China Safety Science Journal

Training system study on fire engineering professional education in college

LU Xinxiao, WANG Haiyan, WU Bing, CHEN Bin

2023, 33(7): 1-8. doi:10.16265/j.cnki.issn1003-3033.2023.07.2164

Asbtract ( 433 )

HTML ( 8)

PDF (10953KB) ( 86 )

Figures and Tables | References | Related Articles | Metrics

In order to break through the construction deficiencies of college fire engineering education system, the professional education curriculum system of fire engineering was put forward based on the outcome-oriented concept. Firstly, the reversal design was applied on the training plan, course content and method. The curriculum system focused on on four levels of fire protection standard, prevention, fire fighting and evaluation. Then, the innovation and entrepreneurship education of fire engineering was strengthened, and a fire engineering undergraduate full-course total tutorial system was established as the starting point of innovation. To stimulate the innovative thinking and ability of students, the whole chain innovation training system was proposed as the scientific research carrier. Finally, three core kernel modules of pre-disaster perception, fire engineering disaster relief and post-disaster treatment, were constructed. A professional laboratory centered on five typical fire fighting systems was established to present the real fire response and disaster relief scenarios, which undertook the function of fire engineering course experiment, design and part of internship. The results indicate that the training system of outcome-oriented fire engineering professional education clarifies the curriculum logic of professional education. Emphasis is placed on hierarchical and progressive cultivation and the exploration and guidance on the hot field of fire engineering. It clarifies the structural correlation of the professional laboratory system and its supporting role in the practical education. The training system can provide some reference for the talent cultivation of fire rescue team and the future development of fire engineering discipline.

Study on influence of informal group cohesion on miners' unsafe behavior

LI Naiwen, FANG Xiaokai, NIU Lixia

2023, 33(7): 9-15. doi:10.16265/j.cnki.issn1003-3033.2023.07.2031

Asbtract ( 273 )

HTML ( 2)

PDF (1718KB) ( 124 )

Figures and Tables | References | Related Articles | Metrics

In order to analyze the mechanism of informal group cohesion on miners' unsafe behaviors, safety psychological capital and inner safety impetus were introduced to construct a chain mediation model. Based on the four hypotheses proposed in the literature review, a structured questionnaire was made using four scales of informal group cohesion, safety psychological capital, inner safety impetus and unsafe behavior. 516 valid samples of miners were retained and quantitatively studied after screening. The chain mediation model was validated by sample data analysis and mediating effect test. The results show that informal group cohesion can not only directly affect miners' unsafe behavior, but also indirectly affect miners' unsafe behavior through the independent mediating role of safety psychological capital and inner safety impetus and the chain mediating role of safety psychological capital and inner safety impetus. Enhancing informal group cohesion and improving safety psychological capital and inner safety impetus can effectively reduce the frequency of miners' unsafe behavior and prevent accidents.

Safety risk assessment of civil aviation air parking events based on DBN

CHEN Fang, CUI Qingmin, XIANG Qianqiu

2023, 33(7): 16-23. doi:10.16265/j.cnki.issn1003-3033.2023.07.1884

Asbtract ( 308 )

HTML ( 4)

PDF (4341KB) ( 196 )

Figures and Tables | References | Related Articles | Metrics

In order to explore the impact and evolution of organizational and human factors on IFSD events of engine and to evaluate the risk level of airline IFSD events, a risk assessment model was built for civil aviation IFSD based on DBN. Firstly, the active and passive methods were used to identify the organizational and human factors that affected the occurrence of IFSD. Secondly, Pythagorean fuzzy DEMATEL was used to explore the causal relationship between risk factors. Then, the DBN of civil aviation IFSD was constructed based on the obtained causal relationship, and the parameters were obtained based on statistical analysis and expert experience. The occurrence probability of IFSD events was obtained through GeNle probability reasoning. Finally, the CFM56-5B engine of S Airlines was taken as an example to conduct the safety risk assessment of IFSD events. The results indicate that the probability of air stop of CFM56-5B engine of S Airlines from 2020 to 2021 is 1.260×10^-6 and 1.352×10^-6, respectively. The main reason for the change in safety risks of civil aviation IFSD events is that the decrease in "resource investment" leads to the decrease in the effectiveness of "education and training", which in turn affects "work style awareness" and "cooperation and communication".

A risk assessment method of driving behavior considering severity of safety-critical events and individual heterogeneity

ZHANG Hui, LIU Yongjie, WU Chaozhong, DING Naikan, ZHANG Qi, XIAO Yiying

2023, 33(7): 24-31. doi:10.16265/j.cnki.issn1003-3033.2023.07.1120

Asbtract ( 338 )

HTML ( 4)

PDF (4110KB) ( 163 )

Figures and Tables | References | Related Articles | Metrics

Aiming at the lack of risk degree measurement and insufficient consideration of individual differences in the driving behavior risk assessment method, the natural driving experimental data of 15 subjects were collected, and the paired T-test and DBSCAN (Density-Based Spatial Clustering of Applications with Noise) clustering were used to obtain the deviation of the indicator from the normal state in driving safety events and driver risk propensity level. The indicators were selected to quantify the severity of a single driving safety event, and the driving risk weights were corrected to construct a driving behavior risk assessment method that considered the severity of driving events and individual differences. The validity of the model was verified by using time head (TH). The results show that speed standard deviation, speed range and mean and maximum value of acceleration are more important for driving risk assessment. The risk score obtained by the optimized evaluation methods ranges from [21,42.6], with a mean value of 32.93 and a standard deviation of 6.62. The driving behavior risk score in this study is closer to the actual situation than the traditional score. The above indicators can be used to evaluate the comprehensive driving behavior risk and improve the accuracy of driving risk identification.

