China Safety Science Journal

Research on relationships between community participation, protective action and socioeconomic status

LI Xiaowei, LIU Tiezhong, LIU Xia, ZHANG Hubo

2018, 28(10): 1-6. doi:10.16265/j.cnki.issn1003-3033.2018.10.001

Asbtract ( 149 )

PDF (1422KB) ( 265 )

References | Related Articles | Metrics

In order to improve the effectiveness of propaganda and education in the context of hazardous chemicals and enhance the willingness of community residents to adopt protective action, the relationship between community participation willingness and protective behavior willingness was studied, the moderated role of socioeconomic status also was examined. Two forms of community participation including ritual participation and substantive participation and six indexes of socioeconomic status including income, education, political affiliation, household registration, real estate and hosing ownership of present residence were identified. 521 effective copies of a questionnaire from Beijing were collected and analyzed by using the SEM method. The results show that there is a positive correlation between community participation awareness and protection behavior intention, and the influence relationship between ritual participation and protection behavior intention is more obvious, although there is stronger willingness of substantial participation, and that the socioeconomic status has a negative moderate role in the correlation.

Model considering driving workload for predicting vehicle lane changing in freeway work zones

OUYANG Nan, ZHAO Wei

2018, 28(10): 7-12. doi:10.16265/j.cnki.issn1003-3033.2018.10.002

Asbtract ( 145 )

PDF (1623KB) ( 251 )

References | Related Articles | Metrics

In order to prevent the traffic accidents caused by vehicle lane change in freeway maintenance area, firstly, the driving simulation tests with different traffic flow densities were carried out.The distance between vehicle lane change position and end of transition zone, lane change distance and driver's heart rate were collected. Then,based on the test data,vehicle lane-changing position and lane-changing distance were defined by vehicle trajectory and steering wheel angle. Effects of both the vehicle flow density and the driver's heart rate on lane-changing position and lane-changing distance were analyzed. Finally, a lane change prediction model based on vehicle flow density and driver heart rate was built by using forced entry variable regression. The results show that the location of vehicle lane change increases firstly and then decreases with the increase of vehicle flow density, and increases with the increase of driver's heart rate, that the distance of vehicle lane change increases firstly and then decreases with the increase of vehicle flow density, and decreases with the increase of drivers' heart rate, and that the model can predict the relationship between driver heart rate and lane change in freeway maintenance area.

Analysis of EEG detection of driver active fatigue on expressway

LIU Tianjiao, MA Jinfei

2018, 28(10): 13-18. doi:10.16265/j.cnki.issn1003-3033.2018.10.003

Asbtract ( 178 )

PDF (2390KB) ( 440 )

References | Related Articles | Metrics

To develop a system for warning the expressway driving fatigue and ensure road traffic safety, this study was aimed at exploring the relationship between EEG indicator (θ+α)/β and driver's active fatigue based on EEG data power spectrum analysis. EEG indicator (θ+α)/β was calculated by assessing three frequency bands: alpha (8-13 Hz), beta (13-30 Hz) and theta (4-8 Hz), during a simulated driving session in 21 subjects. SOFI scale was adopted to analyse fitigue state before and after driving, and regression method was used to examine the fitting validity of psychological measures and EEG algorithm (θ+α)/β.The results show that there is a negative correlation between the (θ+α)/β activity and time, that there is a positive correlation between EEG indicator (θ+α)/β and the driver's active fatigue, and the fitting interpretation rate is 50%, and that the EEG indicator (θ+α)/β is able to predict active fatigue in real time.

Influences of emotions on driving behaviors

ZHANG Dianye, CHENG Jing, ZHANG Yi

2018, 28(10): 19-24. doi:10.16265/j.cnki.issn1003-3033.2018.10.004

Asbtract ( 474 )

PDF (1562KB) ( 807 )

References | Related Articles | Metrics

Emotion is one of the significant factors that cause traffic accidents. In order to prevent traffic accidents caused by drivers' emotions, a three-level causal decomposition(arousal,reaction,vehicle state) is proposed to further analyze the influences of emotions on driving behaviors. Simulated driving experiments were designed and carried out to collect data on drivers in four emotional states: happy, sad, angry and fear. By using the baseline signal elimination method, the change value of the driver's heartbeat interval, steering angle and maximum lane deviation under different emotional sources were analyzed. The results indicate that all emotions incur significant increases in mean sympathetic arousal accompanied by significant increases in mean steering, that both the happy emotion and the anger emotion will result in a significantly larger range of lane departure, indicating more dangerous driving behaviors, and that both the sad emotion and the fear emotion will result in a smaller range of lane departure, indicating safer driving behaviors.

