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Table of Content

    28 March 2022, Volume 32 Issue 3
    Safety science theory and safety system science
    Research on discipline construction and content system of intelligent safety ergonomics
    DONG Longjun, WANG Jiachuang
    2022, 32(3):  1-8.  doi:10.16265/j.cnki.issn1003-3033.2022.03.001
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    In order to further improve the disciple system of safety science, in view of the shortage of traditional safety ergonomics theory and method, studies were carried out on basic construction of intelligent safety ergonomics discipline theory and course content system. Firstly, according to development process of ergonomics, concept of intelligent safety ergonomics was put forward from a perspective of information technology, and its subject connotation and main attributes were analyzed. Secondly, the disciplinary basis, disciplinary tasks, disciplinary research objects, and research content were analyzed. Finally, considering the future challenges it faces, research tasks and application prospects were discussed. By analyzing several basic problems of the disciplines, it can be concluded that intelligent safety ergonomics is more effective than traditional safety ergonomics.

    Portrait of China Safety Science Journal in past 30 years
    LI Jie, LIU Jiao, LIANG Xushu, QIAN Jinxin, HAO Limin
    2022, 32(3):  9-17.  doi:10.16265/j.cnki.issn1003-3033.2022.03.002
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    In order to have an overall understanding of the development of CSSJ in the past 30 years, 8 894 papers were collected from the Chinese Citations Database (owned by CNKI), and the data was cleaned and processed by using Bibliographic Analysis Tool(BAT) software. Bibliometrics approach was adopted to analyze publish and download trends, overall impact distribution, major provincial regions, leading institutions and authors, hot topics and research methods, and highly cited papers of CSSJ. The results show that CSSJ has an increase trends in both outputs of publications and download frequencies since 1991. Distribution of impact factors, cited frequencies and h-index demonstrates the high influence of CSSJ in the safety area. Moreover, highly productive regions of safety science have been formed, represented by provincial regions such as Beijing, Jiangsu and Hunan etc., and representative high-yield institutions include Beijing Jiaotong University, Liaoning Technical University and Central South University. The number of authors also become larger and larger along with the development of CSSJ, and co-authored papers have become the major type. WU Chao, FU Gui and CHEN Guohua etc. have ranked among the most productive authors in the journal in the past 30 years. And during its development, it has formed six topic groups, including safety and emergency management, safety engineering simulation and experiment, safety and risk evaluation, traffic safety, safety behavior and culture as well as safety prediction. In the research methods aspect, numerical simulation, analytic hierarchy process, neural network and structural equation model are the widely used in CSSJ papers.

    Safety social science and safety management
    Research on classification and gradation of offshore oil accidents in China
    CAO Yang
    2022, 32(3):  18-24.  doi:10.16265/j.cnki.issn1003-3033.2022.03.003
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    In order to improve statistics and analysis of offshore oil accidents in China, firstly, relevant laws, regulations, standards and guidelines were analyzed to clarify definition of these accidents and specify their gradation and classification. Then, a comparative analysis was conducted on current regulations or practices regarding accident classification and gradation of the State Council, Ministry of Emergency Management, industries of different fields, three Barrel of Oil and international oil companies. Finally, scope and definition of offshore oil accidents were proposed, as well as the new gradation and classification, including their specification or applicable situation. The results show that based on the previous classification released by the Ministry of Emergency Management of People's Republic of China, accident classification can be expanded to eight types including thirty-nine sub-types in China. And on the basis of previous gradation by the State Council, accidents can be graded into six levels in China.

    Psychological load of drivers in multi-lane interweaving areas of urban roads
    ZHANG Xueyu, PAN Cunshu, LIN Wei, XU Jin
    2022, 32(3):  25-32.  doi:10.16265/j.cnki.issn1003-3033.2022.03.004
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    In order to clarify characteristics of drivers' deceleration behaviors when driving in multi-lane interweaving areas of urban roads and its correlation with their psychological load, field driving tests were carried out. Drivers' electrocardiograph signals and vehicle operating parameters were collected, and the relationship between characteristics of their heart rate change and deceleration behaviors was analyzed by dividing them into two types according to different lane changing states. The results show that in the interweaving areas, psychological load of drivers in non-interference states is significantly greater than that in interference states, but the latter features more frequent psychological fluctuations. Female drivers are more likely to have a greater psychological load than male ones when entering interweaving sections. In both interference and non-interference states, drivers' heart rate growth rate demonstrates high partial correlation with the maximum deceleration, that is, the latter has a greater impact on the former.

