China Safety Science Journal

Situation awareness and behavior response model of crane drivers based on DEMATEL-AISM

JIN Lianghai, LIU Hao, WU Bangjie, SHI Hui, HE Shiyu

2024, 34(9): 1-8. doi:10.16265/j.cnki.issn1003-3033.2024.09.0096

Asbtract ( 352 )

HTML ( 2)

PDF (3793KB) ( 11 )

Figures and Tables | References | Related Articles | Metrics

To have a deep understanding of the causal relationship between crane drivers' situation awareness information and behavior, the situation awareness and behavior response model of crane drivers was proposed by combining the ENDSLEY situation awareness model with the DEMATEL-AISM method. Firstly, the situation awareness theory was used to analyze the driver's behavioral response process and obtain information factors during the crane operation task. Secondly, the DEMATEL method was used to quantitatively analyze the association between the factors and determine a comprehensive influence matrix. Moreover, the attributes and characteristic values of the factors were analyzed to identify the key factors. Finally, a stable hierarchical structure of cause-effect attributes obtained by the AISM was used to propose the situation awareness and behavior response model of crane drivers. The results revealed that a five-layer information model consisted of 22 elements and influence relationships such as key elements of trajectory prediction and planning, and collision avoidance. Furthermore, the proposed model clarified the attribute characteristics, influence relationships, and influence degree among the information elements, offering a deep understanding of the crane driver's situation awareness and behavior response.

Statistical analysis and countermeasures of major accidents in coal mines in China

WANG Haijun, QI Qingjie, LIANG Yuntao, QI Qingxin, LIU Yingjie, SUN Zuo

2024, 34(9): 9-18. doi:10.16265/j.cnki.issn1003-3033.2024.09.0208

Asbtract ( 381 )

HTML ( 2)

PDF (13080KB) ( 24 )

Figures and Tables | References | Related Articles | Metrics

To reveal the characteristics of coal mine accidents in China in recent years, and put forward targeted countermeasures and suggestions for accident prevention, firstly, the major and catastrophic coal mine accidents in China from 2013 to 2023 were collected and analyzed from the aspects of the year, type, month, province and cause of the accident. Secondly, taking "2·22" particularly serious collapse accident in Inner Mongolia Xinjing coal mine as an example, the accident was analyzed based on 24Model. Finally, combined with the above analysis and research results, the accident prevention countermeasures and suggestions in line with the current situation of coal mine safety production in China were put forward. The analysis and research results show that the number of major accidents and deaths in coal mines has shown an overall downward trend, and the level of coal mine safety production in China has significantly improved since the 12^th Five Year Plan. Gas accidents are still the main accidents in coal mines in China, accounting for 51%. The fourth quarter of each year is a period of high incidence of coal mine accidents, accounting for 30.43% of the total number of accidents. Affected by geological conditions and occurrence, accidents often occur in the main coal producing areas. The proportion of accidents caused by unsafe human behavior is as high as 74%. When there are hidden dangers at both the individual and organizational levels and the dual prevention measures are not in place, accidents are likely to occur. Countermeasures and suggestions for reducing coal mine safety accidents are put forward from four dimensions, including safety supervision, strengthening safety through science and technology, team development and safety culture.

Model of identifying entities of safety specification for hydropower engineering construction

CHEN Shu, ZHANG Chao, CHEN Yun, ZHANG Guangfei, LI Zhi

2024, 34(9): 19-26. doi:10.16265/j.cnki.issn1003-3033.2024.09.0008

Asbtract ( 156 )

HTML ( 0)

PDF (4608KB) ( 3 )

Figures and Tables | References | Related Articles | Metrics

To accurately identify the entities of hydropower engineering construction safety specification, the named entity recognition model of hydropower engineering construction safety specification was constructed. The rich semantic information in the text was mined by the BERT. The semantic features of the specification were extracted by using BILSTM. The dependency relationship between entities was analyzed by relying on CRFs. The Technical Specification for Safety Protection in Construction of Water Conservancy and Hydropower Projects (SL714-2015) was taken as an example to calculate the named entity recognition model accuracy rate. The results show that the accuracy rate of the BERT-BILSTM-CRF model is 94.21%. Compared with the three traditional methods, the accuracy is significantly improved. The research will effectively assist in the intelligent management of safety regulations knowledge for hydropower engineering construction, and provide important support for the intelligent identification of construction safety hazards.

Coupling mechanisms of risk communication and sustainable development based on social justice

XU Xinlong, CHEN Yujie, LIU Shunjia

2024, 34(9): 27-33. doi:10.16265/j.cnki.issn1003-3033.2024.09.0415

Asbtract ( 176 )

HTML ( 0)

PDF (5697KB) ( 4 )

Figures and Tables | References | Related Articles | Metrics

In order to identify the different dimensions of social justice in the risk communication of public crisis events for the promotion of sustainable social development, the theoretical mechanism between the four dimensions of social justice: procedural, interactive, distributive, and corrective justice and sustainable social, ecological, spatial, and temporal characteristics were explained by constructing a theoretical framework of risk justice. Then, we defined risk justice as the fair and reasonable quality of stakeholders' right to participate in the governance and management of public crisis events. To validate the constructed risk justice frameworks, we conducted a detailed content analysis of the risk management guideline, the Sendai Framework for Disaster Risk Reduction 2015-2030, which was used to elucidate the prospective potential of the risk justice framework. The results suggest that this risk management guideline emphasizes the social and spatial issues of distributive and procedural justice, and less consideration in interactivity, corrective justice, and temporal and ecological issues, which may lead to the negative impacts of public crisis events risk communication on the sustainable development of society.