A lane changing behavior based method for detecting driver distraction

LUO Yi, GAO Yan, YOU Zhidong

2018, 28(10): 25-30. doi:10.16265/j.cnki.issn1003-3033.2018.10.005

Asbtract ( 186 )

PDF (2053KB) ( 323 )

References | Related Articles | Metrics

In order to prevent traffic accidents caused by driver distraction, a method was developed for distraction detection by using the radial basis function neural network model. The driving behavior during the lane change process was analyzed through driving simulation experiments. On the basis of the data from the experiments, effects of driver's three states, normal driving, hand-held answering phone and hand-free answering phone on the lane changing behavior were studied. An RBF neural network model was built based on orthogonal least square(OLS)method to monitor whether the driver is driving distracted. The results show that driving distraction during the lane change process has a significant influence on 6 driving performance parameters such as vehicle's longitudinal velocity, lateral velocity, lateral acceleration, steering angle, steering wheel velocity and opening degree of accelerator, and the average detection accuracy of the model reaches 88.7%, which could accurately identify the distracted state of the driver and provide theoretical support for the prevention of distraction accidents.

Method for predicting truck's failure rate in open-pit mine based on Mallat algorithm and ARMA model

BAI Runcai, CHAI Senlin, LIU Guangwei, LI Haoran, ZHANG Jing

2018, 28(10): 31-37. doi:10.16265/j.cnki.issn1003-3033.2018.10.006

Asbtract ( 225 )

PDF (1903KB) ( 308 )

References | Related Articles | Metrics

In order to improve the predictive accuracy of open-pit mine transport trucks failure rate, reduce accuracy loss caused by the non-stationary time series data and solve difficulty in the model parameter estimation, this paper puts forward a new method for predicting the failure rate of trucks based on wavelet analysis and ARMA. First of all, according to the characteristics of the non-stationary time series data, this paper first uses Mallat algorithm to process the original data, at the same time, the original time series is decomposed into a set of approximation coefficients and sets of detail coefficients. Then, the wavelet coefficients after single branch reconstruction are fitted and predicted by ARMA model. To effectively solve the ARMA model identification and parameter estimation problem, this paper introduces the relevant variables of the original model, and parameter estimation problem can be converted to the parameter estimation problem of multi-dimensional Gauss distribution with the related variables. Finally, ordering and parameter estimation of ARMA model are realized by calculating the typical correlation variables in the model. Simulation results show that the mean value of absolute error is 0.322, and the mean value of relative error is 5.49%, that compared with other algorithm models, this combination model has higher fitting precision, and that the model is feasible and effective in predicting the failure rate of trucks.

Manual materials handling energy consumption: model research and simulation

ZHANG Wenqian, FAN Shuhai, XIONG Jiawei, CHEN Siyu

2018, 28(10): 38-43. doi:10.16265/j.cnki.issn1003-3033.2018.10.007

Asbtract ( 149 )

PDF (1731KB) ( 299 )

References | Related Articles | Metrics

In order to prevent workers from suffering from work-related musculoskeletal disorders due to fatigue in manual handling, a bi-objective model was built about handling time and energy consumption based on economics and ergonomics. An interactive simulation platform was designed by using IGRIP/ERGO and Matlab are used to carry out simulation experiments. Through the simulation of the model,the case was executed about manual materials handling in an automobile brake pad manufacturing company. The optimal solution was gotten. The results show that both the material quantity and the production procedure have significant effects on energy consumption and handling time, that there is a negative correlation between the change rate of energy consumption and time, that the optimal solution can be usually obtained between productivity and ergonomics according to the proposed bi-objective model, and that the interactive simulation platform is helpful in controlling and preventing WMSDs for workers in modern production operation, and in making the production environment and operation design in accordance with ergonomics.

User equilibrium theory based evacuee assignment method for multi-exit emergency evacuation

LIU Yang, CHEN Juan, MA Jian

2018, 28(10): 44-49. doi:10.16265/j.cnki.issn1003-3033.2018.10.008

Asbtract ( 263 )

PDF (2554KB) ( 272 )

References | Related Articles | Metrics

Due to unfamiliarity with the surrounding environment and some other reasons, evacuees in public multi-exit scenarios often choose the nearest exit to evacuate, which results in unbalanced usage of the exits. As a consequence, the overall public evacuation efficiency is usually very low. To solve this kind of problem, a evacuee assignment method was worked out according to the user equilibrium theory, which can effectively assign evacuees in public areas to different evacuation routes. With the method, the evacuation of a multi-exit public area with complex obstacles was simulated. A comparison was made between the effect of the nearest exit assignment method and that of the user equilibrium assignment method. Results show that considering the evacuation distance and the evacuation exit width, the proposed user equilibrium assignment method can improve evacuation efficiency, namely 38% and 65%, and significantly balance the usage of the exits.

