China Safety Science Journal

Research on mental fatigue risk model based on alertness energy

SUN Ruishan, LIU Xiaohui, WU Di

2019, 29(10): 1-5. doi:10.16265/j.cnki.issn1003-3033.2019.10.001

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In order to scientifically describe and effectively predict mental fatigue, a mental fatigue risk model based on alertness energy is proposed. Firstly, by quantifying mental fatigue with energy and characterizing fatigue with alertness, alertness energy, alertness kinetic energy, and alertness potential energy were put forward to develop a alertness energy function. At the same time, supplemental function and consumption function of alertness energy were proposed, explaining that alertness could be supplemented during sleep and consumed while waking up, and then the formula was used to deduct the model with concrete expression of it being obtained. The results show that this model can describe mental fatigue mechanism and generation process more scientifically, thus providing a new calculation way for its prediction and prevention.

A thought sampling study of characteristics of miners' mind wandering

LI Naiwen, LIU Mengxiao, NIU Lixia

2019, 29(10): 6-11. doi:10.16265/j.cnki.issn1003-3033.2019.10.002

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In order to deeply explore the characteristics of miners' mind wandering, underground line miners were selected to participate in two mind wandering experiments of the resting and task states. In experiment 1, resting state thought sampling was selected, and questionnaire was conducted to investigate characteristics of miners' resting state mind wandering. In experiment 2, SART method was adopted to investigate characteristics of miners' task states mind wandering. The results show that in experiment 1, miners' mind wandering with meta-awareness is more often than mind wandering without meta-awareness, the incentive is given priority to internal ideas and the contents are mostly scenes, and mind wandering is more time to the past, and mostly irrelevant to working assignment but relevant to recent personal life experience, organization management and working environment, and that in experiment 2, there is no statistically significant difference between complicated task and simple task, and the frequency of mind wandering without meta-awareness during a complicated task is significantly greater than that during a simple task.

Research on driver behavior recognition method based on convolutional neural network

XU Dan, DAI Yong, JI Junhong

2019, 29(10): 12-17. doi:10.16265/j.cnki.issn1003-3033.2019.10.003

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In order to explore identification of unsafe driving behaviors of car drivers, concrete studies were carried out on CNN-based driver behavior recognition algorithm building on brief analysis of existing driver behavior recognition methods. CNN forward propagation and back propagation processes were explored and a CNN network architecture that deals with driver behavior recognition was presented. The results show that this method achieves an average recognition rate of 97.13% on state-farm driver behavior dataset, and compared with traditional algorithm, it has improved 3.62% on average in extracting histogram of oriented gradient(HOG) feature and using random forest(RF) classification for identification.

Numerical analysis of geological settlement failure of buried PE gas pipeline

YIN Ying, LAN Chaoxun, LI Jun, MAO Dan, SHI Junlin

2019, 29(10): 18-23. doi:10.16265/j.cnki.issn1003-3033.2019.10.004

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In order to study failure process of buried PE gas pipeline in the process of geological settlement, the stress-strain corresponding relationship of PE pipe was obtained by mechanical tensile experiment firstly. An improved Sherwood equation was fitted and the failure prediction model of PE pipes on the basis of strain rate was obtained. Then the mechanical response of PE pipelines in different settlement stages and with different slopes was simulated by ABAQUS software. The results show that the fourth-order Sherwood constitutive model can express and predict the mechanical response of PE pipes, and that the displacement and the depth of soil settlement have a direct impact on the distribution of stress and strain and the ellipticity of pipes.