Classification model of oil and gas pipeline accidents causes and its social network analysis

GONG Yunhua, ZHANG Zhe, FAN Zhiwei

2024, 34(9): 34-40. doi:10.16265/j.cnki.issn1003-3033.2024.09.1353

Asbtract ( 151 )

HTML ( 1)

PDF (6744KB) ( 5 )

Figures and Tables | References | Related Articles | Metrics

In order to improve the effectiveness of oil and gas pipeline accident prevention strategies, a classification model for the causes of oil and gas pipeline accidents was developed, and social network analysis was applied to the classification model. Firstly, the STAMP model and HFACS model were combined to get the control structure of oil and gas pipeline accident prevention, and then the causes of 35 oil and gas pipeline accidents at home and abroad were analyzed according to the control structure. The analysis results were coded using grounded theory to get the classification model for the causes of oil and gas pipeline accidents. Social network analysis methods were applied to construct a relationship network of factors related to oil and gas pipeline accidents, and core edge analysis, centrality analysis, and correlation direction index analysis were used to identify the core factors and factors with high correlation and strong influence in the oil and gas pipeline accident classification model. The research results show that the classification model for the causes of oil and gas pipeline accidents included 6 levels and 22 bottom cause factors, which are government and regulatory factors, third-party factors, operator organizational factors, operator unsafe supervision and the prerequisites for unsafe behavior of on-site personnel. Among the causal factors, the internal factors of the government and regulatory authorities, organizational factors of operators, unsafe supervision of operators, and third-party factors are core factors. System flaws, insufficient supervision, improper operation plans, third-party sabotage behavior, pipeline and weld defects, construction/repair/accessory issues, and skill errors are factors with high correlation and strong influence.

Vulnerability and resilience analysis of safety behavior of organizations participating in bridge engineering based on GRA-SD

ZHANG Siyuan, YU Bo, LI Ruipu, WANG Qun

2024, 34(9): 41-49. doi:10.16265/j.cnki.issn1003-3033.2024.09.0079

Asbtract ( 105 )

HTML ( 0)

PDF (8594KB) ( 1 )

Figures and Tables | References | Related Articles | Metrics

To effectively implement safety production investment in bridge construction projects, GRA was used to analyze the correlation between the influencing factors of construction safety behavior from both the project supervision organization and construction units, and then the core causal factors were determined. Subsequently, a SD model was proposed to investigate the interaction mechanisms among the core causal factors. Finally, the vulnerability and resilience of the core causal factors affecting construction safety behavior were analyzed. The results indicated that extreme fines imposed by construction units, high supervision costs for project monitoring organizations, and low initial proportions between parties were the key vulnerability factors of the safety behavior in bridge construction. Reasonable economic fines, appropriate supervision costs, and enhanced training to improve frontline personnel's safety awareness significantly improved the construction safety behavior resilience.

Effects of fatigue on operator monitoring behavior based on EEG experiments

ZHANG Mian, YI Cannan, JIANG Fuliang, HU Hong, WU Wen, ZHANG Sijia

2024, 34(9): 50-58. doi:10.16265/j.cnki.issn1003-3033.2024.09.0997

Asbtract ( 128 )

HTML ( 0)

PDF (7503KB) ( 0 )

Figures and Tables | References | Related Articles | Metrics

To optimize operator fatigue risk management and reduce the impact of fatigue on operator performance, the monitoring tasks before and after fatigue induction were conducted. Firstly, the fatigue-inducing task of the 2-back paradigm and the monitoring task of the oddball paradigm were designed with the digital main control room of a pressurized-water reactor nuclear power plant, and the control interfaces of low, medium, and high complexity were used. Then, human trials with 23 participants were performed to obtain subjective fatigue ratings, behavioral data, and EEG signals. Moreover, the effectiveness of fatigue induction was verified using relevant fatigue indicators. Finally, the participator's behavioral data and event-related potential P3 components under three different complexity interfaces before and after fatigue induction were analyzed. The results showed that the shortest 2-back task lasting 30 to 60 min induced fatigue. Fatigue or interface complexity increase resulted in a decrease in the monitoring behavior performance, and the maximum performance difference was observed between high-complexity and medium-complexity interfaces under fatigue conditions. Moreover, a 4.9% decrease in accuracy and a 10.4% increase in reaction time were observed. The trend of P3 latency was consistent with that of reaction time, and P3 amplitude increased significantly only under high-complexity interfaces. Based on the performance analysis and event-related potential data, it was concluded that the interface complexity increased the negative impact of fatigue on operators' mental workload.

Key patent analysis of China's power grid intelligent safety technology

XIE Kefan, ZUO Lingyu, PENG Huatao

2024, 34(9): 59-68. doi:10.16265/j.cnki.issn1003-3033.2024.09.0232

Asbtract ( 116 )

HTML ( 0)

PDF (12164KB) ( 0 )

Figures and Tables | References | Related Articles | Metrics

In the new security pattern, the power grid safety management was promoted to transform from the traditional mode to the digital, information, and intelligent mode during the life-cycle of safety production. Based on patent data of China's power grid intelligent security from 2008 to 2023, the patent map was performed using network centrality analysis and main path analysis. Then, key patent technology subgroups were obtained to systematically analyze technological development and key points of power grid intelligent safety. Based on patent maps and expert opinions, the entropy weight-TOPSIS method was used to evaluate the support of China's existing intelligent safety technology community for power grid security and intelligence. The results showed there were 11 key technology communities for the power grid intelligent safety technology, and power grid intelligent safety process technology was the most excellent knowledge group. Among the 11 types of power grid intelligent safety technology communities, technologies including intelligent control, intelligent dispatching, and network communication safety were with higher support for power grid intelligent safety. Intelligent security technology can well support the safety control and stability capabilities in the traditional safety goals of the power grid. Furthermore, it supports the safety governance and active security capabilities in the modern safety goal of the power grid. However, the support for security resilience capabilities was insufficient.

