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An innovative solution for aluminium-glass partition walls that can withstand seismic actions without damage is presented. The key feature characterising the proposed innovation is a dissipative coupling between the components of the partition wall, i.e., the glass plates and the surrounding aluminium frame, accomplished through the interposition of high-damping rubber pads (HDRPs). Sliding mechanisms between glass panels and the aluminium frame are permitted through specific detailing solutions, which allow the partition wall to be unsensitive to the inter-storey drift imposed by the hosting structure. A detailed discussion of the system conception is illustrated, showing the main intermediate steps that led to the final solution. The implementation of a refined numerical model is illustrated, and its characteristic parameters are calibrated according to a set of experimental tests previously performed on materials and subcomponents. A numerical application to a case study consisting of a partition wall system installed within a three-storey building is provided to assess the performance of the proposed innovative solution under severe earthquakes. [ABSTRACT FROM AUTHOR]

Base‐isolated hospitals are frequently preferred to fixed‐base ones because of their improved seismic structural performance. Despite this, the question remains open on the advisability of using this modern seismic protection technology in preference to other conventional solutions, on the grounds of a holistic approach based on limiting non‐structural damage as well as continuity of service to the community in the aftermath of an earthquake. Two full‐scale four‐storey (fixed‐base) and three‐storey (base‐isolated) hospital buildings have been recently built and subjected to three‐dimensional shaking table tests at the National Research Institute for Earth Science and Disaster Prevention (Japan), with particular attention to evaluating and classifying functionality of non‐structural components and vital medical equipment. A two‐phase experimental campaign was carried out considering two earthquakes scaled at different intensity levels and applied along the horizontal and vertical directions. The current study aims to provide results of a numerical structural and non‐structural blind prediction of these hospital settings. A homemade numerical code is developed to account for lumped plasticity modelling of steel frame members and variability of the friction coefficient of spherical sliding bearings. Moreover, three non‐structural components are modelled in the fixed‐base structure: that is, elastic single degree of freedom systems representing two tanks filled with sand at the top floor; elastic beam elements for piping at the third floor; five‐element macro‐model for the in‐plane‐out‐of‐plane nonlinear response of partition walls at the first floor. The identification of predominant vibration periods of the fixed‐base structure is carried out using a homemade numerical code based on the continuous wavelet transforms in combination with the complex Morlet wavelet. Finally, the sliding and rocking motion of three items of medical equipment (i.e., incubator at third floor, dialysis machine at second floor and surgical bed at first floor) are analysed by means of a homemade numerical code, considering acceleration time histories of selected structural nodes of the fixed‐base structure. [ABSTRACT FROM AUTHOR]

The implementation of fluid viscous dampers has been proven as a feasible method to improve the seismic performance of buildings. However, the different variables involved in the damper's design affect the structural response, especially in terms of seismic demand on non-structural elements. This paper presents a parametric study on the floor acceleration response of three case study buildings equipped with fluid viscous dampers through nonlinear time-history analysis. The results show that the different design parameters of fluid viscous dampers significantly modify the floor acceleration response, with some damper configurations yielding floor accelerations larger than those of the buildings without dampers. [ABSTRACT FROM AUTHOR]

This paper presents a study of acceleration demands in low-rise reinforced concrete (RC) buildings with torsion, evaluated by quantifying peak floor accelerations (PFAs) and floor response (acceleration) spectra (FRS). The study was performed with the aim to provide simple empirical formulas to quantify the amplification effects due to torsion, which can occur in most of the existing and new RC buildings. With this goal in mind, a set of eight archetype buildings was selected, characterized by an increasing floor eccentricity obtained by moving the centre of rigidity (CR) away from the centre of mass (CM). Numerical models of the proposed set of archetype RC buildings were considered in both linear elastic and nonlinear configurations. For the latter, the properties of models were widely varied, by systematically modifying parameters of plastic hinges, in order to obtain a sample of 1000 models. Non-structural components (NSCs) were considered linear elastic in all cases. To investigate acceleration demands, a set of forty Eurocode 8 spectrum-compatible ground motion records were used as input. For linear elastic building models, it was observed that the change of demands depends on the position of the NSC (in-plan and in-height), and on the distance between CR and CM. On the other hand, for nonlinear models, additional parameters must be considered, such as the building ductility (μ) and yielding force (Vy). New regression models were proposed for quantifying the observed differences in PFAs and FRS when torsion occurs. The efficiency of the proposed models was assessed by testing the new formulas on an existing case study building, as well as on the well-known SPEAR building. [ABSTRACT FROM AUTHOR]

An innovative solution for aluminium-glass partition walls that can withstand seismic actions without damage is presented. The key feature characterising the proposed innovation is a dissipative coupling between the components of the partition wall, i.e., the glass plates and the surrounding aluminium frame, accomplished through the interposition of high-damping rubber pads (HDRPs). Sliding mechanisms between glass panels and the aluminium frame are permitted through specific detailing solutions, which allow the partition wall to be unsensitive to the inter-storey drift imposed by the hosting structure. A detailed discussion of the system conception is illustrated, showing the main intermediate steps that led to the final solution. The implementation of a refined numerical model is illustrated, and its characteristic parameters are calibrated according to a set of experimental tests previously performed on materials and subcomponents. A numerical application to a case study consisting of a partition wall system installed within a three-storey building is provided to assess the performance of the proposed innovative solution under severe earthquakes.