    Safety engineering technology
    An improved betweenness for importance assessment of network nodes and links
    HU Xiaobing, LI Jiaru, LIU Chengyue, LI Hang, ZHOU Hang
    2022, 32(3):  33-40.  doi:10.16265/j.cnki.issn1003-3033.2022.03.005
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    In order to accurately evaluate importance of nodes and links in the network system, three kinds of situations concerning anti-attack capability of network system were analyzed, and based on the definition of traditional betweenness, an improved definition of network node and link betweenness was proposed, which was the number of times that all OD pairs passed through a node or link to meet the given constraint condition. Then, a new RSA was proposed to solve the improved betweenness of nodes and links. Finally, the traditional and improved betweenness of each node and link in Beijing subway network were calculated to evaluate their importance, and calculation results of traditional and improved betweenness were compared. The results show that the improved betweenness is a universal definition, while the traditional one is only one of its special cases, and it can evaluate importance of nodes and links from a more comprehensive perspective.

    Research on remaining life prediction and maintenance strategy of corroded submarine pipelines
    ZHANG Xinsheng, WANG Xuye, ZHANG Yingying, CHANG Yingge
    2022, 32(3):  41-47.  doi:10.16265/j.cnki.issn1003-3033.2022.03.006
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    In order to predict remaining life of submarine pipelines and optimize maintenance cost, a maintenance strategy modeling method was proposed based on Gamma process residual life prediction under accelerated stress degradation test. The data of pipeline corrosion and degradation were obtained by temperature and pressure double stress accelerated degradation experiment, and their residual life prediction model was established by using Gamma process. Relationship between average life and stress of pipelines was reflected by generalized Eyring model, and maximum likelihood method was used to estimate model parameters as a whole. Then, a maintenance decision optimization model aiming at minimum expected cost ratio was developed to determine optimal maintenance times and expected consume ratio (ECR). Finally, with N80 pipeline as an example, the effectiveness and correctness of residual life prediction and maintenance model were verified. The results show that the use of accelerated degradation test can greatly shorten data acquisition time. And according to the optimized maintenance model based on remaining life, the optimal times for maintenance is 7 and minimum expected cost rate is 4.435 yuan/h.

    Fast generation method of 3D mine roadway model and its application
    ZHU Quanjie, ZHANG Zhen, LIANG Juan, LIU Xiaohui, GU Lei, ZHONG Leilei
    2022, 32(3):  48-57.  doi:10.16265/j.cnki.issn1003-3033.2022.03.007
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    In order to achieve rapid construction and visual characterization of 3D mine scenes, a fast generation method of 3D mine tunnel model based on opensource program was proposed considering the drawbacks of current method, such as great difficulty and poor operability. Firstly, based on collected mine shaft and lane attribute information, automatic import and standardized storage of data were realized with help of MySQL database. Then, geometric characteristics of connecting roadway were explored, different types of roadway, including conventional straight, inclined and vertical roadway, were deconstructed, and parameterized expression of 3D model was proposed. Then, Python and blender development platforms were used to generate 3D roadway system model. Finally, T type and Y type connecting roadways and typical development models were reconstructed rapidly to verify effectiveness of this method. The results show that the proposed parametric modeling method simplifies 3D modeling into "parameter + algorithm", thus achieving rapid construction of 3D tunnel model, and it also solves problems like distortion. Moreover, the developed system platform can realize rapid construction of mine virtual scenes based on key data.

    Study on erosion wear mechanism of choke valves at outlet of ultra-high pressure sour natural gas wells
    JIA Wenlong, LI Xiaoyu, CHENG Tingting, LUO Zhaoqian, XU Jiashuang, HAN Xicheng
    2022, 32(3):  58-64.  doi:10.16265/j.cnki.issn1003-3033.2022.03.008
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    In order to ensure safe production and operation of ultra-high pressure sulfur-bearing natural gas wells, influencing factors of erosion wear rate were analyzed. Firstly, based on erosion wear theory and Fluent software, an erosion model was established by taking cage sleeve choke valves of natural gas wellheads with pressure above 70 MPa and H2S volume content of 0-2% as an example. Then, motion track and wear mechanism of solid particles in the valves were studied and compared with actual situation. The results show that when these particles are in upstream straight pipe section of the valves, erosion wear can be ignored, but it will be the worst when they are at valve chamber wall directly opposite the 180° choke hole, and be mildly severe at downstream. The wear principle of lower half arc of valve cavity is secondary erosion, while semi-arc of straight section entrance and upper half arc of throttle valves are mostly micro cutting wear. It is also found that the higher the H2S content and average flow rate are, the heavier erosion wear will be. Therefore, the flow rate of natural gas can be controlled within 331 m/s.