A method for interpreting work safety accident based on system dynamics theory

HU Zhihong, ZENG Rong, LIU Zude

2018, 28(10): 50-55. doi:10.16265/j.cnki.issn1003-3033.2018.10.009

Asbtract ( 174 )

PDF (1937KB) ( 320 )

References | Related Articles | Metrics

In order to analyze the causes of work safety accidents, find leverage solutions to safety problems and guide the handling, prevention and control of accidents better, a work safety accident interpretation method based on SD theory was worked out with the applying of literature research method and case analysis method. Based on the meta-event model of ontology, an accident description method combining accident description atlas and auxiliary description table was proposed, and a "DRAC" accident interpretation method was proposed based on system dynamics theory which was divided into four parts including Deconstruction, Reconstruction, Analysis and Conclude to explain the accidents. The applicability and maneuverability of the above method were studied by selecting cases. The results show that the method has good manifestation on both parts.

Full-scale experimental study on effects of forced ventilation on tunnel fire

SUN Shaohua, CHENG Jiaji, CONG Beihua, YANG Wanbao

2018, 28(10): 56-61. doi:10.16265/j.cnki.issn1003-3033.2018.10.010

Asbtract ( 149 )

PDF (3652KB) ( 290 )

References | Related Articles | Metrics

The relationships between the forced ventilation speed and heat release rate, temperature in tunnel, smoke components et al were studied by carrying out full-scale experiments, with an experimental tunnel of 50.0 m (L)×5.5 m (W)×8.2 m (H). A timber crib was used as the combustion source. The results show that the forced ventilation speed had a significant impact on the burning in the tunnel, that increasing of the forced ventilation speed reduces the temperature above the fire and in the tunnel, that increasing of the forced ventilation speed would increase the heat release rate of the fire, but does not affect the trend of the heat release rate curve, and that the volume fractions of both carbon dioxide and carbon monoxide are affected by the forced ventilation obviously.

Effects of foam on LNG vapor emission rate average value and deviation

YANG Jie, LI Yuxing, ZHU Jianlu, ZHANG Yixiang, HAN Hui

2018, 28(10): 62-66. doi:10.16265/j.cnki.issn1003-3033.2018.10.011

Asbtract ( 237 )

PDF (1492KB) ( 284 )

References | Related Articles | Metrics

To investigate the LNG vapor mitigation mechanism imposed by the high expansion foam, HYSYS analyses and experimental measurement were employed to verify the existence of the natural gas hydrate in the application of high expansion foam on LNG pool. By Taguchi analyses, the effects of foam property, LNG spill amount and foam submergence height on the vapor emission rate average value and standard deviation were examined. It is discovered that at the initial foam addition the foam properties affect the average value and standard deviation greatly, and standard deviation is greater than 0.2 kg/min, that more stable foam tends to decrease the average value and standard deviation, while the foam with higher expansion ratio tends to reduce the average value but increase the deviation, that the expansion ratio influences the deviation greater than the stability, that the vapor emission does not change monotonously with the LNG spill amount, as the foam generation ceases, the effect of the submergence height becomes greater, that at the earlier stage, the vapor emission increases with better stability and lower expansion ratio, and that the standard deviation changes monotonously with both the LNG spill amount and submergence height.

Development of non-contact automatic detector for defects in large tank bottom weld seam

ZHANG Ying, ZHANG Wei, XU Lei, WANG Bing

2018, 28(10): 67-72. doi:10.16265/j.cnki.issn1003-3033.2018.10.012

Asbtract ( 139 )

PDF (3028KB) ( 259 )

References | Related Articles | Metrics

Seeing that there was no automatic detection means for defects in large tank bottom plate weld seam, the authors devoted themselves to developing an automatic detector based on the electromagnetic acoustic detection method. As for the key detection transducer, an electromagnetic acoustic transducer for exciting oblique incident SV waves was developed. The transducer's detection capability was tested on weld seam test panels. An echo signal wavelet noise reduction method was investigated and experiments were carried out on the simulated tank bottom plate to test the detector's walking-recording ability. The results show that the transducer can accurately find the defects in the weld seam whether there is anti-corrosion paint on the test panel or not, that according to the minimaxi threshold method, the noise reduction of the echo signal can be realized by using the db4 wavelet, and that the detector can implement the non-contact inspection of the tank bottom weld seam, record and mark defects to form a test map with the defect mark, which can replace the manual detection and reduce the casualties that may be caused by the personnel entering the tank cleaning and repairing.

