2003 Vol. 3, No. 3

Display Method:
Gradation scope of Superpave
XU Zhi-hong, CHEN Xing-wei, LIU Hong, LI Shu-ming
Abstract: Based on the maximal density graph theory, Marshall experiments were done with crushed stone when the values of n equal to 0.35, 0.40, 0.45, 0.50 and 0.55. The values of n were ascertained when the asphalt mix density was maximal.After a series of calculation and taking the Superpave's regulations about restricted zone and control points and the wave range of each sieve in engineering experience into account, the gradation scopes of super-layer, mid-layer and under- layer were put forward. The mix manufactured within these gradation scopes is proved having scarf joint-compact state to both reduce penetration, and have good anti-rutting performance by engineering experience and Bailey's method.More>
2003, 3(3): 1-6.
Road performance of SMA mixture with PAN fiber composite
NI Fu-jian, GUO Yong-mei, CENG Lan-ying, ZHAN Qian, SHEN Heng
Abstract: This paper studied the influence of PAN fiber composite and the imported xylon fiber on stone mastic asphalt(SMA) by performance tests of asphalt mixture. It is pointed that after adding PAN fiber composite the dynamical stability of SMA is markedly increased, the total deformation is markedly reduced, the flexural failure strain in low temperature is increased, and unconfined compressive strength is increased by 30%. What is more, whether the percentage of PAN fiber composite is 0.2% or 0.3%, the performance of SMA is stable. The results show that PAN fiber composite has better road performance.More>
2003, 3(3): 7-11.
Permeability of asphalt pavement at expressway
GAO Ying, CAO Rong-ji, LIU Chao-hui, ZHANG Qing-yun
Abstract: Permeability test was done at three expressways in 2001. Based on the test data, it is concluded that permeability of asphalt pavement is affected by mixture type, in place air void, thickness of layer and surface structure; coarse mixture is more permeable to water than dense one with the same in place air void. Increasing in place air void and surface structure can cause larger permeability; thicker pavement is less permeable to water; permeability should be worked as a quality control index, and a suggested control value is given based on the statistical analysis.More>
2003, 3(3): 12-16.
Vertical design method of intersection based on bilinear Coons surface model
ZHAO Yi-fei, YANG Shao-wei, XU Jin-liang
Abstract: This paper studied fundamental operations and dividing method of surface slices on the basis of bilinear Coons surface model for the vertical design of intersection.It is pointed that this model can more accurately describe the vertical surface, and is suitable for computer process with higher speed and precision, so it improves the adaptability of intersection CAD system, and raises the design efficiency. The practical result indicates that tihs method is feasible.More>
2003, 3(3): 17-20.
Three-dimensional numerical simulation of ground deformation of high-fill block and detritus
XIE Chun-qing, QIU Yan-jun, XU Qiang
Abstract: Based on airport construction practice in southwest China, this paper studied the deformation behavior of block and gravel fills. With engineering geological conditions and settement data, a prediction model was established.Three dimensional simulation was conducted using 3D FLAC software to simulate the deformation process of high-fills in airport engineering, especially surface settlement, lateral deformation, and potential shear failure plane. Simulation results are similar with practice.More>
2003, 3(3): 21-25.
Plastic collapse mechanism of seismic assessment for existing RC bridges with flexible foundation and bearing pads
SONG Yi-fan, WANG Yu-ping
Abstract: The deformations of reinforcement concrete bridge piers were divided into three parts, elastic deformation caused by a unit horizontal force at the top of the bridge piers, the rotation deformation and foundation translation deformation. A plastic collapse mechanism analysis mode of seismic assessment for existing reinforcement concrete bridges with flexible foundation and bearing pads was developed. Its analysis procedures and formulas with respect to the effect of elastic ground and elastic bearings were newly derived, and the practical analysis approaches of bilinear stiffness of bridge piers were given. An improved analysis method of seismic assessment for reinforcement concrete bridges was derived from equivalent elastic response acceleration at the limit state by considering the variety of the structural displacement ductility capacity caused by flexible foundation and bearing pads. An example shows that the structural displacement ductility capacity of reinforcement concrete bridges and seismic capacity are apparently reduced owing to considering flexible foundation and bearing pads.More>
2003, 3(3): 26-31.