    Research on dynamic change characteristics of three-dimensional spontaneous combustion zone in caving coal face
    ZHAO Wenbin, LIU Fangshun, SHI Xinyan, LIU Hui, WANG Zhongmi, LI Zhenwu
    2022, 32(3):  65-74.  doi:10.16265/j.cnki.issn1003-3033.2022.03.009
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    In order to explore dynamic distribution characteristics of spontaneous combustion zone in goaf, a combination of theoretical analysis, numerical simulation and field measurement were used to study effects of changes in voids, fracture structure and oxidation rate on features of air leakage and oxygen volume fraction distribution, and it was revealed that spontaneous combustion zone of fully mechanized top coal caving changed from the back of goaf to top coal in working face. The results show that the fracture of top coal and void structure of mined-out area change with extension of exposure time due to influence of mining stress and overburden caving lag. Free diffusion air leakage is formed in open field of upper and middle eaves behind the support, and as exposure time of caving coal and rock mass increase, oxygen consumption rate increases, top coal fracture structure develops, caving space in goaf moves up, and internal void structure in middle and lower part declines, leading to the expansion of spontaneous combustion zone from the back of goaf to top coal of fully mechanized mining support.

    Study on safety and stability of high altitude dumps under intense drying-wetting alternation
    DONG Jianjun, YANG Di, YAN Bin, MEI Yuan
    2022, 32(3):  75-83.  doi:10.16265/j.cnki.issn1003-3033.2022.03.010
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    In order to reveal impacts of intense drying-wetting alternation on safety and stability of high altitude dumps, numerical calculation was carried out for open mining No. 1 and No. 2 dump of limestone mine for cement in high altitude mining area. The distribution law equation of matric suction and shear strength equation were introduced for unsaturated soil based on unsaturated-saturated seepage theory. Therefore, the evolution characteristics of the unsaturated-saturated seepage field and stability of dumps were studied under intense drying-wetting alternation. The results show that as drying-wetting alternation intensity increases, the soil changes from unsaturated state to saturated one on dumps' slopes, and its shear strength decreases. There is no slippage on slope of No. 1 dump. However, the No. 2 dump is affected by intense alternation, and slip area is located between slope foot and the second step, which develops into deep layer as the alternation intensity grows. The slope displacement of dumps increases continuously while safety factor decreases along with the increase of the intensity.

    Trajectory design and control method of life-support hole in mine rescue
    ZHOU Jing, LIU Yongsheng, DOU Zijun, YIN Huisheng, ZHANG Biao, CHEN Guoqiang
    2022, 32(3):  84-89.  doi:10.16265/j.cnki.issn1003-3033.2022.03.011
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    In order to solve target problem of actual drilling trajectory of life support hole during emergency rescue process in mine roadway, analytical geometry method was used for design and modelling of connected trajectory and roadway, and research on design and control method of life support hole trajectory was carried out. Firstly, considering the relative position between wellhead and connecting point, profile type of the trajectory was determined, and a vector calculation method for it was provided. Secondly, in view of the uncertain position of rescue target and high requirements for trajectory control, "increase-stability-increase" design profile was selected, and a segmented trajectory connection design method was proposed. Then, with the goal of reducing uncertainty of rescue target position, a point-to-surface trajectory connection method and a secondary connected trajectory control model were put forward. Finally, based on wellbore design material and actual drilling data, an example was utilized to verify the established model. The results show that the proposed design calculation method avoids tedious calculations and checks, and at the same time reduces length of connected trajectory by 6.7%. Moreover, the trajectory control method overcomes the disadvantages of frequent twisting and azimuth operations of traditional rescue techniques.

