China Safety Science Journal

Inference modeling of mountainous highway rainstorm-flood disaster chain based on Bayesian network

LUO Junhua, LIN Xiaosong, MU Fengyun, YU Qing, LU Xiaoping

2018, 28(12): 1-6. doi:10.16265/j.cnki.issn1003-3033.2018.12.001

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In order to provide reference basis for the disaster prevention and mitigation work of rainstorm-flood disaster on mountainous highway, the Bayesian network was used to study the damage to highway structures in the disaster chain under different circumstances. The evolutional process of rainstorm-flood disasters on mountainous highway with chain-rules characteristic was divided into a rainstorm disaster chain and a highway-structure destruction chain. Based on the Bayesian complex network theory, interaction modes between highway structures were analyzed. A Bayesian network inference model was built for rainstorm-flood disaster chain on mountainous highway on the basis of historical data on disasters in Chongqing city and Hunan province. The effectiveness of the model was checked by a case study of a disaster occurred on the section of provincial highway 221 between Wuyang and Lixiqiao town in Suining county Hunan province on June 18, 2015. The result shows that Bayesian network inference under different combined evidence can be implemented by using Bayesian network toolbox with network framework construction, node parameter setting, joint tree inference engine calling and so on, and that prediction result obtained by using the conforms with the actual disaster condition.

A two-step method for identifying weld damage ofgrid structure connections

LIU Hui, WANG Qian, CHEN Shichao, ZHU Shengnan

2018, 28(12): 7-13. doi:10.16265/j.cnki.issn1003-3033.2018.12.002

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The grid structural welding connections are prone to damage. In order to ensure the safety of a structure in its service life, a two-step damage identification method was worked out based on wavelet transformation and strain modal methods. In the first step, the acceleration response of every connection was calculated when weld damage occurs at given connection. The singular value of the high-frequency component of the calculated acceleration signal was analyzed by using wavelet transformation method, and then the impacted range by the damaged connection was determined according to the amplitude of singular value, which was used to divide the structural sub-regions. Besides, an accelerometer was placed at the given connection. In the second step, the acceleration responses of these accelerometers were measured and analyzed by using wavelet transformation method to identify the damaged sub-region in the structure. Then, in the identified damaged sub-region, the strain modal analysis method was selected to locate the damaged connection. Finally, the proposed method was verified by the experiment on a gird structural model. The results indicate that the proposed method can be used to identify the sub-region containing damaged welded connection in the structure by using acceleration signals measured from finite accelerometers, and locate the damaged connections in the sub-region, and that the proposed method is feasible to realize damage identification on large complex grid structures because very few sensors are required.

Improved damage diagnosis method for offshore platforms based on modal strain energy

LENG Jiancheng, TIAN Hongxu, XU Shuang, ZHOU Guoqiang

2018, 28(12): 14-19. doi:10.16265/j.cnki.issn1003-3033.2018.12.003

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In order to improve the effect of damage diagnosis for offshore platforms, and accurately determine both location and degree of damages, an improved diagnosis method based on modal strain energy was worked out, with which the mistakes of multi-judgement and mis-judgement happening in the traditional analysis and processing of modal strain energy can be avoided. Firstly, the modal strain energy based indexes under actual condition were calculated for the elements. Then the indexes were decomposed into several single damage condition indexes, and the weight coefficients of each single damage condition index to actual condition index were extracted and calculated. Finally, the diagnosis indexes were corrected according to the distribution difference of weight coefficient in different modes, and used to diagnose the damage. Finite element simulation tests of an indoor jacket offshore platform model were performed to verify the improved method. The results show that the damage diagnosis reached by using the method is consistent with the multi-damage conditions of the platform structure, which proves the method is effective and feasible for offshore platform damage diagnosis.