Sensor based information integrated safety protection system for live working

LUO Richeng, FANG Mengge, LI Zhiqian, LI Wen, ZOU Dehua, LI Zhe

2018, 28(10): 73-78. doi:10.16265/j.cnki.issn1003-3033.2018.10.013

Asbtract ( 169 )

PDF (2250KB) ( 237 )

References | Related Articles | Metrics

In order to effectively ensure the safety of workers during live working, a safety protection system for live working was worked out according to the statistics of unsafe behavior of workers. A video detection device and an ultrasonic ranging sensor are installed at appropriate positions of the tower to quickly detect the distance between the worker and the surrounding crossarm, the tower body and other charged bodies, to determine whether the safety distance is beyond the limit. The parameters of pulse, body temperature, oxygen saturation and electrocardiogram signal of the worker can be detected through the wearable device to identify and warn the safety hazards quickly during the working. And the worker is reminded by auditory way to grasp the abnormal conditions during the operation in real time. The audio and video information on the job site is transmitted to the on-site command unit and the control command center through the 4G wireless network. The results show that the live working safety protection system can avoid the occurrence of safety accidents during live working.

Evaluation model of muscular fatigue for force exertion task

HU Hong, YI Cannan, LI Kaiway, TANG Fan, ZUO Huali, CHEN Chengfeng

2018, 28(10): 79-85. doi:10.16265/j.cnki.issn1003-3033.2018.10.014

Asbtract ( 373 )

PDF (1526KB) ( 405 )

References | Related Articles | Metrics

A force (F) based evaluation model for subjective muscular fatigue was developed to explore workers' development of muscular fatigue during force exertion tasks. Firstly, pull strength and RPE for arm and waist over time period were obtained by simulated pulling tasks. Then, FD was normalized to describe the variation among participants. Secondly, the relationship between normalized FD (NFD) and RPE was analyzed by correlation analysis. Lastly, RPE regression equations (RPE-NFD regression equation) using the NFD as independent variable for arm and waist, respectively, were constructed via regression analysis. Also, the change of RPE along with time was analyzed. Results showed that RPE of arm and waist were both positive linear with NFD and that RPE regression equations were reasonable to describe the RPE-NFD relationships during force exertion tasks. Also, the constructed evaluation model of muscular fatigue for force exertion task was capable of showing the development of muscular fatigue. According to this model, RPE over time could be obtained for force exertion tasks .

DEMATEL-ISM model for analysis of risk factors in terminal area control system

ZHANG Zhaoning, LI Wenya

2018, 28(10): 86-91. doi:10.16265/j.cnki.issn1003-3033.2018.10.015

Asbtract ( 261 )

PDF (1759KB) ( 355 )

References | Related Articles | Metrics

To improve the safety management level of the air traffic control system, a process-based FMEA method was worked out for identifying the potential risk factors in the terminal area control system. A DEMATEL-ISM model was built, and the affecting degree and affected degree of each risk factor were calculate by using the decision making trial and evaluation laboratory (DEMATEL) model. The causal attribute and centrality order were determined. The ISM was used for constructing the system risk hierarchical structure presenting the attributes of causes of and hierarchical relationships between the various risk factors in the regulatory system. A terminal area control system was taken as an example to verify the effectiveness of the DEMATEL-ISM model. According to the results, the DEMATEL-ISM model can be used to classify the causal properties of risk factors into three categories in the system, respectively, six direct causes, ten transition causes and three essential causes. In addition, the constructed hierarchical structure can be used to effectively characterize the correlations between the risks in the terminal area control system, complete system analysis and provide a decision-making basis for the system's risk management.