    Dynamic early warning model of household gas leakage in communities
    LI Chao, DENG Xiaobao, SHI Yuntao, SUN Dehui, JIAO Yanzong
    2022, 32(3):  90-97.  doi:10.16265/j.cnki.issn1003-3033.2022.03.012
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    In order to improve gas leakage warning performance for community safety, a dynamic early warning model for household gas leakage was proposed. Firstly, indoor gas data of each home in the community were collected by using wireless sensor network, and uploaded to the cloud by smart gateway. Secondly, inputs of random forest algorithm were optimized by utilizing fuzzy control algorithm to reduce interference of features with lower importance on the cloud platform, based on which a fuzzy-random forest model was established with optimized data as input of random forest algorithm and leakage grade as output. Then, a visual module was developed to present gas leakage grade of each home. Finally, the model's effectiveness was verified through simulation test under lab conditions based on historical gas data collected form a certain community in Beijing. The results show that this model can effectively improve ability of online monitoring and dynamic early warning of gas leaks in the community. Compared with other algorithms, the fuzzy-random forest algorithm shows better performance in detecting early small leaks.

    Joint analysis method for process deviation of HAZOP in chemical operation units
    GAO Ming
    2022, 32(3):  98-102.  doi:10.16265/j.cnki.issn1003-3033.2022.03.013
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    In order to improve application effect of HAZOP in chemical operation units, based on the practical experience of its application in modern large chemical plants over the past 10 years, a joint analysis method was proposed. Firstly, behavioral factors of HAZOP participants were studied and process risk attention model was established. Then, its deviation funnel was put forward, possible deviation trends and risk factors of the whole system were identified by using mathematical model before they were manually confirmed and listed into key points of HAZOP. Finally, a HAZOP report was generated by synthesizing various professional resources, and then a method set featuring man-machine complementarity and layer by layer screening was formed. The results show that the joint analysis method can improve HAZOP sustainability as well as risk identification accuracy of chemical operation units, therefore upgrading safety performance of enterprises.

    Method for determining range of inner wheel difference of hinged vehicles turning right
    LI Yingshuai, YAN Qiruo, ZHEN Yunzhu, WANG Weijie
    2022, 32(3):  103-108.  doi:10.16265/j.cnki.issn1003-3033.2022.03.014
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    In order to solve traffic safety problem at intersections caused by inner wheel difference of hinged vehicles, a method for determining range of inner wheel difference of the vehicles turning right was proposed, which considered geometric parameters of intersections and vehicle parameters. With vehicles at different model parameters in Jinyuan District and Qingxu County of Taiyuan City as research object, a calculation model was established based on changes of difference of right-turning inner wheels at different types of intersections, and trajectory of front inner wheel of tractors and rear wheel of trailers were generated and the difference range were calculated more accurately. Then, Python software was used to build a program for visualization of the range, and with coordinate values of front inner wheels of tractors and rear wheels of trailers at the same time point as evaluation index, driving trajectory data were extracted by utilizing Tracker software so as to verify the model. The results show that the maximum relative error between predicted value of the proposed method and the actual one is 8.32%, and average relative error is 5.12%, indicating that the method can effectively determine range of inner wheel difference of hinged vehicles turning right.

    Experimental study on smoke back-layering length and temperature distribution in bifurcation tunnels
    GAO Yunji, LUO Yueyang, LI Zhisheng, ZHANG Yuchun, YU Yangyang, LI Tao
    2022, 32(3):  109-115.  doi:10.16265/j.cnki.issn1003-3033.2022.03.015
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    In order to study smoke flow characteristics in case of fire in bifurcation tunnels, a series of fire experiments in the 1∶10 scale tunnel model were carried out with fire source located in bifurcation tunnels. Two heat release rates (15.9 and 31.9 kW) and 7 ventilation wind speeds (0, 0.45, 0.60, 0.75, 1.0, 1.3 and 1.6 m/s) were selected, and smoke's back-layering length, temperature distribution in the main tunnel and bifurcation tunnel under different longitudinal ventilation speeds were analyzed. The results show that when the fire source is located in bifurcation tunnels, smoke back-layering length in the main tunnel conforms to THOMAS prediction model, but coefficient Cd is much smaller than previous research results in single-hole tunnel. The dimensionless smoke temperature distribution in the main tunnel agrees with longitudinal temperature attenuation model, with coefficient k attenuating in a power function along with increase of longitudinal ventilation, and that in bifurcation tunnel corresponds with longitudinal temperature attenuation model too, but with coefficient k' demonstrating linear attenuation as longitudinal ventilation increases.

