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In this technical note, a consistent finite element formulation of the Hyperstatic Reaction Method (HRM) for tunnel linings design is proposed by introducing a variational consistently linearized formulation. It permits to consider a nonlinear interaction between a lining structure and the surrounding ground. Recent advances of the HRM in regard to the consideration of the nonlinear response of the segmented tunnel lining exposed to design loads use an iterative algorithm for solving the nonlinear system of equations. In the proposed Variationally consistent Hyperstatic Reaction Method (VHRM), a distributed nonlinear spring model representing the interaction between the lining and the ground soils is considered in a variationally consistent format. Computing the tangential spring stiffness via consistent linearization, and using Newton-Raphson iteration, requires significantly smaller number of iterations as compared to the original HRM model based on nodal springs. Furthermore, the method is applicable for simulations using solid finite elements (2D and 3D), as well as beam or finite shell elements, respectively.

Fire safety considerations have an impact on the design of almost all structures, ranging from small residential structures to high‐rise buildings. One important aspect of building fire safety is structural‐fire safety, with the goal of preventing or delaying collapse of structures during severe fires. Structural‐fire safety is of particular importance for steel structures, because of the high thermal conductivity of steel. Structural‐fire safety design is most often accomplished using non‐engineered prescriptive approaches. However, there is increasing interest in engineered structural‐fire safety design for potential advantages in safety, economy and design flexibility. This paper provides an overview of engineered structural‐fire safety design for steel buildings, and discusses some of the challenges in this field.

The Continuous Strength Method (CSM) provides accurate cross-section resistance predictions since allowance is made for the partial spread of plasticity and the beneficial effects of strain hardening. Although CSM design provisions for different loading conditions are available, the method was limited to the determination of cross-sectional resistance until recent research by Arrayago et al. (2020) proposed a consistent new approach to the design of stainless steel hollow section members subjected to compression. Extension of the CSM to the design of stainless steel members subjected to combined compression and bending moment is presented in this paper. The analysis is based on numerical results generated in the current study and existing results collected from the literature on stainless steel hollow section members. The results demonstrate that the adoption of the CSM design equations to predict column strength considerably improves the ac-curacy of the calculated beam-column capacities. The reliability of the proposed approach is demonstrated through statistical analyses performed in accordance with EN 1990. The authors acknowledge the funding from the MINECO (Spain) under Project BIA2016-75678-R, AEI/FEDER, UE “Comportamiento estructural de pórticos de acero inoxidable. Seguridad frente a acciones accidentales de sismo y fuego”. The first author would also like to acknowledge the financial support received from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 842395.

This paper will focus on fixed roof storage tanks and its sub-category cone roof tanks. Paper presents major factors and outputs of tank design process. Theoretical analysis is done for a cone roof tank model and correlation between tank surface, shell thickness and total steel weight used. Detailed algorithm for tank design was realized using MathCAD software using Eurocode standards. Using this algorithm, 432 hypothetical tanks were designed. Data analysis of the collected output data was analysed using R statistics programming language. Using regression models and testing them led to the optimum statistical model. For the purpose of this work, data for 21 real world tanks including fixed roof and floating roof tanks were collected. The data was collected with help of MOL, INA and few other EPC contractors. Paper compares real world data with outputs of the model. Model can be used for quick estimates and control of material consumptions. Taking few input parameters and applying minimal effort can lead to a very accurate steel consumption prediction. With additional real-world data, acceptable ranges of deviation from the mean could be set-up. Thus, allowing for better control on Client part or EPC companies.