Construction of a risk evaluation index system for vaccine supply chain

NIU Lixia, YANG Manyi

2023, 33(7): 32-38. doi:10.16265/j.cnki.issn1003-3033.2023.07.0995

Asbtract ( 168 )

HTML ( 3)

PDF (1525KB) ( 90 )

Figures and Tables | References | Related Articles | Metrics

In order to control the risk of the vaccine supply chain, a vaccine supply chain risk evaluation index system was constructed. Firstly, based on the SCOR model and total quality management theory, the initial set of vaccine supply chain risk factors was determined. Secondly, using grey correlation analysis and rank correlation methods, the initial set of risk factors was screened and simplified to construct a vaccine supply chain risk index system. Finally, the rationality of the index system was verified by using the principal component-information entropy method. The results show that the risk evaluation index system of the vaccine supply chain constructed in this paper contains five primary indicators of planning process risk, procurement process risk, production process risk, distribution process risk and return process risk, as well as 20 secondary indicators such as the accuracy of supply and demand forecast. The risk evaluation index system reflects 83% of the risk information of the vaccine supply chain with only 69% of the indicators, which is scientific and rationable.

Visual analysis of research status and hotspots for driving anger based on mapping knowledge domain

WAN Ping, DENG Xinyan, MA Xiaofeng

2023, 33(7): 39-50. doi:10.16265/j.cnki.issn1003-3033.2023.07.1977

Asbtract ( 219 )

HTML ( 1)

PDF (8598KB) ( 74 )

Figures and Tables | References | Related Articles | Metrics

In order to analyze the research status and hotspots in the field of driving anger at home and abroad in recent years, 1 190 papers from the core collection of Web of Science (WOS) database and 230 papers from China National Knowledge Infrastructure (CNKI) database were selected as data sources. This paper used bibliometric software of VoSviewer and CiteSpace to generate knowledge mapping.The current status, hotspots and trends of research in the field of driving anger were systematically analyzed in terms of volume distribution, author cooperation and citation, published journals, keyword clustering and emergence, etc. The conclusions are as follows: The amount of relevant literature is increasing, and the international and domestic academic communities are paying more and more attention to the field of driving anger. The cross-unit cooperation in the international academic community is more popular than that in the domestic academic community. Research hotspots in the field of driving anger include driving anger related scales, influencing factor of driving anger, relationship between driving anger and dangerous/aggressive behaviors, driving anger identification and driving anger interventions. Driving performance under anger, driving anger detection systems and driving anger management and control from the perspective of traffic engineering are the future research trends.

Prediction model of safety competency of construction workers based on machine learning

ZHAO Wei, LI Shuquan

2023, 33(7): 51-57. doi:10.16265/j.cnki.issn1003-3033.2023.07.1630

Asbtract ( 306 )

HTML ( 12)

PDF (3338KB) ( 175 )

Figures and Tables | References | Related Articles | Metrics

In order to explore the mechanism and key influencing factors of the safety competency of construction workers, this study established a multi-indicator dataset based on organizational network and individual behavior, referring to social capital and behavioral motivation theory. A safety competency indicator system was constructed based on previous scales, and data were obtained from 457 construction workers in China through a questionnaire survey. The multi-indicator comprehensive evaluation method based on the entropy weight and coefficient of variation method was used to calculate and screen the indicators. Then, five machine learning methods, such as GBDT, were used to establish regression models, respectively. The grid search method was used for hyperparameter optimization to improve the prediction ability of the model. The results show that the ensemble learning method is superior to the traditional machine learning method, and the GBDT algorithm has the best fitting performance. The optimized dataset can improve the prediction accuracy of the model. The safety participation and the structural and cognitive dimension of social capital significantly affect the construction workers' safety competency. In addition, their working experience and education level also have a correlation with their safety competency.

Experimental study on influence of multiple factors on liquid CO₂ freeze-thaw cracking coal

ZHOU Xihua, ZHOU Luhan, JIANG Yanhang, BAI Gang, LIU Tianxiang, WANG Xuepeng

2023, 33(7): 58-67. doi:10.16265/j.cnki.issn1003-3033.2023.07.0116

Asbtract ( 179 )

HTML ( 3)

PDF (4758KB) ( 242 )

Figures and Tables | References | Related Articles | Metrics

In order to study the coupling influence of multi-factor on liquid CO₂ freeze-thaw cracking coal, a liquid CO₂ freeze-thaw cracking test device was designed. The nuclear magnetic resonance testing technology was used to measure the porosity of coal after liquid CO₂ freeze-thaw cracking under different influencing factors. The effects of liquid CO₂ freezing time (t), number of freeze-thaw cycles (n) and water saturation (W) on coal porosity (φ) were studied. The quadratic regression response surface model of φ with t, n and W was constructed by response surface method. The sensitivity of t, n and W to φ single and coupled was analyzed, and the influence characteristics were predicted, optimized and verified under different influencing factors. The results show that the φ changes exponentially with the increase of t and n, and linearly with the increase of W. The influencing factors t, n and W are all extremely significant terms of φ (significant discriminant value P<0.01), and the influence relationship of to φ is as follows: n>W>t. The interaction between nt and Wt is very significant, followed by nW and Wt. The primary and secondary effects on φ are nt>nW>Wt. When t, n and W are 57 min, 19 times and 96%, respectively, the maximum value of φ is 9.47%. The average error between the four test values and the predicted value of the model is 2.98%, and the measured average value of φ is 9.58%, which is 7.16% higher than that before optimization (8.94%).

