交通运输工程学报

Test method of SBS content in modified asphalt

WU Jian-min, ZHANG Xue-lin, CHEN Zhong-da, LIN Jie, ZHANG Hong-liang

Abstract: The performance indexes of three kinds of base asphalts modified with different SBS contents were tested, grey correlation analysis method was used, SBS content was as reference sequence, the performance indexes of modified asphalt, such as penetration, softening point, ductility, elasticity recovery and kinematic viscosity at 135 ℃, were as comparison sequence, correlation grades between SBS content and main performance indexes were calculated and sequenced.The weight of each performance index was calculated by normalizing correlation grade coefficients, the relationship between conventional performance indexes and SBS content was set up, a test method of SBS content based on multiple indexes was put forward, and the method was validated by using sample groups with known SBS contents.Analaysis result indicates that the main performance indexes with significant correlation to SBS content are softening point, elasticity recovery and kinematic viscosity at 135 ℃.The absolute deviations of SBS contents for three kinds of modified asphalts are all within 0.15%, so the method is reliable.More>

2012, 12(3): 1-8. doi: 10.19818/j.cnki.1671-1637.2012.03.001

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Deformation rule of loess highway tunnel with two lanes

CHEN Jian-xun, WANG Meng-shu, XUAN Jun-jie, QIAO Xiong

Abstract: Relying on seven single-tunnel double-lane loess tunnels at Wubu to Zizhou section in Shaanxi Province on national main trunk line GZ35 from Qingdao to Yinchuan, the constructing deformations were messured by in-situ test method, and the regression analysis of test results was carried out.Analysis result shows that in the constructing process by using bench method, the arch settlements are far bigger than the clearance convergences.The tunnel deformation of surrounding rock experiences three stages: rapid deformation stage at the initial stage of excavation, sustainable growth stage and slow increasing stage.The deformation rule of loess tunnel accords with logarithmic distribution, but the logarithmic function is divergent, so the final displacement is not predicted.The deformation of surrounding rock is slowly increasing for a long time.It is not in accordance with the actual requirements and can not guarantee the stabilities of tunnel surrounding rock and supporting structure, and construction safety when the constructing time of secondary lining is estimated by using norms.So the deformation of tunnel should be controlled by using arch settlement in the constructing process of tunnel.The constructing principle of rapid excavating, rapid supporting and rapid closing is put forward for loess tunnel.Strengthening initial supporting, adding crus-locking anchors, quick constructing side walls and timely constructing secondary lining are carried out to avoid large settlement of arch surrounding rock and to ensure the stability of tunnel structure.More>

2012, 12(3): 9-18. doi: 10.19818/j.cnki.1671-1637.2012.03.002

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Loading test and finite element analysis on convex steel box section of arch rib

WU Qing-xiong, CHEN Kang-ming, CHEN Bao-chun, NAKAMURA S Z

Abstract: The convex steel box section of arch rib for Yongjiang Bridge in East Outer Ring Road of Ningbo City was taken as object, the 1/4 scale-model loading experiment of arch rib segment was conducted by using the self-balanced loading mode of prestressed steel strand. A finite element model was built based on shell and solid elements, and nonlinear analysis was carried out. The mechanical characteristic, actual bearing capacity and local instability mechanism of convex steel box section of arch rib were studied considering initial imperfections and local buckling. Analysis result shows that the measured stress of each measurement point is close to section average stress, and measurement points can be categorized into four kinds according to the relationship between measured stress and section average stress. The stresses from experiment and finite element analysis show the same tendency and similar value. The strength reduction coefficient of convex steel box section of arch rib is 0.94-0.98. The local buckling of stiffened plate can be prevented effectively by longitudinal stiffeners and diaphragms. Segment has wave shape under ultimate load, and fails to resist applied load due to the larger out-of-plate deformation of each stiffened plate. 1 tab, 18 figs, 12 refs.More>

2012, 12(3): 19-27. doi: 10.19818/j.cnki.1671-1637.2012.03.004

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Construction risk analysis of butterfly arch continuous girder bridge with large angle V-shaped pier