The design and financing of commercial‐scale floating offshore wind projects require a better understanding of how power generation differs between newer floating turbines and well‐established fixed‐bottom turbines. In floating turbines, platform mobility causes additional rotor motion that can change the time‐averaged power generation. In this work, OpenFAST simulations examine the power generated by the National Renewable Energy Laboratory's 5‐MW reference turbine mounted on the OC3‐UMaine spar and OC4‐DeepCWind semisubmersible floating platforms, subjected to extreme irregular waves and below‐rated turbulent inflow wind from large‐eddy simulations of a neutral atmospheric boundary layer. For these below‐rated conditions, average power generation in floating turbines is most affected by two types of turbine displacements: an average rotor pitch angle that reduces power, caused by platform pitch; and rotor motion upwind‐downwind that increases power, caused by platform surge and pitch. The relative balance between these two effects determines whether a floating platform causes power gains or losses compared to a fixed‐bottom turbine; for example, the spar creates modest (3.1%–4.5%) power gains, whereas the semisubmersible creates insignificant (0.1%–0.2%) power gains for the simulated conditions. Furthermore, platform surge and pitch motions must be analyzed concurrently to fully capture power generation in floating turbines, which is not yet universal practice. Finally, a simple analytical model for predicting average power in floating turbines under below‐rated wind speeds is proposed, incorporating effects from both the time‐averaged pitch displacement and the dynamic upwind‐downwind displacements.

International audience; The number of EVs and charging facilities is expected to increase significantly in the near future, further coupling the existing transportation system with the power system. This may bring new stresses and risks to such system of systems. This paper presents a mathematical framework to analyze the resilience of an electrified road network (ERN) subject to potential failures of its supporting fast-charging stations (FCSs). Within this framework, a novel linear optimization model is proposed for the first time to solve the system optimal dynamic traffic assignment problem of ERN. The characteristics considered in the modeling framework include the location, capacity, and charging speed of FCSs, as well as the driving range, charging time and state of charge (SoC) of EVs. The linear model is proposed based on the cell transmission model. It is used as the first stage model to assign the traffic under normal FCS operations. A second stage model is, then, extended to minimize the total travel time after the stochastic occurrence of FCS failures, i.e., in the failure and recovery phases. Two metrics are considered to quantify the ERN performance and the impacts of FCS failures. A numerical example is studied to illustrate the usefulness of the proposed framework for analyzing ERN resilience. The results show that deploying FCSs near the highway entrances and maintaining their operation are relevant factors to enhance the system's resilience. The analysis can provide guidelines to the system operators for effective management of the ERN operation and identify resilience-critical FCSs for system resilience improvement.

The feasibility of using sugar-cane bagasse as a reinforcement for natural fiber composites and the performance of these composites under fire conditions was investigated. Plies were manufactured using a process, which involved alkali-treating bagasse, blending, pressing, and drying. Soaking durations of 30 minutes and 24 hours were compared. Composites were then made with these plies using a light resin transfer molding process. The composites were characterized and compared to a commercial hemp fabric using thermogravimetric analysis for thermal stability and char yield, isotropic hot disc method for thermal conductivity and specific heat capacity, and cone calorimeter for flammability. The investigation found that bagasse plies could be successfully used in composite manufacture, but posed a greater ignition hazard, and a comparable burning behavior hazard to the commercial product when tested at a radiant heat flux of 35 kW/m. Thirty minutes treating resulted in a ply, which resulted in a char yield of 28%. Although in the composite form, there were no significant differences between all sample groups. With regards to ignition, the hemp composite had the latest time-to-ignition of 137 seconds. Comparison of the thermal properties to the ignition times showed that higher values of thermal properties resulted in later ignition times. The composite with the 30-minute treated bagasse had a total heat release of 159 MJ/m and average heat release rate of 263 kW/m, while the peak heat release rate was lower for the 24-hour treated bagasse at 537 kW/m. Overall, no significant differences in the two treatment durations were observed.

