Search Results (368)

Fire is the core safety threat to the survival and development of timber-framed buildings, and passive fire prevention intervention is the core foundation of fire protection systems for timber-framed buildings. Existing reviews suffer from limitations such as incomplete scenario coverage, insufficient breakdown of intervention mechanisms, and a lack of methodological standardization. This study strictly followed the PRISMA 2020 systematic review guidelines, searching the relevant literature from January 2016 to April 2026 on the Web of Science, Scopus, and Science Direct databases. After standardized screening, 89 valid articles were finally included and a systematic study was conducted through bibliometric analysis, keyword visualization, and multi-dimensional classification coding. The results show that the number of publications in this field has been continuously increasing from 2016 to 2025, with China accounting for 31.46% of the total, ranking first globally. The study constructed a core intervention mechanism system for passive fire prevention in timber-framed buildings, covering four categories: intrinsic flame-retardant modification, isolation protection, structural optimization, and spatial control. The working principles, application effects, advantages and disadvantages, and engineering application scenarios of each mechanism were clarified. This study systematically sorts out the core intervention mechanisms of passive fire prevention in timber-framed buildings, clarifies the research status and development trends in this field, and can provide evidence-based support for the design optimization, technology development, and engineering practice of passive fire protection for timber buildings. Full article

In recent years, the rapid expansion of low-temperature facilities—such as cold storage and indoor ice and snow venues—has underscored their pronounced vulnerability to fire, as evidenced by multiple severe incidents. Due to their distinct environmental conditions, existing theoretical frameworks, technical approaches, and standards exhibit limited applicability. Consequently, the fire risk characteristics of such facilities remain insufficiently defined, and systematic methods for hazard identification and assessment are lacking. This study conducts a detailed analysis of fire incident data from representative low-temperature facilities to identify the fire risk characteristics across all lifecycle stages, including construction, renovation and expansion, operation, maintenance, and demolition. An integrated framework combining the WBS/RBS (Work Breakdown Structure/Risk Breakdown Structure) matrix and complex network (CN) methods is then proposed to establish a structured methodology for full lifecycle fire hazard identification and classification. The results address critical gaps, including the absence of clearly defined lifecycle fire risk profiles and a robust scientific basis for hazard identification, and provide a technical foundation for lifecycle fire risk management in low-temperature facilities. Full article

This study develops an integrated computational framework to assess the passage efficiency of a dam crest serving as a critical inter-regional corridor following a severe explosion event. The framework combines a physics-based damage model with an agent-based cellular automata (CA) approach that incorporates pedestrian behavioral heterogeneity. The damage model conceptualizes three concentric zones: a complete fragmentation zone (0–1.5 m) with total material disintegration, a primary damage zone (1.5–5 m) following an exponential decay in structural integrity, and a secondary damage zone (5–20 m) governed by a power-law attenuation of fragmentation effects. Pedestrian behavior is parameterized by the Allowable Conflict Coefficient (ACC), the inverse of interpersonal friction, and the Emergency Level (EL), which scales the desired velocity. Extensive simulations under stochastic and targeted impact scenarios reveal a consistent evacuation performance hierarchy: Center (C) > Bottom-Left (BL) > Top-Left (TL) > Bottom-Right (BR) ≈ Top-Right (TR). Exit-proximal damage (TR, BR) increased evacuation time by up to 85% compared with central impacts. Results demonstrate a strong coupling between physical friction and urgency: the “faster-is-faster” effect is maximized under low friction (high ACC), while high friction not only suppresses the benefits of elevated EL but can also induce “faster-is-slower” phenomena under extreme conditions. These findings underscore that optimal evacuation strategies depend critically on both impact location and crowd behavior management, providing actionable insights for emergency planning and highlighting the importance of conflict mitigation in enhancing infrastructure resilience. The proposed framework thus offers a versatile and validated simulation tool for emergency planners to proactively assess and optimize evacuation strategies under various damage scenarios. Full article

