交通运输工程学报

Image analysis of aggregate, mastic and air void phases for asphalt mixture

ADHIKARI Sanjeev, YOU Zhan-ping, HAO Pei-wen, Pei-wen Hai-nian

Abstract: The shape characterization and spatial distribution of aggregate, mastic and air void phases for asphalt mixture were analyzed. Three air void percentage asphalt mixtures, 4%, 7% and 8%, respectively, were cut into cross sections and polished. X-ray scanning microscope was used to capture aggregate, mastic, air void phase by the image. The average of polygon diameter was chosen as a threshold to determine which aggregates would be retained on a given sieve. The aggregate morphological image from scanned image was utilized by digital image processing method to calculate the gradation of aggregate and simulate the real gradation. Analysis result shows that the air void of asphalt mixture has influence on the correlation between calculation gradation and actual gradation. When comparing 4.75 mm sieve size of 4%, 7% and 8% air void asphalt mixtures, 7% air void asphalt mixture has 55% higher than actual size gradation, 8% air void asphalt mixture has 8% higher than actual size gradation, and 4% air void asphalt mixture has 3.71% lower than actual size gradation. 4% air void asphalt mixture has the best correlation between calculation gradation and actual gradation comparing to other specimens. The air void percentage of asphalt mixture has no obvious influence on the air void orientation, and three asphalt mixtures show the similar air orientation along the same direction.More>

2013, 13(2): 1-9. doi: 10.19818/j.cnki.1671-1637.2013.02.001

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DSC modelling for predicting resilient modulus of crushed rock base as a road base material for Western Australia roads

KHOBKLANG Pakdee, VIMONSATIT Vanissorn, JITSANGIAM Peerapong, NIKRAZ Hamid

Abstract: In order to increase the applied efficiency of crushed rock base(CRB) in pavement structure design for Western Australia roads, the material modelling based on the experimental results was investigated, and the disturbed state concept(DSC) was used to predict the resilient modulus of CRB because of its simplicity and strong ability in capturing the elastic and inelastic responses of materials to loads. The actual deformation of DSC, at any loading state, was determined from its assumed relative intact(RI) state. The DSC equation of CRB was constructed by using a set of experimental results of resilient modulus tests, and an idealized material model, namely the linear elastic model, of relative intact(RI) part was considered. Analysis results reveal that the resilient modulus-applied stress relationships back-predicted by using the DSC modelling are consistent with the experimental results, so, the DSC equation is suited for predicting the resilient modulus of CRB specimen. However, the model and the equation coming from the test results are conducted in accordance with the Austroads standard, so further investigation and validation with respect to the field behaviours of pavement structure should be performed.More>

2013, 13(2): 10-16. doi: 10.19818/j.cnki.1671-1637.2013.02.002

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Pavement performance analysis of asphalts modified by different types of tourmalines

SHI Xin, WANG Chao-hui, LI Yan-wei, ZHAO Juan-juan, WANG Xuan-cang

Abstract: Two kinds of tourmaline powders and four kinds of tourmaline anion powders were selected to modify asphalt, and the tourmaline modified asphalt was prepared by using a melting-blending method. The penetration, softening point and ductility were tested, and the effect laws of tourmaline types and mixing amount on asphalt temperature sensitivity, high-temperature and low-temperature properties, adhesion property were studied. The effect of tourmaline on asphalt low-temperature property was studied by using improved bending beam rheometer(BBR) test, and the adhesion property between tourmaline modified asphalt and aggregate was evaluated by using water-boiling method. The improved mechanism of tourmaline on asphalt pavement performance was analyzed by using scanning electron microscope(SEM) test, differential scanning calorimetry(DSC) test, piezoelectric test and thermoelectric test. Analysis result shows that the temperature sensitivity of tourmaline powder modified asphalt improves firstly and then reduces with the increase of mixing amount, and that of tourmaline anion powder modified asphalt shows an opposite law. The high-temperature performances of all tourmaline modified asphalts improve with the increase of mixing amount. The pavement performance of tourmaline powder modified asphalt improves significantly with the increase of tourmaline powder mesh, that of tourmaline anion powder modified asphalt reduces unceasingly with the increase of anion release amount.In the same mesh, the effect of tourmaline anion powder on asphalt pavement performance is better than that of tourmaline powder. Tourmaline can well improve the low-temperature property of tourmaline modified asphalt. Tourmaline can disperse in asphalt uniformly and stably, and can form a stable whole. The electric property of tourmaline can be played fully when tourmaline is added into asphalt.So tourmaline can improve the road performance of asphalt significantly.More>