Analysis of risks in "FPSO+CTV+ tanker" offloading operation based on functional resonance accident model

HU Jinqiu, TANG Jingjing, HU Zhongqian, WANG Honghong, WANG Yingying

2018, 28(10): 92-97. doi:10.16265/j.cnki.issn1003-3033.2018.10.016

Asbtract ( 295 )

PDF (1824KB) ( 456 )

References | Related Articles | Metrics

"FPSO +CTV + ordinary tanker" new offloading operation has a double risk of collision and leakage. Existing researches only consider the accident as an orderly occurrence of single event or superposition of potential factors. To solve this problem, FRAM was used to analyze the risks in the CTV transfer operation from the system perspective. First, the human factors, technical factors, and organizational factors having the potential to cause an accident are identified based on common performance conditions of FRAM. Then,functional performance changes were evaluated to determine the key operations and accident evolution process. Finally, prevention and control barriers against accidents were established. The results show that there are 25 kinds of risk factors and 2 key operation aspects in CTV transfer operation, and that the comprehensive quality of the operators, the berthing technology of CTV, and the communication effect between CTV and FPSO are the key factors inducing accidents.

Research on effective extraction radius based on natural gas emission law

ZHANG Mingjie, JIA Wenchao, LIANG Ximing, LI Zhe

2018, 28(10): 98-104. doi:10.16265/j.cnki.issn1003-3033.2018.10.017

Asbtract ( 163 )

PDF (1684KB) ( 251 )

References | Related Articles | Metrics

In order to determine the effective extraction radius of the boreholes through strata, a method based on the natural gas emission characteristics of boreholes was proposed. The gas flow law around boreholes was analyzed by COMSOL Multiphysics software. According to the simulation results and the theory of coalbed methane flow, a function relationship was established between gas content, gas emission and residual gas quantity in the gas natural discharge of borehole. It is proposed that the effective extraction radius under the influence of extraction negative pressure was replaced by that based on natural gas emission law of the borehole. Field measurements were carried out in Hebi No.3 Mine, No.10 Mine and Guhanshan Mine. The results show that the gas pressure is linearly distributed within the effective extraction radius, that the natural gas emission has obvious periodic characteristics under the influence of pressure relief due to creep deformation, and the effective extraction radius is up to 4m, and that the research result conforms with the reality.

Test and analysis of thermal conductivity of loose coal based on response surface method

ZHOU Xihua, TONG Yao, SONG Dongping, BAI Gang, LI Ang

2018, 28(10): 105-110. doi:10.16265/j.cnki.issn1003-3033.2018.10.018

Asbtract ( 190 )

PDF (2069KB) ( 256 )

References | Related Articles | Metrics

To explore the variation law of thermal conductivity of loose coal with its influencing factors, based on parallel hot line method and cross hot line method, thermal conductivity values of loose coal samples with different particle sizes, temperature and water content were measured by using a self-made test device. Curves of thermal conductivity with temperature and water content were fitted. By introducing the secondary response surface method, a Box-Behnken test design was made for the particle size, temperature and water content to obtain to list them in order of importance. The results show that the test device can be used to accurately measure the thermal conductivity of loose coal with a measurement error within 3.0%, and the thermal diffusivity and specific heat capacity can be obtained at the same time, that the thermal conductivity of loose coal decreases with the increase of particle size, decreases with the increase of temperature, and increases with the increase of water content, that for the importance to the first-order term of the thermal conductivity formula, there is an order of water content > particle size > temperature, and for the importance to the second-order term of the formula, there is two orders of particle size and temperature > particle size and water content > water content and temperature, and that there is interaction between particle size and temperature merely.

Study on gas drainage effect in outburst coal seam after static expansion and cracking

XIE Xionggang, ZHANG Bo, DENG Aiping, XU Shiqing

2018, 28(10): 111-117. doi:10.16265/j.cnki.issn1003-3033.2018.10.019

Asbtract ( 107 )

PDF (5018KB) ( 288 )

References | Related Articles | Metrics

In order to improve the gas permeability of outburst coal seam and solve the problem of gas drainage in low permeability outburst coal seam in China, the relationships between static expansive agent, additional stress and gas permeability were studied theoretically, and the effective stress reduction and gas permeability increase after injecting static expansive agent into the borehole of outburst coal seam were deduced. A comparison of the gas drainage effect parameter of the single hole was made between the zone of expansion and crack and the zone of regular drainage in the M3 outburst coal seam in the right of 1235 working face.The result shows that the gas drainage result is obviously improved by the static expansion and crack in the M3 outburst coal seam, the single hole drainage parameters of the expansion and crack zone is obviously better than the parameters of the drainage hole of the regular drainage zone in the right of 1235 working face, that under this test condition, in the different drilling diameter test scheme which with the same μ, the expansion crack zone increases with the drilling diameter, the single hole gas drainage parameters show an obvious rising trend, mean value of gas drainage flow is 0.104 m³/min and the mean value of gas drainage volume fraction is 63% in the Φ94 mm No.1 drainage hole in the expansion and crack zone, the expansion and crack effect of the drainage hole is the best, compared with the Φ94 mm No.6 drainage hole in the regular drainage zone, the mean values of gas drainage flow and volume fraction is improved by 39% and 15%.