    Dynamic early warning method of open-pit mine slopes based on integrated displacement information
    FENG Gong, XIA Yuanyou, WANG Zhide, YAN Minjia
    2022, 32(3):  116-122.  doi:10.16265/j.cnki.issn1003-3033.2022.03.016
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    In order to effectively use information of multiple measurement points for early-warning and monitoring of slope safety in open-pit mines, considering the importance of displacement monitoring and its variation along with time of measuring points setting and slope height during mining, a dynamic warning method using integrated displacement information was proposed. Firstly, with monitoring profile as a unit, dynamic grading early warning threshold for displacement of each profile was determined through numerical simulation. Secondly, federated Kalman filter was used to integrate monitoring information of different measuring points from the same profile and obtain integrated displacement value representing timely stable state of each profile. Finally, by comparing integrated value with early warning threshold, real-time early-warning for steady state of each profile was realized. Application of the method in a limestone open-pit mine slope, located in Zhongxian county of Chongqing, shows that it can not only fully utilize information of multiple measurement points to send early warning in different regions in real-time, but also predict stability of slopes during mining process.

    Gas diffusion test in low temperature environment and analysis on compatibility of different models
    MA Xingying, WANG Zhaofeng, YU Rui, ZHOU Xiaoqing, LI Qianrong
    2022, 32(3):  123-130.  doi:10.16265/j.cnki.issn1003-3033.2022.03.017
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    In order to effectively control coal and gas outburst disasters, given the important role of gas diffusion coefficient in determining coal seam gas content, a self-developed gas-containing coal freezing response device was adopted to measure gas desorption and diffusion capacity at temperature of 0, -10, -20, -30 ℃ and adsorption equilibrium pressure of 0.5, 1.0, and 1.5 MPa. And data of classical diffusion model and two dynamic diffusion models were compared with experimental data. The results show that low temperature affects increase of free energy on coal surface, and thermal movement of gas molecules reduces, indicating that low temperature inhibits gas desorption and diffusion in coal. According to the comparison between simulation data of three diffusion models and experimental data, two dynamic diffusion models are better than classical diffusion model, and their exponential function model is better than power function model. Gas diffusion coefficient undergoes two stages of rapid decline and slow decline under influence of temperature.

    Safety engineering technology
    Concentration measurement of combustible gas mixture based on gas viscosity
    YANG Songcheng, WANG Jizhe, WANG Lihua, ZHANG Hongming, ZHAO Lanming
    2022, 32(3):  131-136.  doi:10.16265/j.cnki.issn1003-3033.2022.03.018
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    In order to make a quantitative analysis on gas composition, response signals of pressure drop generated by gas samples were measured after they flew through a specially designed viscosity sensor. Then, according to Poiseuille's Law and theoretical model of gas mixture viscosity, quantitative analysis was conducted to obtain concentration of combustible gas, and measurement experiments were carried out for different concentration of hydrogen. The results show that concentration of gas samples can be calculated by utilizing measured pressure drop based on theoretical relationship of mixed gas viscosity, and the absolute deviation between measurement results and benchmark concentration are no more than ±1.0 %. And the relative error is no more than ±3% when volume fraction is over 15%. It has been proved by the quantitative test results that the proposed method has a high accuracy and is capable of predicting volume fraction of combustible gas accurately.

    Experimental and numerical study on pyrolysis and autoignition of OSB exposed to radiant heat fluxes
    FENG Quan, ZHANG Mingrui, GONG Junhui
    2022, 32(3):  137-143.  doi:10.16265/j.cnki.issn1003-3033.2022.03.019
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    In order to predict autoignition time of OSB exposed to radiant heat fluxes, firstly, milligram-scale thermogravimetric analysis(TGA) tests were conducted to parameterize the established pyrolysis model by model fitting method. Subsequently, gram-scale autoignition experiments, using seven predesigned constant heat fluxes, were implemented in a cone heating apparatus. Then, inversion model of OSB thermodynamic parameters was established by combining an improved numerical model and measured surface temperatures and mass loss rates to determine thermal conductivity and specific heat of OSB. The results show that the ignition time predicted by critical temperature and critical mass loss rate are 194, 116, 67, 47, 24, 16, and 129, 103, 59, 42, 27, 20 s respectively under six constant heat flows (28, 30, 35, 40, 45 and 50 kW/m2).

