The increasing frequency and intensity of heatwaves raises questions about the thermal vulnerability of buildings and, in particular, on how to assess their resilience to extreme heat. In this context, thermal fragility curves, which describe the probability of achieving or exceeding specific temperature thresholds for a building, serve as an effective measure to define the thermal vulnerability of existing buildings and identify tailored retrofit strategies. This study focuses on deriving thermal fragility curves for a case study: a 6-storey residential building constructed in the 1980s with a reinforced concrete structure and masonry infill walls. Dynamic thermal modeling and simulation were conducted over a one-year period using synthetic weather files generated to account for future heatwaves. The simulation results provide useful relationships in particular between: outdoor temperature and indoor Standard Effective Temperature (SET); and between outdoor daily maximum temperature and indoor SET. These relationships were finally analyzed to create and compare fragility curves using maximum likelihood fitting and the so-called Cloud methodology.@en

The growing concern over environmental impact and the significant improvement in the quality of engineered wood products have led to the rapid growth of the timber building industry in the last decades. Although traditional, yet recent, mass timber structural systems, such as cross-laminated timber walls, can provide satisfactory seismic performance during earthquakes in terms of life-safety, the crucial need for more resilient timber buildings has prompted the development of low-damage high-performance self-centring and dissipative solutions based on unbonded post-tensioned hybrid connections, referred to as Pres-Lam technology. The flexibility of design and construction speed, combined with the enhanced seismic performance, create a unique potential towards an earthquake-proof sustainable building system. Despite the growing popularity of the technology, a comprehensive framework for the fragility analysis, to be used in risk and loss modelling applications, has not yet been developed for both component and building levels.@en

Facades play a pivotal role in the performance of a building, serving various environmental, structural and operational functions. As climate-induced extreme events become more frequent, developing resilient facades is becoming crucial. Although facades can contribute significantly to the total post-disruption losses, their resilience is not sufficiently addressed in current design approaches. In response to this research gap, this study proposes a multi-criteria decision-making methodology to select optimal facade designs using resilience criteria: resilience loss and economic loss. The framework addresses the complexity of facade design, considering multiple hazards such as earthquakes and heatwaves. For seismic hazard, the facade’s resilience is defined as its ability to mitigate damage. In the case of heat hazard, resilience is assessed based on the ability to keep indoor conditions within a comfortable thermal range. To demonstrate the applicability of the proposed methodology, a case study of an 18-story office building in Izmir (Turkey) is used to compare alternative facade packages. These packages identify the facade design cases, each coupled with a dataset of seismic and thermal fragility curves. Numerical simulations are conducted to derive seismic and thermal resilience curves for each facade package, along with resilience criteria. These criteria are embedded into a practical decision-making process to enable the selection of the optimal design case based on project specifications.@en

Recent earthquakes have confirmed the vulnerability of our built environment, resulting in significant socio-economic losses, market disruptions, and environmental damage. Additionally, climate change is causing more frequent and severe weather-related events such as heat waves, which are impacting the construction sector and the health and well-being of building occupants. This emphasizes the pressing need to increase society's overall resilience by focusing on the various hazards that buildings may encounter throughout their lifespan. Although the need for a multi-risk analysis has been recognized in current performance-based design approaches, existing studies mostly focus on single hazards thereby neglecting the impact assessment of multiple hazards on the building performance.

This paper explores the economic and social losses of buildings due to earthquakes and heat waves. The study focuses on a high-rise building consisting of a reinforced concrete structure and masonry/cladding facades, and designed for two different locations in Europe. By means of a numerical model, time-history non-linear analyses are carried out to estimate the probable maximum losses in terms of repair costs and injuries/fatalities. In addition to earthquake scenarios, the study conducts dynamic energy simulations and comfort analyses that consider local climate scenarios and extreme heat events. The energy analysis calculates the economic losses caused by weather-related power consumption while the impact on occupants is assessed in terms of discomfort hours. Results from the seismic and energy simulations are finally compared to quantify and discuss the impact of the two different extreme hazards on the building performance and their potential consequences.

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In the last decades, recent earthquakes have further highlighted the high vulnerability of non-structural components. Post-earthquake damage due to building envelope, equipment and building contents can lead to substantial economic losses in terms of repair costs and daily activity interruption (downtime). Moreover, non-structural damage can represent a life-safety threat for both occupants and pedestrians. These considerations confirm the crucial need for developing low-damage systems for either structural or non-structural elements. This paper aims to assess the seismic performance of glazed facade systems, widely adopted in modern buildings, focusing on point fixed glass facade systems (PFGFSs), also referred to as “spider glazing”. In this work, a numerical investigation is developed to study the seismic performance of such systems at both local-connection level through a 3D FEM in ABAQUS as well as at global system level through a simplified lumped plasticity model in SAP 2000 to assess the overall in-plane capacity of the facade. Based on the local connection and global facade system behavior, a novel low-damage connection system is herein proposed, and a parametric study is carried out on the key parameters influencing the facade capacity. The benefits of implementing low-damage connection details are highlighted by an increase of the in-plane capacity of the facade system when compared to a traditional solution. To further investigate the potential of the proposed low-damage details in preserving the integrity of the facade system itself, non-linear time history analyses have been carried out on a case-study building equipped with the innovative PFGFSs.