Analysis of progressive rupture process in surrounding rock for a deep homogeneous and circular opening

WANG Dong, JIANG Juyu, HAN Xinping

2018, 28(10): 118-123. doi:10.16265/j.cnki.issn1003-3033.2018.10.020

Asbtract ( 151 )

PDF (1685KB) ( 225 )

References | Related Articles | Metrics

In order to study the influence of the failure mode and failure scope of surrounding rock rupture zone on the stability of the roadway. Mohr-Coulomb (M-C) yield criteria is used to study the general pattern of rupture progress in the surrounding rock of circular openings on the basis of circular hole analytic solution of stress in elasto-plastic mechanics. The concept of the sub-rupture zone in surrounding rock is proposed,the criterion for rupture of sub-rupture zone is derived, the calculation formula of the radial stress of the outer boundary in the sub-rupture zone and the calculation method of radii in the sub-rupture zone are obtained.The equality of radii of adjacent sub-rupture zones is taken as the criterion of cessation of rupturing in a rupture zone, and is the criterion upon which the solving equations of maximum radius and maximum radial stress are deduced based. The theoretical calculation is verified by the FLAC^3D numerical simulation. The results show that: the ruptureprocess in surrounding rock of homogeneous and circular openings is a dynamic process of gradual development in the mode of annuli under condition of hydrostatic pressure, the theoretical calculation coincides with the radius of the fracture zone obtained by numerical simulation, the results can provide a theoretical basis for the optimal support design of underground engineering.

Pressure pipe leakage location based on of VMD and relative entropy analysis

HAO Yongmei, QIN Ni, XING Zhixiang, LU Guirong

2018, 28(10): 124-130. doi:10.16265/j.cnki.issn1003-3033.2018.10.021

Asbtract ( 143 )

PDF (1975KB) ( 329 )

References | Related Articles | Metrics

In order to reduce pipeline leakage positioning error, so as to timely deal with pipeline leakage and prevent accidents, a pipeline leakage location method based on relative entropy analysis of VMD components was worked out. In the process of working out it, VMD was used to decompose the leakage signal into multiple components, the relative entropy analysis adaptive selection method was used to remove the non-leakage signals mixed with the pipeline leakage signal and obtain the best observation signal. Then, pipeline modal acoustic emission theory and generalized S-transformation time-frequency analysis were used to reduce the effect of the dispersion of the leak acoustic emission signal on location, and the delay and sound velocity of the leak signal were obtained accurately. Finally, the leak location was calculated by the pipeline leakage time difference positioning formula to achieve accurate positioning of the pipeline leakage. The results show that the method can realize the precise location of pipeline leakage points, and that the positioning accuracy is significantly improved compared with those by the direct mutual time-frequency analysis method and the correlation coefficient analysis method.

Influence of nanoscale pore on gas adsorption capacity of deformed coal

YAN Jiangwei, BO Zengqin, YANG Yalei

2018, 28(10): 131-136. doi:10.16265/j.cnki.issn1003-3033.2018.10.022

Asbtract ( 139 )

PDF (1596KB) ( 236 )

References | Related Articles | Metrics

In order to clarify whether tectonic coal has superior gas adsorption capacity and the relationship between nanoscale pores and adsorption capacity, mercury injection, cryogenic liquid nitrogen adsorption and high pressure isothermal adsorption experiments were carried out. Differences in pore structure and gas adsorption capacity between the Ⅳ-Ⅴ tectonic coals from different coal grades and the symbiotic primary structural coals collected from the Jiaozuo, Pingdingshan and Yongxia mining areas were compared and analyzed. The relationship between nanoscale pores and adsorption capacity was explored. Experimental results show that the nano-pores in coal are the major contributor to the specific surface area, and are the determinants of coal's ability to adsorb gas, that compared with the original structural coal symbiotic with the same layer, the nano-scale pores and specific surface area increase slightly, and the adsorption capacity increases little, and does not have super-adsorption capacity, and that the effect of structural deformation on the change of nanoscale pores is far less than that of metamorphism.

