交通运输工程学报

Experiment of seismic performance for steel-concrete composite box-beam

ZHOU Wang-bao, JIANG Li-zhong, LI Fang-fang, HUANG Zhi

Abstract: Four steel-concrete composite box-beams (SCCBBs) with different shear connection degrees and height-width ratios of web were experimentally studied under low-cyclic reversed loading.The seismic performances, such as failure mode, hysteretic behavior, skeleton curve, energy-dissipating capacity, ductility, and rigidity degeneration rule, were deeply studied.The influences of shear connection degree and height-width ratio of web on the seismic performance were mainly analyzed.Study result shows that according to different shear connection degrees and height-width ratios of web, there are four types of failure modes, which are local buckling failure, bending-cutting failure, compressing-bending failure, and shear failure.Load-deflection hysteretic curve and skeleton curve can be divided into three stages that are elasticity, elastoplasticity, and failure.Load-deflection hysteretic loops, with different shear connection degrees and height-width ratios of web, are plump and do not have obvious rheostriction, which shows that SCCBB has good seismic performances.Skeleton curve becomes plumper and energy-dissipating capacity becomes higher when shear connection degree increases, but the change of ductility is not obvious.Ductility becomes better and energy-dissipating capacity bocomes higher when the height-width ratio of web increases.The influences of shear connection degree and height-width ratio of web on rigidity degeneration are greater at earlier stage and less at later stage.More>

2014, 14(6): 1-9.

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Rigidity quantitative identification method of bridge based on step-forward loading

NIU Yan-wei, HAO Jing-xian, SU Ying-ping, YAMAO Toshitaka, HUANG Ping-ming

Abstract: Aiming at the rigidity identification of bridge, based on general bridge loading test, a step-forward loading method was proposed for bridge rigidity quantitative identification.Rigidity effect factor matrix was introduced, measured deflection variation matrix and calculated deflection variation matrix were established by step-forward loading and finite element model respectively, then the deviation was controlled to get convergence to identify rigidity effect factor, and related analysis flow was illustrated.Based on a project of tie-arch bridge, the identification accuracies of single zone damage and multi-zone damage of bridge were verified.Test result shows that the accuracy of bridge identification is 6.6% except the zones near arch feet.The rigidity of concrete bridge can be located and quantitatively identified based on step-forward loading method.Using polynomial fitting to correct the measured data can improve the identification accuracy, and the convergence level increases by 18%.More>

2014, 14(6): 10-16.

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Deflection calculating method of damaged concrete beams strengthened with BFRP

QIN Li-hui, LI Yan, WANG Zong-lin, AL-DULAIMI A F N

Abstract: In order to accurately calculate the deflection of damaged concrete beam strengthened with basalt fiber reinforced plastics (BFRP) and provide theoretical foundation for the design and construction of the beam, according to different reinforcement ratios, eleven test beams with different amounts of strengthened BFRP sheet and loading methods were designed.The loaddeflection curves of different test beams were obtained.Under different pre-loading programs, the changing rules of deflection of un-strengthened beams, strengthened beams with one layer and two layers of BFRP sheet were analyzed respectively.The calculation formulas of mid-span deflection of damaged concrete beam strengthened with BFRP were presented, and the calculated deflections and measured values were compared.Analysis result indicates that the deflections of damaged concrete beams strengthened with BFRP are influenced by initial load and amount of BFRP sheet layer.The deflections of strengthened beams with initial load increase by 30%-94%compared with strengthened beams without initial load, and the deflections of strengthenedbeams with two layers of BFRP sheet increase by 19%-42% compared with strengthened beams with one layer of BFRP sheet.The impact of post-strain of BFRP should be considered in deflection calculation.The average value of the maximum difference between the calculated deflection and measured value is 7.26 mm.When the initial load is small and the reinforcement ratio is high, the calculated deflection of concrete beam is closer to the measured value, and the method can be used in the engineering practice.More>

2014, 14(6): 17-26.