WANG Li-feng, XIAO Zi-wang, ZHANG Zhen-wei, JIA Yan-min, SUN Yong

Abstract: The risk analysis problem of bridge construction was studied based on HGMFN comprehensive evaluation method, and a practical approach was proposed for V-shaped pier in construction process.The highest risk factor in V-shaped pier construction was confirmed by using AHP and grey theory, and construction plan comparison was carried out.Numerical simulation of stress state for V-shaped pier was done by using ANSYS software.Risk factor analysis was carried out on the basis of Monte Carlo theory and radial basis function artificial neural network technology.Analysis result indicates that when the simulation of structural stress state is more than two million times, the connection between V-shaped pier top and main beam has 8.5% higher failure risk than root of slant leg, which is the main structure failure risk location.HGMFN comprehensive evaluation method can analyze risk factors quantitatively, and has higher risk analysis accuracy and efficiency.More>

2012, 12(3): 28-36. doi: 10.19818/j.cnki.1671-1637.2012.03.005

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Dynamics simulation models of coupler systems for freight locomotive

WU Qing, LUO Shi-hui, WEI Chong-feng, MA Wei-hua

Abstract: The working principles of two types of coupler systems were analysed.Based on considering the friction pairs of coupler tails and real-time aligning shoulders, coupler system models were set up by using control system simulation method.Nonlinear draft gear with hysteresis characteristic was modelled by using table lookup method.DFC-E100 system and 13A/QKX-100 system were simulated in a train model consisting of two 8-axle locomotives and one simplified wagon.The theoretical calculation of carbody-stabilizing-coupler ability was performed.Calculation result indicates that the models can rationally reflect the dynamic behaviour of freight locomotive's coupler systems.The distinct angling behaviour of DFC-E100 system is only observed when buff forces are larger than a certain value, but the aligning shoulder of DFC-E100 system can effectively prevent coupler from excessive angling.The error of carbody-stabilizing-coupler ability between simulation value and field test value is 4.23%, and the error between theoretical calculation value and field test value is 10.65%.The friction pair of 13A/QKX100 system is key element in the control of coupler dynamic behaviour, and can prevent coupler from distinct angling under buff condition.More>

2012, 12(3): 37-43. doi: 10.19818/j.cnki.1671-1637.2012.03.006

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Control strategy of power performance and fuel economy for CVT vehicle on long uphill highway

YAN Guang-hui, YU Qiang, GUAN Zhi-wei, DU Feng

Abstract: The control strategy of CVT transmission ratio, the power performance and fuel economy of vehicle on long uphill highway were analyzed. Multiple work points between the best dynamic and best economical rotational speeds of engine at equal interval were selected, and the influence of transmission ratio of every working point on the power performance and the fuel economy was studied. The optimal control strategy of CVT transmission ratio under considering the two properties was found by Simulink simulation. Simulation result indicates that the acceleration response time of the optimal control strategy decreases by 1.2 s compared with the best dynamic control strategy, the fuel consumption rate of the optimal control strategy decreases by 7.9% compared with the best economical control strategy, and the acceleration curve is smooth. Therefore, the two performances of vehicle on long uphill highway can be effectively improved by using the optimal control strategy of transmission ratio. 3 tabs, 12 figs, 14 refs.More>

2012, 12(3): 44-52. doi: 10.19818/j.cnki.1671-1637.2012.03.007

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Frictional noise analysis of gas-solid interface with circular dents for high-speed train

LIN Shi-cai, WANG Jiu-gen

Abstract: Based on Prandtl boundary theory and frictional noise theory, a noise model of gas-solid interface of high-speed train was established, and the fields of pressure, rate and noise intensity were examined.The surface texture with circular dents for railway carriage was designed by mimicking eagle feather to yield micro whirl field resulting in less frictional air drag, and the influence of textural parameters on the distribution of noise intensity was studied.Simulation result demonstrates that the optimal depth-radius ratio, area ratio and topology type of surface texture can remarkably reduce frictional noise.Compared with smooth surface, the maximum reducing value of noise intensity for the surface texture with optimal depth-radius ratio is 11 dB, and the maximum reducing values of noise intensities for other optimal surface textures are 4-5 dB.More>

2012, 12(3): 53-59. doi: 10.19818/j.cnki.1671-1637.2012.03.008

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Safety analysis of railway vehicle in leakage process of air spring