Research on diffusion properties of inorganic solidified foam slurry in air leakage fracture

WANG Tao, LU Yi, SHI Shiliang, WANG Gang, YAN Zhihong

2019, 29(10): 24-30. doi:10.16265/j.cnki.issn1003-3033.2019.10.005

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In order to explore diffusion properties and pressure field distribution of inorganic solidified foam slurry in air leakage fracture, the force and flow analysis of inorganic solidified foam slurry in air leakage fracture was carried out based on its time-varying model of viscosity. The mechanical and flow characteristics of inorganic solidified slurry in air leakage fissures were studied, and the characteristics of diffusion and pressure field distribution under constant air volume and leakage airflow were discussed. A theoretical model of adverse wind flow and diffusion of inorganic solidified foam slurry in horizontal air leakage single crack was established, and a numerical model for horizontal crack diffusion with constant leakage rate was set up. The rationalities of theoretical and numerical models were verified by comparison. The results show that under the constant flow grouting condition, prolonging the grouting time will greatly increase the grouting pressure, but the increase in the diffusion distance of inorganic solidified foam slurry against the wind tends to stop, and that under the condition of air leakage, the grouting pressure should be preset according to the grouting project and influence parameters of air leakage should be set at the same time.

Causation analysis of container ship collision accidents based on improved BN

SI Dongsen, ZHANG Yingjun, LANG Kun

2019, 29(10): 31-37. doi:10.16265/j.cnki.issn1003-3033.2019.10.006

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In order to address BN structure learning difficulties caused by insufficient data samples when BN is used to analyze causation of container ship collisions, a BN structure learning algorithm based on kernel density estimation and model weighted averaging was proposed. Firstly, kernel density estimation was used to expand small data set so as to meet minimum data size of BN structure learning. Then, model averaging strategy was utilized to integrate various learning algorithms by allocating different weights, which improved learning effect of the algorithm with small sample data. Finally, a BN model was established to analyze causation of container ship collision accidents based on a small number of samples. The results show that this proposed algorithm can quantitatively analyze causation of collision accidents on the basis of small sample data, and obtain accident causation chain. It is helpful to improve safety of container shipping.

A distortion analysis of probability importance formed by equal power law

YIN Xiaobei, HUA Chengjie, WANG Haoze, ZHAO Rui

2019, 29(10): 38-42. doi:10.16265/j.cnki.issn1003-3033.2019.10.007

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For the sake of improving accurancy of probability importance of repeated events, it was demonstrated that the use of equal power law would eliminate the influence of repeated events probability on the top event probability. Firstly, the equal power law of Boolean algebra, the probability function of the top event, the definition of probability importance and its mathematical essence were introduced in detail. Then a general formula for probability importance of basic events was derived by using the partial derivative formula of compound multivariate function. Finally, three kinds of deviation laws caused by distortion were demonstrated through examples. The results show that for non-repetitive events, the formula can be degraded to the existing probability importance formula, and that for repeated events, the application of equal power law to the solution of probability importance will lead to distortion of results.

Discrimination of relevant concepts of safety risk classification control

LUO Cong, XU Ke, LIU Qian, ZHAO Yunsheng

2019, 29(10): 43-50. doi:10.16265/j.cnki.issn1003-3033.2019.10.008

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In order to solve the problem that relevant concepts of safety risk classification control are not unified and confusion used in actual work safety, the connotation and definition of six basic concepts, including hazard, accident potential, cause of the accident, accident category, hazardous and harmful factors and safety risk, were summarized and clarified based on comparative analysis of relevant domestic standards and scholars' opinions. Then the interrelationship between concepts was discussed and the conceptual relationship diagram of safety risk classification control was proposed. Finally, based on basic concepts and safety management, a full-time safety risk control model based on key time points was established which clarified relationships between safety risk management and accident potential investigation and control, accident prevention and emergency response. The accident control system of "5E" countermeasures was constructed which clarified the relationship between accident prevention, risk assessment and emergency management. The results show that basic concepts are the basis of safety risk classification management and control, and that the relationship among safety risk management and control, accident potential investigation and control, accident prevention, risk assessment and emergency response is related to the implementation effect of safety risk classification control, which should be clarified and standardized.