Verursacht durch die alternde Bausubstanz, den kontinuierlich gestiegenen Schwerlastverkehr, in Verbindung mit vorhandenen Defiziten bestehender Strasenbrucken, wird der Ersatzneubau zunehmend an Bedeutung gewinnen. Die Umsetzung von Ersatzneubauten verursacht gegenwartig starke Verkehrsbeeintrachtigungen, da diese in aller Regel vor Ort am vorhandenen Bruckenstandort hergestellt werden. In dem vorliegenden Projekt wurden neben der Darstellung des gegenwartigen Vorgehens fur den Ersatzneubau von Betonbrucken schwerpunktmasig innovative und nachhaltige Bauweisen und Bauverfahren entwickelt, welche die Verkehrseinschrankungen und die Bauzeit am Bauwerksstandort stark verkurzen. Es erfolgte dabei die Betrachtung der vier auf deutschen Autobahnen am haufigsten realisierten Systeme: Rahmen bis 30 m Stutzweite, Einfeldbauwerke mit einer Gesamtlange zwischen 10 m – 30 m, Zweifeldbauwerke mit einer Gesamtlange bis 70 m und Dreifeldbauwerke mit einer Gesamtlange von bis zu 100 m. Das derzeitige Vorgehen wurde mit den innovativen Ansatzen uber eine Bewertungsmatrix, auch unter Berucksichtigung der Nachhaltigkeit verglichen und entsprechende Vorzugslosungen herausgearbeitet. Fur die vier Tragsysteme wurden auf Grundlage der bewerteten Varianten Bauweisen und Verfahren ausgewahlt und daraus Konzepte fur die Realisierung erarbeitet. Im Einzelnen ist fur jedes Tragsystem ein Konzept in Form eines Bauwerksentwurfes entwickelt worden. Im Ergebnis der Konzeptbearbeitung ist festzustellen, dass durch Modularisierung der Bauwerke und Verlagerung der Fertigung in ein Fertigteilwerk und der Einsatz von geeigneten Bauverfahren, wie dem Verschubverfahren, die Verkehrseinschrankungen in einem erheblichen Mas reduziert werden konnen. Gleichzeitig fuhrt die Verringerung der Verkehrseinschrankung auch dazu, dass die durch baustellenbedingte Staus verursachten CO2-Emissionen erheblich reduziert werden konnen.

Industrial waste has rapidly increased day by day due to the fast-growing population and usage of products, which dumps unscrupulously, resulting in environmental pollutions. Waste foundry sand (WFS) is one of the industrial solid wastes. River sand is generally used in concrete as a fine aggregate, which is limited (scant), and river excavation for sand leads to environmental deterioration. To resolve these problems, a study was performed on WFS as a partial substitution instead of natural sand in concrete. The effects of WFS on concrete performance were assessed through durability and mechanical performance. The results from experimental tests show that, compared to concrete blends with WFS up to 30% substitution, the control mix strength was only 7.6% (28 days) higher, and this improvement is not too high. In the same manner, concrete mixtures that contain WFS up to 30%, and their durability properties were somewhat same to blank max (control). Test results showed that WFS with a substitutions ratio up to 30% can be successfully used in concrete without disturbing its durability and strength properties.

This paper develops a vehicle scheduling method for the electric bus (EB) route considering stochastic volatilities in trip travel time and energy consumption. First, a model for estimating the trip energy consumption is proposed based on field-collected data, and the probability distribution function of trip energy consumption considering the stochastic volatility is determined. Second, we propose the charging strategy to recharge buses during their idle times. The impacts of stochastic volatilities on the departure time, the idle time, the battery state of charge, and the energy consumption of each trip are analyzed. Third, an optimization model is built with the objectives of minimizing the expectation of delays in trip departure times, the summation of energy consumption expectations, and bus procurement costs. Finally, a real bus route is taken as an example to validate the proposed method. Results show that reasonable idle times can be generated by optimizing the scheduling plan, and it is helpful to stop the accumulation of stochastic volatilities. Collaboratively optimizing vehicle scheduling and charging plans can reduce the EB fleet and delay times while meeting the route operation needs.