Influence parameters of additional longitudinal force of continuously welded rails on bridge
ZHAO Zhi-jun, SHAO Tian-bao
Abstract: According to the boundary conditions of the influence area ends of additional longitudinal force, this paper studied the influence area length outside bridge in different calculation conditions, analyzed the additional longitudinal force's influence parameters of continuously welded rails on bridge, and clarified the variety rules of influence area length outside bridge, rail's maximum force and maximum displacement.The results indicate that the influence area length is not a fixed value. The maximum force and maximum displacement of rail will decline when longitudinal resistance force, span, span number, inertia moment decline, or pier stiffness increases, at the same time, the probability of rail broken will decline too.The force of abutment or pier will decline when the longitudinal resistance force decline.More>
2003, 3(3): 32-35.
Stochastic evaluation method on financial post-evaluation of railway construction project
ZHANG Fei-lian, CHEN Tao, SHI Feng
Abstract: Chinese policy change of transport price is mainly influenced by market factor. This paper analyzed the weakness of the method on financial post-evaluation of railway construction project. By applying the stochastic process theory to describe the passenger traffic rate and the cargo freight rate in railway respectively, the stochastic model of financial post-evaluation for railway construction project was developed. With stochastic simulation, the stochastic evaluation method was proposed. The results indicate that the stochastic evaluation method can more accurately image actual case, and will be a new method to financially post-evaluation of railway construction project objectively.More>
2003, 3(3): 36-39.
Route line decision method and model for high speed railway
WU Xiao-ping, CHEN Xiu-fang
Abstract: This paper discussed the characteristics of deciding schemes for high speed railway route lines, and developed a decision model. In this model, its indices weight was calculated with analytic hierarchy procees method. With this model the schemes can be evaluated scientifically. The practice shows that this model can reflect all information to decide which one is the best, so this model has a good reference for decision maker.More>
2003, 3(3): 40-45.
Metro stray current corrosion of pipelines buried underground and resisting corrosion method
ZHAO Yu-zhen, LIU Yue-chen, YANG Chuan
Abstract: This paper discussed the mechanism of metro stray current corrosion of pipelines buried underground to design a test plant of simulating stray current corrosion.By the simulating test, a new method of resisting stray current corrosion was developed, which various elements were permeated into the surface of steel pipes in low temperature.The result of comparison tests in same corrosive environment shows that the corrosion resistance of the materials after the low temperature gas multicomponent thermochemical treatment is improved greatly, a compound layer is found on the surface of steel pipes, by micromechanism analysis of corrosion resistance.More>
2003, 3(3): 46-49.
Crashworthy raiway car-body with energy absorbing
GAO Guang-jun, TIAN Hong-qi, YAO Song
Abstract: Evaluation system of end and middle part of car was established according to the American criterions. Using numerical simulation method, the deformation of 25 type original passenger car crashed with rigid wall was calculated. The results show that the crashworthy car's end part has plastic deformation, middle part has small elastic deformation, the displacement of plastic deformation is larger than the former, and crash force is smaller, the criterion of acceleration is improved obviously.More>
2003, 3(3): 50-53.
Ride quality of articulated high speed train
ZHOU Jing-song, REN Li-hui, YANG Guo-zhen, JIN Xin-can
Abstract: Based on the object-oriented modelling technique and SIMULINK graphic modelling language, the vertical and lateral dynamic behaviors of single vehicle, three connected vehicles and three articulated vehicles were researched with the frequency and time domain methods.The simulation results show that inter-vehicle suspension affects the vehicle ride quality greatly. Inter-vehicle suspension with proper parameters can attenuate the yaw and pitch vibration significantly. Comparison researches show the articulated form is better than the simple inter-vehicle suspension configuration, not only to the middle car but also to the end cars in the train set. The ride quality experiments of the articulated vehicles on vibration test rig demonstrate that the articulated train can achieve excellent ride quality at 350 km/h.More>
2003, 3(3): 54-58.