GAO Hao, LUO Ren, CHI Mao-ru, DAI Huan-yun

Abstract: The leakage model of air spring with stiffness decay characteristics and the nonlinear stick-slip contact model were established.The dynamic process in loss of gas and the state of emergency after loss of gas were simulated by combining the two models with vehicle system dynamics.The stability of vehicle system with air spring failure was analyzed.The impact of air spring's sudden leakage on the dynamics performance of vehicle was simulated.The running safeties of vehicle under different times of loss of gas, different speeds and curve negotiation conditions were studied.Analysis result shows that the critical speed of vehicle system with air spring failure significantly decreases from 623 km·h^-1 to 351 km·h^-1.Because of air spring's sudden leakage, wheel-rail vertical force decreases and reduction rate of wheel load increases.The shorter the leakage process is, the greater reduction rate of wheel load is.It reaches 0.651 when the leakage time is 0.2 s.The influence of speed on reduction rate of wheel load and wheel-rail force is not obvious when vehicle speed is less than 300 km·h^-1.But, when it is greater than 300 km·h^-1, reduction rate of wheel load increases rapidly with speed increase.Leakage occuring on circular curve is most dangerous when vehicle runs, and the maximum of reduction rate of wheel load is 0.652.More>

2012, 12(3): 60-66. doi: 10.19818/j.cnki.1671-1637.2012.03.009

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Travel choice behavior based on regret theory view

XIANYU Jian-chuan, JUAN Zhi-cai, ZHU Tai-ying

Abstract: Based on random regret minimization(RRM) theory and random utility maximization(RUM) theory, RRM-MNL model and RUM-MNL model were set up to research the choice behaviors of travel modes respectively.Aiming at RRM-MNL model and RUM-MNL model, the parameters and the goodnesses of fit were compared, their difference on the evaluation of traffic management measures was analyzed through direct elasticity, and practical verification was carried out based on four travel data such as aircraft, train, coach and car during intercity travel.Analysis result shows that compared with RUM-MNL model, in RRM-MNL model, the partial compensatory decision-making behavior and compromise effect during the choice process of multi-attribute method are described better, and the choice process of travel behavior can be reflected more really.The choice probabilities of wait time, travel time and travel cost on three travel methods such as aircraft, train and coach have significant elaticities.In RRM-MNL model, the elasticities of wait time for aircraft, train and coach all are lower than those in RUM-MNL model, and reduce by 7.30%, 13.14% and 7.70% respectively.So, for the same attribute variable, while the traveler has different choice preferences, the different choice behaviors will be displayed.More>

2012, 12(3): 67-72. doi: 10.19818/j.cnki.1671-1637.2012.03.010

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Temporal-spacial characteristic of urban expressway under jam flow condition

DONG Chun-jiao, SHAO Chun-fu, MA Zhuang-lin, ZHUGE Cheng-xiang, LI Yang-yang

Abstract: Based on the auto-correlation function method of time sequence, the stationarities of time sequences for traffic flow, time occupancy and average speed were judged.Based on the G-P algorithm of chaos analysis, the non-stationary time sequence of traffic flow parameter was transformed to the stationary time sequence of traffic flow parameter.The concept of cross-correlation coefficient was introduced.Under jam flow condition, the cross-correlation coefficients of upstream section on observation section and observation section on downstream section were calculated, and K-S test were used to determine the characteristics of vehicle arrival at import and export ramps on urban expressway.Research result shows that traffic flow and time occupancy belong to non-stationary time sequence, but average speed belongs to stationary time sequence.When time lags are 2, 3 and 5 min respectively, the embedding dimension of reconstruction phase space is 4 under jam flow condition.The traffic flow parameters of observation section is not only influenced by the traffic flow parameters transmission of adjacent upstream section, but also influenced by the traffic flow parameters backtrack of adjacent downstream section.Under jam flow condition, the characteristics of vehicle arrival at import and export ramps on urban expressway are accordance with the negative binomial distribution.More>

2012, 12(3): 73-79. doi: 10.19818/j.cnki.1671-1637.2012.03.011

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Predictive method of highway freight volume based on fuzzy linear regression model

ZHAO Jian-you, ZHOU Sun-feng, CUI Xiao-juan, WANG Gao-qing

Abstract: The influence factors of highway freight volume were determined, such as GDP, population quantity, the total amount of social consuming retails and the output value of sideline products, and a predictive method of highway freight volume based on fuzzy linear regression model was set up.The highway freight hub planning in Yan'an City was taken as an example, the statistical freight volumes from 1995 to 2004 were taken as dependent variables, and the fuzzy coefficients of fuzzy linear regression model were determined.The statistical freight volumes from 2005 to 2010 were taken as verified values, and the goodness of fit for fuzzy linear regression model was analyzed.The predictive results among fuzzy linear regression model, exponential smoothing method, grey model and elastic coefficient method were compared.Analysis result shows that in the fuzzy linear regression model, the average value of t test is 0.673 07, which shows that the difference between predictive value and actual value is not significant, and the prediction effect is better.The average relative errors of four methods are 0.073 1, 0.100 3, 0.167 8, 0.232 9 respectively, so the error of predictive method is smallest.More>