Um Stahlbauteile im Brandfall vor einer zu schnellen Erwarmung zu schutzen, wird haufig auf reaktive Brandschutzsysteme (RBS) zuruckgegriffen. Die Produkte eigenen sich besonders aufgrund der profilfolgenden Applikationsmoglichkeit und der vergleichsweise geringen Beschichtungsdicken. Bei einer Brandbeanspruchung schaumt das RBS auf und bildet eine thermische Schutzschicht um das Stahlprofil aus. Dadurch wird die Erwarmung des Stahls verlangsamt und der temperaturbedingte Festigkeitsverlust verzogert, wodurch sich die Feuerwiderstandsdauer des Stahlbauteils verbessert. Aus Brandversuchen ist bekannt, dass die Leistungsfahigkeit von RBS auf Stahlprofilen mit gekrummter Oberflache meist schlechter ausfallt als bei vergleichbaren Bauteilen mit ebener Oberflache. Zum Einfluss der Oberflachenkrummung auf die thermische Schutzwirkung von RBS werden in dem folgenden Beitrag sowohl theoretische Hintergrunde als auch die Ergebnisse aus Brandversuchen an kleinformatigen Probekorpern vorgestellt. Die systematischen Untersuchungen zeigen, dass mit zunehmender Oberflachenkrummung die Leistungsfahigkeit des RBS tendenziell abnimmt. Bei der Beurteilung der thermischen Schutzwirkung eines RBS sollte die Oberflachenkrummung eines Bauteils berucksichtigt werden. Die alleinige Fokussierung auf den Profilfaktor eines Stahlprofils ist im Allgemeinen nicht ausreichend. Die Untersuchungen bilden die Grundlage fur die Entwicklung von Screening-Tests zur Beurteilung der Eignung von RBS fur gekrummte Oberflachen, wodurch eine Vorauswahl von Produkten fur diesen Einsatzzweck ermoglicht wird.

This research was carried out in collaboration with Anglia Ruskin University (ARU) and West Yorkshire Fire and Rescue Services, prevention department. ARU funded the research assistant to carry out the research and is an author on the paper. open access article The Medicines and Healthcare products Regulatory Agency (MHRA) update in 2018, reported 50 fatal fires linked with emollient use. It detailed the fire risk and new advice aimed at fire service and health care professionals in reporting of such fire incidents and educating the public on safer use of emollients. This study investigates how this has been communicated internally and publicly, with 52 Fire and Rescue Services (FRSs) websites and, 191 Clinical Commissioning Groups (CCGs) and 21 Local Health Boards (LHBs) formularies accessed. A Freedom of Information Request (FOIR) was also made, giving further details of implementations. Our study revealed that 63% of FRSs, 32% of CCGs and, 72% of LHBs gave no safety advice within their website or formularies. Of the 37% of FRSs and 68% of CCGs that did, only 5% and 4% were sufficiently up to date. 27% of FRSs and 28% of CCGs/LHBs revealed they had no warning/advice internally in their FOIR responses and 25% of FRSs and, 35% of CCG/LHBs had not disseminated advice on using emollient safely to the public. We suggest improvements in safety campaigns using a multiagency and national approach and recommend organisations to educate professionals to improve reporting and effective dissemination

To maximize the potential of earthquake early warning (EEW) as a credible tool for seismic resilience promotion, it should be combined with next‐generation decision‐support tools that use ...

The use of cameras for safety monitoring, progress tracking, and site security has grown significantly on construction and civil infrastructure sites over the past decade. Localization of ...

Event‐based methods are commonly used to assess the risk to distributed infrastructure systems. Stochastic event‐based methods consider all hazard scenarios that could adversely impact the...

Railroad bridge inspection manuals recommend measuring bridge displacements under train crossing events. Traditional displacement measurement methods require humans climbing the infrastruc...