Reinforcement rock creep control model based on cementation coefficient

XIN Yajun, HAO Haichun, LYU Xin, JI Hongying

2018, 28(12): 20-26. doi:10.16265/j.cnki.issn1003-3033.2018.12.004

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Broken surrounding rock, complex grouting ways and obvious rheology are widespread in the deep gateway. Exploring cementation mode and creep control model of broken rock body in deep gateway is beneficial to surrounding rock stability. Specimens of marble and gritstone were obtained by four steps: sampling, splitting, creep, and cementation. Creep tests of cementation reinforcement on two groups of marble specimens and gritstone ones were carried out by means of an RLW-2000 triaxial rheological system. Basic creep characteristics of splitting damaged cementation rock were analyzed. A basic cementation mode of split rock was determined. A basic creep constitutive model of split cementation rock was deduced, and the inversion analysis was carried out. The results show that as creep stress level increases continuously, creep strain of the marble will undergo a process including a slow increase stage, a rapid increase stage, and an abrupt increase stage, creep strain of the gritstone will undergo a process including a decrease stage, a stable stage, and an increase stage, and the fractures in all the specimens will be compacted continuously, extended, interconnected and failed, which results in failure, that there are two modes of rock cementation: the tight cementation and the thickness one, the tight cementation is better than thickness one, that the thicker the cementation is in thickness cementation specimen, the higher the strength of the cementation specimen will be, while the increasing trend will be damped, that the M-K-B constitutive model can reflect the basic creep characteristics of cementation rock, and that when cementation coefficient increases, the creep strain of cementation rock decreases, while the decreasing rate tends to decrease under the same creep stress level.

Expectancy model for occurrence mechanism of college students' unsafe behavior

AN Yu, ZHAI Cunli, FANG Yingqian, XU Surui, TONG Ruipeng

2018, 28(12): 27-32. doi:10.16265/j.cnki.issn1003-3033.2018.12.005

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For preventing university safety events and creating a good campus safety climate, this paper analyzes the occurrence mechanism of unsafe behavior of college students from the perspective of social psychology. Based on Maslow's hierarchy of needs, the behavior characteristics of college students in different dominant needs were analyzed, the psychological motivation of college students' unsafe behavior was explored. Then, a expectancy model was built for the occurrence mechanism of college students' unsafe behaviors based on expectation theory. After that, this model was used to explain the behavioral process of using electrical appliances in violation of dormitory regulations, and also to discuss how to reduce the probability of unsafe behavior of college students. The results show that dominant needs determine the behavior of college students, that the expectation model reveals that the unsafe behavior of college students is mainly due to their subjective cognition and judgment, and that their subjective error decisions can be reduced by improving their own safety awareness, safety cognition and safety capability.

Research on defective lane-changing behavior based on system dynamics

ZHOU Xingnan, WANG Jingsheng, ZHU Yin

2018, 28(12): 33-39. doi:10.16265/j.cnki.issn1003-3033.2018.12.006

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To study the influence of a change in the traffic management policy on vehicle defective lane-changing behavior, a hypothetical model of SD for vehicle defective lane-changing behavior was built, including subsystems of human, vehicle, road, environment and traffic management policy. Based on the actual survey data, the feasibility analysis of hypothetical model was carried out by using AMOS software. On this basis, a complete SD model of vehicle defective lane-changing behavior was constructed. Finally, the SD analysis software VENSIM was used to simulate the model, and the dynamic influence sequences of the factors in the system on the defective lane-changing behavior of vehicles were explored. The results show that the subsystems of human, vehicle, road and environment will be regulated accordingly, and the defective lane-changing behavior of vehicles will be weakened to varying degrees by adjusting the traffic safety policy, including law enforcement intensity, timely law enforcement rate, the number of safety inspectors and the learning ability of trainers, and that the interactions between the factors make the evolution process of defective lane-changing behavior have several stages.