Research on a modified model for adsorption of methane on coal under temperature effect considering excess adsorption

YANG Kang, LI Bobo, REN Chonghong, LI Jianhua, XU Jiang, YUAN Mei

2018, 28(10): 137-142. doi:10.16265/j.cnki.issn1003-3033.2018.10.023

Asbtract ( 156 )

PDF (1985KB) ( 313 )

References | Related Articles | Metrics

In order to study the adsorption characteristics of coal in deep mining, isothermal adsorption of methane on coal experiments were carried out at different temperatures by using an isothermal adsorption device. Based on the theory of adsorption heat, an adsorption model considering the correction of temperature and excess adsorption(the modified L-F model) was built, and its effectiveness was verified by comparing the experimental results with the predicted by the model. The results show that the adsorption of methane on coal is a physical adsorption process, an exothermic reaction, that the adsorption heat decreases with the increase of adsorption volume, that the methane excess adsorption on coal is a none-linear function of methane pressure, that the methane adsorption volume gradually decreases with increasing temperature, and that compared with the conventional adsorption models(L and dual-site L model), the modified L-F model fits the experimental data and can better predict the methane adsorption volume on coal at different temperatures.

Analysis of UK government dilemma over safety supervision

CONG Zhiming, FAN Yunxiao, GAO Yuan

2018, 28(10): 143-148. doi:10.16265/j.cnki.issn1003-3033.2018.10.024

Asbtract ( 143 )

PDF (1876KB) ( 234 )

References | Related Articles | Metrics

In order to solve problems of over pressure on the government's safety supervision, and heavy burdens on the companies,the systematic thinking method was adopted to analyze the dilemma that occurs in the process of the UK government's safety supervision development,the system boundary and elements were determined according to the British government's safety supervision mechanism, and a systemic thinking cycle diagram was established. Certain solutions were proposed to relieve similar problems in China's government safety supervision according to the analysis presented. The results show that UK government's dilemma over safety supervision accords with the drinking poison to quench thirst system archetype, achieving good safety supervision results but leading to negative influence such as overburden on companies, damaging compensation culture and obstructing economic development, and resolving the dilemma requires modifying the safety regulation from the aspect of legislation amongs others.

Study on mechanism of emotional contagion in group based on improved epidemic model

CHEN Weiming, ZHOU Haojie, ZHANG Yiying

2018, 28(10): 149-155. doi:10.16265/j.cnki.issn1003-3033.2018.10.025

Asbtract ( 199 )

PDF (1709KB) ( 323 )

References | Related Articles | Metrics

For the sake of studying the mechanism of emotional contagion in a group and control emotional hazards under emergencies, the authors introduced a concept of contact relation according to the actual emotional characteristics, and improved emergency emotional contagion model (SOSPa-SPSOa), so an improved emotional contagion mechanism in a group was presented. Moreover, the authors discussed the situations that different emotional valences appear in a group with the actual emotional characteristics, analyzed the influence of model parameters on the process of emotional contagion by Matlab. The results indicate that an increase in the initial size of the subgroup showing negative emotions could increase the time of emotional contagion in the group, but the increase has only a marginal effect on the final state of emotional balance, that the effect of contact contagion is lower than that of the spontaneous contagion process or the spontaneous recovery process, and that increasing probability of spontaneous recovery can reduce the time of group emotional contagion, which is beneficial to controlling and regulating group emotions.

Research on basic principles and procedure for assessing urban accident disasters risk

YANG Guoliang, DUO Yingquan, WANG Rujun, WEI Lijun, WU Zongzhi

2018, 28(10): 156-161. doi:10.16265/j.cnki.issn1003-3033.2018.10.026

Asbtract ( 383 )

PDF (1576KB) ( 664 )

References | Related Articles | Metrics

Basic principles and a procedure for assessing systematically and effectively urban safety risk were established in this paper. The basic principles include a grid principle, a classification principle and an inherent risk principle. The procedure consists of 6 steps such as identification of risks in ranges of activity, identification of risks at work posts, assessment of risks in ranges of activity, assessment of risks at work posts, superposition of risks, and identification of enterprises, industries and areas having a high risk. An empirical analysis demonstrated that the principles and the procedure can be used to get urban risk management priorities right, which would promote urban safety risk dynamic management.