This paper presents a general seismic classification procedure for acceleration‐sensitive non‐structural elements (NSEs) based on seismic qualification shake table testing and provides an application example for electrical cabinets in Italy. The proposed seismic classification procedure requires the definition of a set of required response spectra (RRS) for qualification shake table testing defined at different seismic hazard levels and the definition of a formal procedure to generate a test input motion. Each required response spectrum at a given seismic hazard level is then linked to different class levels and the requirements that an NSE should present to achieve each class level are defined. Using this framework, a seismic classification procedure for NSEs is developed for Italy, in which, the RRS are defined according to a peak floor spectral acceleration seismic hazard map of the territory so as to predefine regions in which an NSE belonging to a given class can be installed or not according to either a life safety performance objective or a continuous operation performance objective. Also, the limitations of the proposed seismic classification procedure are outlined. Finally, a nominal application example is presented in which four electrical cabinet specimens were tested on a shake table and their class levels were defined. The results of the application example are used to nominally show how the proposed classification procedure could be applied to discriminate between different types of the same NSE depending on the specific desired application. [ABSTRACT FROM AUTHOR]

The simulation of the authentic evacuation process is conducive to accurately evaluate the casualties of buildings under earthquake. This study improves the traditional cellular automata model to simulate the crowd evacuation process in buildings under earthquake. The modified model simulates the attraction of exits to crowds, herd behavior of crowds, avoidance behavior for obstacles, decision-making behavior for paths/exits selection, and conflict between pedestrians in the evacuation process. Based on the video, which records authentic evacuation under earthquake, the influence coefficients of each factors are determined. In addition, the modified cellular automata model uses the refined cellular space to describe the geometric dimensions of the evacuation environments and obstacles, and therefore it improves the accuracy of the evacuation model. The explicit finite element method is used to simulate the seismic damage process of structural and non-structural components. The judgment criterion of casualties which combines the finite element model with the evacuation model, is proposed. The number and distribution of casualties are predicted based on the criteria. Finally, a seven-story official building with reinforced concrete frame structure located in Dujiangyan City, Sichuan Province, China is considered as example to verify the rationality and applicability of the proposed method.

Non-structural components (NSCs) should be analysed properly using the floor response spectra (FRS) method to reduce financial loss due to earthquakes. There are various methods available in the literature to scale recordings. However, there is little or no agreement among researchers regarding the correctness of these methods in the analysis of NSCs. Therefore, the present study examines the influence of different amplitude scaling techniques (geometric mean and Sa(T1)) and spectral matching procedures on the seismic demands of NSCs. The spectral matching method shows the lowest ground motion parameter dispersion. The results reveal that the Sa(T1) scaling method produces lower floor responses. The spectral matching method shows smaller dispersion in the spectral ordinates and median response quantities. The amplification factors estimated in this study were compared to those from the existing code formulations. Based on the findings of this study, the spectral matching approach in the time domain may be utilized to better estimate seismic demands on NSCs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Seismic damage affecting the non-structural components of buildings (such as infills) can significantly impact the expected economic losses over a structure’s service life. Recently, autoclaved aerated concrete (AAC) infills have gained attention in the construction industry due to their light weight, energy efficiency, and durability.Methods: This study investigates the out-of-plane behavior of an innovative AAC infill wall system by means of shake table tests. The wall system was made of low-density AAC units with innovative joints made from polyurethane resin and steel plates for connection to a structural frame. Shake table tests were carried out using artificial accelerograms based on ICBO-AC156, which can reproduce a wide range of interstory drift demands. The study is articulated in three stages: the mechanical characterization of the AAC infill wall, shake table tests, and seismic behavior analysis of the wall based on current code requirements.Results and Discussions: The results demonstrate the effectiveness of the innovative AAC infill wall system in resisting out-of-plane seismic loads, also considering different levels of seismic action, with base accelerations reaching up to 0.80 g.

The lateral wind load applied to high-rise buildings results in movements that can cause creaking noises in drywall partitions with suspended ceiling systems. These noises can be disruptive to the residents and impair the structure's serviceability. In this study, a sequence of large-scale three-dimensional (3D) experiments was conducted on two assemblies of drywall partitions with a suspended ceiling system to address this serviceability issue. The goal was to explore the 3D response of these assemblies, with a key emphasis on validating the effectiveness of adhesives in mitigating noise introduced by screw fixings, not only for individual walls but also when interacting with neighbouring walls and ceilings, which represent the real-world conditions. The six-degree of freedom (6-DOF) Multi-Axis Substructure Testing (MAST) system at Swinburne University Technology was used to simulate realistic wind load conditions. Two sets of test specimens were constructed using different methods to fix the plasterboard wall lining to the cold-formed steel (CFS) frame, which was rigidly bolted to both the MAST crosshead and the floor below. The first set of specimens (Assembly 1) had the plasterboards screw-fixed to the steel frame, while the second set (Assembly 2) used adhesive-only or a combination of adhesive and screw-fixing methods. Additionally, the instrumentation employed for acoustic measurements was strategically chosen to capture the noise generated by the overall system-level response. This served as a means of validating the serviceability noise experienced by users/occupants. Sound pressure level measurements and an acoustic camera were used simultaneously to identify the noise sources. The creaking noise measurements were compared for different specimens of Assemblies 1 and 2 and the effects of different construction details (e.g. fixing method, plasterboard ceiling lining, etc.) on wind-induced creaking noises were discussed. The results of this study can provide valuable insights for manufacturers and designers to minimize creaking noises in drywall partition systems and propose new construction techniques to improve the serviceability of high-rise buildings. • Wind-induced creaking noises in drywall partitions were assessed. • Multi-axis substructure testing (MAST) system was used for 3d full-scale experiments. • Two different methods of screw vs adhesive fixing plasterboards to steel frames were evaluated. • Adhesive fixing significantly reduced wind-induced creaking noises. [ABSTRACT FROM AUTHOR]