Quantitative prediction method for safety of old building structures based on digital twins

ZHAI Yue, LEI Shangxue, WANG Yihong, WANG Aochen, XIE Zihan, JIA Yu

2024, 34(9): 69-77. doi:j.cnki.issn1003-3033.2024.09.1975

Asbtract ( 37 )

HTML ( 0)

PDF (9243KB) ( 0 )

Figures and Tables | References | Related Articles | Metrics

In order to improve the safety analysis of old buildings, a method was introduced for quantitatively predicting their structural safety based on digital twins. Identifying risk factors in the buildings' structures, setting up an intelligent monitoring system, and using monitoring data in numerical simulations to assess the safety of critical structural elements were included. The method provided quantitative predictions for damaged areas and the extent of destruction in the buildings. This study validates the proposed method using an old building in Xi'an with a history of over 70 years. A two-year structural safety monitoring was conducted following an actual engineering design monitoring plan. The numerical model of the building was created using Revit software and imported into ABAQUS. Monitoring data was used as external parameters in numerical simulations, with the assumption that monitored values exceeding settlement thresholds indicate a quantitative prediction of building damage. The outcome demonstrates that the old building is currently in a safe condition. However, if the settlement of the building exceeds the safety threshold, the likelihood of structural damage occurring at the front side of the stairs will be increased. The study verifies the high feasibility of a quantitative prediction method that integrates real-time monitoring data with numerical simulations based on digital twin technology for analyzing and assessing the overall and local structural safety of aging buildings.

Impact of internal parameters on the fracturing performance of 38mm CO₂ fracturing tool

LU Zhaijun, WANG Zhifu, YAO Shujian, ZHONG Mu, SHI Xiangshi, CHEN Feipeng

2024, 34(9): 78-86. doi:10.16265/j.cnki.issn1003-3033.2024.09.1378

Asbtract ( 79 )

HTML ( 0)

PDF (7058KB) ( 2 )

Figures and Tables | References | Related Articles | Metrics

In order to swiftly elucidate the influence of internal parameters on the fracturing performance of a liquid CO₂ fracturing tool and optimize its functionality for enhanced coal seam gas extraction efficiency, a rapid assessment experimental apparatus was designed. A set of 9 orthogonal experiments involving 4 horizontal and 3 influencing factors was conducted utilizing a 38 mm mining-specific fracturing tool. The study analyzed the relative significance of the internal charge quantity in the heating tube, liquid CO₂ filling volume in the main pipe, the thickness of the fracture plate, and the caliber of the release aperture on the fracturing tool's performance. Furthermore, pivotal influencing factors were subjected to fixed-variable experiments to explore their impact patterns on the fracturing performance of the liquid CO₂ fracturing tool. Results indicate that, for the 38 mm mining-specific CO₂ fracturing tool, the thickness of the fracture plate exerts the most substantial influence on the fracturing tool's performance, followed by the internal charge quantity in the heating tube. The impact of the liquid CO₂ filling volume in the main pipe and the caliber of the release aperture is comparatively weaker. The fracturing performance of the liquid CO₂ fracturing tool gradually stabilizes with an increase in the thickness of the fracture plate, reaching a point where the plate does not rupture. When the internal parameters of the 38 mm fracturing tool are set to a CO₂ mass of 0.33 kg, a release caliber of 18 mm, a charge quantity of 60 g, and a fracture plate thickness of 2.0 mm, the tool's fracturing performance corresponds to a TNT(Trinitrotoluene) equivalent of 0.202 kg which is enhanced by 21.9 % compared to the current on-site parameters.

Obstacle detection on mining roads based on multi-scale feature fusion and attention mechanism

LI Gang, DU Yabo, YANG Qinghe, MAO Mengying, JIA Dongping

2024, 34(9): 87-98. doi:10.16265/j.cnki.issn1003-3033.2024.09.1631

Asbtract ( 146 )

HTML ( 2)

PDF (20922KB) ( 3 )

Figures and Tables | References | Related Articles | Metrics

In order to solve the problem of travelling obstacle detection in the context of complex open pit mines, a mining road obstacle detection algorithm based on improved cross-scale feature fusion is proposed. Firstly, to address the problem of unbalanced small target sample categories in the original mine dataset, a data enhancement method based on geometric transformation and weighted Poisson fusion is used to expand the number of samples.Secondly, a cross-stage connectivity network that is more suitable for obstacle detection is proposed in the feature extraction stage to increase the detection scale and improve the algorithm's learning ability of the small target features, and then a 3D parameterless attention (SimAM) and de-weighted Bi-directional feature fusion pyramid network (Bi-FPN) are proposed in the feature fusion stage to improve the multi-scale detection performance by enlarging the predicted feature map and feature receptive field. Finally, to address the problems of sample imbalance and imprecise obstacle bounding box localisation in the training, the quality focal loss function (QFL) and the scalable Intersection and combination ratio loss function (SIoU), which combines the classification score with the quality prediction of the position to improve the localisation accuracy for dense occlusion targets. The results show that the improved method can effectively identify unstructured road obstacles in open pit mining area under complex background, and in practical application, the detection accuracy reaches 91.88% and the detection speed reaches 68.7 f/s, which has a better performance of small-target and multi-scale detection compared with the mainstream detection methods, and it can satisfy the requirements of obstacle safety detection in the travelling of unmanned mine cards in open pit mining area.