Quantitative damage identification of jacket platform structure based on variation of stiffness parameters

LENG Jiancheng, MAO Houbin, QIAN Wandong, PANG Zhe

2023, 33(7): 68-74. doi:10.16265/j.cnki.issn1003-3033.2023.07.1810

Asbtract ( 167 )

HTML ( 1)

PDF (7996KB) ( 39 )

Figures and Tables | References | Related Articles | Metrics

In order to solve the problem of uncertainty of structural damage identification of offshore jacket platforms under random environmental loads such as wind, wave and current, a structural damage identification method of jacket platform based on the change of stiffness parameters was proposed according to the mapping relationship between structural stiffness and damage. Taking the indoor scale model of a jacket platform as the test object, two damage conditions were set up, including a diagonal bar sawing off 2/3 of the outer diameter and completely sawing off on the third layer-X surface of the structure. Under the premise of knowing the structural modal parameters and lumped mass matrix, the most probable value (MPV) of the stiffness parameters of each substructure of the platform under different damage conditions was quantitatively identified. The corresponding posterior uncertainty was analyzed, and then the location and degree of damage were judged. The results show that the posterior uncertainty of stiffness parameters is small, and the identification results of stability and accuracy are good. The identified structural damage location is consistent with the test setting location, and the damage degree under the two damage conditions is 1%-12% and 20%-31%, respectively.

Theoretical research and practical exploration on nuclear security

CHEN He, LIU Yong, ZHAO Guohai, ZHANG Xiaocong, NIU Xinrui, CHEN Shicong

2023, 33(7): 75-81. doi:10.16265/j.cnki.issn1003-3033.2023.07.1450

Asbtract ( 168 )

HTML ( 1)

PDF (3009KB) ( 123 )

Figures and Tables | References | Related Articles | Metrics

In order to further improve the national nuclear material supervision system, consolidate the foundation for the development of China's nuclear security cause and provide an effective Chinese nuclear security plan for the international community to prevent nuclear terrorism and international cooperation in the nuclear energy field in the "the Belt and Road", in-depth research and practical exploration on nuclear security related theories were carried out. Based on the analysis of the essential goals and core concerns of nuclear security, we proposed the establishment of a framework for nuclear security defense lines at the national and nuclear facility levels, and specified the content of the framework. The results show that the national nuclear security work should ensure nuclear materials within the scope of national regulation throughout their entire lifecycle are under controlled and protected conditions. At the national level, nuclear security work should strengthen the safety supervision of nuclear materials nationwide from three stages of control: source, process, and consequences. The nuclear security work at the level of nuclear facilities is a specific control measure at the implementation level of national nuclear material safety supervision, and its core purpose should be to prevent the threat of nuclear terrorism.

Personnel detection algorithm in fully mechanized coal face based on improved YOLOv5s

ZHANG Lei, LI Xiwei, YAN Qianru, WANG Haosheng, LEI Weiqiang

2023, 33(7): 82-89. doi:10.16265/j.cnki.issn1003-3033.2023.07.2226

Asbtract ( 243 )

HTML ( 7)

PDF (6522KB) ( 139 )

Figures and Tables | References | Related Articles | Metrics

In order to intelligently monitor the intrusion of personnel entering dangerous areas and the wearing of safety helmets in the fully mechanized mining face of underground coal mines, an improved object detection algorithm based on YOLOv5s was proposed to solve the problem of dust interference and uneven illumination affecting image detection accuracy in monitoring videos. Firstly, in the neck network section, DwConv was used to replace ordinary convolutions, which reduced parameters and computational complexity. Then, an improved PANet was introduced to improve the feature extraction capability, replacing the bounding box Loss function CIOU (Complete-Intersection Over Union) with EIOU to improve the detection accuracy. Finally, the personnel images in the video of the fully mechanized mining face were selected for detection, and monitoring videos of coal mine underground personnel entering and wearing safety helmets were selected as the detection dataset for training and verification. The results show that, compared with the initial YOLOv5s algorithm network model, the number of parameters of the YOLOv5s-DPE algorithm network model is decreased by 14.2%, the number of floating-point arithmetic calculations is decreased by 7.6%, the size of the algorithm network model is decreased by 12.5%, mAP@0.5 is increased to 93.7%, and mAP@0.5:0.95 is increased to 65.8%. The YOLOv5s-DPE model has better detection performance for small targets, with a reduction in false detections and missed detections.

Path planning method of rescue ships in waters with multiple obstacles

LIU Zhao, LUO Chenhan, ZHANG Mingyang

2023, 33(7): 90-97. doi:10.16265/j.cnki.issn1003-3033.2023.07.2046

Asbtract ( 191 )

HTML ( 0)

PDF (4255KB) ( 153 )

Figures and Tables | References | Related Articles | Metrics

A path planning method for rescuing ships was proposed to address the challenges associated with navigating in waters containing numerous obstacles, while ensuring safety and efficiency. The proposed method incorporated the safe distance constraint approach and an improved ant colony algorithm to enhance the applicability of rescue ships in complex environments. The method involved determining the target water area range based on the initial and target positions of the rescue ship, employing a grid-based approach to divide the operational environment into navigable and non-navigable areas, and enforcing a minimum safe distance between the rescue ship and obstacles through safety distance constraints. To further improve the efficiency of the path planning process, the ant colony algorithm was enhanced by optimizing the initial concentration of pheromone, heuristic factor and volatilization factor. Additionally, the expected value heuristic factor and distance heuristic function were introduced to enhance the search purpose and speed of the improved ant colony algorithm. The proposed method was applied to a grid map to plan the path of the rescue ship. The waters near the Zhoushan Islands were selected as the experimental waters, and the Donghai Rescue 102 rescue ship was used as the experimental vessel for verification. Experimental results demonstrate that the proposed path planning method exhibits faster convergence compared to the comparison model, resulting in shorter path lengths, fewer turning points and reduced running time. This method overcomes the challenges of slow convergence speed and local optimization in the path planning of rescue ships, thereby enhancing robustness.