Cross-laminated timber (CLT) is increasingly used in multi-story timber construction, but its combustible nature requires reliable fire protection, particularly in layered wall assemblies with concealed cavities. This study compares two medium-scale cross-laminated timber (CLT) sandwich wall assemblies exposed to radiant heat flux of 20 kW/m² for 90 min: an uncoated reference assembly and an assembly with PROMADUR^® intumescent coating applied to the CLT surfaces. Both specimens consisted of a 90 mm three-ply CLT panel encapsulated with 12.5 mm gypsum-fiber boards fixed to a wooden stud frame forming a 40 mm installation cavity. Fire-test observations were supplemented by simultaneous thermal analysis (STA), i.e., thermogravimetry (TG)/differential thermogravimetry (DTG)/differential scanning calorimetry (DSC), of uncoated and coated CLT specimens under oxidative conditions. During the applied medium-scale radiant exposure, the unexposed-face temperatures of both assemblies remained below the insulation temperature-rise limits defined in STN EN 1363-1; however, these limits were used only as a comparative benchmark and the test does not represent a formal fire-resistance classification. The coated assembly showed improved thermal protection during the early and intermediate stages of exposure, delaying a critical thermal event near the wooden stud by approximately 35 min. However, flaming combustion of the stud occurred at about 75 min and led to degradation of the intumescent char within the cavity. In contrast, the uncoated assembly reached higher early CLT surface temperatures but showed no flaming combustion during the test. STA results supported the fire-test interpretation: the coated specimen showed a 37% reduction in peak DTG rate, a higher residual mass at the end of the test, and substantially greater mass loss in the 150–280 °C range, consistent with intumescent activation and volatile release. The results indicate that, under the tested medium-scale exposure, the intumescent coating improved early and intermediate thermal protection of the CLT surface, but did not prevent late-stage cavity flaming involving the wooden stud. Therefore, the behavior of intumescent-coated CLT in partially enclosed cavities with combustible framing should be validated under replicated, standardized and larger-scale fire exposure. Full article

Accurate prediction of electrical fire risk is important for early warning, but real-world monitoring data are often affected by sensor noise, transient anomalies, and non-Gaussian interference. This study proposes an HL-Transformer that incorporates an HL-Pooling layer based on the Hodges–Lehmann estimator into the Transformer feature aggregation process. The HL-Pooling layer replaces conventional mean- or max-based pooling by using the median of pairwise averages, aiming to suppress abnormal perturbations while preserving temporal information. Experiments were conducted on a real-world electrical fire monitoring dataset and the public ETTh1 dataset, with additional robustness tests under different outlier ratios and intensities. The results show that, within the same Transformer backbone, HL-Transformer reduced the MSE by 75.4% compared with the Max-Pooling variant and achieved an R² of 0.879 on the electrical fire risk prediction task. Under injected outliers, the HL-Pooling layer showed more stable error trends, and its transfer to TCN, CNN-LSTM, and 1D-CNN models further improved predictive performance. These findings indicate that HL-Pooling is a robust and portable alternative to conventional pooling for time-series forecasting in noisy monitoring environments. Full article

Double-skin façade (DSF) systems are important for energy efficiency because they effectively utilize natural ventilation and daylight. However, the uninterrupted vertical gaps in these systems may pose safety risks in the event of a fire by causing the rapid spread of smoke and hot gases. This study presents a hybrid approach that combines computational fluid dynamics (CFD)-based simulations and machine learning (ML) techniques to predict heat flow and fire-room control-volume heat release rate (FR-HRR). Within the scope of the study, 400 different scenarios were modeled with different combinations of basic natural ventilation design parameters consisting of gap width, gap height, window opening area, and air inlet and outlet area. The data obtained were evaluated with different ML models, including Fine Tree, Bagged Tree, Support Vector Machine, and Artificial Neural Network models; in particular, the Fine Tree model gave the most successful results with high accuracy rates (R² = 0.99 for FR-HRR; R² = 0.91 for heat flow). The analysis showed that DSF gap width provided a dominant model-based contribution within the investigated CFD-generated dataset. This approach provides a preliminary CFD-informed ML framework for the rapid comparative assessment of fire-related responses in open-boundary naturally ventilated DSF configurations during the early design stage. Full article

Accurate simulation modeling of the danger zone and real-time visualization of the toxic cloud spread during a fire and explosion at an industrial facility in a nearby urban area are in demand by rescue services conducting evacuation. Using a cellular automaton method allows us to create an optimal predictive model of the danger zone spread, combine modeling accuracy with computational speed, and consider multiple input variables and the cascading nature of an accident during visualization. The objective of this study was to develop a mobile application for calculating the parameters of the danger zone during an accident at an industrial facility caused by a toxic cloud spreading into an urban area, based on the selection of a cellular automaton algorithm. The primary objective of the study was a highly detailed visualization of the danger zone with several predicted values of toxic substance concentrations in the air. The authors developed a cellular automaton-based model, which forms the basis of the mobile application. It takes into account several variables characterizing chemicals in the explosion and fire zone, climate factors, occupancy, building parameters, and the availability of respiratory protection. The FireSoft Mobile app was developed using the Visual Studio 2022 development environment, C# 10.0, and .NET MAUI, adapted for Android 8.0 and higher. The mobile app was tested to visualize a cloud of toxic pollutants forming a hazardous zone in an urban agglomeration for cases involving an ammonia tank explosion and a large fire involving a large amount of polyvinyl chloride. The results demonstrate the app’s feasibility and effectiveness in predicting, planning, and managing evacuation measures during accidents at an industrial facility. Full article