Systemverbinder für Holz‐Holz Verbindungen von Nebenträgern an Hauptträger sind zweiteilige Verbinder aus Metall, deren Vorteil sich u.a. im hohen Vorfertigungsgrad auszeichnet. Für die Entwicklung von neuartigen Haupt‐Nebenträger‐Systemverbindern aus Kunstharzpressholz wurden verschiedene Oberflächenbehandlungen untersucht und die jeweiligen Reibbeiwerte zwischen Verbinder und Holz ermittelt. Aufbauend auf diesen Ergebnissen wurden in Vorversuchen Verbindungen mit geneigten Schrauben untersucht. Dabei wurden sowohl die Anordnung als auch die Anzahl und Länge der Schrauben systematisch variiert. Überprüft wurde dabei mögliches Blockscherversagen ganzer Schraubengruppen als auch die wirksame Verbindungsmittelanzahl. Das Prüfprogramm umfasste Versuche mit Lasten in drei Hauptrichtungen für verschiedene Prototypen. Zu Beginn wurden Verbinder für eine Tragfähigkeit in Einschubrichtung von 180 kN geprüft, daraufhin Schwerlastverbinder für Traglasten bis 500 kN. Aus den Versuchen resultierten neue Erkenntnisse für die Bemessung solcher Verbindungen. Das ursprünglich vorgeschlagene Rechenmodell wurde sukzessive angepasst und eine auftretende Moment‐Normalkraft‐Interaktion in den Schrauben berücksichtigt. Mit einem mittleren Verhältnis aus Versuchsergebnis zu rechnerischer Schätzlast von 1,05 trifft das angepasste Modell die Tragfähigkeit sehr gut. Im direkten Vergleich der charakteristischen Tragfähigkeiten der Prototypen mit handelsüblichen Verbindern schneiden diese sehr gut ab und übertreffen zum Teil Verbinder aus Aluminium.

Performance-based design of the timber structures' fire resistance is often based on the reduced cross section and thus relying on empirical and numerical assessment of the charring propagation. The current work aims to construct models for the pyrolysis of spruce and pinewoods to allow coupled simulations of the cross-section reduction and burning rate in fire models. Kinetic models are formulated based on thermogravimetric data and supported by the heats of pyrolysis and combustion measurements by differential scanning calorimetry and microscale combustion calorimetry, respectively. The results from these small-scale measurements are consistent with each other, and the heats of pyrolysis and combustion are determined for the wood primary components by fitting the simulations to the experimental results. Heat release models are constructed based on the small-scale tests, and cone calorimeter experiments are used for the estimation of the physical properties and for the heat release model validation.

Author(s): Kenawy, M; McCallen, D; Pitarka, A | Abstract: Broadband physics-based simulated earthquake ground motions are utilized to characterize the regional-scale seismic risk to modern reinforced concrete (RC) structures. A highly dense dataset of ground motions covering a 100-km (Formula presented.) 40-km domain was generated using kinematic fault rupture models with varying rupture characteristics to represent shallow crustal earthquakes and resolved up to frequencies of 5 Hz. Over 40,000 nonlinear response history simulations of short- and mid-rise RC special moment frame buildings were conducted using simulation models that are capable of representing nonlinear behavior and component deterioration effects. The spatial variability of structural risk within a single earthquake scenario and between different rupture scenarios is examined, and the regions of strongest directivity effects and highest structural demands are identified. The structural demands may vary by factor of up to 8.0 at very short distances from the fault, and the large dispersion in the demands decreases significantly beyond a distance of 15 km. The interstory drift and member rotation demands are substantially impacted by important features of the geological structure and the characteristics of the rupture scenarios, particularly the presence of localized high-slip regions. The frequency characteristics of the structures are found to play an important role in determining the effects of near-fault ground motions on the structural response and expected damage. The results of this study suggest that the simulated ground motions, particularly those generated using the hybrid rupture approach, may offer reasonable structural risk estimates for low-frequency structures and conservative estimates for high-frequencynstructures.

Durch die Einbeziehung von gemessenen Daten bei der Bewertung von bestehenden Bauwerken konnen Unsicherheiten bei der Beurteilung des Tragverhaltens reduziert werden, ohne das normative Zuverlassigkeitsniveau einzuschranken. Informationen sind die wesentliche Grundlage fur die Analyse der Zuverlassigkeit von Tragwerken. Umso wichtiger ist die Kenntnis uber die Prazision und die Richtigkeit der verwendeten Informationen. Aus messtechnischer Sicht kann ein Messwert, dem keine Messunsicherheit beigeordnet wurde, als wertlos erachtet werden. Liegt ein vollstandig dokumentiertes Messergebnis vor, so ist die Qualitat der gemessenen Information bekannt und deren Vergleichbarkeit gewahrleistet. In diesem Beitrag wird am Beispiel einer Spannbetonbrucke und zweier Grenzzustande gezeigt, wie Messergebnisse aus der zerstorungsfreien Prufung in probabilistische Nachweise von Bestandsbauwerken einfliesen konnen und welche Auswirkungen die Implementierung von gemessenen Daten bei der Bewertung von Bestandsbauwerken haben kann.