Key technology of efficient drilling and mining in extremely thin coal seam

XU A'meng, HU Yang, YIN Li, JIA Jinzhang, YANG Tao

2023, 33(7): 98-104. doi:10.16265/j.cnki.issn1003-3033.2023.07.0421

Asbtract ( 132 )

HTML ( 2)

PDF (3838KB) ( 146 )

Figures and Tables | References | Related Articles | Metrics

In order to improve the drilling ratio and gas extraction efficiency of extremely thin coal seam, the drilling construction equipment was improved through numerical calculation and field test. The key drilling and production technology was put forward by combining the directional drilling system with the azimuth gamma-ray logging instrument while drilling. Combining with the medium-high pressure hydraulic impactor, a new technology suitable for extremely thin coal seams was formed. The results show that the length of the lower non-magnetic tube is shortened to 2 m, which can effectively improve the measurement accuracy of drilling system and meet the exploration needs of the extremely thin coal seam. The coupling degree between the actual trajectory and the design trajectory of the drilling construction is high. The actual trajectory and the gangue trajectory are controlled within the target area, and the whole process monitoring and trajectory control of the drilling trajectory are realized. The average drilling ratio of the extremely thin coal seam is about 88%, which is increased by nearly 40%. Combined with the rock breaking drilling construction method of medium-high pressure hydraulic impactor, the accidents such as hole collapse and sticking in the drilling process are effectively solved, the hole forming rate of the borehole is improved, and the equipment system suitable for extremely thin coal seam is formed. The drilling efficiency is increased by 3 times, and the gas drainage purity has been increased by more than 3.8 times.

Study on optimal wind speed parameters of construction tunnel under condition of double-channel air supply

QIAO Liwei, SANG Conghui, WANG Lieni, ZHAO Yanfa, YUAN Wenchao

2023, 33(7): 105-112. doi:10.16265/j.cnki.issn1003-3033.2023.07.1720

Asbtract ( 135 )

HTML ( 1)

PDF (12518KB) ( 61 )

Figures and Tables | References | Related Articles | Metrics

Aiming at the problems of matching of wind speed and difficulty in measuring the related characteristics of high deposited respirable dust in the double-channel air supply of the construction tunnel, taking a large section railway tunnel under construction as the research background, the return air vector characteristics under different wind speeds were tested. The multi-mode ventilation simulation analysis of the experimental tunnel was carried out by using the two-stage solution mode of ANSYS Fluent. The results show that the parameters in the numerical simulation are set correctly and the results are reliable. When the outlet wind speed V_f of auxiliary pipe is more than 9.5 m/s, the mean value of vector wind speed $\overline{V}_{\lambda}$ on the detection section P_i is negatively correlated with V_f. When V_f ≤ 9.5 m/s, $\overline{V}_{\lambda}$ and V_f are positively correlated. When V_f=9 m/s, the wind speed matching degree of the main and auxiliary air pipes is the best, and class I respirable dust has the highest dust reduction efficiency. Class I respirable dust is easy to gather around the trolley, and Class II respirable dust is more likely to pass through the lower space of the trolley and enter the backlog swirl area under the action of deflected airflow, resulting in long-term cluster aggregation of this type of respirable dust. Under the optimal wind speed matching condition, the impact of the return flow conflict on the swirl region is not obvious, but it still exists. During construction, additional ventilation and dust reduction equipment shall be arranged in the region.

Prediction method of heat exhaust efficiency of centralized smoke exhaust system during tunnel fire

HE Lu, ZHANG Xiaojin, WANG Dongwei, ZHU Guoqing, YUAN Diping, XU Zhisheng

2023, 33(7): 113-120. doi:10.16265/j.cnki.issn1003-3033.2023.07.2276

Asbtract ( 279 )

HTML ( 1)

PDF (8032KB) ( 82 )

Figures and Tables | References | Related Articles | Metrics

In order to explore the impact of heat removal efficiency on the smoke exhaust performance of tunnel smoke exhaust systems during fires, this paper proposed a theoretical prediction method for the heat exhaust efficiency of tunnel centralized smoke exhaust system under fire conditions. The influences of various parameters on heat exhaust efficiency were analyzed. A series of experiments were carried out in a 1:20 scale model tunnel to verify the accuracy of the theoretical prediction results. Research shows that increasing the smoke exhaust volume of the centralized smoke exhaust system is the most effective means to improve the smoke exhaust capacity of the system. As the increase of the ignition sources power, the heat removal efficiency of the smoke exhaust system gradually decreases. The total heat removal efficiency of the system is less affected by parameters such as the spacing and size of smoke exhaust valves, cross-sectional area of smoke exhaust ducts and frictional resistance. However, in actual design and construction, it is necessary to consider the issue of reducing resistance and sealing to avoid excessive system resistance and reduce the smoke exhaust volume.