Compared with gaseous hydrogen at ambient temperature, liquid hydrogen (LH₂) possesses a higher volumetric energy density and is therefore regarded as one of the most economically viable hydrogen storage and transportation options. However, the extremely large temperature difference between the storage temperature of LH₂ and the ambient environment may give rise to serious safety hazards once a leakage accident occurs. Focusing on an integrated hydrogen production and refueling station (IHPRS), this study investigates the suppression effect of a novel synergistic protection system—combining a barrier wall and an air curtain—on LH₂ leakage and dispersion. By comparing the dispersion distances of hydrogen clouds under different barrier wall–air curtain configurations, the optimal synergistic structure was identified as a barrier wall with a planar size of 36 m × 12 m and a height of 3 m, combined with an air curtain velocity of 40 m/s. The reliability of this structure is further evaluated under practical influencing factors: under varying natural wind conditions, the maximum downwind dispersion distance is reduced by up to 58.02%; at a flash evaporation mass fraction of 20%, horizontal dispersion is suppressed by 42.18% and 33.17% in the X- and Z-directions, respectively; and at a leakage mass flow rate of 5.15 kg/s, the X-direction dispersion distance is reduced by 33.88% with a 40.14% increase in cloud height. The results show that the proposed barrier wall–air curtain synergistic protection structure can effectively alter the dispersion path of the FHC (refers to the hydrogen cloud with a volume concentration within the flammable range between 4 and 75% vol) formed by LH₂ leakage, shorten the hazardous downwind distance, and enhance the vertical dispersion of the FHC. These findings provide theoretical support and safety guidance for the risk control of LH2 leakage accidents in IHPRS. Full article

As key units in China’s new urbanization process, municipal districts exhibit distinct fire risk characteristics due to dense populations, concentrated infrastructure, and intensive socio-economic activities. Taking Xiaoshan District as an illustrative case of a highly urbanized and industrialized municipal district, this study analyzes fire incidents from 2020 to 2023 from temporal, spatial, and causal perspectives. During the study period, 5011 fire incidents were recorded, resulting in 3 deaths, 2 injuries, and direct property loss of 73.41 million CNY. The results indicate that highly urbanized and industrialized districts such as Xiaoshan may simultaneously face frequent fire occurrence pressure, relatively low casualty levels, and strong sensitivity to large-loss incidents. Temporally, fire occurrence was strongly coupled with human activity patterns rather than being dominated solely by seasonal factors. The period from 4 p.m. to 8 p.m. accounted for 32.47% of daily fire incidents, whereas only 9.10% occurred between 2 a.m. and 6 a.m.; however, early morning fires were associated with more serious property loss. Spatially, resident population and industrial output value above designated size were identified as the primary socio-economic factors associated with the spatial differentiation of fire incidents and direct property loss at the town/subdistrict scale. In terms of causation, electrical issues were the leading cause of fire incidents, accounting for 31.95% of fires and 32.92% of direct property loss. In addition, direct property loss attributed to “other” causes was disproportionately high, highlighting the need to improve the professionalism, granularity, and consistency of fire cause investigation. These findings provide case-based empirical evidence for refined fire prevention, electrical fire control, early warning, and targeted fire safety management in highly urbanized and industrialized districts with similar development conditions. Full article

This research investigates the effect of seismic loading on FRRs of RC structures using different machine learning (ML) algorithms. First, 20 portal RC frames with varying span numbers and stories are designed for seismic loads. This is then expanded to over 1760 frames by including further specifications such as span length, soil type, and seismic levels. This dataset is derived using decision tree algorithms, ensuring a robust and comprehensive analysis of the relationship between seismic design considerations and FRRs. All the models are subjected to the ISO 834 fire curve. Employing different ML algorithms indicate that the Random Forest Regression provides an accuracy of 81.88%, outperforming alternative algorithms such as Gradient Boosting and Support Vector Regression. Overall, the results suggest that structural elements designed for higher seismic demands exhibit higher FRRs. Additionally, as the number of spans increases, the associated FRRs also increase. An equation is then proposed to correlate the required sprinklers and the FRRs of seismically designed structures, making it possible to adopt a cost-reduction strategy in establishing fire protection systems. The ML-based algorithms here present a functional approach that can assist engineers in reducing structural and fire protection design costs while meeting the fire safety needs. Full article