Progress of full-scale experimental study on metro fire

ZHONG Maohua, LIU Chang, SHI Congling

2019, 29(10): 51-63. doi:10.16265/j.cnki.issn1003-3033.2019.10.009

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Full-scale experiment is an important means to verify and optimize the metro fire smoke diffusion theory and smoke control design method. To have a systematic overview on full-scale fire experimental findings and predict the development trend, the progress of full-scale experimental researches on metro fire both at home and abroad were reviewed in this study, mainly including the promotion of full-scale fire experiments in subway trains, tunnels, stations and parking lots on the development of smoke control technology. The main trend of full-scale experiments focusing on large complex hub station, tunnels with complex structures, different types of trains and ancillary engineering were prospected. The results show that the current researches focus on smoke control design of single and two lines transfer stations and tunnels utilizing full-scale experiments, and the modification on train fire heat release rate curve, and that there are still some deficiencies in integrating testing method, enlarging experimental scale, and combining with large passenger evacuation, which should be focused on in the subsequent research.

Research progress of positive pressure foam extinguishing technology

DENG Tiandiao, LIU Changchun, HUANG Linyuan, SHEN Jinhua

2019, 29(10): 64-70. doi:10.16265/j.cnki.issn1003-3033.2019.10.010

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For the sake of wider application and promotion of positive pressure foam extinguishing technology, current researches on this technology are reviewed. Firstly, application advantages of the technology and both advantages and disadvantages of several gas-liquid mixing chambers were summarized. Secondly, types of spoilers and gas supply modes in gas-liquid mixing chambers were summarized. Finally, major studies on extinguishing performance and flow characteristics of positive pressure foam were outlined and evaluated.The results show that gas-liquid two-phase flow is most fully mixed in coaxial mixing chambers and conical spoilers, and liquid nitrogen source supply mode has the strongest foaming ability while aspirating gas source supply mode has the weakest one. Researches on foam extinguishing performance both at home and abroad mainly focus on fire extinguishing categories and foaming agent types, and those on flow characteristics of foam in tubes concentrate on foam rheology and its resistance loss.

Study on slurry diffusion law of high level drilling grouting fire prevention and control in goaf

WANG Lijie, WANG Jiren, ZHANG Xun, GUO Xiaoyang

2019, 29(10): 71-77. doi:10.16265/j.cnki.issn1003-3033.2019.10.011

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In order to study effects of grouting time and amount on spatial diffusion behaviors of slurry in high-level borehole grouting in goaf, FLUENT numerical calculation method was adopted to construct a mathematical model of slurry diffusion in three-dimensional heterogeneous goaf under a condition of grouting with variable gravity and constant inclination. Then with 29406 working face of certain mine as a research object, it was confirmed through simulation analysis that fire prevention effect would be the best when grouting volume of a single hole is 40 m³/h and the maximum distance that slurry tends to flow is 50.8 m. The research shows that diffusion radius of slurry increases gradually and would have a peak value during vertical diffusion in goaf while during diffusion at bottom plate peak concentration of slurry will not change significantly with time. And as grouting amount increases, the maximum distance at which slurry tends to flow along with inclination shows a nonlinear upward trend. According to indicating gas monitoring data of goaf, simulation analysis results are consistent with that of field application.

Protection effects of explosion-proof film on insulating glass

ZHANG Jinju, WANG Liqiong

2019, 29(10): 78-83. doi:10.16265/j.cnki.issn1003-3033.2019.10.012

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In order to quantitatively analyze protection effects of explosion-proof film on insulating glass under explosion shock wave load, comparative experiments of insulating glass with and without film were carried out. Broken states of glass under different explosive loads were obtained by adjusting burst distance and explosive charge, and threshold overpressure values of broken insulating glass with and without film were obtained according to overpressure values of explosion shock wave measured with pressure sensor. The results show that explosion-proof film can effectively reduce damage to glass side which has film on it and increase threshold overpressure value of glass fragmentation. Explosion-proof capability of glass with film back to explosion wave front is greater than that with film face to the front, and it cannot give full play to its protective effects if explosion-proof film is pasted on glass directly.