    Cloud model identification of coal face stability in steeply inclined working faces
    XIONG Yu, KONG Dezhong, YANG Shengli, WU Guiyi, ZUO Yujun, CHENG Zhanbo
    2022, 32(3):  144-151.  doi:10.16265/j.cnki.issn1003-3033.2022.03.020
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    In order to ensure safe and efficient mining on steeply inclined working faces, a stability evaluation index system of steeply inclined coal faces was constructed with quantified grade intervals on the basis of AHP method. Then, a standard stability cloud model based on cloud theory was established. With working face 3402 as an example, its coal face stability evaluation cloud image was generated, and similarity between this image and grades of cloud model was calculated through Dice coefficient to effectively identify stability and verify scientificity and validity of the model. The results show that the main influencing factors of coal face stability in steeply inclined seams are roof pressure at the face of mildly inclined ones, coal body cohesion and mining height, as well as inclination angle of coal seam and pseudo-inclination angle of working face. According to cloud model's identification, similarity between evaluation cloud image and standard grades for general stability indexes of 3402 working face is 0, 0.345 3, 0.787 2 and 0 respectively. It can be concluded that its stability is at level III, an unstable state, which is basically consistent with actual situation, demonstrating that the proposed model is scientific and effective to some extent.

    Study on radon control performance of mulch on beach surface of uranium tailings reservoirs under low frequency vibration
    LIU Jiehao, LIU Yong, HONG Changshou, XU Zhenghua
    2022, 32(3):  152-157.  doi:10.16265/j.cnki.issn1003-3033.2022.03.021
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    In order to study safety of uranium tailings reservoir beach and its surrounding area, numerical analysis and experimental simulation were utilized to find the mulch with good radon control performance. With a uranium tailings in south China as an example, effects of three kinds of covering materials (zeolite, gypsum powder and fly ash) on radon exhalation from beach surface of the reservoir were compared, and the best material was selected. Then, radon control experiments under 15,20,25 Hz frequency cumulative vibration were conducted to verify difference in control performance of the mulch. The results show that different mulches have different effects in inhibiting radon exhalation rate, and for the case of same mulch depth, addition of zeolite layer to covering material results in better performance in restraining radon exhalation rate than that of gypsum powder or fly ash layer. With the increase of vibration frequency, radon control performance will be more remarkable.

    Characteristics and movement of upper spray droplets in exhaust air flow heat recovery device
    FAN Siyu, CHEN Shiqiang, HE Weiguo, TIAN Feng, LIU Chunyu, LIU Gang
    2022, 32(3):  158-166.  doi:10.16265/j.cnki.issn1003-3033.2022.03.022
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    In order to effectively improve the efficiency of heat and wet energy extraction from mine exhaust, effects of nozzle atomization pressure and airflow speed on up-spray droplet group's characteristic particle size and dispersed phase fraction were tested by using Malvern laser particle size analyzer in the mine exhaust heat and humidity extraction device with upper spray type, and data of 21 engineering conditions were tested and collected. Then, influence of nozzle operation parameters and exhaust airflow mechanical parameters on dispersed phase fraction of droplet groups was determined by using critical Weber number and ligament diameter calculation formula. Finally, a single droplet's migration correlation with droplet group characteristic particle size was derived by introducing dispersed phase fraction. The results show that the primary breakage type of liquid film is linear instability breakage with long wavelength. When nozzles' atomizing pressure increases, particle size of liquid droplets decreases while fraction of dispersed phase increases. The resistance coefficient increases with the introduction of dispersed phase fraction, which has a quasi-lubrication effect on droplet migration.

    Public safety
    Assessment on fire safety resilience of old industrial building regeneration projects
    LUO Fuzhou, YUAN Huiqing, ZHANG Yang
    2022, 32(3):  167-173.  doi:10.16265/j.cnki.issn1003-3033.2022.03.023
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    In order to eliminate existing fire hazards of old industrial building regeneration projects, improve their safety, and to promote development of resilient cities, concept of fire safety resilience for these projects was proposed based on theory of resilience. Then, according to relevant norms and documents, a resilience evaluation index system was constructed from three aspects, absorption capacity, disaster adaptability and recovery capacity. In order to reduce influence of subjective factors, combined index weighting method was used to determine weights of indicators, and TOPSIS was adopted to evaluate their fire safety resilience. Finally, with regeneration project of Shaanxi Iron and Steel Plant as engineering background, four concrete examples were selected to evaluate and verify scientificity and effectiveness of the method. The results show that the absorption capacity and disaster resilience of regeneration projects are poor, which makes their fire safety resilience generally low. Implementing corresponding countermeasures proposed from these perspectives can significantly improve fire safety resilience of the projects.