Masonry infill walls are among the most vulnerable components of reinforced concrete (RC) frame structures. Recently, some techniques for enhancing the performance of the infills have been proposed, aiming at improving both the global and the local behaviour of the infilled frame structure. Among the most promising ones, there are those that aim to decouple or reduce the infill‐frame interaction by means of flexible or sliding joints, relying respectively on rubber or low‐friction materials at the interface between horizontal subpanels or between the panels and the frame. Numerous models have been developed in the last decades for describing the seismic response of masonry‐infilled RC frames, but these have focused mainly on the case of traditional infills. This study aims to fill this gap by proposing a two‐dimensional macro‐element model for describing the in‐plane behaviour of RC infilled frames with flexible or sliding joints. The proposed modelling approach, implemented in OpenSees, is an extension of a discrete macro‐element previously developed for the case of traditional infill panels. It is calibrated and validated in this study against quasi‐static tests from the literature, carried out on masonry‐infilled RC frames with sliding and rubber joints. The study results show the capabilities of the proposed modelling approach to evaluate the benefits of using flexible joints in terms of minimising the negative effects of the interaction between infill and RC frame and limiting the increase of global stiffness of the system with respect to the bare frame condition. [ABSTRACT FROM AUTHOR]

Metal replacements for automotive and aerospace components are already a consolidated reality, in light of the advantages offered by fibre-reinforced polymers, consisting of reduced costs, weight, and environmental impact. As a result, engineering has been studying the possibility of replacing currently used metallic alloys with alternative materials, such as thermoplastic fibre-reinforced polymers, in the manufacturing of non-structural sections of marine engines. Given the peculiar characteristics of the working environment of such parts, i.e., ship engine spaces, and the strict requirements regarding safety, the selection of the polymer must be properly performed through a tailored material design process. Consequently, the redesign of the components must be carried out with the aim of exploiting the best of the materials' properties while ensuring the correct resistance and simplifying installation operations. In this framework, finite element simulations may represent a suitable approach to validate the conformity of the proposed material and design. In this paper, this methodology is applied to a camshaft cover of a four-stroke marine engine, currently made of aluminium alloy. A 30% wt GFs/PA6,6 was identified as the most promising material and the novel plastic cover proved to guarantee the correct resistance while ensuring an important reduction in weight, processing costs, and required energy. [ABSTRACT FROM AUTHOR]

Bidirectional quasi-static cyclic loading was applied to a subassembly of drywall partition walls integrated with cross-laminated timber rocking walls. Details aimed to reduce seismic damage to the partition walls were investigated, such as slip connections of partition walls to the diaphragm and gap detailing for the wall intersections. Telescoping detailing eliminated damage to the framing at the wall ends compared to traditional slip-track detailing. The distributed gap wall delayed the damage to about 1% inter-story drift. In the corner gap wall, the sacrificial corner bead opened up at low drifts (0.43%), but the wall was damage-free until more than a 2% drift. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The suitability of 'design' height amplification factors (HAF) for the purpose of seismic assessment of existing non-structural unreinforced masonry (URM) components with known strength was evaluated through a numerical study. Four building typologies were included that represented pre-1940 URM construction in Australia and New Zealand. Through pushover and incremental dynamic analyses, the effects of diaphragm flexibility and nonlinear building response on floor accelerations were studied. It was found that Australia/New Zealand code procedures include significant inelastic building behaviour that reduces HAF. An interpretation was made on the applicability of the assumptions in the context of assessing non-structural URM components. [ABSTRACT FROM AUTHOR]

The effect of partition walls and non-structural elements on the dynamic response of floors is still not well understood, and there is a need for vibration testing of floors at various stages of construction. The best way to shed some light on the effect of non-structural components is to test additional floors (preferably the same floor) before and after the installation of non-structural elements and compare the dynamic properties. For that purpose, the authors conducted vibration testing on a building floor under construction at various stages of fit-out to quantify the effects of various non-structural elements on the vibration response. An elevated floor of a steel-framed building in the Southeastern United States was tested: the first test was performed for the bare slab conditions with minimal non-structural elements, while the second test was conducted after the installation of non-structural components and in the presence of various construction materials spread over the test floor. The modal tests were conducted by applying measured dynamic forces using an electrodynamic shaker while accelerations were measured at critical locations on the slab. The measurements were post-processed to determine the frequency response functions, which provided general information on the dynamic response. The selection of the test points and excitation functions were primarily to extract maximum data regarding the performance of non-structural elements rather than as part of a standard vibration serviceability assessment of the floor structure. The modal tests were repeated after the installation of non-structural components, electrical and mechanical ductwork, to determine their effect on the vibration characteristics of the floor. The resulting frequency response functions were compared for each condition, and finite element models were created to represent each test condition. As a result, the installation of non-structural components was observed to influence the dynamic response of the floor. Combined with the other test data in the literature, the results of the experimental testing presented in this paper might lead to more effective modeling techniques and provide guidance as to their inclusion into analytical models.

Traditional Hysteretic Dampers (HDs) are installed in buildings to enhance their seismic performance by increasing the effective stiffness and damping and are usually designed to guarantee the structural safety for severe Ultimate Limit State (ULS) seismic events. As a negative consequence, only minimal damping is provided during weak but more frequent Serviceability Limit State (SLS) earthquakes since HDs mainly operate in their elastic regime. This can cause high Peak Floor Accelerations (PFAs) that are detrimental for sensitive non‐structural components (NSCs), like electric network, elevators, and computers, whose integrity is crucial in high‐technological buildings (e.g. hospitals, and emergency centers). In order to improve this unacceptable situation, a novel Adaptive Hysteretic Damper (AHD) was developed by the authors. The AHD can modulate its effective damping and stiffness to its actual deformation (i.e. PGA level) leading to: (i) reduced PFAs and enhanced building response to minor SLS earthquakes; (ii) not impaired structural safety under severe ULS events. The AHD force‐displacement characteristics are experimentally assessed and nonlinear time‐history analyses are carried out on a case‐study structure to demonstrate the enhanced seismic performances compared to common HDs. [ABSTRACT FROM AUTHOR]