Beds are a prevalent combustible in fatal fires in the United States effective 1 July 2007, the US Consumer Product Safety Commission promulgated a standard to severely reduce the heat release rate and the early heat output from mattresses and foundations when ignited by a flaming ignition source. This study estimates the Standard’s success over its first decade using fire incidence, US population, and mattress sales data. The technique mitigates the influence of some exogenous factors that might have changed during this decade. The Standard is accomplishing its purpose, preventing approximately 65 fatalities (out of an estimated 95 fatalities in 2002–2005) from bed fires annually during 2015–2016, although not all pre-Standard mattresses had yet been replaced. Compared to residential upholstered furniture fires, which were not affected by the Standard, the numbers of bed fires decreased by 12%, injuries by 34%, and deaths by 82% between 2005–2006 and 2015–2016. Per bed fire, injuries decreased by 25% and fatalities decreased by 67%, indicating that the severity of bed fires is being reduced.

Controlled Rocking Braced Frames (CRBFs) have been developed as a high-performance seismic force resisting system that can self-centre after an earthquake and avoid structural damage. A CRBF is designed to uplift and rock on its foundation, and this response is controlled using prestressing and energy dissipation devices that are engaged by uplift. Although CRBFs have been shown to have desirable structural performance, a comprehensive assessment of this system must also consider the performance of nonstructural components, which have a significant impact on the safety and economic viability of the system. The purpose of this paper is to evaluate the demands on nonstructural components in buildings with CRBFs in comparison to demands in a reference codified system, taken here as a buckling restrained braced frame (BRBF), as well as to identify which design parameters influence these demands. The responses of various types of nonstructural components, including anchored components, stocky unanchored components that slide, and slender unanchored components that rock, are determined using a cascading analysis approach, where absolute floor accelerations generated from nonlinear time-history analyses of each system are used as input for computing the responses of nonstructural components. The results show that the downside of maintaining elastic behaviour of the CRBF members is, in general, larger demands on nonstructural components compared to the BRBF system. These demands are not highly influenced by impact during rocking or by the supplemental energy dissipation provided, as the vibration of the CRBF in its higher modes is primarily responsible for the higher demands. Natural Sciences and Engineering Research Council of Canada (NSERC); Ontario Ministry of Economic Development, Job Creation and Trade

Stahlbetonrahmentragwerke mit Ausfachungen aus Mauerwerk weisen nach Erdbeben häufig schwere Schäden auf. Gründe hierfür sind die Beanspruchungen der Ausfachungswände durch die aufgezwungenen Rahmenverformungen in Wandebene und die gleichzeitig auftretenden Trägheitskräfte senkrecht zur Wandebene in Kombination mit der konstruktiven Ausführung des Ausfachungsmauerwerks. Die Ausfachung wird in der Regel knirsch gegen die Rahmenstützen gemauert, wobei der Verschluss der oberen Fuge mit Mörtel oder Montageschaum erfolgt. Dadurch kommt es im Erdbebenfall zu lokalen Interaktionen zwischen Ausfachung und Rahmen, die in der Folge zu einem Versagen einzelner Ausfachungswände oder zu einem sukzessiven Versagen des Gesamtgebäudes führen können. Die beobachteten Schäden waren die Motivation dafür, in dem europäischen Forschungsprojekt INSYSME für Stahlbetonrahmentragwerke mit Ausfachungen aus hochwärmedämmenden Ziegelmauerwerk innovative Lösungen zur Verbesserung des seismischen Verhaltens zu entwickeln. Der vorliegende Beitrag stellt die im Rahmen des Projekts von den deutschen Projektpartnern (Universität Kassel, SDA-engineering GmbH) entwickelten Lösungen vor und vergleicht deren seismisches Verhalten mit der traditionellen Ausführung der Ausfachungswände. Grundlage für den Vergleich sind statischzyklische Wandversuche und Simulationen auf Wandebene. Aus den Ergebnissen werden Empfehlungen für die erdbebensichere Auslegung von Stahlbetonrahmentragwerken mit Ausfachungen aus Ziegelmauerwerk abgeleitet.