    Prediction model for road transport accidents of hazardous chemicals based on Bayesian network
    LU Yi, WU Jiangle, SHAO Shuzhen, SHI Shiliang, ZHOU Rongyi, WANG Wei
    2022, 32(3):  174-182.  doi:10.16265/j.cnki.issn1003-3033.2022.03.024
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    In order to accurately predict road transport accidents of hazardous chemicals, firstly, data of 1,727 such transport accidents in China from 2015 to 2020 were collected, and a Bayesian network (BN) was developed with accident influencing factors, accident types, accident emergency treatment time and the degree of casualties as main nodes. Then, a prediction model for the accidents was established in Netica, and its validity was verified according to the mean absolute error (MAE). Finally, through forward causal reasoning and reverse diagnostic reasoning, the posterior probability changes of each variable of target nodes were observed, and accident development trend and evolution process under set conditions were explored. The results show that the model can effectively predict accidents under set conditions. Through positive causal inference, it is concluded that the most likely form of accident at noon is the leakage accident caused by rear-end collision or tank leakage, while based on reverse diagnostic reasoning, it is found that carrying capacity <30 t is a significant condition for flammable liquid leakage accidents to be successfully disposed of within 0 to 3 hours.

    Study on location selection of linkage fire stations based on demand level and distance loss
    HUO Feizhou, DONG Geli, LI Moxiao, MEI Yiyun
    2022, 32(3):  183-193.  doi:10.16265/j.cnki.issn1003-3033.2022.03.025
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    In order to improve urban fire resistance, designing fire stations based on urban development status could be an effective means to improve firefighting efficiency and optimize allocation of resources. Firstly, regional fire potential was assessed based on population density and distribution of high-risk fire potential units, and ArcGIS was adopted to simulate distribution of fire potential and classify it. Then, with influence of fire station response distance on fire loss being taken into consideration, an optimized model of linkage fire station location selection based on demand grade and distance loss was established, and multi-objective optimization algorithm NSGA-Ⅱ was used to solve it iteratively. Finally, with Xiangzhou district, Xiangcheng district and Fancheng district of Xiangyang as examples, the model was compared with layout of fire stations in active service and that of site selection considering single factor. The results show that the optimization model comprehensively considers both factors of demand level and distance loss, and implements multi-level coverage for high-risk units according to the actual demand. As a results, it features a better location than that considering a single factor, and it proves to be more reasonable in fire resources' utilization.

    Technology and engineering of disaster prevention and mitigation
    Landslide susceptibility assessment model based on multi-class SVM with RBF kernel
    DING Xi, ZHAO Xiaodong, WU Xinjun, ZHANG Taili, XU Zhentao
    2022, 32(3):  194-200.  doi:10.16265/j.cnki.issn1003-3033.2022.03.026
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    In order to evaluate susceptibility of geological disasters reasonably and effectively, a multi-class SVM model with RBF kernel was established by using supervised machine learning model of SVM based on geological disaster survey data of Feiyun River basin in Wenzhou, Zhejiang Province. In geographic information system (GIS) platform, nine kinds of feature data for training were selected to analyze weight of each indicator by utilizing RF algorithm. Then, Gaussian function was used as RBF kernel function that mapped input feature data of SVM into high dimensional space for identification. In the meantime, an optimal method was put forward to calculate hyper parameters of C and γ in Gaussian function that were difficult to solve out in SVM model. After the model is learned from the training set, its evaluation index, i.e. area under curve (AUC), is up to 0.97 by using receiver operating characteristic curve (ROC) evaluation method, and the AUC of micro-multi-classification ROC is 0.87. The trained evaluation model not only guarantees accuracy of important classifications, but also avoids over-fitting.

    ISBN:9787517026006
    2022, 32(3):  206-206. 
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