Synergistic effect of melamine borate in intumescent fire-retardant coatings

XU Zhisheng, ZHOU Huan, YAN Long, JIA Hongyu

2018, 28(12): 40-45. doi:10.16265/j.cnki.issn1003-3033.2018.12.007

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To study the synergistic effect of MB on the flame retardancy and smoke suppression properties of intumescent fire-retardant coatings, the properties of the coatings with different contents of MB were analyzed by cone calorimeter test, cabinet method test, tunnel method test, thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The results showed that a proper content of MB could improve flame-retardant and smoke suppression properties of the intumescent coatings. The optimum mass fraction of MB corresponding to the best synergistic effect is 5%, which makes the flame spread rating value decrease to 11.9 and the expansion ratio reach 48.4 and that the addition of MB promotes the formation of more thermostable P-O-C, B-O-P and C=C structures in the char residue that improve the high-temperature thermal stability and char-forming ability of the coatings, thus exhibiting a more compact and intumescent char as well as high flame-retardant and smoke suppression efficiencies.

Prediction of vehicle ignition time based on fire spreading in tunnel

WANG Mingnian, TIAN Yuan, YU Li, YAN Zihai, JIN Wei

2018, 28(12): 46-51. doi:10.16265/j.cnki.issn1003-3033.2018.12.008

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In order to obtain a method of predicting time of the vehicle on fire to ignite its adjacent vehicles in the urban highway tunnel under a blocking scenario, the ignition time was studied based on the law of fire spreading in the tunnel. A calculation method of the radiation heat flux received by the adjacent vehicle in the tunnel was worked out by theoretical analysis. A method of predicting the ignition time of vehicles under fire was developed by linear fitting. The effectiveness of the prediction was verified by field test. The results show that the predicted value of ignition time is basically consistent with the experimental value which indicates the method has higher precision, and when the initial vehicle on fire is a small vehicle and the surrounding vehicles are randomly distributed, the small vehicles in the adjacent lanes will not be ignited, that the ignition times of the medium and large vehicles are about 30 min and 9 min respectively, that when the initial vehicle on fire is a large vehicle, the ignition time is about 5min when the adjacent vehicle is a small car, and that preliminary firefighting measures should be taken and personnel evacuation should be organized within 5 min when a fire breaks out.

Study on form of smoke plume at facade of building in fire under windless condition

LEI Jingjing, WANG Yan, ZHOU Ru, JIANG Juncheng, ZHU Dezhi, HE Jiapeng

2018, 28(12): 52-57. doi:10.16265/j.cnki.issn1003-3033.2018.12.009

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In order to explore the impacts of the overflowing smoke of fire compartment on the building facade and the upper rooms, a 4∶1 experimental model was built based on similarity principle to carry out the combustion experiment. Different window aspect ratios and fire power values were set under windless condition. The law of morphological characteristics of overflowing smoke near the wall,and the change of overflowing smoke width were analyzed. The temperature and CO concentration in the upper room were discussed. The results show that when the aspect ratio of the window is greater than 1 and the fire power value is lower, the heating effect of the overflowing smoke near the wall is not obvious, and the impacts on upper compartments and adjacent compartments are smaller, and that controlling the aspect ratio and the fire power can restrain the harm caused by the overflowing smoke.

Full-scale simulation of gas explosion at longwall coalface in coalmine

LIU Rucheng, ZHU Yunfei

2018, 28(12): 58-64. doi:10.16265/j.cnki.issn1003-3033.2018.12.010

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For improving accident investigation and flame-proof technology application in coalmines, the gas explosion simulator-FLACS was used to model the full-scale longwall coalface and calculate the flame propagation, attenuations of shockwave overpressure and dynamic pressure on straight roadways, corners and bifurcations in a worst-case gas explosion based on the information from accident investigations. It was found that the free spaces provided by bifurcations limit the flame propagation obviously, that overpressure decays dramatically at corners and bifurcations, that the blast wind velocity just declines distinctly on bifurcations, and both corners and long straight roadway have little impact on it, and that the high-speed blast wind with debris and toxic smoke are the most important destructive factor at far field disaster areas. The quantitative results are helpful in percepting the full-scale gas explosion characteristics, rebuilding accident scenarios and optimizing flame-proof technology application.