Author(s): Petrone, F; Abrahamson, N; McCallen, D; Miah, M | Abstract: Ground-motion simulations generated from physics-based wave propagation models are gaining increasing interest in the engineering community for their potential to inform the performance-based design and assessment of infrastructure residing in active seismic areas. A key prerequisite before the ground-motion simulations can be used with confidence for application in engineering domains is their comprehensive and rigorous investigation and validation. This article provides a four-step methodology and acceptance criteria to assess the reliability of simulated ground motions of not historical events, which includes (1) the selection of a population of real records consistent with the simulated scenarios, (2) the comparison of the distribution of Intensity Measures (IMs) from the simulated records, real records, and Ground-Motion Prediction Equations (GMPEs), (3) the comparison of the distribution of simple proxies for building response, and (4) the comparison of the distribution of Engineering Demand Parameters (EDPs) for a realistic model of a structure. Specific focus is laid on near-field ground motions (l10km) from large earthquakes (Mw7), for which the database of real records for potential use in engineering applications is severely limited. The methodology is demonstrated through comparison of (2490) near-field synthetic records with 5nHz resolution generated from the Pitarka etnal (2019) kinematic rupture model with a population of (38) pulse-like near-field real records from multiple events and, when applicable, with NGA-W2 GMPEs. The proposed procedure provides an effective method for informing and advancing the science needed to generate realistic ground-motion simulations, and for building confidence in their use in engineering domains.

This study experimentally investigates the radiation heat flux distribution received on the floor due to fire plume impinging upon an inclined ceiling, which has not been quantified previously. The radiation heat fluxes were measured on the floor for 160 experimental conditions, involving various fire source heat release rates, source-ceiling heights, angles of ceiling inclination and dimensions (aspect ratios) of the rectangular sources. The main findings include that the declining rate of the radiation heat flux along with distance received by the downstream floor decreases, while that received by the upstream floor increases, with the increasing of ceiling inclination angle. The radiation heat flux received by the floor is higher as the ceiling inclination angle is smaller for the downstream side, while it is lower as the ceiling inclination angle is smaller for the upstream side. Both of these variations can be explained by change of the flow distribution as well as flame length due to combustion and heat released in the two directions beneath the inclined ceiling. Further, a model with various fire source heat release rates, source-ceiling height, and ceiling inclination angles is proposed, to globally describe the radiation heat flux received by both the upstream and downstream floors.

Virtual trial assembly (VTA) simulates the preassembly by verifying the correspondence of as‐built and as‐designed prefabricated component (PC) models in virtual reality. Notably, obtainin...

The use of virtual reality in human behavior in fire research has the advantage of being able to produce results comparable to more traditional laboratory or field experiments. This method relies not only on the technology employed but also on the participants' perception of realism when exposed to a virtual emergency scenario. A virtual scenario can be perceived as realistic based on the way it looks and on the way objects in it operates. However, in some experiments, behavioral realism can be the most relevant feature to obtain meaningful results. In this article, knowledge gained by running four different virtual reality experiments is presented in the form of challenges and recommendations to enhance the realism of the virtual experience. Although not in a comprehensive way, these challenges and recommendations refer to different parts of the process of running a virtual reality experiment for research in human behavior in fire, from the design of the environment to the behavior of the participants in it. The recommendations provided are based on observations. By spreading this knowledge, it is expected to aid the broader fire safety engineering community to develop more realistic virtual reality experiments for data collection on human behavior in fire. (Less)

