Cable bridges such as cable-stayed bridges and suspension bridges are supported by members such as cables, reinforced girders, and pylons. Fires on the bridge can cause structural degradation in ...members, which can pose a severe danger to the bridge. However, in most countermeasure standards for structures, no information regarding the installation of firefighting facilities on cable bridges is available. In this paper, a fire risk assessment method for the installation of fire hydrants and standpipe systems on cable bridges is proposed. To determine the grade of the fire hazards for these bridges, the fire risk was classified into categories, such as the likelihood of fire occurrence, fire response conditions, the vulnerability of the bridge to fire, and impact of fire on the society and economy. The degree of fire hazard was determined by assigning weightage factors to each category, and the fire risk for 70 existing cable bridges and those under construction in Korea was evaluated. Application of these results can ensure adequate fire extinguishing facilities are installed on any bridge based on its fire risk.
Security of water distribution systems is of highest importance to public health. In this study, a novel dynamic hydrant flushing strategy is developed to remove the injected contamination mass in ...the shortest possible time after being detected by the sensors. The coupled EPANET-IHS simulation-optimization model is developed to determine the hydrant flushing strategies (the hydrant sets and their opening/closing time). This allows water utility managers to utilize the hydrants instantly after the sensor alarm with no need for excessive investigations, which enhances the flushing effectiveness. Developed based on thousands of contaminant injection scenarios (contamination events), the proposed hydrant flushing strategies are reliable to remove any injected contamination mass. Moreover, the operation of hydrant sets is dynamically validated by closing/opening of hydrants throughout the total hydrant flushing duration, which enables the model to flush up to more 20%. The methodology is examined on the mid-sized WDS of Mesopolis city.
•In this study, the axial compression test of pebble aggregate recycled concrete (RAC) after high temperature exposure and fire hydrant water cooling is carried out for the first time.•The ...performance degradation law of RAC after high temperature exposure and fire hydrant spray cooling and the mechanical properties of recycled pebble aggregate concrete at room temperature are obtained.•In this study, a method for calculating the residual bearing capacity of RAC after high temperature exposure and fire hydrant spray cooling is proposed.•In this study, the constitutive equation of RAC after high temperature exposure and fire hydrant spray cooling is proposed for the first time.•The constitutive equation proposed in this paper is verified by ABAQUS finite element analysis software.
In urban fire, the structure will not only be subjected to high temperature, but also cooled by fire hydrant. This paper presents the experimental results of the residual mechanical performance and the complete compressive stress–strain relationship of recycled pebble aggregate concrete (RAC) after exposure to high temperature of 20 to 600 ℃ and cooled by fire hydrant. In the experiments, five different concrete compositions were designed by substituting natural coarse aggregates with recycled coarse aggregates at the replacement ratios of 0%, 30%, 50%, 70% and 100%. Results exhibit that with the increase of exposure temperature, the surface color of the specimens changes from light to dark, the mass of RAC first increases and then decreases, and the residual mass of RAC at 200 ℃ is higher than that at room temperature. The compressive strength and the strain at the peak point decrease rapidly with the increase of temperature. The compressive strength and the strain at the peak point fluctuate with the increase of aggregate replacement percentage, and the temperature and aggregate replacement percentage have little effect on the ductility of RAC. The residual bearing capacity calculation method and constitutive equation of RAC after high temperature exposure and cooled by fire hydrant are proposed and verified. The accuracy of the constitutive equation is verified by ABAQUS finite element analysis software.