Analysis of influencing factors on severity of ship accidents in ice-covered Arctic waters

FU Shanshan, LIU Yanping, XI Yongtao, ZHANG Mingyang, HU Shenping

2019, 29(10): 84-90. doi:10.16265/j.cnki.issn1003-3033.2019.10.013

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In order to analyze influencing factors of ship accidents in Arctic waters, 311 ship accident data in Arctic waters from 1998 to 2017 were collected, cleaned and converted from maritime accident database from Lloyd's List Intelligence and Transportation Safety Board of Canada. Then a bivariate probit model was constructed and marginal effect analysis was conducted to identify and study influencing factors and associated impact levels of ship accidents (serious accidents and pollution accidents) in Arctic ice-covered waters. The results show that bivariate probit model can not only identify influencing factors of serious accident and pollution accident, but also sort out potential relationship between them which is a negative correlation. It is also found that gross tonnage, ship type, ship age, accident type, accident year, accident location, wind, and sea ice are notable factors that influence severity of ship accidents in Arctic waters.

Experimental study on evolution characteristics of coal pores under impact loadings

LI Sheng, WANG Xiaohe, FAN Chaojun, ZHANG Haohao, LIU Zheng, YIN Kun

2019, 29(10): 91-97. doi:10.16265/j.cnki.issn1003-3033.2019.10.014

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In order to study evolution characteristics of coal pores and fractures under impact loadings, with outburst coal of Machang Mine in Guizhou as a research object, Separate Hopkinson Pressure Bar (SHPB) test system, NMR and Scanning Electron Microscope(SEM) system were utilized to investigate their evolution features under different impact loadings. Then their evolution law and influence of coal impact on coal and gas outburst were analyzed. The results show that with the increase of impact pressure, micro pores' peak value semaphore and diameter ratio increase first and then decrease and connectivity of pores and fractures is enhanced, but peak value diameter ratio of medium and large pores decreases first and then increases. And pore throat distribution of micro pores in Machang Mine accounts for 38.85%～56.14% of the total while that of medium and large ones makes up for 43.86%-61.15%. Under impact loadings, evolution of pores and fractures in coal is carried out in the form of pores expansion, expansion of fractures and formation of secondary fractures. Moreover, impact loading strengthens connectivity of pores and fractures, breaks gas adsorption and desorption balance, causes an increase of gas pressure, and produces stress set and energy accumulation in coal body, thus increasing possibilities of coal and gas outburst.

Study on damage-energy evolution characteristics of coal under triaxial stress

LI Bobo, ZHANG Yao, REN Chonghong, YANG Kang, LI Jianhua, XU Jiang

2019, 29(10): 98-104. doi:10.16265/j.cnki.issn1003-3033.2019.10.015

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In order to prevent coal dynamic disasters effectively, triaxial servo-controlled seepage equipment of thermo-fluid-solid coupling was used for a triaxial compression test of coal to study its deformation and failure characteristics under triaxial stress and mechanism of energy evolution in process of damage. Then, a constitutive model of coal damage was established and mathematical expression of damage-energy coupling was constructed. The experimental results show that change trend of partial stress-strain curve of coal under different confining pressure is basically consistent. Its energy conversion form shows a periodic change in accordance with deformation and failure rules. Confining pressure has a great influence on energy consumption characteristics, since as it increases, the growth rate of total energy absorbed by coal, elastic performance and dissipation energy will also increase, and at peak partial stress point, with its increase, total energy, storage limit and dissipation energy of critical failure point would increase linearly. Energy dissipation is the main cause of damage to internal structure of coal, and it will change in an S type with an increase of damage variables.

Prediction of correlation between gas emission and tectonic coal

TIAN Shixiang, LIN Huaying, MA Ruishuai, XU Shiqing, ZENG Jianhua, YU Zhaoyang

2019, 29(10): 105-109. doi:10.16265/j.cnki.issn1003-3033.2019.10.016

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In order to study gas emission variation of tectonic coal during mining process along with change of drilling depth, gas flow of self-developed continuous flow method prediction system was adopted to measure the gas emission and drilling depth of boreholes with a drivage face of Xuehu coal mine 2104 roadway as a experimental object. Then based on initial gas emission trends, locations of borehole tectonic coal ahead were predicted. The results show that when drilling into coal with primary structure, gas emission of boreholes increases with the increase of drilling depth, and gas emission curve is stable, but when drilling into tectonic coal, it increases rapidly with a steeper curve which would come to a sudden change point at a drilling distance of 9.9 m and will reach maximum value of 89.9 L/min at 10.2 m, 2.05 times of normal value. With No. 3 borehole as an example, the accuracy and precision of prediction method are verified by mining activities.