Metal replacements for automotive and aerospace components are already a consolidated reality, in light of the advantages offered by fibre-reinforced polymers, consisting of reduced costs, weight, and environmental impact. As a result, engineering has been studying the possibility of replacing currently used metallic alloys with alternative materials, such as thermoplastic fibre-reinforced polymers, in the manufacturing of non-structural sections of marine engines. Given the peculiar characteristics of the working environment of such parts, i.e., ship engine spaces, and the strict requirements regarding safety, the selection of the polymer must be properly performed through a tailored material design process. Consequently, the redesign of the components must be carried out with the aim of exploiting the best of the materials’ properties while ensuring the correct resistance and simplifying installation operations. In this framework, finite element simulations may represent a suitable approach to validate the conformity of the proposed material and design. In this paper, this methodology is applied to a camshaft cover of a four-stroke marine engine, currently made of aluminium alloy. A 30% wt GFs/PA6,6 was identified as the most promising material and the novel plastic cover proved to guarantee the correct resistance while ensuring an important reduction in weight, processing costs, and required energy.

This paper investigates the elastic and inelastic seismic response of non-structural components in multi-storey steel moment framed structures and derives predictive relationships for their displacements and spectral accelerations. Within 38 primary structural steel frames, non-structural components characterised by various periods and strength reduction factors, are modelled as single-degree-of-freedom systems which are fixed to individual floors. The primary structures are three, five, and seven-storey steel moment-resisting frames, designed according to the provisions of Eurocode 8. Detailed nonlinear time history analyses are conducted, employing a large set of 100 ground motion records from both far-field and near-field sources. These records are scaled to two distinct levels to simulate the response of primary structures in both elastic and inelastic states. The influence of the ground motion type and the inelasticity level in the non-structural components is examined in detail. The sensitivity to strain hardening and viscous damping considerations is also assessed and discussed. Based on the results, representative relationships for predicting the inelastic displacement ratios are proposed. In addition, various provisions stipulated in European design guidance for determining the spectral accelerations are critically evaluated and improvements are suggested with due consideration for the inelasticity of both the non-structural components and the primary structures. • The seismic response of non-structural components in steel frames is investigated. • A wide range of multi-storey frames and component characteristics are considered. • The behaviour is examined under a large set of far-field and near-field records. • Detailed nonlinear dynamic time history assessments are carried out. • The influence of inelasticity in both the components and the frames is evaluated. • Prediction relationships for the displacement and acceleration response are proposed. [ABSTRACT FROM AUTHOR]

This paper describes a detailed numerical investigation into the inelastic displacement ratios of non-structural components mounted within multi-storey steel framed buildings and subjected to ground motions with forward-directivity features which are typical of near-fault events. The study is carried out using detailed multi-degree-of-freedom models of 54 primary steel buildings with different structural characteristics. In conjunction with this, 80 secondary non-structural elements are modelled as single-degree-of-freedom systems and placed at every floor within the primary framed structures, then subsequently analysed through extensive dynamic analysis. The influence of ground motions with forward-directivity effects on the mean response of the inelastic displacement ratios of non-structural components are compared to the results obtained from a reference set of strong-ground motion records representing far-field events. It is shown that the mean demand under near-fault records can be over twice as large as that due to far-fault counterparts, particularly for non-structural components with periods of vibration lower than the fundamental period of the primary building. Based on the results, a prediction model for estimating the inelastic displacement ratios of non-structural components is calibrated for far-field records and near-fault records with directivity features. The model is valid for a wide range of secondary non-structural periods and primary building fundamental periods, as well as for various levels of inelasticity induced within the secondary non-structural elements. [ABSTRACT FROM AUTHOR]

Spectral floor-acceleration demands are necessary for the seismic design of acceleration-sensitive non-structural components (NSCs). Existing studies to estimate floor response spectra (FRS) using empirical equations are based on elasto-plastic and stiffness degrading hysteretic behavior of the primary structure. In the present study, the FRS for self-centering (SC) structural systems with flag-shaped hysteretic behavior under far-fault ground motions are investigated. The FRS and dynamic amplification factor (DAF) are obtained from nonlinear response history analysis (NLRHA) of SC structural systems with flag-shaped hysteretic behavior. An equation to estimate the FRS is proposed and verified by carrying out NLRHA using a different set of far-fault ground motions. The equation to estimate FRS is shown to predict floor acceleration demands with very good accuracy.

Abstract Earthquakes, despite being a mostly natural phenomenon, may also be induced by a wide range of anthropogenic activities such as mining, fluid injection and extraction, hydraulic fracturing and geothermal reservoir processes. In recent years, the occurrence of induced and triggered seismicity and its potential impact on the built environment have heightened both public concern and regulatory scrutiny, motivating the need for an integrated risk management framework. Non-standard monitoring approaches provide valuable tools for mitigating the risk associated with earthquakes. These solutions include the use of advanced sensors and the implementation of performance-based rapid response systems for infrastructure, as well as monitoring the structural response of buildings and infrastructure in real time. Such technical solutions can be further used for validating damage forecasts determined by probabilistic approaches. The goal of this study is to establish a performance-driven monitoring system for induced seismicity. For this purpose, it is necessary to integrate analytical fragility curves in real time. These fragility curves can be derived by simplified vulnerability models that require input obtained from advanced exposure-monitoring techniques. Considering the case of induced seismicity, this also requires the expected damage to refer to non-structural components. Hence, the derived fragility curves are based on the non-structural damage criteria of typical residences. Therefore, a new approach is presented for defining analytical fragility curves of traditional or historic masonry structures, which can be found in large numbers near the geothermal platforms considered in this work.