Numerical simulation of gas explosion in enclosed interconnected vessel based on HLLC algorithm

LIU Yujiao, GAO Ke, JIA Jinzhang

2018, 28(12): 65-70. doi:10.16265/j.cnki.issn1003-3033.2018.12.011

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HLLC algorithm based on density solver was embedded into the OpenFOAM to accurately capture shock wave induced by gas explosion. In order to overcome stiff problems in the flow field calculation, a method was developed based on tabulation methodology of detailed chemical reactions(TDC). Propagation characteristics of shock wave induced by gas explosion in ducts under different gas volume fractions were studied in an 1 m³ confined vessel connected to ducts, and the results of numerical simulation were verified through the experiments. The transient flow field in the transfer vessel was also studied by numerical simulation. Research results show that the flame is accelerated to jet into the transfer vessel after passing through the pipeline, and the shock wave arises suddenly and intensely due to the Interaction between reflection wave and flame, that the longer the pipeline is, the stronger the pressure will be in the transfer vessel, that the flame propagation speed in ducts increases initially and then decreases when the length of the pipeline is 6 m and 10 m, and that when the length is 4 m, the flame speed increases continuously.

Research on JD-R model of miners' unsafe behavior based on Meta-analysis

YANG Xiaoyi, TONG Ruipeng

2018, 28(12): 71-76. doi:10.16265/j.cnki.issn1003-3033.2018.12.012

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In order to investigate the factors which lead to coal miners' unsafe behavior and contribute to their safety behavior more systematic, and explore the mechanism of miners' unsafe behavior, a JD-R model was built for miners'unsafe behavior. For miners'unsafe behavior, components of the model were listed and hypotheses about the relationship between them were given. Then, the model was examined by Meta-analysis and a revised JD-R model was built. The model variables, correlation coefficents and verified hypotheses about the relationship between variables were also presented. The results show that the revised JD-R model for miners' unsafe behavior consists of job demands and impaired factors containing 4 variables each, and job resources and motivational factors containing 5 variables each, that there are 3 significant interaction processes among the factors, and that miners' unsafe behavior was is a result produced by the interactions between the job demands and the job resources.

Adsorption characteristics of micropores in coal at low temperature and pressure

HONG Lin, GAO Dameng, WANG Jiren, ZHENG Dan, DU Yuanhong

2018, 28(12): 77-82. doi:10.16265/j.cnki.issn1003-3033.2018.12.013

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To explore the relationship between the power source of coal and gas outburst and coal microporous adsorption, coal samples low-temperature nitrogen adsorption experiments were carried out by means of a physicochemical adsorber. Based on the theory of micropore filling and multi-layer adsorption, the demarcation point between micropore filling and adsorption on mesoporous surface of coal was analyzed by using the non-linear fitting method. The micropore filling rate of coal and the pressure of gas in the process of desorption were calculated with the aid of the Dubinin-Radushvich (D-R) equation and the ideal gas equation of state. The results show that the demarcation point between micropore filling and multi-layer adsorption of coal is the relative pressure of 0.01, that more than 48% of the microporous volume is filled with gas (methane), that the pressure generated by the gas during desorption is over 30.38 MPa, which will lead to the fragmentation of the coal, induce a release of a large amount of gas, and provide a power source for coal and gas outburst.

Technology for controlling gas in goaf of contiguous lower adjacent coal seam group

SU Weiwei

2018, 28(12): 83-88. doi:10.16265/j.cnki.issn1003-3033.2018.12.014

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The gas (methane) concentration in the upper-corner of coal mining face was always higher extremely than the limit after releasing the pressure of the lower coal seams group, and the gas in the bottom of goaf and among the supports also could not be drainaged in time. To address these problems, a new auxiliary technology of the roof drainage tunnel for gas drainage in goaf was developed.The technology is characterized by inner interlocked oblique drilling. According to the evolution law of roof collapse and drill hole form, the gas was drainaged from the upper-corner, among the supports and the bottom of goaf. The drainage effect of the technology was investigated in the coal mining face of 2203 in Gaojiazhuang mine. The test results show that the average volume fraction of gas is 15.1%, which increases by 1.3 times as compared with the single drainage technology of the roof drainage tunnel, that the average net gas amount is 18.61 m³/min, which increases by 1.9 times, that the superposition gas drainage efficiency is 50%, and the drainage volume accounts for 83% of the total gas emission from adjacent layers and the goaf, and that by using the technology, the volume fraction of gas in the air return way and upper-corner of coal mining face is limited to 0.6% or lower, and the smooth mining of working face is effectively guaranteed.