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Complementary ventilation modes of extralong highway tunnel

XIA Feng-yong, XIE Yong-li, WANG Ya-qiong, HU Yan-jie

Abstract: A ventilation calculation model of complementary ventilation system for highway tunnel was established, its calculation program was designed, and the operation modes of complementary ventilation system for Dabieshan Extralong Highway Tunnel were studied.Fulljet longitudinal ventilation mode, single U-type ventilation mode and double U-type ventilation mode were put forward, and their conversional control conditions were analyzed.The functions of two cross ventilation passages in the tunnel were studied.The pollutant concentrations in the operational state of the tunnel were tested and compared with the result calculated by the model.Analysis result shows that the operation modes of complementary ventilation system for Dabieshan Extralong Highway Tunnel are flexible and practical.When the traffic volume of uphill tunnel is less than 11 500 pcu·d^-1, full-jet longitudinal ventilation mode is used only.When the traffic volume is within 11 500-14 100 pcu·d^-1, single U-type ventilation mode is used only.When the traffic volume is within 14 100-18 255 pcu·d^-1, double U-type ventilation mode is used.The main function of cross ventilation passage near to the entrance of uphill tunnel is to reduce the ventilation volume and speed of uphill tunnel, while the main function of cross ventilation passage away from the entrance of uphill tunnel is to reduce the pollutant concentration of uphill tunnel.When double U-type ventilation mode is used, the ventilation volume of cross passage near the entrance of uphill tunnel reduces, which results in that the energy consumption and operating cost of ventilation system decrease.The absolute values of relative errors between the calculation result and the test result are less than 10%, so the proposed model has high precision and can be applied to the calculation of complementary ventilation.More>

2014, 14(6): 27-34.

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Numerical simulation of embankment on sloped weak ground reinforced by pile-net structure with collar beam

HUANG Bing, GENG Jian-yu, JIANG Xin, LIANG Duo-wei, QIU Yan-jun

Abstract: To investigate the working mechanism of pile-net structure with collar beam applied in the embankment on sloped weak ground, the finite element model of embankment on sloped weak ground reinforced by pile-net structure with collar beam was established.Some mechanical responses with or without reinforcement, including potential slip surface behaviors, stability safety factors, geogrid tensions, embankment top surface settlements and ground lateral displacements, were compared.The sensitivities of core design parameters, such as collar beam location type, elastic modulus and thickness, were analyzed.Study result shows that the pile-net structure with collar beam can decrease the embankment maximum settlement, differential settlement and ground lateral deformation by 88.7%, 90.3% and 96.6%, respectively, and improve the stability safety factor by 26.2%.Arranging the collar beam crossbar is beneficial toimprove the embankment stability safety and reduce the ground lateral displacement.Decreasing the elastic modulus of collar beam appropriately will not cause relatively large unfavorable effect, and too thin collar beam is not suitable.More>

2014, 14(6): 35-43.

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Evaluation method of fatigue strength for carbody of high-speed train under influence of aerodynamic loads

LU Yao-hui, FENG Zhen, CHEN Tian-li, CENG Jing, WU Ping-bo, PAN J

Abstract: The design requirements of aerodynamic loads in domestic and overseas carbody design standards were compared.The transient pressure waves of carbody sidewall were analyzed when trains passing by each other.The transient pressures were changed into the aerodynamic loads by using time integration method.Based on the code BS EN 12663-1—2010, the fatigue load conditions combined with aerodynamic loads were defined.Taking a head car of EMUs (electric multiple units) as research object, the finite element model of carbody was established.The fatigue characteristic of carbody was analyzed by using the post-processing program based on Goodman curves of carbody fatigue strength.Computation result shows that under considering aerodynamic load conditions, the high-stress amplitudes mostly appear at the door's corners and the window's corners of carbody sidewall, while the high-stress amplitudes mostly appear on underframe without considering aerodynamic loads.Under the fatigue load conditions, themaximum stress amplitude is 33.63 MPa and the fatigue strength safety factor is 2.26 at the corners, while the stress amplitudes are smaller than 10.00 MPa and the safety factors are larger than 10.00 on the underframe.The maximum Von-Mises stress of sidewall is 85.31 MPa with considering aerodynamic loads, and increases by 25.14% compared with 68.17 MPa under only considering vertical loads, so the aerodynamic loads have larger influence on sidewalls and easily result in their fatigue failure.In the carbody design of high-speed train, the fatigue strength of carbody should be evaluated by considering aerodynamic loads.More>

2014, 14(6): 44-50.