Effects of multi-dimensional parameters of abrasive water jet on cracking concrete

LI Kunyuan, LIU Jialiang

2019, 29(10): 110-116. doi:10.16265/j.cnki.issn1003-3033.2019.10.017

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In order to improve application of AWJ technology in emergency demolition of post disaster concrete structures, breakage impact of concrete under AWJ was investigated. Firstly, a model of concrete impacted by AWJ was constructed based on coupled SPH and FEM. Then, its impact mechanism on broken concrete with AWJ was explored by changing abrasive particles' diameters, physical properties and abrasive volume fraction. The results indicate that AWJ with a diameter of 0.2 mm causes largest damage to concrete matrix, rupture point of matrix caused by AWJ with a diameter of 0.1 mm is closest to top surface of concrete, and AWJ with a diameter of 0.4 mm tends to cause matrix cracking and accounts for most cracks. It also reveals that garnet abrasive water jet is beneficial to axial propagation of concrete cracks while emery abrasive water jet is beneficial to their radial propagation. Influence of concentration on radial propagation of concrete cracks is as volume fraction of 10% ＞ volume fraction of 20% ＞ volume fraction of 15%, and that on their axial propagation is volume fraction of 20% ＞ volume fraction of 10% ＞ volume fraction of 15%.

Experimental study on characteristics of flashing jet released from superheated liquid tank

ZHU Xueliang, SONG Zeyang, PAN Xuhai, WANG Xilin, WANG Tao, JIANG Juncheng

2019, 29(10): 117-123. doi:10.16265/j.cnki.issn1003-3033.2019.10.018

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Experiments were conducted to investigate the two-phase release of superheated liquid with high temperature and high pressure after accidental releases based on the two-phase release experiment system. The characteristics of flashing jets during the release under different storage and release conditions such as storage pressure, superheat, and nozzle diameterwere studied by high-speed camera and PDA. Results show that the spray angle of flashing jet gradually increases first, then remains stable, and suddenly expands and decreases rapidly when superheated liquid is released completely. Droplets three-dimensional velocities increases with the increase of storage pressure, superheat and nozzle diameter, while droplets diameter decreases with the increase of superheat and nozzle diameter but increases with the increase of storage pressure.

Study on gas adsorption process of coal at low and variable temperature

MA Shujun, WANG Zhaofeng, REN Haoyang, HAN Enguang, WANG Bin

2019, 29(10): 124-129. doi:10.16265/j.cnki.issn1003-3033.2019.10.019

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In order to ensure reliability and accuracy of measured results of coal seam gas content, freezing core sample technology was introduced, an experimental study on coal gas adsorption process was conducted at low temperature and variable temperature by using high and low temperature adsorption test device, and variation characteristics of gas adsorption capacity during cooling process was analyzed. The results show that during programmed cooling process, temperature of coal samples in tanks slowly decreases first and then tends to be stable, and these changes generally happen in the first three hours after which temperature will maintain stable and basically close with that of external environment. During experimental cooling process, adsorption capacity would increases and decrease alternately (increase for general trend) before it achieves a stable status along with stability of temperature. It is also found that adsorption capacity decrease stage basically shows a linear change trend with a decline rate increasing first and then decreasing.

Study on transmittance uniformity and angle dependence of welding filter

LIU Qinggang, SHI Wenze, ZHUANG Yihuan, GUO Dehua

2019, 29(10): 130-134. doi:10.16265/j.cnki.issn1003-3033.2019.10.020

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In order to ensure the product quality of AWF to guarantee the safety of the welding workers' eyes, the measuring mechanism and methods for the transmittance uniformity and angle dependence of the AWF were analyzed. An innovative AWF measuring system including scanning controller based on 4-dimensional motion platform were developed, and the experiments and result analyses for transmittance uniformity and angle dependence of the AWF were completed. The results show that transmittance uniformity and angle dependence are important technical indexes for evaluating the quality of AWF products as both of them can indicate the characteristics of AWF, and that the experimental results obtained by the measuring system are in good agreement with the nominal data of products. The results also show that the proposed measuring system can be widely used as standard testing instruments to detect the transmittance uniformity and angle dependence of AWF.