Review for measuring hydrogen sulfide content in coal seams

DENG Qigen, XIANG Sisi, ZHOU Yinzi, LI Shuai, ZHANG Zhecheng

2024, 34(9): 99-106. doi:10.16265/j.cnki.issn1003-3033.2024.09.0204

Asbtract ( 82 )

HTML ( 0)

PDF (2250KB) ( 0 )

Figures and Tables | References | Related Articles | Metrics

In order to develop the measurement of hydrogen sulfide content in coal seams towards informatization, intelligence, and automation, it is necessary to innovate the measurement equipment and technical methods. By analyzing the adsorption characteristics of H₂S in coal seams, the achievements in the development and application of hydrogen sulfide determination devices in recent years were summarized from the aspects of the convenience and accuracy of the construction of hydrogen sulfide determination devices. The current research status of methods for measuring hydrogen sulfide content in coal seams both domestically and internationally was elaborate. Finally, in view of the limitations of the equipment and methods for measuring hydrogen sulfide in coal seams, the future development direction of coal seam hydrogen sulfide measurement technology was discussed, and a technical system for improving the calculation error of coal seam hydrogen sulfide loss was proposed. An integrated coal sample underground crushing and desorption system, an automated desorption gas metering system, an intelligent monitoring and automated data analysis and processing system are constructed. The results show that the coal mine underground sampling method with internal and external double drill pipes, the loss of hydrogen sulfide during drilling and sampling is compensated. The measuring device is equipped with underground direct crushing equipment, filters, negative pressure vacuum tanks, and sensors for direct underground gas extraction and analysis, improving the accuracy of measuring hydrogen sulfide content in coal seams.

Simulation study on lithium battery vehicles transported by roll on/roll off ships

WANG Yanfu, ZHANG Haoran, QIAO Jian, XIONG Zixun, ZOU Li

2024, 34(9): 107-113. doi:10.16265/j.cnki.issn1003-3033.2024.09.1864

Asbtract ( 98 )

HTML ( 0)

PDF (6026KB) ( 3 )

Figures and Tables | References | Related Articles | Metrics

In order to address the severe consequences of lithium battery vehicle fires during ship transportation, a vehicle fire simulation model of a ro-ro ship deck lithium battery was constructed. Firstly, the accuracy of the fire simulation model of single and dual lithium battery vehicles was verified by using the full-scale fire experiment data of lithium battery vehicles. Then, the verified simulation model was applied to simulate the fire of a lithium battery vehicle on the deck of a ro-ro ship, and the variation rules of fire heat release rate, temperature and radiant heat under different vehicle spacing were analyzed. The results show that in the initial stage of the lithium battery vehicle fire, the flame first spreads to the side-parked vehicles, especially the side of the vehicle affected by the jet fire, and then expands to the front and rear vehicles. The front vehicle suffers significantly more fire damage than the rear vehicle. At the same time, jet fire aggravates the spread and development of lithium battery vehicle fires. The temperature of the area with jet fire is significantly higher than that of the area without jet fire, and the adjacent vehicles affected by jet fire are ignited first. The numerical simulation method can effectively simulate the fire development and spreading process of the vehicle carrying lithium battery on a ship.

Insulating properties of ultra-thin fireproof coatings for steel structure under various heating conditions

ZHANG Jiaqing, HUANG Yubiao, JIANG Gonghua, HE Lingxin, DING Yanming

2024, 34(9): 114-120. doi:10.16265/j.cnki.issn1003-3033.2024.09.0647

Asbtract ( 99 )

HTML ( 1)

PDF (5245KB) ( 3 )

Figures and Tables | References | Related Articles | Metrics

To achieve the accurate evaluation of steel structure fire resistance in the converter station, based on the possible standard, power and hydrocarbon fire scenarios, the thermal insulation mechanism of ultra-thin fireproof coating as well as its thermal insulation performance on steel members with different steel materials and different cross-section shape factors were investigated through micro-scale thermogravimetric-Fourier transform infrared (TG-FTIR) spectroscopy experiments and small-scale fire test furnace heat insulation experiments. The experimental results show that the faster the fire heating rate, the higher the peak mass loss rate and the higher the peak temperature of the fireproof coating. Different fire heating curves have no effect on the type of gases escaping from the thermal decomposition of fireproof coatings, but have an effect on the amount and peak temperature of escaping gases. Compared with the power and hydrocarbon fire, in the condition of standard fire, more gases are produced before 750 ℃, resulting in better expansion and heat insulation. Furthermore, the fire resistance of the ultra-thin fireproof coatings on the carbon steel and stainless steel at various cross-section shape factors at power and hydrocarbon fire is worse than that of standard fire, indicating poor heat insulation abilities.