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Harmonic resonance analysis of gear transmission system for high-speed train

HUANG Guan-hua, ZHANG Wei-hua, SONG Shu-qi, ZHU Shao-cheng, LIANG Shu-lin, WANG Xing-yu

Abstract: The time-varying mesh stiffness of gear transmission system for high-speed train was calculated by using finite element method, the mesh stiffness and the transmission error were expressed by using Fourier series, the tooth backlash was fitted by using polynomial expression, and a bending-torsion coupling dynamics model of cylindrical helical gear transmission system was developed based on considering some nonlinear factors such as the time-varying mesh stiffness, the transmission error, the tooth backlash, etc.The nonlinear method of multiple scales was used to derive the harmonic resonance frequency factors of gear transmission system.The frequency response curves of gear transmission system were obtained by using numerical integration method to solve the dynamics equations of gear transmission system.The influences of static loads, dynamic loads and dampings on the harmonic resonance responses of gear transmission system were analyzed.Analysis result indicates that there are many harmonic resonance frequency factors in gear transmission system.A jumping phenomenon is found in thesuper-harmonic resonance response of gear transmission system.The double frequency vibrations are found under the harmonic excitations.The gear system has intense vibration when the meshing frequency is lower than the natural frequency.The reasonable operating speed of train should be set to avoid the harmonic resonances.More>

2014, 14(6): 51-58.

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Model-free adaptive vector control method of SSP propulsion motor for ship pod

YAO Wen-long, ZHANG Jun-dong, CHI Rong-hu, ZHANG Gui-chen, SHI Zhen-hua

Abstract: Considering the control problems of propulsion motor of ship SSP (siemens schottel propulsor) system under uncertain dynamic state, load change and sea condition disturbance, a model-free adaptive vector control method was proposed.The dynamic linearization equations of propulsion motor were derived.A model-free adaptive vector controller was designed based on the speed tracking error and its convergence was proved.The pseudo-partial-derivative was online adjusted to ensure the tracking error of propulsion motor control system uniformly bounded.The control performances of model-free adaptive vector controller and self-adjusting PI vectorcontroller were compared.Computed result shows that based on model-free adaptive vector control, the speed average oscillations are within 6 r·min^-1 and 7 r·min^-1 in rough sea and maneuverable navigation, respectively, and the torque average oscillations are 8.20×104 N·m and 1.08×105 N·m, respectively.But based on self-adjusting PI vector control, the average speed oscillations reach 13 r·min^-1 and 12 r·min^-1, respectively, and the torque average oscillations are 2.13×105 N·m and 2.81×105 N·m, respectively.Obviously, the model-free adaptive vector control system has lower speed and torque fluctuations and smaller static error of steady state operation, so its dynamic responses are better.More>

2014, 14(6): 59-66.

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Transportation status of Chinese expressway network in 2013

XIAO Run-mou, LI Bin, 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 2013 was analyzed.Analysis result shows that compared with the transportation status in 2012, passenger transportation density in expressway network in 2013 raised by 1.36%.55.65% of passenger turnover volume was produced by mini-type buses (the seat amount of every bus is less than 8), and the volume raised by 5.66%.The average speed ofⅠ-type bus raised by 1.42%, the average speed of Ⅱ-type bus raised by 0.64%, the average speed of Ⅲ-type bus raised by 2.16%, and the average speed of Ⅳ-type bus reduced by 4.47%.Freight transportation density raised by 3.22%, and 81.01% of freight turnover volume was produced by tractor-trailer combination.The percentage of empty to loaded truck kilometers was 24.15% and raised by 2.93%.According to the standard of GB 1589—2004, the percentage of trucks with the overweight more than 30% was 2.99%.In 2013, the mini-type bus passenger transportation of Chinese expressway network kept continuous high-speed growth, the freight transporation raised lightly, and the increasing speed of commercial buses (the seat amount of every bus is more than 19) passenger transportation reduced.More>

2014, 14(6): 67-73.