2012, 12(3): 80-85. doi: 10.19818/j.cnki.1671-1637.2012.03.012

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Path optimization algorithm of dynamic scheduling for container truck

LI Guang-ru, YANG Da-ben, REN Da-wei

Abstract: From the point of integrated scheduling, the dynamic scheduling method of whole terminal operating field was analyzed, and a new adaptive ant colony optimization of dynamic scheduling for container truck was put out.The GPRS system of terminal was used, and the perception chain was set up by using related data such as the speed, flow and position of container truck.Through judging obstruction status and adjusting feasible point set, the calculation methods of updating strategy and transition probability for pheromone concentration were determined.Aiming at the complexity of terminal road network and the real-time calculation efficiency of ant colony optimization, the steps of ant colony optimization were designed.The information entropy was introduced into ant colony optimization, the MATLAB software was used, and the simulation calculation of dynamic scheduling method for container truck was carried out.Simulation result shows that when the initial speeds of container trucks are 50, 75 km·h^-1 respectively and the initial flows of container trucks are 800, 1 000 veh·h^-1 respectively, the shortest driving path of container truck is 4.3 km, and the driving time is 0.057 h.The optimal driving path of container truck is 8.3 km, and the driving time is 0.111 h.By using the proposed algorithm, the obstruction problem of terminal can be remitted effectively, and the utilization ratio of container truck and the operating efficiency of terminal can increase obviously.More>

2012, 12(3): 86-91. doi: 10.19818/j.cnki.1671-1637.2012.03.013

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Integrated scheduling model of mixed cross-operation for container terminal

CHEN Chao, ZHANG Zhe, CENG Qing-cheng

Abstract: Aiming at the relations among several links such as berth distribution, loading operation and unloading operation and horizontal handling in the import and export operation system of container terminal, the effect of existed import and export operation system on the production efficiency and operation cost of container terminal was analyzed.By using optimization theory of system engineering, the integrated scheduling method of mixed cross-operation and synchronous optimization technology were put forward.The berth distribution, equipment configuration and the driving path of container truck were taken as decision variables, the minimum operation cost of container terminal was taken as objective function, 3-stage integrated scheduling optimization model was established, and the hierarchic genetic algorithm was designed to solve the model.In the hierarchic genetic algorithm, the upper layer genetic algorithm was used to search for the reasonable configuration combinations of facilities and equipments for container terminal, and the lower layer genetic algorithm was used to optimize the driving path of container truck based on the upper layer genetic algorithm.Calculation result indicates that compared with the independent loading and unloading operation process, by using integrated scheduling model of mixed cross-operation, container truck number is 22, and reduces by 66.2%.The total driving distance of container trucks is 10 389.8 km, and decreases by 17.4%.Compared with the single scheduling system, by using integrated scheduling model of mixed cross-operation, the total driving distance of container trucks decreases by 14.5%.The total operation cost of container terminal is 84 266.2 yuan, and reduces by 4.6%.It is clear that by using the integrated scheduling model of mixed cross-operation for container terminal, the production efficiency of container terminal can increase significantly, and the operation cost of container terminal can reduce obviously.More>

2012, 12(3): 92-100. doi: 10.19818/j.cnki.1671-1637.2012.03.014

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RLRM control method of single entrance ramp for highway