2013, 13(2): 17-24. doi: 10.19818/j.cnki.1671-1637.2013.02.003

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Application of con-aid soil stabilizer in expedient airfield pavement

SHI Bao-hua, NING Wen-pu, XU Wei, DAI Sheng-rui

Abstract: Based on the characteristics and construction requirement of expedient airfield, the indoor tests of liquid limit, plastic limit, compaction, resilient modulus, CBR and unconfined compressive strength were designed for Jining soil. The outdoor test roads were constructed with con-aid soil stabilizer, cement, lime and cement-lime, the field tests of resilient modulus, CBR, deflection, soil pressure and rolling friction factor were done, the reinforcement effects of con-aid soil stabilizer and traditional inorganic binder were compared. Analysis result shows that the physical properties of water, resilient modulus and unconfined compressive strength greatly increase after adding con-aid soil stabilizer in Jining soil. After adding the AC101 stabilizer about 0.8%, plasticity index reduces by 21.9%, the optimum water content decreases by 3.1%, the maximum dry density and CBR value increase by 1.32%, 61.5% respectievly. After adding HOD1 stabilizer, CBR values increase by 212% with the flooding of test specimen and by 146% without the flooding of test specimen respectievly. In field tests, the bearing capacity of con-aid soil stabilizer reinforced soil is similar to cement reinforced soil and cement-lime reinforced soil, and is higher than lime reinforced soil during early period, but the growth rates of bearing capacities for cement reinforced soil and cement-lime reinforced soil are greater than con-aid soil stabilizer reinforced soil with the increase of age, the bearing capacity of con-aid soil stabilizer reinforced soil is similar to lime reinforced soil at 28 d.More>

2013, 13(2): 25-33. doi: 10.19818/j.cnki.1671-1637.2013.02.004

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Deformation rule and mechanical characteristic of tunnel in water-rich full-weathering granite area

REN Wen-feng, GAO Xuan, WANG Xing-hua, TU Peng

Abstract: Undisturbed soil was drilled for soil test by using geological drilling rig above the tunnel center line. The settlements of tunnel surface and vault were measured by using electronic level. Tunnel horizontal convergence values were measured with JSS30A digital convergence instrument. Pressures among surrounding rock and initial support, initial support and secondary lining were measured with JTM-V2000D vibrating wire pressure gauge. The surrounding rock deformation and pressure of Zhaizigang Tunnel were measured, the surrounding rock deformation rule and mechanical characteristic of tunnel in water-rich full-weathering granite area were got. Analysis result shows that the dividing line of deep and shallow submersion tunnels is 2 times tunnel diameter. Vertical displacement and horizontal displacement appear simultaneously in tunnel entrance. The horizontal convergence stability time of surrounding rock and settlement stability time of vault have little relationship with tunnel depth. The horizontal convergence value and vault settlement increase with the increase of shallow submersion tunnel depth, but they have little relationship with the depth of deep submersion tunnel. Pressures are evenly distributed between surrounding rock and initial support, pressure difference among measurement points of shallow submersion tunnel is little, pressure gradually increases with the increase of tunnel depth. The uneven degree of pressure distribution increases for deep submersion tunnel, pressure value changes very little with the increase of tunnel depth. The pressure between surrounding rock and initial support is greater than that between initial support and secondary lining, the maximum pressure between initial support and secondary lining is not greater than 100 kPa.More>

2013, 13(2): 34-41. doi: 10.19818/j.cnki.1671-1637.2013.02.005

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Simulation model of air braking system for subway train