Research on power plant dust monitoring node coverage control based on improved genetic algorithm

WANG Bo, SHANG Yuhang, YAO Lichao, JIANG Yongqing

2024, 34(9): 121-130. doi:10.16265/j.cnki.issn1003-3033.2024.09.0960

Asbtract ( 90 )

HTML ( 0)

PDF (4684KB) ( 1 )

Figures and Tables | References | Related Articles | Metrics

In order to effectively reduce the risk of blind zones and lack of control in dust environment monitoring, optimize the node coverage control of the dust environment monitoring system in thermal power plants, and prolong the lifetime of WSN, an energy-saving optimization method based on improved genetic algorithms was proposed. Firstly, based on node coverage, total energy consumption of node deployment and total energy consumption of node communication and transmission, the network coverage quality objective function was constructed. Then, aiming at the problems of the local optimization and coding duplication existing in traditional genetic algorithms, the chromosome combination scheme of integer coding, the adaptive adjustment method of crossover and mutation probability and the elite retention strategy were proposed. Finally, the simulation comparison and analysis were performed to determine the optimized node number and distribution scheme. The results show that the improved genetic algorithm significantly improves the convergence speed. The number of iterations required is reduced to 20, and the fitness value is optimized by 52.18%. In the node deployment and coverage study, the optimized number of nodes is 42, the coverage rate is 97.28%, and the node dormancy rate is 76.19%, which effectively improves the energy-saving effect of the dust environmental monitoring system in the thermal power plant.

Consequences analysis of H₂S-containing gas leakage on offshore platform

MA Chenbo, LU Xinyi, GONG Jingwen, HU Dong, ZHAO Siqi, CAO Yang

2024, 34(9): 131-137. doi:10.16265/j.cnki.issn1003-3033.2024.09.0065

Asbtract ( 88 )

HTML ( 2)

PDF (5910KB) ( 9 )

Figures and Tables | References | Related Articles | Metrics

In order to evaluate the consequences of H₂S-containing associated gas leakage on the platform, ANSYS Fluent software was used to simulate the spatiotemporal changes of the gas diffusion. According to the development process of H₂S-containing gas diffusion, the toxic area of the associated gas cloud in two scenarios, namely no protective measures and emergency protective measures, were compared. A quantitative evaluation of the degree of toxic risk of H₂S-containing associated gas leakage was conducted by using the dose-response model. The results showed that compared to the scenario with no protective measures, after taking the “shutdown” measure, the volume and horizontal diffusion distance of the gas cloud with H₂S concentration ranging from 500-2 000 mg/m³are reduced by 20%-37.5% and 15.4%-47.6%, respectively. After that, the toxic gas cloud volume and horizontal diffusion distance can be further reduced rapidly by taking the "blowdown" measures. By considering the H₂S accumulative concentration and exposure reaction, “shutdown + blowdown” measures can obviously reduce the fatality probability. The fatality of three monitoring spots near the leakage hole decreases from 0.998, 0.034 and 0.000 239 to 0.759, 0.002 9 and 0.000 000 65 respectively. The area of intolerable section and ALARP section of horizontal plane on the middle deck decrease by 63.7% and 81.7% after taking the emergency protective measures. The hazardous degree of toxic consequences caused by associated gas leakage can be significantly reduced.

Diffusion characteristics of thermal runaway gas from lithium-ion batteries under longitudinal ventilation

WANG Zhi, YIN Bo, SHI Bobo, YU Xianyu

2024, 34(9): 138-144. doi:10.16265/j.cnki.issn1003-3033.2024.09.1816

Asbtract ( 124 )

HTML ( 2)

PDF (8863KB) ( 18 )

Figures and Tables | References | Related Articles | Metrics

A two-dimensional diffusion model was developed using the computational fluid dynamics software Fluent across various longitudinal wind speeds to examine the impact of longitudinal ventilation in underground tunnels on the dispersion of thermal runaway gases from lithium-ion batteries. The findings demonstrate that the diffusion of thermal runaway gas on the upwind side of the gas inlet is restricted by longitudinal ventilation, while it is enhanced on the downwind side. At a wind speed of 3 m/s, the time it takes for thermal runaway gas to diffuse to the exit boundary in about 40% that when there is no wind. Moreover, increasing wind speed within the computational domain results in a larger diffusion area under the same diffusion time. The expansion of the explosion area generally exhibits an increasing-then-decreasing trend as diffusion time advances. In the wind speed range of 0.25-3 m/s, the maximum explosion area grows proportionally with wind speed, forming an exponential relationship. Notably, the maximum hazardous area reaches a minimum of 6.79 m² at a wind speed of 0.75 m/s. Considering the maximum explosion range, wind speeds between 0.5 and 0.75 m/s appear optimal for diluting and diffusing thermal runaway gas in the tunnel.

Prediction of displacement of tailings dams based on MISSA-CNN-BiLSTM model

LIU Di, YANG Hui, LU Caiwu, RUAN Shunling, JIANG Song

2024, 34(9): 145-154. doi:10.16265/j.cnki.issn1003-3033.2024.09.1091

Asbtract ( 105 )

HTML ( 0)

PDF (10784KB) ( 3 )

Figures and Tables | References | Related Articles | Metrics

A comprehensive and sophisticated multi-algorithm coupled dynamic prediction model is proposed to address the intricate reality and stringent accuracy requirements of predicting tailings dam displacement. Firstly, by employing a time series decomposition model, the cumulative displacement is disaggregated into its trend and cyclical components. The trend term displacement is then forecasted using a Gaussian regression time series prediction model. Secondly, various Copula functions are employed to investigate the overall correlation between the inducing factors and the cyclical term displacement. Owing to the diverse influencing factors and strong nonlinearities associated with the cyclical term displacement, the MISSA-CNN-BiLSTM model is utilized for prediction. Lastly, the predicted trend term displacement from the Gaussian regression model and the predicted cyclical term displacement from the MISSA-CNN-BiLSTM model are merged. The results demonstrate a high degree of consistency between the predicted cumulative landslide displacements and the measured values, with a correlation coefficient of 0.996 and a root mean square error (RMSE) of 0.13 mm. The multi-algorithm coupled model, based on MISSA-CNN-BiLSTM, exhibits remarkable prediction accuracy and effectively captures step changes in tailings dam displacements.

