (BDF) were selected for future physics exploitation using the Super Proton Synchrotron (SPS) at CERN. SHiP is a general-purpose, intensity-frontier experiment designed to search for dark matter-related physics. Proposed approximately a decade ago, the SHiP experiment has passed through multiple design stages and optimizations. This study focuses on the structural design of primary subcomponent of SHiP, i.e., “the decay volume”, where the experiment seeks decay signatures of new particles. Initial concepts included a reinforced-concrete structure with hollow rectangular cross-sections exceeding 10 m × 5 m, evolving to a 50-m-long conical steel vessel under vacuum, and more recently to a metal-framed helium balloon, which is a textile helium seal supported by steel frames. We present the structural and hydraulic configurations now considered the final reference solutions for decay vessel of the SHiP to highlight the unique engineering challenges of minimizing structural mass, thereby reducing particle interactions and enhancing physics performance. To provide context, the paper first summarizes the collaboration status of SHiP and subsequently reviews the sequence of decay vessel structural options explored since the inception of the project. This historical overview depicts how the decade-long, multidisciplinary effort shaped current design choices. Furthermore, it illustrates how a novel, multidisciplinary, integrated approach guided the design evolution of the decay vessel. In the context of large-scale international collaborations such as SHiP, this paper demonstrates that a coordinated strategy integrating structural, hydraulic, and detector requirements has seldom been applied in similar large experimental facilities. As demonstrated in this study, such an approach proved essential for achieving a configuration that satisfies engineering constraints while preserving the experiment’s physics performance goals. The principal outcome of this effort is the proposed final design strategy, which coalesces engineering and physics goals into a unified framework. This methodology ensured that all subsystem interactions were considered concurrently to prevent costly redesigns during project execution. The final design strategy separates the mechanical system of the decay vessel into two key components: (i) a structural steel framework and (ii) non-structural aluminum elements, both integrated with a complex hydraulic system to circulate a specific detection liquid. This division maintains functional and structural efficiency and offers flexibility to adapt to seismic-condition variations throughout the project.

The purpose of this recipe is to provide a classification of existing buildings in Italy based on their physical vulnerability to tsunami loads. This method for large-scale (i.e., urban or regional scale) tsunami vulnerability assessment is an essential tool for tsunami loss analysis, risk management and for prioritizing interventions to protect the built environment.

The Main Building of the School of Engineering at the University of Naples “Federico II” has been for years the core of an experimental program focused on structural and seismic monitoring for risk mitigation and management. The relevance of the case study is dictated by the architectural value of the building and its location in the active volcanic area of Campi Flegrei, which has been recently hit by several earthquakes associated with bradyseism. During some renovation interventions on the building, the former monitoring system installed in 2006 was removed and it has been recently replaced by a new up-to-date vibration based Structural Health Monitoring (SHM) system. The new SHM system has been implemented within the RETURN research project focused on multi-risk science to create resilient communities under changing climate. In that context, vibration-based SHM plays a pivotal role as a technology to enhance resilience in environments exposed to natural hazards. The present paper describes the SHM system in detail, reports some results, and remarks the role of OMA in the development of effective SHM technologies.

The study was aimed at assessing the effectiveness of a rapid and low-cost solution for seismic retrofitting of hollow brick partitions, in the context of both existing and new buildings. The retrofitting solution, consisting in a detailing variant, was implemented by providing lateral and superior thin slots between partition panels and surroundings, injected by self-expanding polyurethane foam. Shake table tests were carried out according to the international shake table protocol AC156. Both dynamic identification and seismic performance tests were carried out up to peak table accelerations representative of high seismic hazard conditions. Dynamic properties, hysteretic behavior, and capacity measures were associated with physical damage conditions and conventional damage states. A safety assessment was carried out by comparing experimental capacities and code demand measures, considering low to high seismicity sites (in Italy) and both importance class II and IV buildings. The retrofitted partition response and performance was compared to the one associated with non-retrofitted conditions, and it was confirmed that the developed retrofitting solution potentially reduces the seismic vulnerability of hollow brick partition panels. A simplified initial cost and seismic loss/repair analysis referred to a realistic building/apartment scenario finally proved the potential effectiveness of the retrofitting intervention.

Additive manufacturing with cement-based materials is increasingly being explored for structural applications in the construction sector. While significant advances have been made in materials and process development, the reliable prediction of structural performance - among the others, the compressive strength at the element scale - remains an open research challenge, especially in the absence of dedicated design codes. This study presents an experimental investigation on the axial compressive behavior of 3D-printed hollow wall panels made with cementitious mortar. In particular, a series of monotonic uniaxial tests were carried out to assess the influence of geometric configuration, printing-induced imperfections, and material properties on the uniaxial compressive response. The results revealed a predominantly brittle failure mode in all specimens. Variability in strength and damage patterns was closely linked to cross-sectional irregularities and layer thickness variation, whereas the in-plane aspect ratio of the panels was characterized by a limited influence exhibited only for larger H/L ratios. The findings highlight critical aspects for modelling and design, suggesting the need for refined qualification procedures for 3D-printed structural elements under compressive loads.