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Robust assignment model of airport gate based on flight delay distribution

LI Jun-hui, ZHU Jin-fu, CHEN Xin

Abstract: In order to increase the stability of airport gate assignment plan and reduce the propagation effect of flight delay, the different probability distributions of flight delay between different airline companies were set up by using the historical flight data of Guangzhou Baiyun International Airport, and the effect of flight delay distribution on the conflict probability of airport gate was analyzed.The minimum conflict probability of airport gate was taken as objective function, the types of airport gate and flight were taken as constraint conditions, the robust assignment model of airport gate was set up, the greedy tabu search algorithm was designed, and example verification was carried out by using real flight data.Calculation result shows that by using the proposed model and the greedy tabu search algorithm, the iteration times is 43 and the calculation time is 0.72 swhen the optimal solution is searched, and the total conflict probability is 2.737 1.By using the proposed model and the traditional genetic algorithm, the iteration times is 72 and the calculation time is 35.00 swhen the optimal solution is searched, and the totalconflict probability is 2.741 2.By using the exited deterministic robust assignment method with the maximum gate idle time and the proposed algorithm, the total conflict probability is 3.018 0.Compared with the exited deterministic robust assignment method, the robustness of airport gate plan raises by 9.31% by using the proposed model.More>

2014, 14(6): 74-82.

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Safety evaluation method of freeway segment based on accident data and safety service level

MENG Xiang-hai, LI Xin, ZHENG Lai

Abstract: The basic division method of freeway segment was analyzed, the unequal-length division method of dynamic clustering segment based on the concentration and dispersion degrees of accident point was put forward.The accident prediction model was calibrated based on negative binomial distribution, the safety evaluation method of freeway segment based on negative binomial distribution was proposed.The concept of safety service level was introduced, the classification standard was determined, the safety evaluation method of freeway segment based on safety service level was proposed, and the example verification was carried out.Verification result indicates that when the 109 segments of Jingzhu Freeway are evaluated by using the two methods respectively, the 57.8% of segments have the same results, the segment amounts of safety conditions in great, good, normal, poor are 5, 63, 36 and 5 respectively by using the safety evaluation method based on negative binomial distribution, while the segment amounts of safety conditions in great, good, normal, poor are 1, 64, 26 and 18 respectively by using the safety evaluation method bassed on safety service level.The evaluation result of safety evaluationmethod based on negative binomial distribution is more in line with freeway actual safety situation.The safety evaluation method based on negative binomial distribution considers traffic volume and geometric alignment, and is more suitable for the freeway with complex geometric alignment conditions.The safety evaluation method based on safety service level considers traffic volume and accident frequency, and is more suitable for the freeway with better geometric alignment conditions..More>

2014, 14(6): 83-91.

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Coordinated scheduling model of berth-truck-block at container terminal with random arrival of export containers

CHEN Chao, QIU Jian-mei, TAI Wei-li

Abstract: Aiming at the influence of the dispersion stacking of export containers with random arrival on the berth allocation, truck route and block choice of container terminal handing operation system, the different handling characteristics between the containers on deck and in cabin were analyzed.The allocating berth of ship and the stacking area of import containers were taken as decision variables, the minimum traveling distance of truck was taken as objective function, and the mixed integer programming model of coordinated scheduling for berth-truckblock under discrete berth condition was set up.Through the three levels of cross in turn, the three-level heuristic algorithm based on genetic algorithm was developed, allocation berth data were searched in the superstratum algorithm, ship data were searched in the interlayer algorithm, the stacking area data of import container were searched in the substratum algorithm, and example verification was carried out.Calculation result shows that compared with the traditional method, the optimal allocating berth of ship, the stacking area of import container and the traveling distance of truck can be confirmed by using the mixed integer programming model of coordinated scheduling for berth-truck-block under discrete berth condition, the total travelingdistance of truck reduces by 11.42%, and the efficiency of container terminal handing operation system significantly improves.So the proposed model is effective.More>

2014, 14(6): 92-99.