Effect of ultrasonic excitation time on pore and crack structure and permeability characteristics of coal

HAO Hejie, WANG Ruizhe, YANG Erhao, QIU Yue, ZHANG Xiaoying, LIN Haifei

2024, 34(9): 155-164. doi:10.16265/j.cnki.issn1003-3033.2024.09.1234

Asbtract ( 105 )

HTML ( 0)

PDF (16835KB) ( 1 )

Figures and Tables | References | Related Articles | Metrics

In order to explore the damage characteristics of coal under different ultrasonic excitation time, the ultrasonic excitation test system, nuclear magnetic resonance imaging system, stereo microscope and automatic permeability test system of coal core were used to analyze the changes of pore structure, surface crack and permeability characteristics of coal under different ultrasonic excitation time. The results show that with the increase of ultrasonic excitation time, the change rates of T2 spectral peak area, total porosity, surface fracture area and permeability of small, medium and large pores in coal are linearly increased. When the coal body is excited by ultrasonic for 30 to 150 min, the change rate of T2 peak area of micro, medium and large pores increase from 14.60%, 52.50% and 24.90% to 61.30%, 145.50% and 235.70%, respectively. The total porosity change rate, surface crack area change rate and permeability change rate increased from 5.04 %, 47.27 % and 41.67 % to 24.93 %, 127.91 % and 208.33 %, respectively. Under the excitation of different ultrasonic time, the change rate of permeability of the coal and the change rate of total porosity and the change rate of surface cracking area are in line with the linear increasing relationship, with the increase of ultrasonic excitation time, the pore and crack modification effect of coal is enhanced, and the permeability can be improved.

Process risk prevention and control analysis for confined space operations based on improved ISM-FRAM-AHP

WANG Hanyu, TAN Qinwen, LIU Juan, LI Shuanglu, TIAN Zhongwei, CHEN Chao

2024, 34(9): 165-173. doi:10.16265/j.cnki.issn1003-3033.2024.09.1313

Asbtract ( 149 )

HTML ( 0)

PDF (4718KB) ( 2 )

Figures and Tables | References | Related Articles | Metrics

To address the issues of ambiguous multi-level, multi-link and multi-functional interaction relationships and the adverse coupling effects during operations in confined spaces, FRAM was introduced. Combined with ISM and AHP, the hierarchical structure and judgment methods were optimized and improved. By dividing the risk hierarchical structure, the impact of system function coupling variability was quantified, and the importance of functional units and hierarchical structures was calculated. Through the results of functional variability and coupling loss degree, the input-output phenotype of upstream and downstream functional changes were determined, and the coupling mechanism among system functional elements was clarified. The results show that by applying the risk prevention and control model for operations in confined spaces based on the improved ISM-FRAM-AHP, 23 functional units and a 10-layer risk hierarchical functional network are obtained. The maximum values of functional variability and coupling loss degree are 4.36 (external environment F₂₃) and 0.808 4 (formulating operation plans F₂), indicating a relatively high operation safety risk degree. The functional changes are mainly manifested in sequence, goal and control. Four effective functional barrier measures, physical, symbolic, functional and invisible, are proposed for 8 failure links.

Risk assessment of chemical industrial park storage tanks struck by lightning based on hybrid causal logic methodology

YANG Zhen, LIANG Junming, GUO Li, DONG Xiaobin

2024, 34(9): 174-182. doi:10.16265/j.cnki.issn1003-3033.2024.09.0090

Asbtract ( 136 )

HTML ( 4)

PDF (2202KB) ( 4 )

Figures and Tables | References | Related Articles | Metrics

Coastal chemical industrial parks have frequently experienced lightning strikes, which seriously threaten production safety. A risk assessment method based on HCL methodology was proposed to assess Natech (Natural-technological) accidents triggered by lightning strikes on storage tanks in these parks. Firstly, ESD and Fault Tree Analysis(FTA) were employed to qualitatively analyze the evolution paths of Natech accidents caused by lightning strikes on storage tanks, providing a visual foundation for blocking the accident transmission process. Secondly, BN were used to quantitatively calculate human error probabilities and assess the hybrid causal relationships of lightning-induced storage tank accidents. Finally, HCl methodology was applied to visually deconstruct the complexity and uncertainty of Natech accidents caused by lightning strikes on storage tanks. The research results indicate that decision-making error is the primary risk source in the human error model. Organizational atmosphere, psychological state, poor working environment and inadequate supervision are identified as the main factors leading to frequent human errors. The lack of effectiveness of lightning protection facilities is recognized as the trigger in the accident chain of lightning strikes on storage tanks. To reduce the severity of risk scenarios, emphasis needs to be placed on strengthening the control of full-surface fires and pool fires.