ZUO Jian-yong, WANG Zong-ming, WU Meng-ling

Abstract: The structure and operating principle of air braking system for subway train were introduced. The modelling methods of three basic types of pneumatic components including capacitive, resistive and inductive unit were explained. The simulation model of air braking system was built based on the similarity principle and the AMESim.The models and simulation parameters of load valve, EP unit and relay valve were analyzed. The characteristics of brake cylinder and Cv pressures were discussed under service brake, emergency brake and phased brake, and the result was verified by test bench. Analysis result shows that Cv pressure response is faster than the pressure response of brake cylinder in service and emergency brake, the maximum delay is no more than 0.5 s, and the stabilities of both pressures are equal. It takes less than 1.5 s when brake cylinder pressure rises to the constant pressure in emergency brake, and the value is less than 2.2 s in service brake. Regarding phased brake, brake cylinder pressure and Cv pressure follow better. In test, stabile Cv pressure is about 15 kPa higher than brake cylinder pressure because of the damping effect of internal rubber parts of relay valve, but the error does not affect the normal use of relay valve.More>

2013, 13(2): 42-47. doi: 10.19818/j.cnki.1671-1637.2013.02.006

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Design of shear stiffness of wheelsets radial device for K7 bogie

ZHOU Zhang-yi, LI Fei, LI Heng-li, PAN Shu-ping, HUANG Yun-hua

Abstract: Through analyzing the stress and stiffness series parallel relations of correlative structures, the geometry and stiffness parameters determining the shear stiffness of wheelsets radial device for K7 sub-frame self-steering radial bogie were defined, and the mathematic calculating formula for the shear stiffness of wheelsets radial device was established. Based on vehicle system dynamics analysis technology, the required shear stiffness of wheelsets radial device was determined as 11 MN·m^-1. Considering the practical constrained conditions of bogie structures, the matching design of geometry and stiffness parameters for the components of wheelsets radial device was carried out. First of all, the diagonal brace angle and axial tension-compression stiffness of link bar were respectively determined as 42° and 150 MN·m^-1. Further, the required structural transverse stiffness of sub-frame, deduced by the mathematic calculating formula of shear stiffness, should not be below 23.6 MN·m^-1. Then, aiming at the requirement of the parameters, the corresponding structural design of sub-frame was carried out. Considering the contact fitting relations among different components, the high-precise nonlinear FE assembly analysis model of wheelsets radial device was established. Calculation result shows that the final structural transverse stiffness is 24 MN·m^-1, so the design requirement for the shear stiffness of wheelsets radial device is achieved. The calculated shear stiffness is 11 MN·m^-1 and equals to the required design value, so the reliability of mathematic calculating formula and design method for the shear stiffness is verified.More>

2013, 13(2): 48-53. doi: 10.19818/j.cnki.1671-1637.2013.02.007

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Influences of air spring models on dynamics performance of railway vehicle

WU Xing-wen, CHI Mao-ru, ZHU Min-hao, CENG Jing, YANG Fei

Abstract: The equivalent model, linear model and nonlinear model of air spring were established, and the influences of three models on the ride comfort of straight track and the safety of curve track were studied. Analysis result shows that the accuracy of equivalent model is smaller for the calculation of ride comfort of straight track, but the linear model and the nonlinear model can provide better accuracy. The linear model is simpler than the nonlinear model, therefore, the linear model is suggested to be adapted for the calculation of ride comfort of straight track. Since the nonlinear model of air spring can reflect the dynamic performance of air spring and provide better accuracy compared with the linear model and the equivalent model, therefore, the nonlinear model is recommended to be used in the safety calculation of curve negotiation.More>

2013, 13(2): 54-59. doi: 10.19818/j.cnki.1671-1637.2013.02.008

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Design of regenerative braking energy feedback system for ultracapacitor heavy-duty tractor