Safety control analysis of new-constructed pipeline overpassing subway station

WANG Kaixuan, WANG Yu, KANG Rongxue, WEI Lijun, SUN Enji

2018, 28(12): 89-95. doi:10.16265/j.cnki.issn1003-3033.2018.12.015

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In order to control the differential settlement of new-constructed pipelines overpassing subway station at a short distance,a deformation calculation model was built based on the Pasternak-type two-parameter model and the three polyline elastic-plastic load transfer model. The finite difference method was used to solve this problem. A case was used to analyze vertical displacement and bending moment of pipeline. The influences of parameters were discussed. The results show that at a certain distance from the station edge line, vertical response of pipeline tends to be stable, and taking two times of the station width as the impact length can meet the practical requirements, that it is advisable to use materials with larger elastic modulus in the underlying soil, that for the pipeline of the impact section, improving pipeline stiffness is helpful to control differential settlement, and grouting reinforcement underlying soil can obviously reduce the differential settlement, and that when the engineering grouting length is 0.5 L, the area between area of 0.5-0.75 L and 1.75-2 L away from the subway station edge should be reinforced.

Research on optimization of U-shaped steel support for deep roadway in complex geological mine

WANG Jian, ZUO Yujun, DONG Longjun, WANG Hao, LIU Huaiqian

2018, 28(12): 96-101. doi:10.16265/j.cnki.issn1003-3033.2018.12.016

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To analyze the optimization problem of U-shaped steel support for deep complex geological roadway, the middle section of -550 in a certain mine in Shandong province was taken as engineering background, a three-dimensional model of deep roadway supporting mechanics was built by using ANSYS finite element method, and the stability of deep roadway surrounding rock was analyzed. The orthogonal test method is used to carry out the orthogonal test on three influencing factors, such as the support spacing of U-shaped steel, lateral stress coefficient and monitoring point. The validity of numerical simulation and orthogonal test was verified by a field blasting seismic test. The results show that when the lateral stress coefficient is less than or equal to 1, the vertical stress plays a dominant role, and that the optimum spacing of U-shaped steel support is 1 m, which can meet the stability requirement of IV class surrounding rock.

Experimental study on thermal risks of double-propylene latex production process and its products

WEI Chenye, JIANG Huichun, PAN Xuhai, HUANG Jiaxing, CUI Fusheng, JIANG Juncheng

2018, 28(12): 102-108. doi:10.16265/j.cnki.issn1003-3033.2018.12.017

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In order to analyze the thermal hazard of double-propylene latex production process and the thermal decomposition heat of its products,the test of double-propylene latex production process was carried out.An Mettler Toledo RC1e calorimeter was used to determine of exothermic characteristics during the production of double-propylene latex. A TG analyzer was applied to test the pyrolysis performance in both air and nitrogen atmospheres. The thermal hazard of the reaction process was evaluated. The thermal decomposition process of the double-propylene latex produced by the reaction was analyzed. The apparent activation energy (E_a) during thermal decomposition of the product was estimated by using the isokinetic methods (Starink method and Friedman method). The results show that the reaction thermal risk grade of the double-propylene latex production process is class 1, means it is relatively safe, that in the air condition, the thermal decomposition process of the double-propylene latex has four stages with almost no residue, that in the nitrogen condition, the thermal decomposition process of the double-propylene latex has three stages, and the residual char rate is about 9.22%, and that the E_a ranges calculated by Starink method and Friedman method are 32.65-113.45 kJ/mol and 29.70-175.90 kJ/mol respectively.