Research on'status and trends' scenario construction and combination deduction method of stampede accident in large-scale activities

LIU Yi, LI Maoyuan, WANG Xinzhi, ZHANG Hui

2024, 34(9): 183-190. doi:10.16265/j.cnki.issn1003-3033.2024.09.0575

Asbtract ( 128 )

HTML ( 0)

PDF (8474KB) ( 6 )

Figures and Tables | References | Related Articles | Metrics

In order to address the challenges associated with characterizing the scenarios of stampede accidents and facilitating comprehension of these scenarios among decision-makers, a method for constructing and combining scenarios of large-scale event stampede accidents was proposed. Firstly, the scene elements of stampede accidents were extracted in large-scale events from the four factors that affect the formation of large-scale activities: people, venue, management, and environment, and a formal expression method for "state" and "trends" of large-scale activities research was established. Secondly, based on Markov model, a deduction description and calculation method for the transformation of situational "state-trends" was provided. Finally, an example analysis was conducted using Shanghai Bund accident. The findings of empirical analyses indicate that deductive results are largely aligned with the actual development process of the 2014 Shanghai stampede. This evidence substantiates the scientific rigour and efficacy of methodology proposed in the paper.

S-FCN fire image detection method based on feature engineering

LI Hai, XIONG Shenghua, SUN Peng

2024, 34(9): 191-201. doi:10.16265/j.cnki.issn1003-3033.2024.09.2063

Asbtract ( 106 )

HTML ( 0)

PDF (9938KB) ( 0 )

Figures and Tables | References | Related Articles | Metrics

The S-FCN fire image detection method based on feature engineering was proposed to address the issues of high computational complexity and poor real-time performance of deep learning algorithms for fire image detection in complex backgrounds. Firstly, this method extracted color features from images in multiple color spaces and reduced the dimensionality of these features using mutual information. Secondly, the network structure of the deep learning model was simplified by using a single hidden layer of a fully connected network as its backbone. The color features in multiple color spaces can better represent fire smoke and flames, and reducing the dimensionality of color features in multiple color spaces effectively reduces the redundancy of input features. The single hidden layer fully connected network can significantly reduce the number of parameters during the model propagation process. Finally, this method was evaluated on a real and complex background fire image dataset. The experimental results show that the detection accuracy achieved by this method is 93.83%, and the real-time frame rate is 10 869 f/s. This method achieves high accuracy and high-speed fire image detection in complex scenes.

Resilience assessment method of urban rail transit system under cascading failure

CHEN Jinyi, LI Tiezhu, GUO Jingwen, LIU Hui, CHEN Haibo

2024, 34(9): 202-208. doi:10.16265/j.cnki.issn1003-3033.2024.09.1963

Asbtract ( 105 )

HTML ( 0)

PDF (1852KB) ( 1 )

Figures and Tables | References | Related Articles | Metrics

In order to identify high-risk stations in urban rail transit systems and improve network resilience and operational safety, a performance function model was constructed to evaluate the network resilience by selecting network efficiency, average shortest path length and maximum connection sub-graph as indicators, and an evaluation method for critical stations was proposed, considering topological structure and passenger flow distribution equilibrium. Taking Nanjing Metro as an example, three cascading failure modes, descending critical degree, descending betweenness centrality and random sequence, are adopted. The characteristics of resilience degradation under different cascading failures are simulated respectively in the unweighted network and the weighted network. The results show that the critical stations are similar on weekdays and weekends. The resilience performance decreases most rapidly in the early stages of failures in descending order of critical stations. Compared with topology networks, the resilience index of passenger flow-weighted networks decreases faster in the early stages of cascading failures. Strengthening the control of critical stations when cascading failures do not spread widely can help reduce the loss of network resilience.

Study on resilience assessment and improvement path of urban public safety from perspective of residents' perception: taking Nanjing as an example

LI Cuixi, WANG Yibao, LIU Zhixiang

2024, 34(9): 209-216. doi:10.16265/j.cnki.issn1003-3033.2024.09.1879

Asbtract ( 126 )

HTML ( 0)

PDF (1878KB) ( 2 )

Figures and Tables | References | Related Articles | Metrics

To improve the city's resilience in responding to public safety risks, an integrated theoretical model of "spatial resilience" for urban public safety was proposed, and an urban public safety resilience evaluation index system was developed from the perspective of residents' perceptions. The entropy weight method was used to evaluate the public safety resilience level for Nanjing comprehensively. The results indicated that the overall score of Nanjing's public safety resilience was 6.851 5, and there was a structural imbalance in the resilience construction for the ternary space. Furthermore, social space safety resilience was the highest, followed by information space safety resilience, and physical space safety resilience was the lowest. The unbalanced development of urban public safety space resilience can be attributed to several factors including the lack of overall public safety resilience governance, insufficient investment in infrastructure and equipment maintenance, an imperfect social environmental risk monitoring system, and weak information security awareness and literacy among residents. Specific measures can be taken from the aspects of humanistic concepts, clear strategies, systematic thinking, and diversified cooperation.

Multi-category multi-objective path optimization algorithm in urban dynamic disaster environments

ZHANG Yingfei, LI Hang, QI Yuliang, WANG Weiming, ZHANG Hailin, HU Xiaobing

2024, 34(9): 217-224. doi:10.16265/j.cnki.issn1003-3033.2024.09.1544

Asbtract ( 129 )

HTML ( 0)

PDF (8494KB) ( 2 )

Figures and Tables | References | Related Articles | Metrics

To improve urban response capabilities in dealing with dynamic disasters, a MCMPOP was proposed for planning emergency vehicle paths in dynamic disaster environments. This model considered path safety as a multiplicative weight and vehicle path length and travel time as additive weights. Then, MCMPOP was addressed by improving the RSA. To verify the effectiveness of the improved RSA in solving the MCMPOP, 510 simulation experiments were conducted comparing the computer time and solution quality of the Non-dominated Sorting Genetic Algorithm(NSGA)-Ⅱ and the improved RSA. Furthermore, "7·20" Zhengzhou rainstorm event was selected as a case study to validate the model. The results show that, compared to the NSGA-II, the improved RSA can find a complete set of Pareto optimal paths, effectively ensuring the optimality and computational efficiency of the algorithm. By using RSA to solve MCMPOP, it is possible to successfully select Pareto optimal paths with the shortest travel path lengths and the lowest time costs within the acceptable path safety range for emergency vehicles, providing more reliable routes for emergency vehicles and enhancing the urban emergency management capabilities.