LIU Xi-bin, MA Jian, HAO Ru-ru, SONG Qing-song

Abstract: In view of regenerative braking energy feedback problem for electric vehicle(EV), based on the SX4186EV prototype of ultracapacitor pure-electric heavy-duty tractor of Shaanxi Automobile Group Co., Ltd., a hybrid braking system was proposed. the system was made up of two independent subsystems, including energy recovery braking subsystem and double-loop air braking subsystem. Based on braking intensity and real load, a rule-based braking force allocation strategy for the subsystems was put forward. A road experiment under the actual running condition at Shanghai Dock was carried out to test the braking energy recovery efficiency of the system. Experimental result shows that the braking energy recovery efficiencies under full-loaded running condition and unloaded running condition are 14.534% and 55.617% respectively, and the average is 35.076%. The efficiencies of electric vehicles powered with lead-acid and lithium batteries are usually about 10%, so the ultracapacitor heavy-duty tractor has higher braking energy recovery efficiency.More>

2013, 13(2): 60-65. doi: 10.19818/j.cnki.1671-1637.2013.02.009

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Calculation method of running distance for aircraft takeoff on plateau airport

CAI Liang-cai, WANG Hai-fu, ZHU Zhan-qing, ZHONG Xiao-lei

Abstract: Aiming at the complicated environment of plateau airport and the characteristic of significant decline for aircraft engine performance, the running process of aircraft takeoff on plateau airport was analyzed. The practical pressure of airport was transformed into standard atmosphere pressure, the running distances under different times were calculated by using the correctional instantaneous thrust of aircraft engine, and the calculation method of running distance for aircraft takeoff on plateau airport was put out. The influences of altitude, takeoff mass, temperature and wind speed on the running distances of aircraft takeoff were analyzed, the simplification formula of running distance was put forward, and example verification was carried out. Analysis result shows that when altitude is 3 569.5 m, temperature is 16.4 ℃ and upwind speed is 2.1 m·s^-1, the maximum absolute error between the running distance calculated by the proposed method and test running distance for aircraft Ⅰ is no more than 48 m, and the maximum relative error is no more than 2.7%. The maximum absolute error between the running distance calculated by the proposed method and test running distance for aircraft Ⅱ is no more than 100 m, and the maximum relative error is no more than 4.2%, The maximum relative errors between the running distances calculated by simplification formula and test running distances for aircraft Ⅰ and aircraft Ⅱ are 3.9% and 2.8% respectively, which meet the engineering requirement.More>

2013, 13(2): 66-72. doi: 10.19818/j.cnki.1671-1637.2013.02.010

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Transportation status of Chinese expressway network in 2011

LI Bin, XIAO Run-mou, CHEN Yin-san

Abstract: Based on the database of expressway network toll system and the typical sampling investigation data at toll stations, the transportation status of Chinese expressway network in 2011 was analyzed. Analysis result shows that compared with the transportation status in 2010, passenger transportation density in expressway network in 2011 rose by 4.09%. 47.10% of passenger turnover volume was produced by mini-type buses(the seat amount of every bus is less than 8), and the volume rose by 2.01%. The average speed of Ⅰ-type bus reduced by 1.97%, the average speed of Ⅱ-type bus rose by 2.07%, the average speed of Ⅲ-type bus reduced by 0.84%, and the average speed of Ⅳ-type bus reduced by 0.35%. Freight transportation density reduced by 1.01%, and 82.31% of freight turnover volume was produced by tractor-trailer combination. The percentage of empty to loaded truck kilometers was 22.24% and rose by 2.19%. According to the standard of GB 1589—2004, the percentage of trucks with the overweight more than 30% was 3.92%. In 2011, the passenger transportation of Chinese expressway network kept continuous high-speed growth, however, the increasing speed of freight transportation reduced.More>

2013, 13(2): 73-79. doi: 10.19818/j.cnki.1671-1637.2013.02.011

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Division method of node level for highway network