Reinforced concrete (RC) multi-column bents in bridge overpasses exposed to aggressive environments are highly susceptible to corrosion-induced deterioration, which can significantly compromise their lateral load-carrying capacity and seismic performance. This study investigates the influence of corrosion on the nonlinear lateral behavior of RC bridge bents through a comprehensive set of static pushover analyses. A parametric study is performed assess the lateral behavior of typical bridge bent configurations considering variable corrosion levels affecting reinforcement properties and confinement efficiency. The modeling approach captures the degradation of flexural capacity, stiffness, and ductility. Two simulation strategies are examined: one exhibiting only flexural failure, and another characterized by coupled flexure-shear mechanisms. This dual comparison allows assessment of how corrosion impacts the balance between flexural and shear capacities and the possible transition from flexure-shear to flexure-dominated behavior as corrosion progresses. Pushover analyses are carried out for multiple corrosion scenarios, enabling a quantitative assessment of lateral strength degradation, displacement capacity, and ductility reduction. The results highlight the nonlinear progression of damage as corrosion intensifies and emphasize the need to incorporate realistic degradation models in seismic vulnerability assessment of bridge systems. This study provides valuable insights for the evaluation and prioritization of retrofitting strategies for RC overpass bents in aggressive environments.

In India, a large stock of RC wall-frame buildings with deficient structural wall plan density (SWPD) is potentially vulnerable to combined ageing-induced deterioration and repeated seismic excitation. The primary objective of the present study is to evaluate the seismic risk of such building stock and to analytically derive the insurance parameters for the risk management, considering both ageing effects and sequential ground motion (GM) records. Three levels of corrosion rate (CR) or corrosion deterioration are considered, representing severe ageing, moderate ageing, and no ageing. A performance-based framework is adopted in which nonlinear response history analyses are used to develop seismic fragility and vulnerability functions. These functions are subsequently integrated with a site-specific seismic hazard curve to estimate annual seismic damage rate and seismic financial risk. The results show that the combined influence of corrosion deterioration and sequential GMs leads to a substantial increase in annual seismic damage rate, with the maximum amplification observed at near-collapse damage state. The financial risk results further show that the sequential GM records increase absolute financial loss with the increase in corrosion rate; however, its relative (multiplicative) impact across different hazard levels is highest for no ageing effect (CR = 0%). Finally, using a novel approach, the insurance parameters are determined, and the effect of corrosion-induced deterioration on the annual premium rate is quantified. Overall, the findings demonstrate the importance of accounting for the coupled effects of corrosion deterioration and sequential GMs in the seismic risk evaluation of RC wall-frame building stock. The results also provide quantitative support for risk-informed mitigation strategies and insurance decision-making.

Existing performance assessment methods for structures subjected to flow-type loading (i.e., flood, tsunami) rely on assumptions and previous knowledge derived from other hazards, such as earthquakes. However, flow-type induced loads on structures are fundamentally different in nature from seismic action, inducing long-duration non-uniform pressures on inundated components. Flume or wave basin tests on large-scale structural components under fluid loading are limited due to the difficulties in scaling. The present paper proposes a novel quasi-static testing method for performing full-scale tests on masonry infill walls in reinforced concrete (RC) frames subjected to simulated flow-type loading in a structural laboratory setting. The innovative test set up involves the use of an array of 28 pneumatic actuators and a novel testing procedure (i.e. test set-up and load protocols) is developed for simulating quasi-statically flow-type induced loads with increasing flow depth on full-scale building components. The feasibility of the proposed testing method is herein demonstrated on four full-scale masonry infill walls (dimensions 4.2 m x 2.3 m) in RC frames. The tests allow for the out of plane (OOP) performance of masonry infill walls to be assessed under flow-type loading conditions with increasing flow depth. Masonry walls are tested with and without plaster to point out the effect of the latter on the overall capacity of the wall. Original experimental data from flow-type testing are presented and discussed to provide insights into the OOP capacity of infill walls under flow-type loading. Finally, the OOP performance of infill walls under flow-type loading is compared with that of the same specimen previously tested under seismic loading conditions. Results attest the feasibility of the proposed testing method to characterise the structural response of full-scale building components under flow-type loading.