Background: Every shipyard has a fire hazard that needs to have a sufficient fire protection. PT. Dok dan Perkapalan Surabaya (Persero) has the potential for fire do to hot work and usage of high ...vultage electricity. Active fire protection facilities at PT. Dok dan Perkapalan Surabaya (Persero) need to be evaluated to ensure that the active fire protection facilities are always in good condition. Purpose: The purpose of this research was to evaluate the application of active protection means in PT. Dok dan Perkapalan Surabaya (Persero) to comply with the rule and standard namely : Permenakertrans No. Per 04/MEN/1980 for fire extinguisher, Permen PU No. 26/PRT/M/2008 and SNI 03-1745-2000 for hydrant. Method: This research was observational descriptive one. The object of this research were : fire extinguisher and hydrant in PT. Dok dan Perkapalan Surabaya (Persero). Data collected by questionnaire,checklist, and observation. Result: The result showed that the active protective means for fire extinguisher in good category with a level of suitability of 92,9% and for hydrant in sufficient condition with a level of suitability of 73,5%. Conclusion:. There were some elements that were not suitable, such as some fire extinguisher covered by items, some fire extinguisher installations exceed 120 cm from the floor surface, some fire extinguisher were defective due to rusting, there were no hydrant use instructions, and no fire hydrant have been examined. PT. Dok dan Perkapalan Surabaya (Persero) is suggested to move items that cover fire extinguisher to be easily seen, the height of the fire extinguisher installation should not exceed 120 cm from Permenakertrans No. Per 04/MEN/1980, replacing inappropriate fire extinguisher, carrying out rountine fire check.
As a critical element in preserving the health of urban populations, water distribution systems (WDSs) must be ready to implement emergency plans when catastrophic events such as contamination events ...occur. A risk-based simulation-optimization framework (EPANET–NSGA-III) combined with a decision support model (GMCR) is proposed in this study to determine optimal locations for contaminant flushing hydrants under an array of potentially hazardous scenarios. Risk-based analysis using Conditional Value-at-Risk (CVaR)-based objectives can address uncertainties regarding the mode of WDS contamination, thereby providing a robust plan to minimize the associated risks at a 95% confidence level. Conflict modeling by GMCR achieved an optimal compromise solution within the Pareto front by identifying a final stable consensus among the decision-makers involved. A novel hybrid contamination event grouping-parallel water quality simulation technique was incorporated into the integrated model to reduce model runtime, the main deterrent in optimization-based methods. The nearly 80% reduction in model runtime made the proposed model a viable solution for online simulation-optimization problems. The framework's capacity to address real-world problems was evaluated for the WDS operating in Lamerd, a city in Fars Province, Iran. Results showed that the proposed framework was capable of highlighting a single flushing strategy, which not only optimally reduced risks associated with contamination events, but provided acceptable coverage against such threats, flushing 35–61.3% of input contamination mass on average, and reducing average time-to-return to normal conditions by 14.4–60.2%, while employing less than half of the initial potential hydrants.
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•Hydrant flushing is a practical way to deal with incidents of contamination.•Critical injection nodes, times, and durations are considered injection parameters.•Risk-based analysis using CVaR can address uncertainties about the contamination mode.•Hybrid event grouping-parallel water quality simulation reduces runtime dramatically.•GMCR with a comprehensive viewpoint shows promise in decision-making.
Portable Fire extinguishers and hydrant are tools used for overcoming the fire. The purpose of this research is to learn about fire portable and hydrant application as a defensive action of fire in ...PT X. This research is a descriptive research with a cross sectional approach. Variable of this research are portable fire extingusher, hydrant and company policy. The result of this research showed that almost installation of portable fire estingusher is comply with Permenakertans No. 04/PER/MEN/1980 abaout the requirments of portable fire estingusher, either the hydrant also comply with Kepmen PU No. 02/KPTS/1985 about regulation of preventive and defensive action of fire for bulding , but there is one hydrant which covered by the rest of production materials and there is no white writting or mark “HYDRANT” on some box hydrant. Company is suggested to look at, or aware of the height of portable fire estingusher installation and box hydrant may not covered by anything and give an white writting or mark “HYDRANT’.