LAO Chao-hui, WU Qun-qi, WANG Fang

Abstract: Aiming at the division problem of node level for highway network, the effective population number, effective per capita income, effective transportation demand and highway capacity were taken as the influence factors of node level division for highway network based on transportation demand theory. The gray theory was used, the clustering coefficient was calculated, a new division method of node level for highway network was set up, and example verification was carried out by using 17 highway network nodes in Shandong Province.Analysis result indicates that by using the proposed method, the 17 highway network nodes can be devided into 3 gray class levels according to the importance degrees. The first gray class level is constituted by the key nodes of highway network, including Jinan, Qingdao, Yantai, Weifang, Jining, Linyi, Dezhou and Heze. The second gray class level is constituted by the important nodes of highway network, including Zibo, Tai'an, Liaocheng and Binzhou. The third gray class level includes the general nodes of highway network, such as Zaozhuang, Dongying, Weihai, Rizhao and Laiwu. Compared with the existing division result, the division result by using the proposed method is more excellent, and is accord with the actual situation in Shandong Province.More>

2013, 13(2): 80-85. doi: 10.19818/j.cnki.1671-1637.2013.02.012

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Calculation method of anti-glare plate height on concave vertical curve section

WU Yan, WANG Jian-jun, CAO Guang-bin, LIANG Guo-hua

Abstract: The relationships among glare, driver sight and anti-glare plate height on straight section and concave vertical curve section were analyzed. The parameters such as the radius of concave vertical curve section, car headlamp height, driver sight height, cross-section structure and medial divider width were considered, and the calculation method of anti-glare plate height on concave vertical curve section was put out. The design height of anti-glare plate on Jinghua Expressway was taken as a case, the example verification was carried out, and the calculation results of the proposed method and Guidelines for Design of Highway Safety Facilities(JTG/T D81—2006) were compared.Research result shows that when the lamp distance of car headlamp is 120 m and the radius of concave vertical curve section is 12 000-32 000 m, the design height of anti-glare plate is 1.712 m by using the existing specification.By using the proposed method, the minimum design height of anti-glare plate is 1.720 m and the maximum design height of anti-glare plate is 1.800 m.More>

2013, 13(2): 86-91. doi: 10.19818/j.cnki.1671-1637.2013.02.013

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Car ownership prediction method based on principal component analysis and hidden Markov model

SUN Lu, YU Ye, GU Wen-jun

Abstract: The usual prediction methods of car ownership were analyzed, a new car ownership prediction method based on principal component analysis(PCA) and hidden Markov model(HMM) was put out. The 11 indexes including gross national income, per capita GDP, total population number, urbanization rate, total fixed asset investment, gross import and export, urban resident disposable income, steel output, highway passenger transport volume, highway freight transport volume, total retail sales of consumer goods were taken as the main influence factors of car ownership, and PCA was used to extract the principal components of main influence factors. The principal component and car ownership were taken as independent variable and dependent variable respectively, and the regression analysis model was set up. The annual growth rates of regression prediction values for car ownership were taken as hidden state, the relative errors between regression prediction values and actual values were taken as visible signal, the hidden Markov model was built, and the regression prediction values of car ownership were modified.Analysis result shows that based on car ownerships and the historical data of main influence factors in 1994-2008, the numbers of modified car ownership in 2009 and 2010 are 6.220 96×10⁷ and 7.825 12×10⁷ by using the proposed method.Compared with the actual values of car ownership in 2009 and 2010, relative errors are-0.95% and 0.30% respectively. So car ownership prediction method based on PCA and HMM has a high prediction accuracy and is suitable for short-term prediction.More>

2013, 13(2): 92-98. doi: 10.19818/j.cnki.1671-1637.2013.02.014

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Loose navigation state algorithm of INS two-point calibration in horizontal damping state