Study on explosion characteristics of solid-liquid mixed fuels in low pressure environment

YAO Jian, BAI Chunhua, ZHANG Chi

2023, 33(7): 121-126. doi:10.16265/j.cnki.issn1003-3033.2023.07.1600

Asbtract ( 150 )

HTML ( 2)

PDF (8279KB) ( 51 )

Figures and Tables | References | Related Articles | Metrics

In order to study the combustion and explosion characteristics and reaction mechanism of solid-liquid mixed fuels under low pressure environment in plateau, two kinds of solid-liquid mixed fuels, aluminum powder-ether and aluminum powder-ether-nitromethane, were taken as the research objects by using 20 L explosion ball test system. The influence of initial pressure on explosion peak pressure, lower explosion mass concentration limit and explosion products was studied. The results show that the optimal explosion mass concentration, explosion pressure and explosion risk of the two solid-liquid mixed fuels decrease with the decrease of environmental pressure. Compared with the altitude of 0 m, at the simulated altitude of 4 500 m (57.4 kPa), the explosion pressure of 450 g/m³ solid-liquid mixed fuel decreased by 26.84%-30.80%, and the lower explosion mass concentration limit increased by 5-10 g/m³. As the ambient pressure decreases, the volume fraction of CO increases, while the volume fractions of CO₂, NO and NO₂ decrease. The explosive solid residues are mainly α-Al₂O₃ and Al.

Prediction model of coal spontaneous combustion risk based on PSO-BPNN

WANG Wei, LIANG Ran, QI Yun, JIA Baoshan, WU Zewei

2023, 33(7): 127-132. doi:10.16265/j.cnki.issn1003-3033.2023.07.2235

Asbtract ( 185 )

HTML ( 2)

PDF (3793KB) ( 201 )

Figures and Tables | References | Related Articles | Metrics

In order to improve the accuracy of the risk prediction of coal spontaneous combustion in the goaf, a PSO algorithm was used to improve the connection weight and threshold values of BPNN. A coal spontaneous combustion risk prediction model (PSO-BPNN model) coupling the PSO algorithm with BPNN was constructed. The PSO-BPNN model was compared and analyzed with the prediction results of the standard BPNN model and SVR model respectively. The results show that the optimized mean relative error, mean absolute error and root mean square error are reduced by 9.35%, 0.170 7 and 0.205 6, respectively, and the coefficient of determination is increased by 0.116 9 compared with the BPNN model. Compared with the SVR model, the optimized mean relative error, mean absolute error and root mean square error are reduced by 5.41%, 0.115 2 and 0.171 5, respectively, and the coefficient of determination is increased by 0.0891. It was demonstrated that the PSO-BPNN model has higher prediction accuracy than the standard BPNN model and SVR model.

Study on trend of typical incidents of civil aviation in China

HE Peng, SUN Ruishan

2023, 33(7): 133-139. doi:10.16265/j.cnki.issn1003-3033.2023.07.1459

Asbtract ( 179 )

HTML ( 4)

PDF (1758KB) ( 131 )

Figures and Tables | References | Related Articles | Metrics

To study the trend of the number of civil aviation incidents in China, this study collected 5 591 incident data from 2000 to 2020 through the China civil aviation safety information statistical report, and analyzed the trends and characteristics of total incidents and seven typical incidents by using time series analysis techniques such as Augmented Dickey-Fuller (ADF) test and Engle-Granger (EG) test, and explored the long-term equilibrium relationship between incidents and flight hours. The results show that the number of flight hours and the total number of incidents show an overall increasing trend from 2000 to 2020, which is a non-stationary unit root process. Among the seven typical incidents, bird strike, lightning strike, obstacle hit and near miss are non-stationary, and the first three incidents have an increasing trend. Engine in flight shutdown, runway overrun/excursion and non-landing gear grounding have a stable decreasing trend. The total incidents and the typical incidents of bird strike, lightning strike, and obstacle hit are the same as the integration order of flight hours. There is a long-term and stable equilibrium relationship between lightning strikes and flight hours, which is called co-integration relationship. The co-integration regression model shows that a 1% change in the number of flight hours will be followed by a 2.059% change in the number of lightning strikes in the same direction.

Analysis of gas pipeline leakage and explosion accident based on AcciMap model

SUN Yilin, ZHENG Xiaoqiang, LIU Xianfeng, HE Yanyan, WANG Ye

2023, 33(7): 140-146. doi:10.16265/j.cnki.issn1003-3033.2023.07.1011

Asbtract ( 232 )

HTML ( 8)

PDF (1833KB) ( 208 )

Figures and Tables | References | Related Articles | Metrics

In order to explore the attribute characteristics of causes of gas pipeline leakage and explosion accident, the "6·13" accident was taken as an illustrative example. The AcciMap model of the "6·13" accident was built by identifying causes based on the AcciMap model. The CN and PageRank algorithms were introduced into the AcciMap model to analyze the attribute characteristics of accident systems and nodes and identify key causes. The BN was applied for parameter learning and inference learning to find out the key causes chain. The analysis results prove that the serious oversight of work safety supervision, failure to implement the main responsibilities of work safety, inadequate supervision and guidance of work safety are the key causes of the "6·13" accident. The concept of work safety and territorial responsibilities are not implemented → serious oversight of work safety supervision → defects in safety management system → defects in safety training and education → illegal disposal of gas pipeline maintenance and rescue staff → fire detonates accumulated gas → gas leakage explode and causes serious casualties is the biggest causal chain. It is concluded that diversified risk prevention and control strategies should be taken from the aspects of both government and enterprises to curb the recurrence of accidents.