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Mining method of floating car data based on link travel time estimation

LI Hui-bing, YANG Xiao-guang, LUO Li-hua

Abstract: Based on floating car data, a link travel time estimation method without signal timing data was proposed.The method consisted of four modules, which were intersection boundary dynamic partition module, link influence range partition module, floating car data extraction module, and link travel time estimation module, and the implementation of each module relied greatly on the output of previous one.According to vehicle travel state under the influence of signal control, link unit was divided into different segments by using density method in intersection boundary dynamic partition module and link influence range partition module.According to link travel time estimation mechanism, floating car data that were seriously affected by signal control were filtered off in floating car data extraction module, so the target floating car data could be obtained.Historical floating car data were excavated in link travel time estimation module, and floating car data were divided into 3 types according to different exsited regions of target data.Corresponding section travel time estimation methods were used for different types of data, and corresponding section travel time estimation models were established.Link travel time estimation method was simulated and verified by using software VISSIM, and its result was compared with the results of direct and indirect methods.Analysis result indicates that for coarse-grained floating car data, the average absolute error and average relative error of link travel time estimation method are 12 sand 8.67% respectively, so it performs better than traditional direct and indirect methods.More>

2014, 14(6): 100-109.

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TOD optimal control method of urban traffic based on clustering analysis

YAO Jiao, XU Jie-qiong, HAN Yin

Abstract: To overcome the high failure rate of circular loop vehicle detector in real road, the loss historical data were mended by using moving average convergence divergence method.The historical traffic flow data were clustered by using Ward least square method.A clustering terminal condition was proposed to determine the optimal control plan number and switch time of TOD multi-schedule control based on the modified cubic clustering criterion.TOD optimal control method was simulated and verified by using signal timing optimization software Synchro.Verification result indicates that TOD optimal control method can provide more detailed TOD control plan, which can also respond the fluctuation of real traffic demand.The average decrement rate of each vehicle delay based on the optimal control method is 11.9%, in which the decrement rate in pre-morning peak period is 20.27%, and the values in evening low peak period, evening peak period and morning peak period are 12.99%, 8.07% and 6.25%, respectively.More>

2014, 14(6): 110-116.

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Distribution characteristic of AIS signal field intensity along mountainous waterway

CHU Xiu-min, LIU Tong, MA Feng, LIU Xing-long, ZHONG Ming

Abstract: Due to the shadowing effect of AIS mountains signals, there were many blind areas along mountainous waterways limiting the application of AIS.Okumura-Hata model was used to study the reliability of AIS communication system in those areas.29 test points, which were primarily served by three base stations at Bahekou, Shipai, and Xiba located along the Three Gorges Dam segment, were set.Among the 29 test points, 13 test points were in mountainous areas and 16 test points were in open areas.The actual field intensities of the 29 test points were measured and compared with theoretical field intensities.A linear regression model was used to optimize the corrected parameter of Okumura-Hata model.The correcting field intensities at the 13 test points in mountainous areas and at 9 out of 16 test points in open areas, having a distancegreater than 2.9 km from the base stations, were calculated.In order to verify the correctness of modified model, verification test was carried out for 6 test points along Chongqing—Yongchuan segment.Analysis result indicates that a distance of 3 km is a critical threshold for AIS signal transmission.When the propagation distance is less than 3 km, the AIS signal is good and the AIS field intensity curve is smooth.However, when the propagation distance is more than 3 km, the AIS signal quality reduces sharply and the curve is steep.The distribution trend of theoretical field intensity calculated by Okumura-Hata model is consistent with that of actual field intensity, but there are still gaps between the theoretical values and the actual values.In verification test, the average values of actual field intensity, theoretical field intensity, and correcting field intensity at 6 test points are-106.636, -100.982, -107.710 dBm, respectively.The average error and precision rate of calculated result of Okumura-Hata model are 5.654 dBm and 94.615% respectively, and the values of correcting model are 1.071 dBm and 98.329% respectively.More>

2014, 14(6): 117-126.

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