Due to such characteristics as complicated structure, frequent operation switching and fierce flow fluctuation ofthe apron pipeline network, it is difficult to conduct hydraulic simulation research. ...In order to better integrate the structuralparticularity of apron pipeline network with the hydraulic calculation theory of pipeline network, programming calculationwas conducted with the pipeline network simplified and divided into 3 parts, and for the circular section at the core, pressurebased Newton iteration method was adopted for calculation. In order to verify the accuracy of the model, the specificworking conditions were selected, the calculation results were compared with the PipePhase simulation results and checked, and the comparison results were within the reasonable error range. The solutions were elaborated in detail for the problemsof adapting the fluid flow direction in the pipe, establishing a reasonable relationship between the information of fuelingorder and the bleed-off discharge, and the pres
This study resolved the problem of Part 2 and refined the method for estimating the spatial distribution of vacant houses using public municipal data by addressing the following issues. 1) This ...study realized a more reliable method for estimating the distribution of vacant houses without concern for the simplicity of the method used in Part 2 2) We applied the method developed in this study to the entire area of Kagoshima City and Asakura City covered by Part 2, clarifying the method’s practicality and versatility. 3) By comparing the results of Part 2 and this study, we demonstrated the extent to which the reliability of this paper’s estimation method was improved. 4) The correct answer rate on a building-by-building basis was also revealed, and the results of estimating vacant and non-vacant houses per building could be obtained. Chapter 2 introduced the database for analyzing the characteristics of vacant houses: the vacant house database, developed by combining several public municipal data: the basic resident register (BRR), Hydrant consumption amount information (HCI), and the building registration information (BRI) and the results of a field survey of vacant houses, as used in Part 2. Chapter 3 introduced the method for estimating the distribution of vacant houses in Part 2 and its challenges. Chapter 4 proposed a method for estimating the distribution of vacant houses. In this study, XGBoost, a decision tree-based machine learning model for dealing with missing values and setting optimal thresholds, was applied to estimate the vacant house probability of each building. XGBoost iterated the decision tree until there was no improvement in predictions, and then summed the results of each decision tree to estimate the vacancy probability per building. Chapter 5 verified the reliability of the method proposed in this study, comparing it with the method developed in Part 2. Results show that the correct answer rate for the vacant or non-vacant judgments for each building reached 97.81% in Kagoshima City and 97.25% in Asakura City. Even when we aggregated by the 250-m square grid as in Part 2, the accuracy of this study’s methods exceeded that of Part 2. In addition, when we determined whether a building was vacant or not using the method of Part 2, the determination accuracy of vacant houses was particularly low. However, the method used in this study significantly improved this problem and could estimate both vacant and non-vacant buildings with high accuracy. Finally, Chapter 6 showed the estimated number of vacant houses and the vacant house rate aggregated by a 500-m square grid for Kagoshima and Asakura. Compared to the results of Part 2, the estimated number of vacant houses in Kagoshima City increased from 7,361 to 9,856, while the number of vacant houses in Asakura City remained almost the same. In addition, vacant house rates were higher in the central city and mountainous areas and lower in the suburbs than in Part 2 for both cities. This indicates that it is possible to estimate the distribution of the number of vacant houses accurately.
En Trujillo, una ciudad al norte de Perú, el número de hidrantes es actualmente 497; solo 10% están operativos en el centro de la ciudad. Frente a esta situación, los bomberos no atienden en tiempo ...óptimo diversas emergencias que suceden, haciendo posible que se incremente los daños materiales y las víctimas debido a la falta de agua de los hidrantes inoperativos y a su no óptima distribución. En esta investigación fue localizada estratégicamente una red de hidrantes mediante el diseño y la salida de un algoritmo genético. Hay muchas soluciones candidatas y solamente una debe ser seleccionada, la más eficiente. Fueron evaluadas con una función de calidad que relaciona las distancias entre un punto común del incendio a otros puntos donde están los hidrantes y la mejor solución fue encontrada aplicando operadores genéticos como el cruce y la mutación, lo que representaba la ubicación de los puntos de los hidrantes sobre un mapa de la ciudad. El resultado es una buena solución para una red de hidrantes; además el número de hidrantes que componen la red con su distancia media que reduce el tiempo para atender una emergencia. Será muy útil redistribuir los hidrantes a mejores ubicaciones.
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