Thermodynamicand kinetic characteristics of gas adsorption by coal under temperature effect

QIU Yue, LONG Hang, BAI Yang, LIN Haifei, YAN Min, XIAO Tong

2023, 33(7): 147-155. doi:10.16265/j.cnki.issn1003-3033.2023.07.1934

Asbtract ( 136 )

HTML ( 5)

PDF (3428KB) ( 135 )

Figures and Tables | References | Related Articles | Metrics

In order to study the thermodynamic and kinetic characteristics of the interaction between coal and gas, the isothermal adsorption tests of coal at 298, 308, 318, 328 and 338 K were carried out. In this paper, the thermodynamic parameters and adsorption kinetic characteristics of coal gas adsorption under temperatures effect were analyzed by using the self-developed coal gas-solid coupling test platform. The results show that with the increase in temperature, the gas adsorption capacity of coal decreases gradually, and the isothermal adsorption curve conforms to the Langmuir type change rule. The isosteric adsorption heat of coal increases with the increase of adsorption capacity, and the variation range is -10.191 to -7.127 kJ/mol. The adsorption of coal gas is an exothermic physical process. The increase in temperature inhibits the adsorption capacity of coal gas, and the limited adsorption heat of coal is -11.369 kJ/mol. The adsorption free energy and adsorption entropy at different temperatures were less than 0, which were -6.958 to -2.452 kJ/mol and -14.085 to -12.607 J/(mol·K), respectively. In the kinetic model fitting, the gas adsorption amount at adsorption equilibrium decreases with the temperature increase, and the adsorption rate constant is positively linear with temperature. The adsorption of coal gas is a dynamic exothermic process. With the increase in temperature, the molecular energy of gas is gradually greater than the adsorption potential energy of coal pores. The adsorbed gas gradually transforms into free gas, and the adsorption capacity of coal gas decreases.

Study on regional ventilation and smoke exhaust mode of subway parking line

QIU Peiyun, CHEN Junfeng, CHENG Huihang, LONG Zeng, ZHONG Maohua

2023, 33(7): 156-163. doi:10.16265/j.cnki.issn1003-3033.2023.07.1083

Asbtract ( 146 )

HTML ( 0)

PDF (6564KB) ( 224 )

Figures and Tables | References | Related Articles | Metrics

In order to analyze the fire smoke diffusion characteristics and optimal ventilation strategy in parking line areas under the interaction of complex structures and multiple ventilation systems, full-scale experiments and computer modeling were carried out on a parking line area in Guangzhou. Firstly, the smoke diffusion characteristics were acquired with a full-scale experiment. The airflow velocity was also measured during the experiment with various ventilation modes. Then, the smoke control performance of different ventilation modes was analyzed with numerical simulation. The impact of ventilation volume on smoke diffusion was discussed. The main conclusions are as follows: In the natural ventilation scenario, fire smoke would spread to the interval tunnel and siding area within 180 s after a fire. The use of tunnel ventilation fans could slow down the diffusion and settlement of smoke. But the longitudinal velocity is smaller than the critical velocity, which could not stop the smoke from spreading outside. The best smoke control performance is achieved by using a tunnel ventilation fan to exhaust smoke and an interval jet fan to supply air to the parking line. It is recommended to adopt the design of tunnel ventilation fans with 2 units of 60 m³/s air volume and jet fans with 2 units of 30 m³/s air volume to control the smoke diffusion and improve evacuation safety in the parking line, interval tunnel and siding area at the same time. The results can be used to guide the selection of fan parameters and the design of ventilation strategy in other parking line areas, which support improving the safety level of parking lines.

Analysis on reform logic of emergency management system in railway passenger stations area: a case study in Beijing

CONG Weiqing, HU Cheng, JIANG Chuansheng

2023, 33(7): 164-172. doi:10.16265/j.cnki.issn1003-3033.2023.07.2232

Asbtract ( 135 )

HTML ( 4)

PDF (1889KB) ( 408 )

Figures and Tables | References | Related Articles | Metrics

In order to clarify the reform and development logic of the regional emergency management system of railway passenger stations from the perspective of a long period, taking Beijing railway passenger station area as an example, the reform and development process of its emergency management system in the past 20 years were retrospectively reviewed, and the characteristics and changes of related problems before and after the reform in 2019 were emphatically analyzed, and the common characteristics and trends behind the reform and optimization of the emergency system of railway passenger station area were revealed. The research found that despite the reform of separating government from enterprise in 2013, there are still some deep-seated institutional problems, such as the reversed location of the railway and local government, and decentralized territorial administration; Beijing's reform in 2019 solved some of the problems. However, the "5.1" large-scale passenger detention incident at Beijing West Railway Station in 2021 highlighted the problems at the emergency mechanism level under the new system, such as the narrow buffer space of the station area, the imperfect monitoring and early-warning mechanism, the lack of early handling capacity, and the inherent lack of coordination of municipal power. Based on the practice and experience of Beijing, Shanghai, Chengdu and other places, it proves to be the main logic of the reform and development of an emergency management system of the railway passenger station area to dynamically track and solve the contradictions between railway and the territory, the comprehensive management organization of station area established by the municipal government and the specific administrative region to which the station belongs. It is the development trend of the emergency management system of the passenger station area to establish a unified comprehensive emergency management organization characterized comprehensive coordination, territorial dependency and railway cooperation, and the core task of emergency management system construction is to improve the ability of overall planning, coordination and command.