Study on concrete beam bridge bearing capacitycomprehensive evaluation system

LONG Guanxu, LIU Xiuping, TANG Longlong, WANG Tao, HUANG Pingming

2018, 28(10): 162-168. doi:10.16265/j.cnki.issn1003-3033.2018.10.027

Asbtract ( 134 )

PDF (2794KB) ( 265 )

References | Related Articles | Metrics

Six main factors, including average corrosion potential, chloride ion content, carbonation depth, average crack width, concrete section loss rate and concrete measured strength value were selected as the research object, the influencing factors were classified based on the fuzzy mathematics theory by non-deterministic AHP, and then the fuzzy relation matrix of each factor was established. The improved real genetic algorithm was used to determine the optimal weight of each factor to calculate the bearing capacity comprehensive reduction factor, and a comprehensive evaluation system of bearing capacity was established. Ten experimental beams with different damages were utilized to carry out destructive tests to verify the effectiveness of the comprehensive evaluation system. The results indicate that compared with the standard bearing capacity evaluation method, the reduction coefficient calculated by the comprehensive evaluation system is closer to the measured,and the results are conservative, which is more conducive to the assessment of the bearing capacity of the existing concrete beam bridges.

Research on method of evaluating greenway cycling safety risk: a case study of Wutong greenway, Shenzhen

FU Zhehong, ZHANG Zixuan, LIU Yi, ZHUANG Jiangquan, PENG Shiwei, GU Zhihui

2018, 28(10): 169-175. doi:10.16265/j.cnki.issn1003-3033.2018.10.028

Asbtract ( 197 )

PDF (3563KB) ( 259 )

References | Related Articles | Metrics

To protect the personal safety of the greenway cyclists, improve the management level of greenway, and enhance the ability to investigate and manage the hidden dangers of greenway safety risk, based on the theory of traffic safety risk assessment, a conceptual model of greenway cycling safety risk assessment was built. Corresponding methods of human, material and environmental unsafe conditions assessment and scoring system were proposed by using AHP. The questionnaire survey, observation and Geographic Information Systems (GIS) were used to evaluate the safety risk of the cyclists and cycling environment in Wutong greenway, Shenzhen. The result shows that the evaluation model and method match the recognition result of the cycling safety risk with the actual greenway condition, which reflects their great effectiveness and operability.

Evacuation crowd diversion model for road intersection

ZHENG Xiazhong, CHEN Yan, JIN Lianghai, ZHANG Ming, XIANG Leilei

2018, 28(10): 176-182. doi:10.16265/j.cnki.issn1003-3033.2018.10.029

Asbtract ( 175 )

PDF (1880KB) ( 303 )

References | Related Articles | Metrics

To reasonably formulate the rules of assignment of crowed flow at the road intersection, an evacuation crowd diversion model was built, considering the characteristics of crowd aggregation and dispersion at the intersection. Based on the crowd evacuation process, a crowed evacuation network with capacity limitation was constructed. Coupled with the posterior road real-time congestion degree and the shortest residual evacuation path length, the probability of crowed flow distribution at the intersection node was calculated, and the flow transmission in the evacuation section was analyzed to reveal the rules of crowd movement in the evacuation network. The real-time congestion degree of the road section was considered, the crowed flow evacuation speed of the road section was corrected, and the evacuation time of the evacuation network was calculated to characterize the evacuation efficiency of the crowd diversion. The emergency evacuation of people from a certain a middle school in Shanghai was taken as an example, to which the evacuation crowd diversion model and the traditional crowd evacuation model models were applied. The results show that when the evacuated crowd is diverted at the road intersection, the evacuation time decreases by 13.34%, the evacuation efficiency is higher, the spatial distribution and temporal distribution of the crowd are more balanced, and the evacuation ability of the evacuation road network is fully utilized.

Establishment mechanism and strategy on operational maintenance anagement mfor rural emergency volunteer organization

QIAN Hongwei, LI Mengjie

2018, 28(10): 183-188. doi:10.16265/j.cnki.issn1003-3033.2018.10.030

Asbtract ( 182 )

PDF (1535KB) ( 303 )

References | Related Articles | Metrics

An establishment mechanism and a strategy on operational maintenance management were studied for rural emergency volunteer organization by means of statistics and mechanism design. Through screening types of rural common disasters, mass incidents and fire incidents in rural areas were identified as the object rural emergency volunteers' organizations should focus on. An establishmented framework of rural emergency volunteer organizations were proposed, including recruitment registration mechanism, training mechanism, professional certification mechanism, and incentive mechanism. The characteristics of rural regional differences were taken into account, and operational modes and safeguard measures were studied for rural emergency volunteer organizations. The research shows that this mechanism and the operation strategy can realize the establishment and scientific operation of rural emergency volunteer organizations, so as to improve the ability of response rural emergencies.

Table of Content