• The ACN-BiLSTM model is developed to predict FRS at the top floor of a building with time-stamped GMS. • The DRRNet model is developed to predict the relation between FRS at the top floor and FRS at any other floor. • A total of 56 buildings with different properties under 195 ground motions is used for implementing the methodology. • The effectiveness of the proposed methodology is validated by comparing against other deep learning techniques. The floor response spectrum is an essential element in designing non-structural components (NSC) under earthquakes. However, most available approaches for floor response spectrum estimation involve complex modeling work, require intensive computational resources, and lack generalizability. To address these limitations, this paper proposes a novel deep-learning-based methodology to provide a generalized estimate of nonlinear floor response spectra, which is composed of a bidirectional convolutional long short-term memory network with an attention mechanism (ACN-BiLSTM) and a deep residual regression network (DRRNet). ACN-BiLSTM uses one-dimensional convolution to extract high-dimensional abstract features of ground motion spectrum in each period. The attention mechanism and multi-scale sliding time window are used to improve the network's convergence speed and prediction accuracy. DRRNet uses deep one-dimensional convolution to build a residual shortcut connection, which delivers the proportional relationship between floor response spectrum at different heights. With the input of the ground motion acceleration spectrum and structural characteristics, the proposed method can estimate the nonlinear floor acceleration response spectrum on any floor of a building. To demonstrate its efficacy, the proposed approach is applied to a dataset that includes floor response spectra of 56 buildings subjected to 195 ground motions. The application results indicate that the proposed approach can effectively and reliably predict the nonlinear acceleration response spectrum with an accuracy of 97.29%. Such an efficient method is promising in advancing the seismic design of non-structural components. [ABSTRACT FROM AUTHOR]

Background and objective: Continuous services provision of a hospital before and after a disaster is one of the most prominent issues that all people, especially the authorities must take into huge consideration. Concerning the experiences of previous earthquakes, the role and importance of nonstructural components becomes increasingly clear in the uninterrupted services of hospitals. In this study, non-structural retrofitting status of Kerman teaching hospitals was evaluated against natural disasters. Methods: This cross-sectional study was carried out in the second half of 2014 on the teaching hospitals in Kerman (Iran). The study population consisted of all Kerman teaching hospitals. The research instrument was World Health Organization/Pan American Health Organization (WHO/PAHO) standard checklist. Data analysis was carried out using descriptive statistics through SPSS 19. Results: One hospital had a low retrofitting level, two hospitals had an average level and one had a high level. In the examined hospitals in this study, the medical gas section had the lowest preparedness against natural disasters, while the office, warehouse and furniture section had the highest resistance. Generally, the non- structural retrofitting status was 50% in one hospital and was between 65% and 85% in other hospitals. Conclusions: Generally, the retrofitting status of hospitals was not at the ideal condition, most hospitals were in average condition. Concerning the high risk of hospitals in disasters, it is necessary that senior executives and managers of Kerman Province and Kerman University of Medical Sciences take some measures to retrofit these buildings and to reduce the risk of vulnerability

The paper illustrates an investigation on the effectiveness of dissipative bracing (DB) systems for seismic retrofit of buildings with sensitive non-structural components (NSCs) and technological content (TC), such as medical centers. The “Giovanni Paolo II” hospital, located in a high seismic prone area in Southern Italy, is chosen as case-study. The retrofit intervention with hysteretic braces is designed according to the Italian Building Code. The seismic response of the hospital building is investigated by means of non-linear history analyses carried out in OpenSees FE code and, in order to verify the full-operation after the earthquake, the integrity of NSCs and TC is checked. The retrofit design, thanks to the stiffening and damping effects introduced by DB system, proves suitable to protect both the structural frame and “drift-sensitive” non-structural components and content even under severe earthquakes (PGA = 0.45 g). Nevertheless, some concerns arise about the suitability of hysteretic braces for the protection of the “acceleration-sensitive” elements of the medical complex. Indeed, during weak earthquakes (PGA = 0.17 g), failures of several of these components are detected which can substantially impair the operation of the hospital in the aftermath of the seismic event.

This paper presents an overview on the response of the healthcare system in the area mostly affected by the 2016 Central Italy earthquake based on specific surveys and information from local health authorities. The authors collected in the field information on the seismic response capacity of the healthcare system. They surveyed five hospital complexes from medium to small dimension whose maximum capacity was up to 50 beds. This type of hospitals are representative of those ones present in the small towns located along the Apennines mountain range, usually including few buildings (i.e. 3–5) constructed in different periods and with different structural types. In all the surveyed hospitals there were partially or totally unusable buildings causing severe limitations to the functionality of the healthcare services, forcing to move many patients to other hospitals and to stop outpatient treatment. This was due mainly to severe damage to non-structural components and, in some cases, to moderate damage to structural components. In the present paper, two hospital case studies, namely "Tolentino" and "San Severino" hospitals, both located in Marche region, are analysed and discussed in detail in order to better understand their performance to the earthquakes, by also estimating their seismic risk via simplified methods, including the WHO Safety Index and the Cosenza and Manfredi (in: Fajfar and Krawinkler (eds) Seismic design methodologies for the next generation of codes, Balkema, Rotterdam, 1997) damage index. [ABSTRACT FROM AUTHOR]

A set of mid-rise bare and uniformly infilled reinforced-concrete frame buildings are analyzed for two different seismic intensities of ground-motions (i.e., „Design Basis Earthquake” and „Maximum Considered Earthquake”) to study their floor response. The crucial parameters affecting seismic design force for acceleration-sensitive non-structural components are studied and compared with the guidelines of the European and the United States standards, and also with the recently developed NIST provisions. It is observed that the provisions of both the European and the United States standards do not account for the effects of the period of vibration of the supporting structure and seismic intensity of ground-motions and thereby provides conservative estimates of the in-structure amplification. In case of bare frames, the herein derived component amplification factors for both the design basis earthquake and the maximum considered earthquake exceeds with their recommended values in the European and the United States standards for non-structural components having periods in vicinity of the higher modes of vibration, whereas, in case of infilled frames, component amplification factors exceeds with their recommended value in the European standard for non-structural components having periods in vicinity of the fundamental mode of vibration, and only for the design basis earthquake. As a consequence of these observations, as well as capping on the design force (in case of United states standard and NIST provisions), in case of the design basis earthquake, the combined amplification factor is underestimated for non-structural components having periods in vicinity of the higher modes of vibration of bare frames, and also for nonstructural components having periods in vicinity of the fundamental mode of vibration of infilled frames. At the maximum considered earthquake demand, excepting non-structural components having periods in vicinity of the higher modes of vibration of bare frames, all provisions generally provide conservative estimates of the design floor accelerations. [ABSTRACT FROM AUTHOR]