A comparative study on safety level of four transportation modes in China

PENG Jianhua

2019, 29(10): 135-140. doi:10.16265/j.cnki.issn1003-3033.2019.10.021

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In order to have a general understanding of current transportation safety in China and promote coordinated development of transportation safety systems, safety level of railway, road, waterway and air transport modes in China is analyzed. By using comparative research method, safety level of these four transportation modes were compared comprehensively from four aspects—total accident number, accident rate, serious accidents and international comparison. The results show that there is obvious difference in safety level of four modes. In terms of total accident number and accident rate, their order from high to low is road, railway, waterway and air transportation. While being ranked according to serious accidents, it is road, waterway, railway and air transportation from high to low. Compared internationally, China is basically the same as developed countries in regard to safety of railway transportation, but lags far behind developed countries in that of road transportation. And there is a certain gap between China's waterway transportation safety and that of developed countries, but China's air transportation safety is obviously better than world average and also than that of developed countries.

Recommendations for reform on statistical systems of economic losses caused by work safety accidents in China

WANG Haishun, XU Ming, XIN Panpan, QI Xin, PEI Jingjing

2019, 29(10): 141-146. doi:10.16265/j.cnki.issn1003-3033.2019.10.022

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In order to improve statistical comprehensiveness and accuracy of economic losses caused by work safety accidents in China, five authoritative documents concerning this part were compared and analyzed and major problems existing in statistical systems were sorted out. Then, based on productive practices taken by international world in this regard, corresponding reform proposals were put forward. The research shows that there are several key problems in China's current documents, such as subjects of economic loss statistics are inconsistent, indirect economic loss statistics are not stipulated, direct economic loss data are not disclosed in accident investigation reports, time limit of statistical work is not uniform, definition of space boundary is not clear, and there is no differentiation for industries. In response to these problems, some reform recommendations were proposed, including setting up dedicated accident investigation agencies, weakening "direct-indirect" classification of economic losses of accidents, tracking statistics and disclosing economic losses by stages, establishing relevant database and formulating statistical standards for economic losses of major chemical accidents.

Safety assessment of component hoisting for prefabricated residence based on Cloud-BN model

SHEN Ling, TANG Yewen, MU Yue

2019, 29(10): 147-153. doi:10.16265/j.cnki.issn1003-3033.2019.10.023

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In order to reduce accident rates of component hoisting construction of prefabricated residence, a risk assessment model based on Cloud-BN was constructed to dynamically evaluate these risks. Firstly, feasibility and rationality of the combination of cloud model and Bayesian networks (BN) were analyzed. Secondly, risk index system and BN structure of component hoisting construction were established according to engineering practice, and conditional probability distribution among nodes was obtained through parameter learning algorithm. Then, the obtained prior probability was input into the model through cloud model transformation to reason out risk possibilities at various risk states before final risk levels were obtain through comprehensive cloud generation method. Finally, a prefabricated residence project was taken as an example to verify this model's effectiveness and advantages. It is proved that its results are basically consistent with reality with an average relative error rate within 5%, which is more objective and accurate compared with conventional BN models.

Resilience evaluation for deep foundation pit of metro station under influence of multiple factors

WANG Jingchun, ZHAO Fuquan, WANG Binghua, HE Xusheng

2019, 29(10): 154-159. doi:10.16265/j.cnki.issn1003-3033.2019.10.024

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In order to ensure construction safety for deep foundation pit of subway stations under influence of multiple factors, firstly, resilience concept of deep foundation pit was proposed. Then, time property and functional property of system resilience were stated based on which internal stress, degree of weathering, water level outside of pit, surface settlement, surrounding house settlement, column uplift, support axial force and inclination of wall were selected as evaluation indexes for resilience evaluation. Secondly, Euclidean distance method was used to comprehensively evaluate resilience and evaluation indexes were weighted by using coefficient of variation method to reduce influence of subjective factors. Finally, with deep foundation pit of a subway station in Nanning as a case, Euclidean distance was assessed to be 0.357 5 with corresponding resilience level 4.028. The results show that Euclidean distance method can assess quality of deep foundation pit of subway station under influence of various factors and evaluation results are consistent with the actual project.