Gauge-changeable bogie with independently rotating wheel
HUANG Yun-hua, LI Fei, FU Mao-hai
Abstract: The application and development of gauge-changeable bogie in the world were briefly introduced. According to the situation of China, a new designing project about gauge-changeable bogie with independently rotating wheel was put forward.Its structure traits and mechanism were analyzed, its dynamic characteristics were researched by calculating simulation.The results show that the scheme of the gauge-changeable bogie is feasible, and it has better hunting stability and riding quality, but restoring capability of wheels toward centerline of rails and its curving performance should be improved by adopting necessary measures.More>
2003, 3(3): 59-63.
Affect of engine brake and exhaust brake on bus brake stability
YU Qiang, CHEN Yin-san, MA Jian, GUO Rong-qing, ZHANG Qing-yu
Abstract: Engine brake and exhaust brake can influence the braking force distribution and the braking stability of bus. Road experiments and analysis for the influence were carried out.The results show that there are two synchronizing adhesion coefficients when engine brake and exhaust brake are in action.One occurs at extremely low adhesion coefficient, and the other one is just below the original synchronizing adhesion coefficient.The values of these two coefficients depend on which constant brake is used, as well as the present gear step and the driving speed.Therefore, it is probable that the braking processes are unstable on the roads with extremely low and high adhesion coefficients, so the braking behavior and stability must be changed to a certain degree.More>
2003, 3(3): 64-67.
Combustion characteristics of spark ignition engines with dimethyl ether-LPG blends fuel
WANG Heng, BIAN Yao-zhang, QI Dong-hui
Abstract: This paper measured the combustion characteristics of different fuels on the spark ignition engine with CB-566 combustion analysis instruments, studied the influence of DME-LPG blends fuel on the combustion process of spark ignition engine, and compared it with that of gasoline. It is pointed that the flame development angle and combustion duration of DME-LPG blends fuel engine are longer, maximum cylinder pressure is higher than that of gasoline engine. The two engines are alike in combustion characteristics. The results indicate that the additive with high octane number and high heat volume to dimethyl ether (DME) improves the quality of DME greatly, and the spark ignition engine without changing its structure can use DME-LPG blends fuel.More>
2003, 3(3): 68-71.
Active noise control method of combining VC++ with MATLAB
GONG Shu-li, ZHOU Jie-min
Abstract: This paper studied of sound radiation control from a flexible panel into a three-dimension closure using piezoelectric smart structure. In this experiment, the closure with a flexible panel was used to simulate the aircraft cabin; piezoelectric actuators and sensors were adhered to the flexible panel; as to signal treatment, this paper used VC++ to make main interface and MATLAB to do background analysis work; the signal of 100 Hz was chosed as noise source.It is pointed out that at 100 Hz, the radiate noise of closure decreases about 15 dB.The result indicates the feasibility of this treatment, and that active noise control will be an efficiency way to control radiate noise of cabins like aircraft's.More>
2003, 3(3): 72-74.
Cumulative curve method for calculating saturation flow rate and phase lost time
WANG Dian-hai, YANG Shao-hui, JING Chun-guang
Abstract: Compared with Webster method, cumulative curve method can measure starting time and ending time. As an example, this method was applied in several lanes in Changchun city. The applying results show that the saturation flow rate of one lane is between 1 600~1 900 veh/ h, and the total lost time is less than 2 s without disturbing. The saturation flow rate approxi- mates the assumptive value, 1 700~1 800 veh/h, but the lost time is less than what HCM com- mends, 3~5 s, which is also less than the yellow time, 3 s.More>
2003, 3(3): 75-78.
Changeable phases signal control of traffic intersection
GAO Hai-jun, LI Ling-xi, CHEN Long
Abstract: Compared with the traditional fuzzy control on signal control of traffic intersection, the phase order, phase time and phase combination of changeable phases signal control become more flexible, and can adapt to the real variation of traffic intersection better. The changeable phases signal control can also adapt to the signal control of traffic intersection with different forms. The result of simulation show that changeable phases signal control is better than the traditional fuzzy control, and is an efficient and practicable algorithm.More>
2003, 3(3): 79-83.
Expressway's overall intercom based on internet protocol
CAO Wei, SUN Da-yue, QU Li-cheng
Abstract: Intercom is an important technique for expressway's management and toll control. This paper discussed the technique structure of expressway's toll, communication and surveillance system, developed a kind of intercom based on internet protocol. The intercom is consist of special interphone with serial interface, client software and server software. The practice shows that this intercom don't need to lay special transmission link, has a good performance to solve the difficult problems of long distance transmission and multicast.More>
2003, 3(3): 84-87.