Integrated warning model for structural safety of buildings in urban waterlogged area

DUAN Zaipeng, LI Fan, GUO Jin, LI Jiong

2023, 33(7): 173-180. doi:10.16265/j.cnki.issn1003-3033.2023.07.0759

Asbtract ( 121 )

HTML ( 1)

PDF (9931KB) ( 62 )

Figures and Tables | References | Related Articles | Metrics

In order to explore the important factors affecting the structural safety of houses in urban waterlogged areas, 21 attributes, such as house year, floor and area, were collected and selected to construct an early warning index system, and the discretization and imbalance of samples were solved by over-sampling and unique heat coding. Secondly, four different integrated algorithms and six machine learning models were used to build an early warning model to learn and test the safety data of housing structures. Then, the performance of the early warning model was compared comprehensively by applying the harmonic average of accuracy, accuracy and recall, average accuracy and area under the curve (AUC), and the correlation analysis and importance ranking of each warning index were carried out. Finally, 2 215 houses in 35 waterlogging areas in 11 counties and cities of Fujian Province were taken as examples to verify the scientific and validity of the model. The results show that: whether the house belongs to the key inspection, whether the construction team is professional, house area, year and the number of the ground floor are all more than 150, which are the most important five indicators for building safety warnings in vulnerable waterlogging areas. The early-warning model based on the lifting method strategy has the best early-warning accuracy, and the overall prediction accuracy is 99.10%. The model can detect the structural safety of houses in vulnerable waterlogging areas more accurately and efficiently.

Optimization of public space evacuation guidance signage layout based on three-region integration

ZHANG Zhe, BAIHETIYAER Muhetabaier, YAN Shurong, JIA Limin

2023, 33(7): 181-189. doi:10.16265/j.cnki.issn1003-3033.2023.07.1809

Asbtract ( 173 )

HTML ( 0)

PDF (4506KB) ( 141 )

Figures and Tables | References | Related Articles | Metrics

In order to realize high-efficiency evacuation in public spaces, the layout optimization method of the evacuation guidance signage system was investigated. The information demand and candidate signage locations were abstracted accurately based on the size of the pedestrian's body and signage. The optimization-based layout design model of the evacuation guidance signage system was built from the perspective of safety and economy. A three-region integration-based model was established to model the interaction between pedestrians and signage by analyzing the influencing factors on human cognition, such as obstacles, the field of view, letter size and direction-decision behavior. In order to solve the proposed model and validate its effectiveness, the solution algorithm was proposed based on the orientation discretization and the evacuation simulation model was built by considering the interaction between pedestrians and signage. The model was validated by the simulation and model comparison results. The results show that the evacuation signage layout plan including optimal number, location, orientation and letter size can be produced by our model because much more factors are incorporated into the interaction between pedestrians and signage and the plan resulting from the proposed model can realize high-efficiency and stable crowd evacuation. The effects of letter size and the following probability of pedestrians during evacuation on the optimal number of signs are evaluated by sensitive analysis.

Causes and correlation analysis of urban gas accidents based on text mining

ZHENG Binbin, FENG Tingting, WANG Jiahe, XIAO Yuan, SUN Wenhao

2023, 33(7): 190-195. doi:10.16265/j.cnki.issn1003-3033.2023.07.1644

Asbtract ( 290 )

HTML ( 4)

PDF (3543KB) ( 536 )

Figures and Tables | References | Related Articles | Metrics

In order to effectively prevent the occurrence of urban gas accidents, the causes of accidents affecting urban gas safety and their relevance were systematically analyzed by using the research method of text mining and complex network theory. Firstly, text mining technology was used to extract the causative factors of urban gas accidents from 1 256 gas accident cases from 2017 to 2021, and the Apriori algorithm was used to mine the association rules of urban gas accident causes, and 49 strong association rules were obtained. Then the accident cause network diagram was constructed based on the co-occurrence matrix, and the key causes and accident cause sets of gas accidents were identified through the analysis of degree centrality, compact centrality and intermediary centrality. The research results show that pipeline damage, valve opening, equipment aging, improper operation and use, hose damage and shedding are the key causes of urban gas accidents, and gas leakage is a common type of gas accident. It is mainly related to pipeline damage, valve failure and so on.

Study on system of secondary disasters induced by earthquakes in underground coal mine

WANG Wei, ZHANG Siyuan, QI Qingjie, LIU Wengang, SUN Zuo, LI Yuanyuan

2023, 33(7): 196-202. doi:10.16265/j.cnki.issn1003-3033.2023.07.1699

Asbtract ( 177 )

HTML ( 2)

PDF (1656KB) ( 125 )

Figures and Tables | References | Related Articles | Metrics

In order to study the relationship between the disaster-bearing body and the secondary disaster in the second disaster of the underground coal mine induced by earthquake disaster, based on system science and regional disaster system theory, the secondary disaster system of the earthquake-induced underground coal mine was constructed, and the structure, characteristics, functions and subsystems of the system were defined. The investigation objects of secondary disasters were determined in the earthquake disaster subsystem, the pregnancy environment subsystem, and the underground coal mine disaster-bearing body subsystem. Based on the semantic network, the knowledge representation of the disaster-bearing entities and related relationships in the system was obtained, and the knowledge representation method of the disaster-bearing entities and secondary disasters was obtained. The results show that there is a chain relationship between earthquake disasters, primary disasters and secondary disasters, which will work together with the environment on the disaster-bearing body of the mining coal mine.