Fragility functions are an important tool in earthquake engineering, used to compute the probabilities of different damage states as a function of seismic response. They can be developed for large systems like buildings and bridges, as well as for individual structural and non-structural components, such as those used in the FEMA P-58 Seismic Performance Assessment Procedure. There are currently a number of problems associated with some P-58 non-structural mechanical component fragility functions and related loss predictions, including non-convergence when fitting the fragility functions in some cases and non-monotonic loss predictions. In this study, we recommend improvements to these fragility functions and loss predictions. Firstly, we recommend using the maximum likelihood method to fit the fragility functions to the underlying empirical data. This mitigates the non-convergence problems when fitting and makes predictions that better align with damage observed in past events. To compute predicted losses for anchored mechanical components, it is necessary to additionally consider anchorage damage, which can be predicted using fragility functions based on building code provisions. We recommend refining the current FEMA P-58 method for predicting anchored mechanical component losses, such that component and anchorage damage are calculated directly according to their corresponding fragility functions. The proposed method yields more intuitive loss predictions that vary monotonically with anchorage capacity. It also leads to better predictions of losses relative to damage observed in previous events. If implemented, the recommendations made in this paper would enhance the FEMA P-58 Seismic Performance Assessment Procedure. [ABSTRACT FROM AUTHOR]

This paper describes a shake table test on a one-storey full-scale unreinforced masonry structure, which complements an earlier testing of a two-storey structure with similar characteristics. The building specimen was meant to represent the upper floors of the end-unit of a terraced house, built with cavity walls and without any particular seismic design or detailing. In these specimens, the masonry walls were composed of two leaves: a load-bearing inner one made of calcium silicate bricks sustaining a reinforced concrete floor and an external leaf made of clay-bricks connected to the inner leaf by means of metallic ties. A pitched timber roof was supported by two triangular gable walls. Floor acceleration response histories of the previously tested two-storey specimen were used as input motions. An incremental dynamic test, with vertical and horizontal inputs, was carried out up to the explicit collapse of some bearing elements of the structure. In particular, a two-way bending out-of-plane collapse of a load-bearing wall was observed and described. [ABSTRACT FROM AUTHOR]

Abstract Dissipaters are used for seismic protection of structural and non-structural components. During an earthquake, the dissipaters will absorb seismic energy, and therefore will prevent damage and downtime to the structure or contents. In this research, a new generation of metallic dissipaters are proposed. The dissipaters offer advantages such as cost-effectiveness, simple fabrication and installation, lighter weight, compactness, redundancy during a very large earthquake, higher ductility, multiple activation mechanism, and good fatigue performance. If required, self-centering can also be incorporated in the dissipaters. The dissipaters can be either brace type or mini plug and play. The paper presents concepts, experimental testing, and seismic performance for the innovative dissipaters. Furthermore, potential applications of these dissipaters in buildings, bridges, and non-structural components, within the context of low-damage seismic design, are also presented. Highlights • Seismic resistant design using metallic dissipaters. • Innovative metallic dissipaters for seismic protection. • Potential applications of innovative metallic dissipaters in seismic regions. • Concepts for low-damage seismic design. • Experimental validation in a fully precast bent. [ABSTRACT FROM AUTHOR]

Highlights • Effect of the presence of URM infills on floor acceleration demand is studied. • Correlation of floor spectra with PGA, PFA and ground response spectrum is studied. • Model for construction of floor spectra directly from ground spectrum is developed. • Computation of floor spectra for a targeted ductility demand in supporting structure. Abstract The effect of unreinforced masonry infills on the floor acceleration response of inelastically responding mid-rise RC frame buildings is studied using incremental dynamic analyses. Two structural building configurations, uniformly infilled, and with open ground storey are analyzed by using the FEMA P695 far-field ground-motion suite. It is observed that the effect of structural nonlinearity is much more pronounced in case of infilled RC frame buildings than bare RC frame buildings. Sequential failure of infills results in a significant elongation of period of vibration resulting in the shifting of peaks in floor spectrum towards longer periods. Modified floor spectral amplification functions are presented for both uniformly infilled and open ground storey RC frame buildings. The proposed spectral amplification functions are validated using nonlinear analysis of typical buildings for recorded as well as spectrum-compatible ground-motions and can be used to estimate the floor response spectra directly from the code-based or site-specific design spectra. [ABSTRACT FROM AUTHOR]