Construction of rail transit emergency early warning perception system under YOLOv5 detection algorithm

LEI Bin, YAN Langlang, YU Hua, WEN Yan, ZHANG Liang, LI Zhexu

2024, 34(9): 225-233. doi:10.16265/j.cnki.issn1003-3033.2024.09.0120

Asbtract ( 134 )

HTML ( 1)

PDF (1885KB) ( 1 )

Figures and Tables | References | Related Articles | Metrics

In order to reduce the pedestrian safety problems caused by the lag of the emergency warning system in urban rail transit stations under large passenger flow conditions, the YOLOv5 algorithm was selected to predict passenger flow information. The artificial neural network (ANN) model was used to construct the urban rail transit emergency warning perception system. Firstly, the YOLOv5 algorithm was improved by optimizing the model training hyperparameters and prior frame parameters. Then, the emergency warning perception system was designed by selecting warning indicators, weight analysis and threshold definition. Finally, the self-organizing competitive network emergency warning model based on ANN was constructed by using Matlab software. The data collected by the optimized YOLOv5 algorithm were substituted into the emergency warning perception system through calculation, and the emergency warning perception system was verified by experiments. The results show that the optimized YOLOv5 algorithm can improve the accuracy of pedestrian target monitoring under large passenger flow conditions of urban rail transit by 7.04%. The judgment results obtained by substituting the pedestrian data collected by the optimized YOLOv5 algorithm into the constructed emergency warning perception system are consistent with the actual warning level, which proves the feasibility and effectiveness of the system and helps to improve the emergency warning level of urban rail transit.

Assessment of firefighting and rescue capacity in concentrated area of built heritage in forest environments

YAN Long, LI Qi, ZHENG Jiaxin, XU Zhisheng, LIU Dingli

2024, 34(9): 234-240. doi:10.16265/j.cnki.issn1003-3033.2024.09.0103

Asbtract ( 108 )

HTML ( 0)

PDF (5943KB) ( 5 )

Figures and Tables | References | Related Articles | Metrics

Aiming at the problem that the regional environment of cultural relic buildings in a forest environment is complex, and it is difficult to accurately evaluate the regional firefighting and rescue ability, an evaluation method of firefighting and rescue ability of a single cultural relic building coupled with forest factors was constructed based on Analytic Hierarchy Process (AHP), which covered 19 secondary indicators such as building materials, forest fire separation zones, and fire water sources. Based on single-unit assessment, a firefighting and rescue capacity assessment model based on the variable-rights method was established from the regional perspective for the centralized area of cultural relics buildings in the forest environment. A mixed-type variable-rights function dominated by penalties was introduced. The model was established by setting up the evaluation strategy, determining the penalties and incentives intervals, differentiating the protection level of cultural relics buildings, and putting forward the risk level division method. The firefighting and rescue capacity of the forest environment heritage building concentration area (Yuelu mountain scenic spot) was evaluated by combining the fixed-rights method and variable-rights method through field research and data collection. The results show that the number of individual heritage buildings rated as 'excellent, good, moderate, substandard, poor' accounted for '12%, 20%, 32%, 20% and 16%'. For the centralized area, the fixed-rights method scored 75.27 (Level III, no need to take upgrading measures), while the variable-rights method scored 69.97 (Level IV, need to take upgrading measures). Therefore, it is recommended that measures such as installing additional electrical fire warning systems and increasing forest fire breaks be taken to enhance firefighting and rescue capabilities.

Occupational injury characteristics and risk factors screening of national mine rescuers

WU Fang, LI Qing, YANG Sanjun, GAO Di, MENG Yunchen, CHEN Qiangsheng

2024, 34(9): 241-247. doi:10.16265/j.cnki.issn1003-3033.2024.09.0612

Asbtract ( 181 )

HTML ( 2)

PDF (5249KB) ( 3 )

Figures and Tables | References | Related Articles | Metrics

To prevent occupational injuries of national mine rescuers, the epidemiological characteristics and risk factors of occupational injuries were investigated. Firstly, the injuries of the rescuers of the National Mine Emergency Rescue Team in Datong were investigated through field study, expert interviews, and questionnaire surveys. Then, a national mine rescuer injury causal model was proposed to determine the occupational injury risk factors. Finally, all risk factors were used in binary Logistic regression equation to determine the key risk factors. The results indicated that occupational injuries occurrence of the national mine rescuers was high (54.9%). Furthermore, training injuries (80.3%), pulling and picking force devices (29.1%), and weighted running (15.2%) were the most common training items for injuries. The waist (37.2%), knee joints (11.2%), hands (9.0%), and ankle joints (7.6%) were the most vulnerable body segments. Work-related injuries (28.7%), sprains (25.1%), and strains (22.4%) were the most common injury types.The major internal risk factors affecting occupational injuries of national mine rescuers were training years, and the external factors were drinking alcohol, weekly training frequency, training with injuries, and lack of sleep. The major inducing events for injuries were insufficiency warm-up, recurrence of old injuries, and incorrect technical movements.

Table of Content