Risk assessment model of compound disaster evacuation considering uncertainty

WEI Miling, WANG Wei, RONG Qingwen, LIU Xiaoran, LIU Chaofeng

2023, 33(7): 203-212. doi:10.16265/j.cnki.issn1003-3033.2023.07.0273

Asbtract ( 209 )

HTML ( 2)

PDF (9990KB) ( 53 )

Figures and Tables | References | Related Articles | Metrics

In order to solve the uncertainty problem of evacuation under the typical complex disaster scenario of earthquake and rainstorm, the risk assessment of evacuation was studied. Firstly, based on the planning characteristics of China's evacuation system, the risk control objectives of urban evacuation under the combined disaster of earthquake and rainstorm were put forward. Then, considering the uncertainty of evacuation time and the evacuation characteristics of earthquake-rainstorm compound disaster, a rapid evaluation model of urban road capacity under earthquake-rainstorm compound disaster was established. Secondly, considering the uncertainty of risk acceptance degree of different refuge demand points, the acceptable risk level coefficient based on the characteristics of urban planning land was put forward. Finally, considering the uncertainty characteristics of the above evacuation process, the optimal algorithm was adopted to calculate the decision-making model of the location of the maximum coverage emergency facilities, and the evacuation risk assessment model based on earthquake and rainstorm combined disasters was constructed. Taking the disaster prevention and evacuation responsibility area of a northern city as an empirical object, this paper probed into the risk situation under the combination of multi-risk control objectives and multi-planning schemes, and put forward the planning scheme of the shelter with minimum evacuation risk in this disaster prevention and evacuation responsibility area. The research shows that the model can make a more practical evacuation risk assessment for earthquake-rainstorm combined disaster scenarios, realize the quantitative analysis of uncertain factors, and achieve an effective connection between risk assessment and spatial planning.

Comprehensive evaluation of emergency response capability of urban subway terrorist attacks

WEI Lin, LI Lihua, QIN Liqiang, XIAO Yanhui, TANG Yuguang

2023, 33(7): 213-221. doi:10.16265/j.cnki.issn1003-3033.2023.07.2285

Asbtract ( 213 )

HTML ( 1)

PDF (2150KB) ( 169 )

Figures and Tables | References | Related Articles | Metrics

In order to scientifically evaluate the emergency response capability level of urban subway facing terrorist attacks and improve the construction of urban subway emergency response system, a comprehensive evaluation method of the cloud model for the emergency response capability of urban subway terrorist attacks based on two tuples linguistic DEMATEL-SEWM was established considering the relevance of emergency capacity indicators and the fuzziness and randomness in the evaluation process should as a whole. First of all, the evaluation indicator system of urban subway terrorist attacks emergency response capability was established from the perspective of the whole process equilibrium of emergency management. Furthermore, the weight coefficient of the evaluation indicators was calculated by using two tuples linguistic DEMATEL and SEWM to reflect the correlation between evaluation indicators and the influence of expert judgment difference on weight objectively. Finally, the emergency capability evaluation level was determined by combining the fuzzy proximity method and evaluation cloud map based on the cloud digital eigenvalues obtained by computing the evaluation indicator using the cloud model algorithm. The method was applied to comprehensively evaluate the emergency response capability of the subway terrorist attacks in Q city. The results show that the evaluation level of emergency capacity of the subway in Q city tended to be high, and the evaluation results were basically consistent with the actual survey results, which verified the scientific rationality of the evaluation indicator system and the method, which could provide a theoretical reference.

Evaluate effectiveness of emergency evacuation measures in expressway network based on HNAC-FD model

LIU Xingliang, XIE Ting, LIU Tangzhi, SHANG Ting, WANG Jian

2023, 33(7): 222-229. doi:10.16265/j.cnki.issn1003-3033.2023.07.0829

Asbtract ( 169 )

HTML ( 2)

PDF (1773KB) ( 154 )

Figures and Tables | References | Related Articles | Metrics

This paper aimed to safely and effectively evacuate the expressway network congestion caused by emergency events and to evaluate the effectiveness of different emergency evacuation measures. Firstly, the propagation and dissipation law of expressway network congestion under emergency events were analysed, and the HNAC-FD dissipation calculation model was established. Secondly, through evacuation case traffic data, the effect of different interventions on the speed of traffic flow was simulated by Vissim, and the traffic flow state of the expressway network section was obtained based on the Logistic speed-density model. Finally, according to the case of expressway network emergencies, different intervention measures were designed, and the congestion dissipation time was calculated by the HNAC-FD model. The effectiveness of different measures was evaluated from the event impact dissipation time and the average travel time of the vehicles in the congested queue through case numerical calculations. The results show that the intervention measures delay the dissipation of the event impact, but improve the speed of evacuating traffic flow and reduce the average travel time of the congested queue. The evacuation effect of the combined measures is not significantly better than that of the single one, and the reversible lane evacuation works best.

Multi-objective optimization strategy of emergency material supply based on multi-mode transportation

ZHANG Yanping, CUI Na, ZHANG Bo

2023, 33(7): 230-238. doi:10.16265/j.cnki.issn1003-3033.2023.07.1427

Asbtract ( 221 )

HTML ( 4)

PDF (4108KB) ( 179 )

Figures and Tables | References | Related Articles | Metrics

In order to solve the problem of post-disaster emergency material supply, this paper was targeted at the multi-modal transport mode of truck-aircraft-truck, and the four-layer emergency service network consisting of "material suppliers, transfer stations, distribution center, and demand points" in view of the urgency of emergency needs and the layer-by-layer transportation mode in real logistics operation. A multi-objective mixed integer dynamic program was established with the objectives of minimizing total system operational cost, total transportation time and truck drivers' psychological cost from the perspective of the government, disaster victims and drivers involved in emergency transportation, respectively. The Epsilon constraint algorithm was adopted to solve the model, and a sensitivity analysis was given to test the performance of some key parameters. The results of the case study show that the model can obtain a set of effective nondominated solutions, i.e., Pareto frontier, which can provide helpful multi-stage emergency supply plans with different decision preferences. A longer or shorter operation time in the transfer stations will increase the total emergency response time. The total cost of the system will not move monotonously with the change in the driver's psychological limit driving time.

Table of Content