XIA Wei-xing, YANG Xiao-dong, SHI Wen-ming, WANG Wang

Abstract: In order to satisfy high-accuracy navigation and improve comprehensive calibration accuracy, a INS two-point calibration loose navigation state algorithm in horizontal damping state was designed by using extended state observer(ESO).The principle of traditional two-point calibration, navigation state constraint and its shortage were analyzed.The platform horizontal misalignment angles of inertial navigation system were real-timely estimated by using ESO, and traditional two-point calibration was introduced.The algorithm was simulated and numerically verified.Verification result indicates that the estimation result of traditional two-point calibration considerably reduces and even diverges when navigation state constraint can not be satisfied, neverthelessly, loose navigation state algorithm has a stronger applicability not only to reduce restrictive navigation state, but also to improve comprehensive calibration accuracy.Gyro drifts for east, north and position in experiment 1 reduce from 33.5%, 51.2%, 17.9% to 8.0%, 1.8%, 3.1% respectively, and in experiment 2, the drifts reduce from 83.7%, 39.7%, 77.5% to 2.3%, 0.3%, 1.0% respectively.More>

2013, 13(2): 99-105. doi: 10.19818/j.cnki.1671-1637.2013.02.015

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Traffic signal coordinated optimization of urban arterial road based on Petri net

MOU Hai-bo, YU Jian-ning, LIU Lin-zhong

Abstract: To study the traffic signal coordinated optimization of urban arterial road, a timed Petri net model with a traffic signal display module and a signal phase transition module, and a traffic flow model based on continuous Petri net with variable speeds were established.A traffic signal control system composed of 3 subsystems for monitoring, discriminating and current phase selecting was designed, and concrete control steps were presented. Considering the relationship of parameters in continuous Petri net, next green phase was determined by taking vehicle queue length, traffic flow velocity at upstream section and open degree at downstream section as input variables, and phase priority indexes as output variables.The superior green time of current phase was determined by using fuzzy Petri net, and a simulation calculation was carried out. Simulation result indicates that by combining Petri net with fuzzy control, travel times respectively shorten by 7.1% and 7.6% for west-to-east and east-to-west traffic flow, and the improvement rates of queue length at intersection are 11.9% and 11.2% respectively. The average delays of four phases at intersection decrease from 9.7, 10.3, 11.8, 13.2 s to 8.2, 9.1, 11.4, 11.4 s respectively. So, traffic signal coordinated control on urban arterial road is better realized by using traffic signal coordinated optimization method.More>

2013, 13(2): 106-113. doi: 10.19818/j.cnki.1671-1637.2013.02.016

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Short-term prediction method of freeway traffic flow

XU Yan-yan, ZHAI Xi, KONG Qing-jie, LIU Yun-cai

Abstract: According to the complexity and nonlinearity characteristics of short-term traffic flow, the application of classification and regression tree model in freeway traffic volume prediction was investigated, and its including growing, splitting and pruning of the model was studied.The real traffic volume data of the freeways in Portland State of US was tested and verified.Afterwards, the experimental result of model was compared with the traditional ARIMA model and Kalman filtering model by using the error analysis methods of RMSE and MAPE.Comparison result indicates that the RMSEs of tree model are 42.1% and 13.1% lower than ARIMA model and Kalman filtering model, respectively.More>

2013, 13(2): 114-119. doi: 10.19818/j.cnki.1671-1637.2013.02.017

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Quality evaluation and control method of vehicle detector data on urban expressway

LI Qi, JIANG Gui-yan

Abstract: In order to improve the accuracy of vehicle detector data, a quality evaluation and control method of vehicle detector data on urban expressway was proposed.A data quality evaluation and control process was proposed by comprehensive considering a single location and the law of flow conservation. A data quality evaluation method based on flow cumulative curves was proposed by analyzing the characteristics of the flow cumulative curves of upstream and downstream detected sections. With the objective function that the square sum of the difference between the adjusted and the observed flow cumulative value of vehicles for all detected sections in the road network was minimum, and with the restriction condition of the characteristics of flow cumulative curves, a data quality control method based on the optimization techniques was proposed.The evaluation and control method was verified and compared by using the data collected from inductive loop detectors on a megacity urban expressway. Verified result indicates that when the introduced errors are 0.025, 0.050, 0.075, and 0.100, the mean absolute percentage errors computed by the method are 2.40%, 3.83%, 5.70% and 8.26% respectively, and its accuracy is more than 97%, so the method has better precision than comparison methods.More>

2013, 13(2): 120-126. doi: 10.19818/j.cnki.1671-1637.2013.02.018

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