WANG Xing-ju, GAO Gui-feng, MIYAGI T

Abstract: In order to relieve freeway traffic congestion, reinforcement learning ramp metering(RLRM) control method for single entrance ramp of highway under the incomplete information was proposed based on the artificial intelligence theories of reinforcement learning.Average speeds, average densities, traffic outflows and travel times of numerical cases 1-6 were calculated, and the control effect of RLRM was compared with no control and fixed-time control.Simulation result shows that in case 1 with the lowest traffic inflow, the congestion relief rates of fixed-time control and RLRM control depending on travel time are-6.25% and-9.38% respectively, which indicates that the control effect is not significant.When the traffic inflow increases in case 3, the congestion relief rates of fixed-time control and RLRM control depending on travel time are-8.19% and 3.51% respectively, which indicates that the control has some effect, and RLRM control performs better than fixed-time control.In case 6 with the highest traffic inflow, the congestion relief rates of fixed-time control are 8.20%, 0.39%, 18.97% and 23.99% respectively, and those of RLRM control are 18.18%, 3.42%, 30.65% and 44.41% taking average speed, average density, traffic outflow and travel time as evaluating indexes respectively, which shows that RLRM control effect is more significant than fixed-time control.So the greater the traffic inflow is, the better the control effect of RLRM is.More>

2012, 12(3): 101-107. doi: 10.19818/j.cnki.1671-1637.2012.03.015

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Coordinated control model of regional traffic signals

LIU Qin, XU Jian-min

Abstract: In order to improve the traffic efficiency of traffic area, a coordinated control model of regional signals was constructed under all kinds of traffic conditions.The total queue vehicle number and the total output vehicle number of regional intersection were used as performance indexes of the model.The constraint conditions of the model were established by considering the variable relationship of the adjacent cycle queue vehicle numbers, closed phase difference of intersections and effective green time.The effective green time and waiting vehicle number were initialized by particle swarm algorithm.The effective green time was solved by simulated annealing algorithm.The road network of a certain intersection was simulated under different traffic states.Simulation result shows that the queue vehicle number reduces by 5.3% and the total output vehicle number of region increases by 5.5% in low peak period compared with the TRANSYT model.The queue vehicle number reduces by 17.9% and the total output vehicle number of region increases by 33.4% in peak period compared with the TRANSYT model.The signal optimizing scheme of a regional intersection shows that the lane saturations averagely reduce by 1.8% and the queue vehicle number averagely decrease by 2.9% comparing with the TRANSYT model.It's proved that the model is effective in all kinds of traffic conditions, especially in peak period, its control effect is better than the TRANSYT model.More>

2012, 12(3): 108-112. doi: 10.19818/j.cnki.1671-1637.2012.03.016

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Compression method of traffic flow data based on compressed sensing

LI Qing-quan, ZHOU Yao, LE Yang, YE Jia-an

Abstract: In order to obtain transformation matrix accurately, a new compression method of traffic flow data based on compressed sensing was introduced.The original data were projected into the low-dimension space directly by Gauss projection regardless of transformation matrix selection at the data compression side.Firstly, traffic flow data were proved to have sparse representation under the K-SVD trained dictionary.Secondly, original high-dimension data were projected into low-dimension space at the data compression side by using the random matrix with restricted isometry property, which made efficient and rapid data compression possible.Finally, after data transmission, data decompression were accomplished by convex algorithm at the data processing side.The traffic flow data obtained from the coil sensors located on a certain highway of America were used to validated the new method.The experimental result shows that the data compression method is fast and efficient.When the compression ratio is 4∶1, the relative error of data decompression is only 0.060 8.More>

2012, 12(3): 113-119. doi: 10.19818/j.cnki.1671-1637.2012.03.017

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Quantitative method of traffic conflict severity at intersection

LIU Miao-miao, LU Guang-quan, WANG Yun-peng, TIAN Da-xin

Abstract: In order to improve the precision in traffic conflict severity discrimination, a quantitative method for conflict severity at intersection was proposed based on the circle assumption of motor units and video detection technology.The moving parameters of motor units were obtained by using the video processing program and the real-time collected video images.Conflict detection and conflict time were determined by using iterative method.Considering the braking performance of vehicle, the critical value of conflict severity was obtained by the ratio of braking distance to instantaneous speed.The quantization value of conflict severity was established taking conflict time and critical value as parameters, and the severity of traffic conflict was quantified and classified.A certain intersection in Beijing was analyzed.Analysis result shows that the quantization values of conflict severity between two motor units increase from 1.32 to 2.45, and then decrease until no conflict exists.Driver would take emergency braking measures with the increasing of conflict severity, and then the conflict severity decreases until disappears.The quantitative result accords with the practical situation, and the method could be used in conflict detection and the severity quantification of traffic conflict conveniently.More>

2012, 12(3): 120-126. doi: 10.19818/j.cnki.1671-1637.2012.03.018

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2012 Vol. 12, No. 3

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