Risk measurement method of flight operational quality based on skewed distribution

ZHAO Xinbin, WANG Yan

2019, 29(10): 160-166. doi:10.16265/j.cnki.issn1003-3033.2019.10.025

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In order to prevent and control flight risks, construction of safety risk matrix and probability theory are used to study quantitative analysis method of flight operational quality risks. Firstly, probability and severity of events were obtained based on probability density function of normal distribution after normalizing skewed data. Then, a risk measurement method for flight operational quality was put forward based on the idea that “risk is a product of probability and severity”. Finally, flight risks were measured from four different perspectives: light, medium, heavy and comprehensive, and QAR data were used to analyze and verify the method. The research shows that the proposed method can integrate probability and severity of events and measure four types of flight risks. Results obtained from it can be used to guide differential management of risks.

Risk assessment of subway train door system based on Fine-Kinney and TODIM

ZHU Jianghong, WANG Rui, LI Yanlai

2019, 29(10): 167-173. doi:10.16265/j.cnki.issn1003-3033.2019.10.026

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In order to include interactive relationships between risk criteria and psychological behaviors of decision-makers into consideration for risk assessment of subway train door system, a Fine-Kinney risk assessment model based on Choquet integral and TODIM is proposed. Firstly, uncertainties of assessment information were characterized by linguistic terms, then a maximizing deviation model was established to determine weights of decision-makers and a comprehensive decision matrix was integrated by interval 2-tuple weighted average operators. Secondly, importance of risk criteria was calculated based on similarity degree, and risk priority of hazardous events was derived by combing Choquet integral and TODIM approach. Thirdly, effectiveness and feasibility of the proposed model were demonstrated with an example of electrical control device of subway train door system. Finally, sensitivity analysis for criteria importance was carried out and comparison was made between this model and three other methods including TODIM, TOPSIS, and Choquet-TODIM. The results indicate that failure of electronic door control unit (EDCU) function presents the highest risk while loose of EDCU plug makes the lowest one. Compared with other methods, this proposed model can effectively describe interaction between risk criteria and psychological behaviors of decision makers.

Safety evaluation of asphaltene deposition in river crossing section based on CFD

WANG Bo, LI Changjun, XUE Ju, JIA Wenlong

2019, 29(10): 174-179. doi:10.16265/j.cnki.issn1003-3033.2019.10.027

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In order to ensure safe and efficient operation of river crossing section of crude oil pipeline, it is necessary to study asphaltene deposition and evaluate long-term operation safety of the river crossing section. Based on findings of crude oil components and asphaltene deposition mechanism as well as complex flow environment of certain river crossing section, CFD method was used to study carrying effects of crude oil on asphaltene particles and transport process of these particles. Then deposition amount was quantitatively analyzed so as to evaluate safety of this section. The results show that transportation volume decreases by 0.94% in river crossing section in terms of current current transportation technology, and it is in safe operation stage.

Research on helicopter cooperative rescue scheduling optimization

ZHANG Qingsong, JIN Yijia, QIN Shuaixing

2019, 29(10): 180-186. doi:10.16265/j.cnki.issn1003-3033.2019.10.028

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In order to improve the efficiency of aviation emergency rescue in China and explore how to deploy helicopters scientifically and quickly after disasters, the concept of helicopter collaborative rescue with multiple rescue points and multiple resource demand points was proposed. Targeted by the smallest helicopter configuration time, maximum utility and maximum demand satisfaction, a helicopter rescue optimization model meeting the above requirements was constructed. The multi-objective function was converted into single objective function by coefficient weighting and the model was solved by cooperative differential evolution algorithm. Finally, the feasibility of the model and algorithm was verified based on an example analysis of military-civilian helicopter cooperative rescue. The results show that the proposed algorithm can obtain helicopter dispatching plan of the alternative rescue point within three days of rescue period, and provide decision support for the emergency rescue commander in selection of the helicopter scheduling plan.

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