This study investigated the suppression effects and mechanisms of fine water mist on methane/air explosions through large-scale roadway experiments and numerical simulations. Experiments showed that fine water mist curtains deployed at 40 m and 70 m effectively mitigate flame propagation and reduce overpressure. A coupled gas–liquid numerical model was developed to reproduce flame dynamics and droplet–flow interactions. The simulations revealed droplet breakup, transport, and coupling with the evolving explosion flow field, providing mechanistic insight into gas–liquid interactions in a confined roadway. Suppression by fine water mist is primarily driven by heat absorption and cooling, while radical chain interruption plays a secondary role. These coupled mechanisms significantly reduce flame propagation velocity and pressure rise rate, achieving complete suppression under optimized configurations. This study provides a solid foundation for the design and optimization of water mist explosion suppression systems in large-scale roadways. Full article

Conventional water mist systems require high-pressure pumps and complex piping networks to generate fine water droplets, which often results in high installation costs and maintenance difficulties. Recently, a water mist system with ultrasonic waves has been proposed as a viable alternative system to address those limitations. However, there is a lack of experimental data for evaluating the fire suppression performance of water mist systems using ultrasonic waves. Therefore, in this study, a simplified water mist system with an ultrasonic wave was suggested for evaluating the fire suppression performance. Subsequently, a reduced-scale room corner test (RCT) was conducted to investigate suppression performance under various fire sizes and suppression conditions. The experimental cases were classified according to pool size, door condition, and operation of the ultrasonic water mist system. Ultimately, fire suppression performance was quantitatively evaluated using performance indices derived from fire duration and indoor temperature variation. The results demonstrate that the ultrasonic water mist system effectively suppresses fires through combined cooling and oxygen-blocking effects, while significantly reducing indoor temperature compared to oxygen-blocking suppression. The proposed performance indices enable quantitative comparison of suppression effectiveness and confirm the feasibility of ultrasonic water mist systems as an alternative to conventional high-pressure water mist systems. Full article

This study evaluates the structural performance of sliding-type evacuation ladders under realistic fire evacuation loading conditions using parametric numerical analysis. A series of finite element models was developed based on the original ladder design, and key parameters—including member thickness (1–4 mm), overlap length between modular units (40–70 mm), loading configurations, and boundary conditions at the ladder base—were systematically varied. A total of 288 numerical cases were analyzed to investigate their influence on global displacement behavior. The results indicate that a minimum member thickness of 2 mm is required to satisfy displacement-based serviceability criteria; however, this threshold may be insufficient when connection flexibility is considered. The overlap length has a more pronounced effect on structural performance for thinner members, while the loading height has a significant effect on the displacement response. In addition, the boundary condition at the ladder base plays a critical role, with vertical support conditions substantially reducing overall displacement. These findings highlight the importance of system-level structural evaluation beyond component-based testing. They also provide practical insights for improving the design criteria and installation conditions of evacuation ladders in high-rise residential buildings during fire emergencies. Full article

In a tank farm, even if the separation distance meets the codes and standards, a pool fire in one tank may spread quickly to another tank. Most destructive and uncontrollable fire accidents are induced with multiple pool fires. In current work, the thermal buckling behaviors of a fixed-roof tank subjected to one (two) neighboring pool fire(s) (burning tanks) are numerically studied. The effects of the number of the pool fires, the separation distance between two pool fires, and the distance between the adjacent tank and pool fires are analyzed. The results indicate that the thermal buckling zone of the target tank subjected to two pool fires is larger than that subjected to one pool fire, and the maximum displacement for two pool fires is almost equal to that for one pool fire. The target tank subjected to one pool fire loses stability and reaches a new stable state faster than that subjected to two pool fires. The thermal buckling zone expands as the distance between the two pool fires increases but decreases with increasing separation distance between the pool fire and the target tank. The findings provide useful guidance for the structural optimization of steel storage tanks against pool fire exposure and offer theoretical support for emergency response and fire rescue in tank farms. Full article

Passive Fourier transform infrared (FTIR) spectral imaging technology is easily affected by complex background radiation for leakage monitoring at natural gas stations, leading to low gas identification sensitivity, poor detection accuracy and a high false alarm rate. To address these issues, the spectral characteristics of typical background interference sources and their impact mechanisms were first analyzed in this work. Subsequently, a targeted background denoising method was developed and then on-site gas release experiments were conducted in a typical natural gas station. The results demonstrated that the proposed background denoising method can effectively suppress complex environmental background interference and reduce the false alarm rate. This study provides a solution for enhancing the reliability and practicality of passive FTIR spectral imaging technology in remote gas leakage monitoring at industrial sites. Full article