Study on model for coal rock permeability anisotropy and simulation of gas extraction

ZHANG Haohao, LI Sheng, FAN Chaojun, WANG Xiaohe, GUO Yunfeng, TAO Mei

2018, 28(12): 109-115. doi:10.16265/j.cnki.issn1003-3033.2018.12.018

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In order to further clarify coal rock permeability evolution law and influence of matrix gas seepage on gas extraction, based on the existing fluid-solid coupling model of matrix gas seepage, considering anisotropic characteristics of coal permeability, a permeability anisotropy coupling model of coal rock was built. COMSOL Multiphysics software was used to analyze the anisotropic permeability characteristics of coal rock and the influence of matrix gas seepage on gas extraction. The results show that with the increase of permeability anisotropy coefficient, the ratio coefficient of matrix to fracture permeability decreases, and the effect of gas extraction is obviously reduced, that the peak value of matrix gas seepage rate increases with the increase of anisotropy coefficient, but matrix gas seepage rate in the middle and late stages of gas extraction is gradually stable, and the value is about 0.1%, and that the matrix gas seepage term plays a promoting part at a certain stage in gas extraction.

Research on TTAE safety education mode based on role-playing

HUANG Zhien, WU Chao, LI Ming

2018, 28(12): 116-121. doi:10.16265/j.cnki.issn1003-3033.2018.12.019

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By systematically analyzing the potential advantages of role-playing in safety education, a mode named "Trainer-Trainee-Assessor-Environment (TTAE)" was established based on the role-playing, which has the characteristics of multi-role, multi-scenario, and multi-task during the process of safety education training. Then, a TTAE model of safety education information cognition was built from a perspective of safety informatics, and its application in traffic safety education was analyzed. Finally, aiming at the distortion of the cognitive model of safety education information, a relationship function between safety education effect and information cognitive distortion was established preliminarily, and optimization strategies of main factor sets were discussed. The results show that the TTAE safety education mode based on role-playing can realize the role training and conversion between trainers, trainees and assessors,and that the constructed cognitive model of safety education information can be used to identify and evaluate information sources and their flows during safety education process, which can provide a basis for analyzing the causes of role behavior errors.

SPA evaluation of expressway construction site safety management standardization

LI Guoliang, ZHAO Rui, LIAO Hengxiao, LIU Yu, LI Yulong

2018, 28(12): 122-128. doi:10.16265/j.cnki.issn1003-3033.2018.12.020

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The traditional evaluation method of expressway construction site safety management standardization often ignores the uninvolved items, which affects negatively the accuracy of the evaluation results. In order to solve this problem,a comprehensive evaluation model was built based on the SPA theory. According to the comprehensive factors affecting the expressway construction site safety management, an evaluation index system was set up including construction site layout, safety protection, construction operation, bridge engineering, tunnel engineering, subgrade engineering and pavement engineering. An SPA decision matrix was established and the degree of connection and degree of generalized identity were calculated for the evaluation indexes. A certain freeway project in Yunnan was taken as an example, to which both the SPA evaluation method and the traditional evaluation method were applied. The results show that with regard to evaluation of construction site safety management standardization, a more accurate evaluation result can be obtained by using the SPA comprehensive evaluation model.

ICWGT-IVFS multi-level safety assessment model for quayside container crane metal structure

LI Aihua

2018, 28(12): 129-135. doi:10.16265/j.cnki.issn1003-3033.2018.12.021

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In order to increase the accuracy and reliability of the safety assessment results of quayside container crane metal structure, an evaluation index system and evaluation criteria were established for metal structure of quayside container crane. Subjective and objective weights of the indexes were determined by analytic hierarchy process (AHP) and entropy methods. An improved CWGT method (ICWGT) was worked out, and the combination weights were integrated by the ICWGT. On the basis of an improved VFS (IVFS), an ICWGT-IVFS multi-level evaluation model was built. A practical example was given to verify the effectiveness of the model. The results show that ICWGT can overcome the drawback of negative weight coefficient, and that the ICWGT-IVFS model can avoid the inconsistencies between indicator standard and system criterion of quayside container crane metal structure, which is helpful in improving the accuracy of metal structure safety evaluation of quayside container crane.