• Hysteresis model of grooved fit piping joint is developed and validated based on quasi-static test results. • Generic hysteresis model is further developed based on the calibration results of each specimen. • Finite element modeling method of suspended piping system is proposed and calibrated using shaking table test results. Robust internal building pipeline is one of the most important non-structural components for reducing post-earthquake secondary disasters and maintaining normal use of buildings after an earthquake. The seismic damage of piping systems can result in the loss of firefighting abilities or lead to failure of water supplies and drainage systems in a building which can have serious implications for emergency rescue, post-disaster response and reconstruction work. In this study, moment-rotation hysteresis curves of grooved-fit piping-joints are obtained by quasi-static cyclical tests. Moment-rotation hysteresis models of piping-joints are developed using the Pinching4 uniaxial constitutive in the finite element software OpenSees. The calibrated model parameters are obtained using test data. The developed hysteresis models can accurately reproduce the moment-rotation hysteresis curves obtained in the experiments and simulate moment time-history during the loading process. The predicted accumulated energy dissipation is consistent with the test results. Using this observation, generic piping-joint moment-rotation hysteresis models are further developed and parameter values used to define the generic hysteresis model are obtained. A numerical model of a piping system is then developed using the generic hysteresis model. The numerical results confirm that the model can be used to reproduce the nonlinear behavior of a piping system under cyclic loading with high accuracy. The developed numerical model was further calibrated using shaking table test results. Comparisons between numerical and experimental responses demonstrate that the developed numerical model can be used to analyze the seismic response of a suspended piping system using grooved-fit joints. [ABSTRACT FROM AUTHOR]

Non-structural components, such as inorganics and organic extractives, present in switchgrass were extracted with water and ethanol, and the resulting non-structural components-free materials were pyrolyzed to investigate the effect of the inorganic species on the pyrolytic products. The extraction was performed for switchgrass materials harvested from three consecutive growing seasons, removing 8.5 wt% of the organic extractives in the first season biomass, and 5.8 and 6.3 wt% in the second and third season, respectively, on total dry basis of biomass. In addition to organic extractives, from 0.7 to 2.7 wt% of ash were extracted. Specifically, 99% and 59% of total K and Mg were removed from the switchgrass harvested in the second and third growing season. Thermogravimetric analysis demonstrated that a predominant reduction of K and Mg content in the biomass increased temperature at which mass loss rate is maximized in the decomposition of cellulose, hemicellulose, and lignin. The reduction of K and Mg content also affected pyrolytic products generated at 450°C. The chromatographic peak area percentage of levoglucosan from the extracted samples in the second and third growing season was two to three times higher than that from the extracted samples in the first growing season, showing a strong negative correlation with K and Mg content, whereas most of the light oxygenated and furanic/pyranic/cyclopentanic products exhibited a strong positive correlation with K and Mg content. We concluded that the removal of non-structural components prior to thermochemical conversion processes such pyrolysis can potentially produce a valuable extractives stream while removing catalytic inorganics that negatively impact downstream pyrolysis process.

In current seismic design, earthquake-induced forces in secondary structures are estimated from the acceleration of the primary structure at the support of the secondary structure. However, recent studies had shown that the response of the secondary structure can significantly affect that of the primary structure, which will simultaneously modifies that of the secondary structure. To accurately estimate the response of the secondary structure, the interaction at the interface of the two structures needs to be considered. In this study, a scaled model consisting of primary and secondary structures was designed to capture the interacting forces. The degree of fixity of the secondary structure was varied. Two types of dynamic loading, that is, impact and harmonic loads, were applied to the model structures. The relationship between the interacting force and the response of the secondary structure is discussed. Empirical formulae for predicting the maximum displacement of the secondary structure based on the displacement spectrum at its base were proposed. The formulae provided more accurate prediction of the top displacement of the secondary structure considered, in comparison with that obtained from a conventional floor response spectrum. [ABSTRACT FROM AUTHOR]

The seismic vulnerability of non-structural components has become an issue of paramount interest in the field of earthquake engineering, as demonstrated by the increasing number of studies which started to deal with the item. As reported by different authors, the economic losses related to the failure of non-structural components are by far the highest rate of the total loss in a building. Furthermore, in most of the cases, the collapse of these elements significantly affects the operation of the building and can play a key role for the life safety too. Piping systems have been widely analysed in previous studies because of their high vulnerability to seismic actions as well as their importance in the immediate post-seismic emergency. A comprehensive analysis of the seismic behaviour of the main components characterizing a piping system layout is fundamental to understand the influence of the mechanical properties as well as the geometrical configuration of the single component on the seismic behaviour, since the wide range of materials adopted leads to a high variability of the response and the studies conducted so far do not cover all the possible configurations. In a life-safety view, medical gas and fire-protection piping systems are supposed to be the categories which require a special attention, since their functionality is often fundamental even in case of earthquake. The seismic behaviour of fire- protection and medical gas piping systems is analysed in the present work through experimental tests on T-joint connections, which are the most vulnerable components in case of earthquake. Quasi-Static cyclic tests were performed to define the hysteretic response of cast-iron and copper joints, in terms of Force-displacement and Moment-rotation behaviour. To the best of the author’s knowledge no studies have been conducted yet on copper joints, while the results obtained from the tests on steel joints were compared with results available in literature. Furthermore, the influence of the fitting on the response in case of threaded connection was investigated. The results obtained have been adopted to calibrate simplified numerical models aimed at simulating the cyclic response of the components analysed. The proposed models would be useful in numerical analyses for the vulnerability assessment of piping systems layouts. [ABSTRACT FROM AUTHOR]

In recent years, a novel type of hybrid coupled wall (HCW), which consists of reinforced concrete (RC) wall piers and replaceable steel coupling beams (RSCBs), has been proposed for enhancing the seismic resilience of high-rise buildings. This paper presents the assessment of the seismic performance of an 11-story building located in a highly seismic area and designed per modern Chinese codes. The building adopts the frame-shear wall interacting system. For comparison, two cases are considered: one using the novel hybrid coupled walls and another using conventional RC coupled walls (RCW). The dynamic response of the buildings under high intensities of ground motion shaking is obtained from nonlinear dynamic analysis in OpenSees. The seismic performance, expressed in terms of repair cost and time, is assessed based on the FEMA P-58 method. The results indicate that most of the damage is concentrated in the coupling beams and nonstructural components. The use of novel HCWs instead of conventional RCWs results in maximum interstory drifts up to 24.5% lower in the HCW building than the RCW building when subjected to a maximum considered earthquake (MCE) intensity. Novel HCWs result in a reduction of 50.8% and 60.5% in the median building repair cost and time, respectively, under MCE, due to less damage to coupling beams and RC frames and easy replacement of RSCBs after a damaging earthquake. It is also noted that HCWs have limited influence on the peak floor accelerations, and thus the repair cost and time for acceleration-sensitive non-structural components are similar for both the HCW building and the RCW building. [ABSTRACT FROM AUTHOR]