Bridges are critical components of transportation and communication networks. However, many of these structures are aging and susceptible to damage, underscoring the need for consistent monitoring to ensure their safety. Limited economic and technical resources highlight the importance of adopting smart monitoring strategies to prioritize infrastructure for detailed inspections, evaluations, and interventions. In recent decades, satellite-based remote sensing has gained prominence as a non-invasive tool for large-scale structural monitoring, with particular reference to Multi Temporal Differential SAR Interferometry (MT-DInSAR). This technology enables the collection of extensive data on the temporal and spatial progression of ground displacements, capturing large-scale deformation phenomena such as subsidence, landslides, and settlements. On a more localized scale, such as for individual bridges, high-resolution and frequent data sampling can be useful for preliminary structural assessments of roads, railways, or specific bridges. This study presents a large-scale methodology for the preliminary structural assessment of bridge networks using satellite-derived deformation data. The approach is applied to three different Proof of Concepts developed within the RETURN extended partnership, utilizing MT-DInSAR measurements from both ascending and descending orbits. By analyzing displacement trends of the measure points, the methodology proposes a classification of the bridges. This classification can help stakeholders identify the most vulnerable bridges and develop more targeted monitoring and maintenance strategies.

The catastrophic landslide and flood events that affected Ischia Island on November 26th, 2022, taking place in the same area previously damaged by an earthquake occurred five years before, underscored the urgent need for integrated multi-hazard risk mitigation strategies in complex volcanic and highly urbanized environments. This study presents a comprehensive Mitigation Measures Plan (MMP) developed under the coordination of the Government Commission for the Emergency and Reconstruction for Ischia Island (GCER) to support land planning, accounting for multiple hazards including rainfall-induced debris avalanches, debris flows, rockfalls, floods, and seismic slope instability at the island scale. Moving beyond conventional single-hazard frameworks, the proposed approach integrates geological, geomorphological, hydrological, and geotechnical data with high-resolution topographic information derived from LiDAR and aerial photogrammetry surveys. Physically based numerical models are adopted to reconstruct hazard scenarios and quantify susceptibility patterns. Rockfall trajectories and runout zones, as well as debris-avalanche and debris-flow propagation, are simulated using 3D software. Flood hazard and inundation dynamics are modelled using two-dimensional hydrodynamic simulations under extreme rainfall scenarios, including climate projections based on intensity–duration–frequency analyses. These datasets are further integrated with historical inventories, seismic microzonation studies, and post-earthquake (2017) and landslide (2022) field inspections to ensure a robust multi-source characterisation of hazard processes. Results highlight strong spatial coupling between steep volcanic slopes, incised drainage networks, and densely urbanized areas, where exposure is significantly amplified. In response, the MMP was developed, combining structural and nature-based remedial measures such as slope stabilization works, debris retention systems, and underground hydraulic diversion tunnels with non-structural strategies including land-use regulation, monitoring systems, emergency planning, and harvesting schedules for protective forests. The Ischia case study demonstrates the effectiveness of integrated multi-hazard approaches in translating advanced numerical modelling into operational risk reduction strategies, providing a transferable framework for other Mediterranean volcanic islands exposed to interacting natural hazards.

Undesirable shear failures can be detrimental for the seismic performance of existing RC buildings, particularly at the beam-column joint (BCJ). Experimental tests and analytical studies demonstrated that fiber-reinforced polymer (FRP) materials are effective as local strengthening solutions, enhancing shear capacity and preventing the joint panel shear failures. Furthermore, they have the advantages of rapid and minimally invasive application. Despite these benefits, debonding at the FRP-concrete interface limits their effectiveness to working strains significantly lower than ultimate capacity. Mechanical FRP fan anchors have shown a great potential in avoiding the end-debonding and increasing the strength of FRP systems. However, to date, experimental tests on quadriaxial fabrics, commonly used in the seismic strengthening of BCJs, anchored with FRP fan are missing. This study investigates the influence of FRP fan anchors on the tensile capacity of FRP quadriaxial fabrics. The experimental results of an extensive testing campaign in terms of strength and strain response for anchored and unanchored specimens are presented and discussed along with a comparison with predictions obtained using available capacity models.

Recent seismic events have underscored the role of seismic detailing in earthquake-prone regions, emphasizing the high vulnerability of existing reinforced concrete (RC) structures. Beam-column joints (BCJs) are among the most critical members influencing the overall response of buildings during seismic events. BCJs designed under obsolete regulations often lack adequate transverse reinforcement, making them susceptible to brittle failure, while the use of plain bars is associated with bond degradation and lower steel yield stress. Externally bonded FRPs are proven effective in enhancing the strength of BCJs, preventing shear failure, thereby reducing the overall seismic risk of buildings. However, many of the proposed strengthening layouts disrupt building usability, limiting the effectiveness of seismic risk mitigation at a regional scale. To address this, FRP-based minimally invasive (MinInv) strengthening layouts have been recently proposed. This study reports and discusses the results of an experimental program on four BCJs with plain internal steel bars typical of RC buildings in the Mediterranean built before the 70's. They are tested in both the as-built and FRP-strengthened configuration, to validate the performance of MinInv-layouts. Results demonstrated improved strength, a shift from brittle to ductile failure, and significantly increased energy dissipation. A comparison with available capacity models is proposed.