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Different low-damage technologies have recently been developed to meet society's growing expectations for earthquake-proof buildings. Among others, the PRESSS (PREcast Seismic Structural System) technology has proved its capability to withstand earthquakes with minimal damage, effectively mitigating socio-economic losses. However, applying loss assessment methodologies can pose challenges due to the lack of data regarding fragility functions for low-damage structural components. This paper aims to propose a method for computing numerical fragility curves for rocking dissipative structural components. To achieve this, archetypes of precast concrete structures were analyzed to develop fragility models for this technology.

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Lessons from recent earthquakes have provided a tough reality check of the traditional seismic design approach and technologies, highlighting the urgent need for a paradigm shift of performance-based design criteria and objectives toward low-damage design philosophy and technologies for the whole building system. Modern society is asking for “earthquake proof” resilient buildings that are able to withstand seismic events without compromising their functionality. The EU-funded SERA (Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe Project) project discussed in this paper provided the opportunity to develop and validate within the European context an integrated seismic low-damage prototype, including main structure and non-structural elements, for the next generation of high-performance buildings. This paper presents an overview of the research, involving three-dimensional shake table tests of a two-storey 1:2 scaled timber-concrete post-tensioned dissipative low-damage structure “dressed” by earthquake-resistant gypsum/masonry partitions and glass/concrete facades. Specimen details, construction and assembly phases, test setup, and experimental results are discussed. After many cycles of input motions at increasing levels of seismic intensity (higher than Collapse Prevention Limit State), the integrated building system exhibited a very high seismic performance. The experimental campaign carried out at the National Laboratory of Civil Engineering in Lisbon confirmed the unique potential of low-damage technologies and the opportunity for their widespread implementation into design practice.@en

In recent years, the growing need for reducing non-structural damage after earthquakes has stimulated a dedicated effort to develop innovative types of fasteners for anchoring non-structural components (NSCs) to reinforced concrete (RC) host-structures. To contribute to such need, and building on previous research, this paper presents the results of a series of uni-directional shake-table tests of simulated NSCs anchored to concrete via: (1) expansion, and (2) chemical anchors; post-installed into: (a) uncracked, and (b) cracked concrete. Considering different construction details, the experimental investigation focused on traditional anchorage systems, alternative solutions comprising mortar filling into the gap clearance, and a low-damage system relying on supplemental damping devices, capable of reducing the acceleration of the NSCs as well as the force of the anchorage during seismic shakings. The experimental tests provided significant evidence on the beneficial effects of a dissipative anchorage protecting both the non-structural component and the anchorage itself, even during strong earthquakes. Moreover, when construction details allow to close the fixture clearance with a mortar filling, this stiffer solution provide an additional reduction of NSCs seismic accelerations and forces. Therefore, suggestions for further improvements of the adopted low-damage solution are also proposed.@en

Innovative damage-mitigation technologies have been recently developed to improve the seismic performance of structural and non-structural elements. The combination of these solutions can lead to a high-performance and cost-efficient building system, capable of sustaining earthquakes with limited damage and reduced socio-economic losses. This article investigates the convenience of implementing damage-control solutions through a cost/performance-based evaluation of multi-story-reinforced concrete buildings, comprising alternative combinations of traditional vs low-damage technologies for both structural skeletons (frames, walls) and non-structural elements (heavy/light facades, heavy/light partitions, suspended ceilings). The significant benefits of the innovative systems are investigated through loss assessment studies, implemented using a practical approach based on numerical pushover analyses and the capacity spectrum method. The parametric analyses confirm that the integrated low-damage structural/non-structural system can lead to significant savings, in these specific cases, in the range of 150–300 €/m2 during the 50-year building-life and downtime reductions at ultimate limit state in the order of 2–7 months.@en

Post-earthquake damage reports have continuously highlighted the significant vulnerability of nonstructural elements to seismic events. Nonstructural damage has severe impact in the building recovery, increasing the socioeconomic losses even for low intensity events. In the last few years, research efforts have focused on the development of innovative nonstructural solutions, to be combined with damage-resistant structural skeletons in order to obtain an overall high-performance building. As part of a European Union (EU)-funded project, the effectiveness of such integrated skeleton&envelope low-damage system in reducing the earthquake related losses was investigated. Tridimensional shake table tests on a 1:2 scaled timber-concrete low-damage structural skeleton, “dressed” by different innovative nonstructural elements (glass/concrete facades, gypsum/masonry partitions), were performed at the National Laboratory for Civil Engineering (LNEC) in Lisbon, Portugal. The shake table tests were carried out at increasing seismic intensities to investigate the structural and nonstructural performance up to a higher-than Collapse Prevention Limit State according to the Italian Code (975 years return period). This paper focuses on the dynamic behavior of nonstructural elements with detailed discussion on construction detailing, seismic demand and performance of the innovative solutions. The high performance of nonstructural elements proved the potential of the details introduced in the partitions/facades. Minimal or no damage was observed up to the end of the overall testing sequence, which reached moderate-to-high interstory drift ratios (more than 1.00%) - typically expected to cause severe damage to traditional nonstructural partitions/infills/facades.@en