The importance of non-structural components in building performance under seismic action is well recognized in the scientific community. Damage to residential buildings registered in past earthquakes has demonstrated that the damage to non-structural components represents a substantial percentage to the resulting economic losses. In the context of performance-based earthquake engineering (PBEE), the probabilistic estimation of building-specific losses has highlighted the importance of non-structural walls, in particular, due to their direct influence on building response and contribution to the overall damage. However, limited research has been produced on the subject of seismic retrofit of non-structural components and their economic advantages. In this manuscript, focus is given to non-structural partition walls, with the aim of determining the potential economic benefit of implementing non-structural retrofit solutions, in terms of the corresponding reduction in average annual earthquake losses. Building on an extensive literature review on the state-of-the-art of non-structural retrofit solutions, representative retrofit options are investigated for six combinations of building class and seismic hazard at the building location (in Italy), by means of probabilistic seismic loss estimation and corresponding cost-benefit analysis. The results show that the seismic retrofit of non-structural partition walls only (as opposed to retrofitting both structural and non-structural components) can be sufficient to achieve a reduction of seismic losses that guarantees the return of the retrofit investment during the building’s life cycle, specifically when dealing with highly vulnerable buildings located in regions of high seismicity. [ABSTRACT FROM AUTHOR]

A range of reinforced concrete frame buildings with different levels of inelasticity as well as periods of vibration is analyzed to study the floor response. The derived floor acceleration response spectra are normalized by peak ground acceleration, peak floor acceleration, and ground response spectrum. The normalization with respect to ground response spectrum leads to the lowest coefficients of variation. Based on this observation as well as previous studies, an amplification function is proposed that can be used to develop design floor spectra from the ground motion spectrum, considering the building’s dynamic characteristics and level of inelasticity. [ABSTRACT FROM AUTHOR]

Earthquakes with comparatively low magnitudes can lead to serious damage to non-structural components of historical masonry buildings, such as architectural facade elements. In order to assess the vulnerability of non-structural components, the horizontal floor acceleration is used. This depends on the dynamic characteristics of the building, the ground acceleration and dissipative effects. In the present article comprehensive probabilistic FE time history analyses with different hazard levels have been carried out for selected masonry structures. In order to take induced non-linearities into account, a macroscopic material model for historic masonry was calibrated and applied. It was shown that the chosen methodology enables the determination of the distribution of floor acceleration over the building height for historic masonry structures. In addition, due to the detailed scope, a robust comparison with the simplified design methods is possible. Finally, the applicability of the simplified design approach according to EN 1998-1 [1] is discussed for the investigated case. [ABSTRACT FROM AUTHOR]

Multiply-supported non-structural components (NSCs) can be vulnerable under strong multi-directional earthquake excitations. To date, this topic has not been explored much, not to mention considered in design provisions. Seismic analyses of NSCs with multiple attachments were mostly performed numerically and with simplified assumptions. Experimental investigation is scarce. The goal of this study is to describe the seismic behaviour of a multi-supported NSC under multi-directional excitations through experiments. Large-scale testing was implemented to study the development of acceleration from the ground to the NSC, which would otherwise be too small to detect in a small-scale setup. The influence of the vertical component of the excitation on the response of the NSC is displayed. The interaction between the primary structure and the NSC was showcased through its influence on the response of both the primary structure and the NSC. For the first time, seismic response of a multi-supported NSC is expressed using physical experiments, thus accounting for its interaction with the main structure. The seismic demand for multiply-supported NSCs specified in current design provisions is also evaluated. [ABSTRACT FROM AUTHOR]

This paper is aims at highlighting the main mechanical parameters controlling the behavior of the so-called ‘acceleration-sensitive’ non-structural components (NSCs). The first reports a short review of the current state of knowledge and the critical issues dealing with the prediction of the seismic response of NSCs. Then, the paper presents the results of a numerical parametric analysis intended to capture the key features of the coupled dynamic response of a two-degree-of-freedom (2DOF) system supposed to be representative of both main structure and ‘non-structural’ component (NSC). The main parameters controlling the dynamic response of NSCs emerge from this study, which could pave the way towards formulating more mechanically consistent relationships for evaluating the peak accelerations induced by seismic shakings on NSCs in buildings.

A procedure is developed in this paper that enables modification of the Modal Pushover results to predict the peak dynamic responses. Steps involved in this procedure cannot be strictly derivable from the first principle, but the resulting responses always match with the theoretical results within the elastic regime. A Generalized Single Degree of Freedom system is defined with a displacement profile derived from the maximum (regardless of sign) relative floor displacements and results of which is semi-empirically modified to predict the peak dynamic responses. Three test-beds are considered for assessment of the proposed method: (1) ten-storeyed symmetric building designed and detailed conforming to the Indian seismic code; (2) ten storey plan-asymmetric building designed and detailed per Indian seismic code; and (3) seven-storeyed existing building located in seismic Zone IV of India. Three seismic events recorded at the Large Scale Seismic Testing array in Lotung, Taiwan are used for this purpose. Distribution of the peak absolute floor acceleration and peak relative floor velocity across the height based on the proposed method is found in well agreement with those calculated using the rigorous IDA. The procedure can best be applied to the seismic safety assessment non-structural components (that are acceleration and velocity sensitive) of building adding a little cost to the routine assessment of structural components. [ABSTRACT FROM AUTHOR]

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