The conventional Structural Health Monitoring (SHM) framework focuses on individual structures. However, preliminary studies are required at a large territorial scale to effectively identify the most vulnerable elements. This becomes particularly challenging in urban settings, where numerous buildings of varied shapes, ages, and structural conditions are closely spaced from one another. A twofold task is therefore required: the automated identification and differentiation of various structures, coupled with a ranking system based on perceived structural risk, here assumed to be linked to their deformation patterns. It integrates displacement measurements acquired through the Differential Synthetic Aperture Radar Interferometry (DInSAR) technique, specifically employing the full-resolution Small Baseline Subset (SBAS) approach coupled with Hierarchical Clustering. The effectiveness of this method is successfully demonstrated and validated in two selected areas of Rome, Italy, serving as case studies. The results of this vast-area scale monitoring can be used to select the constructions that need a more in-depth assessment.

The increasing awareness about tsunami risk for urban coastal communities worldwide leads to the development of tools for disaster risk management and loss quantification in a Probabilistic Tsunami Risk Assessment (PTRA) framework. In this study, a time-dependent tsunami fragility analysis framework for physical assets is developed to produce large-scale analytical fragility functions for the Italian Reinforced Concrete (RC) residential building stock. The time-dependent ageing deterioration is simulated on RC buildings for different exposure conditions (i.e., in-land, near the coastline) and deterioration level (i.e., if regular maintenance works are guaranteed or not). A mechanics-based method for the damage assessment of frames under tsunami loading is adopted for the fragility analysis of RC building portfolios, able to account for the building-to-building variability and the tsunami flow variability. The building height and date of construction are selected as main attributes for the definition of homogeneous building classes for the study region. Monte Carlo simulation is performed for the generation of 105 building realizations for each class, accounting for uncertainties in both capacity and demand. Missing information about structural details of RC components are completed through a simulated design procedure, according to the design criteria in force at the time of construction for the study region. Preliminary sets of analytical fragility functions are derived for the Italian residential building stock at different structural and non-structural damage levels, and results are compared with fragility models from the literature, attesting the soundness of the proposed method. The results show that uniform corrosion slightly affects the fragility curves, whilst pitting corrosion increases the probability of occurrence of intermediate damage levels.

The conventional framework for Structural Health Monitoring (SHM) primarily focuses on individual structures. However, to effectively identify the most vulnerable elements, preliminary studies are required at a wide area scale. This becomes particularly challenging in urban settings, where numerous buildings of varied shapes, ages, and structural conditions are closely spaced from one another. A twofold task is therefore required: the automated identification and differentiation of various structures, coupled with a ranking system based on perceived structural risk, here assumed to be linked to their deformation patterns. It integrates displacement measurements acquired through the Differential Synthetic Aperture Radar Interferometry (DInSAR) technique, specifically employing the full-resolution Small Baseline Subset (SBAS) approach, with Hierarchical Clustering. The effectiveness of this method is successfully demonstrated and validated in two selected areas of Rome, Italy, serving as case studies. The results achieved on this wide area scale monitoring can be used to select the constructions that need a more in-depth assessment.

The Italian infrastructure network of roads and bridges is one of the most complex in the world, due to the orography of the territory. Italy is strongly interested by seismic and hydrogeological hazards and, in addition, degradation and obsolescence phenomena are common on infrastructures approaching the end of their nominal life. Furthermore, during their service life these infrastructures can be subjected also to extreme actions such as the fire. In particular, the past examples of damages on infrastructures as consequence of fire event and the high dependency on uncertain factors of fire have motivated the study for developing models to estimate the possible consequences that this phenomenon can cause on infrastructures. In particular, the paper sets a methodology to assess the structural fire fragility of infrastructures, based on fire hazard scenarios, developed specifically for bridges. Then, two existing pilot case studies (a reinforced concrete bridge and a composite steel-concrete one) are modelled, by deriving the structural response under different natural fire scenarios. By means of Cloud Analysis, a linear regression about the key parameters in the fire action definition and the structural response is assessed, by considering different performance levels, specifically proposed for bridges. Finally, the fragility curves are obtained, measuring the capacity of the case study bridges under the selected fire scenarios. The study also shows which of the fire scenarios parameters can be better correlated to the structural response of the bridge, that is useful for a proper fire resistance assessment and design.