Research on evolution of navigation safety risk in Three Gorges dam area

QIN Pan, FENG Zhitao, ZHANG Jie, DU Chao

2018, 28(12): 136-143. doi:10.16265/j.cnki.issn1003-3033.2018.12.022

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In order to improve the navigation safety level in Three Gorges dam area, the evolution process of navigation safety risk in Three Gorges dam area were studied by means of field investigation and the structural equation model (SEM)among others. Factors influencing navigation safety risk were analyzed and classified. A measuring scale was compiled. The indicators were screened and an index system of navigation safety risk evolution was established. A theoretical relationship model of risk evolution was built. The paths were analyzed by statistics software AMOS based on SEM.The results show that the navigation safety risk in the Three Gorges dam area is formed by the evolution of five major risks, such as natural environment risk, risk of channel state, risk of management behavior, ship risk and crew risk, and that the evolution process of risk is divided into three stages of inducing, spreading and upgrading.

Driver risk perception level evaluation based on driver's index

AI Qiannan

2018, 28(12): 144-149. doi:10.16265/j.cnki.issn1003-3033.2018.12.023

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To accurately evaluate the level of driver's risk perception during driving, data on driving behavior, electrophysiological status and eye movement of driver's response to different traffic flow conditions, intersection geometry and sudden events were collected, together with the data on vehicle performance, vehicle behavior and the interaction with other vehicles. The risk assessment indicators were analyzed from the perspectives of driver's physiological and physical indicators. Based on the risk perception quantification, scenario extraction and behavior analysis, an evaluation index system was established. Then, by using the HMM, quantitative values of risk perception were predicted, driving behavior parameters under different risk perception quantitative values were analyzed, and an observation sequence of risk perception quantization values was finally obtained. The validity of the model was verified. The results show that the HMM model can predict the quantified value of driver's risk perception with an accuracy over 85%.

Tailings pond dam break risk classification study based on both ISM and factor frequency method

CHEN Hu, YE Yicheng, WANG Qihu, LUO Binyu, LIU Ran, WANG Xianhua

2018, 28(12): 150-157. doi:10.16265/j.cnki.issn1003-3033.2018.12.024

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To solve the problem that the correlative modes between factors causing tailings dam-break interfere with the assessment and classification of the risks, the causes of tailings dam-break accidents at home and abroad were summarized and analyzed. Sixteen factors leading to tailings dam-break were screened out. The ISM was introduced to construct an interpretative structure model for tailings dam-break, and the factors of tailings dam-break were sorted out. Based on the hierarchical membership relationship, combined with the factor frequency method and the AHP, a method of determining the weight independent of subjective judgment was designed to calculate the weight of each factor in the model. According to the criteria of identification and classification of major hazards in tailings reservoir, a risk classification method for tailings dam break was worked out and applied to a certain tailings dam in China. The results show that the risk classification result of the tailings dam based on ISM and the factor frequency method conforms with the reality, and that the method can avoid the influence of the correlation between factors on the risk classification results of tailings dam break.

Research on emergency resource scheduling decision for railway accidents

YUAN Jiashan, ZHU Changfeng, WU Yonggui

2018, 28(12): 158-164. doi:10.16265/j.cnki.issn1003-3033.2018.12.025

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In order to reduce the loss railway accidents may cause and improve the efficiency of emergency resources dispatching, after taking optimal attribute values and expected attribute values as external reference points and internal reference points respectively and dividing resources dispatching stages to add time reference points, a decision model for emergency resources dispatching schemes that regarded the total loss and delay time of schemes as decision attributes was built based on CPT. According to the model, an emergency resources dispatching scheme with the maximum prospect value was obtained, and the sensitivities of preference coefficients of decision attributes and reference points were analyzed. The results show that the decision model can not only make up for the deficiency of expected utility theory, but also make the decision process more practical,and that the optimal scheme obtained by the model can reduce the psychological perception gap the accident loss brought to the decision makers.

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