This study presents the results from a set of 11 large-scale open fire tests performed on flexible polyurethane foam slabs/mattresses. The purpose of the study was to investigate the influence of the ignition location on the fire behaviour of the foam slabs and to generate data on a highly characterised material that could be used for modelling work in the future. A method for obtaining spatially resolved flame spread data for this type of material was presented using a gridded array of 5 × 10 thermocouples placed on the underside the foam slab and from this, flame spread was examined using three different approaches. The heat release rate (HRR) results showed clear shapes forming that were dependent on the ignition location, with two distinct behaviours being observed between the various different ignition locations, this was also observed in the calculated flame spread rate (FSR) data. Results within an individual test, showed the calculated range of FSRs over the geometry of the slab varied between approximately 1 and 8 mm/s depending on the ignition location. The average FSR values between tests varied between 3 and 7 mm/s and the maximum and minimum values were calculated to be approximately 11 and 2 mm/s respectively.

This paper is to study the influence of sulphate corrosion on the mechanical behaviors of concrete, especially concrete corrosion under actual corrosion environment. This study investigated different immersion methods for concrete in a corrosion environment, and different strengths of concrete specimens with contents of sodium sulphate and magnesium chloride of 10.36% and 12.00%, respectively. Strength tests were performed on the specimens for the different immersion methods of full immersion, half‐immersion, and dry‐wet cycles, and with different strengths for the concrete of C20, C35, and C50. To study the internal mechanisms of the corrosion of concrete with different immersion methods and different strengths, a microscopic pore structure test was conducted. The field tests were performed after 12 years to evaluate the long term performance of the concrete under the actual environmental conditions. The test results show that full immersion mainly led to chemical corrosion, half immersion led to double damage from salt crystallization and chemical corrosion, and dry‐wet cycles accelerated the corrosions of the salt crystallization and chemical corrosion. The higher the strength of concrete, the better its resistance to the sulphate corrosion. In comparison with the strength of the concrete before corrosion, field test results show that the strength of uncorroded concrete after 12 years is increased by 9.5% and the strength of corroded concrete after 12 years is reduced by 56.2%. The results of the strength tests and pore structure tests show that sulphate has a significant impact on concrete strength after 12 years of field tests. This study will contribute to improve long‐term performance of the concrete, provide guidance for concrete structure design in corroded areas, and suggested that increasing attention should be paid to the effects of sulphate on concrete performance.

In den letzten Jahren sind im deutschen Bundesautobahnnetz verstarkt Schaden an vor 2005 errichteten Betonfahrbahndecken aufgetreten, die mit einer Alkali-Kieselsaure-Reaktion (AKR) in Verbindung gebracht werden. Neben dem AKR-fordernden Einfluss von alkalihaltigen Taumitteln werden Fahrbahndecken zyklischen mechanischen Belastungen infolge des Verkehrs und Zwangsspannungen durch klimatische Einwirkungen ausgesetzt. Solche mechanischen Belastungen werden bisher in keinem AKR-Prufverfahren berucksichtigt. Die zyklischen Belastungen konnen zu einer Degradation des Betongefuges fuhren, die ggf. einen AKR-fordernden Einfluss hat. Dieser Beitrag stellt Untersuchungen vor, die zur Beantwortung der Frage nach dem Einfluss einer zyklischen mechanischen Belastung auf den AKR-Schadensprozess beitragen. Dabei wird der Hypothese nachgegangen, dass die ermudungsinduzierte Degradation zu einer Erhohung des Stofftransports fuhrt. Dieser hat einen Einfluss auf die AKR-Schadensentwicklung, da die Reaktionspartner zunachst zum Reaktionsort transportiert werden mussen. Daher wird angenommen, dass sich mit dem Stofftransport auch die AKR-Schadigung verstarkt. Es werden Betonproben aus typischen Fahrbahndeckenbetonen einer vorgeschalteten zyklischen Druckschwellbelastung ausgesetzt. Die Degradation infolge der Vorbelastung wird simultan mittels ZfP-Verfahren charakterisiert. Anschliesend werden die Auswirkungen der zyklischen Vorschadigung auf den Stofftransport sowie auf die AKR vergleichend an Prufkorpern ohne und mit Vorschadigung untersucht. Die Ergebnisse lassen den Schluss zu, dass die zyklische Vorschadigung sowohl den Stofftransport als auch die AKR fordert.