Three-dimensional vehicle dynamics model for road traffic accident simulation and reconstruction
WEI Lang, CHEN Tao, YU Qiang
Abstract: With dynamics theory, a 3-D vehicle dynamics model for road traffic accident simulation and reconstruction was put forward. Through refering to 16 car-to-car impact test datum, the computation error of the 3-D simulation model was defined, and the computation precisions of the 3-D vehicle model and 2-D four-wheel model were compared in quantity. The results of simulation and reconstruction for real traffic accidents show that the general average relative error of the 3-D vehicle model used to compute such the intensive motion as the vehicle impact is 6.65%, and the computation precision of the 3-D model decreases by 1.43% than that of the 2-D model, the proper reduction of computation precision is acceptable because of its advantage in the area of traffic accident type accommodation and visualization.More>
2003, 3(3): 88-92.
Method of service level classification for ETC toll plaza based on neural network
LIU Wei-ming, GUAN Li-ping, YIN Xiang-yuan
Abstract: In view of the difficulty and complexity of mathematical and physical method to classify the service levels and the good self-organization behavior and robustness of Kohonen neural network, this paper applied Kohonen neural network to classify the service levels for a certain toll plaza with ETC toll lanes and stop toll lanes. The results indicate that this method is potentially applicable in practice.More>
2003, 3(3): 93-95.
Design and realizing method of traffic engineering CAE system
ZHAO Xiang-mo, NAN Chun-li, SHI Wei-ying
Abstract: Based on the analysis of the current development of traffic engineering software system, the traffic engineering CAE (computer-aided engineering) systematic designing program based on GIS (geological information system) was presented, and the key technology of the design was also given. The process and analysis of traffic data were made with numerical analyzing theory, and its results were expressed in intelligent model. The system is proved to be feasible by analyzing and dealing with vehicle speed in traffic properties.More>
2003, 3(3): 96-100.
Urban traffic flow control prototype system based on multi-agent
ZHAO Jian-you, ZHAO Li-ping
Abstract: Some problems unsolved in urban traffic flow control system were analyzed. With the view of current system deficiencies, this paper put forward a viewpoint on establishing a intelligent urban traffic flow control system based on multi-agent, and the general prototype structure and development methods were proposed. The structure of traffic agents was discussed, and the coordination and collaboration problems between traffic agents were described. The study result shows that this study provides guide in theory and method for real application system development.More>
2003, 3(3): 101-105.
Traffic volume forecasting method at road interchange based on road network planning
WANG Ying, XIE Hai-hong
Abstract: Traffic volume forecasting at road interchange is a key part of road interchange designing and planning. According to the characteristics of traffic flow at interchange and the volume planning at road network, this paper put forward a new traffic volume forecasting model. The traffic turning volume from entrance to exit could be forecasted, and the calculation of the correlative parameters was discussed with the model. The forecasting model was tested by an example. The result shows that this model is feasible.More>
2003, 3(3): 106-109.
Time value of passengers
ZHOU Wei
Abstract: This paper analyzed the characteristics of time value and its basic calculation method, put forward improvement suggestions, and established the time value models for passengers' free choices in the terms of consumer action theory and benefit-cost principles, which can not only meet the needs of the macroscopic economic evaluation, but also fit for microscopic traffic analysis. Taking the passengers' transportation from Gansu province to Shaanxi province in China as an example, this model was ulitized to calculate the passengers' time value. The results are quite satisfactory.More>
2003, 3(3): 110-116.
Waiting time and service level of locks
WU Ling-li, ZHANG Wei
Abstract: Based on the actual operation of locks, this paper analyzed the individual waiting time and the integral waiting time at locks. It also probed into the relationship among the delay, the transit capability and the service level at locks. It is pointed out that at Shiqiao lock, fleets' daily waiting time distributes mainly in the range from 0 to 4 h, while motorized junks' daily waiting time distributes mainly in the range from 4 to 8 h, and the integral waiting time upwards gathers mainly in the range from 0 to 4 h, while the integral waiting time downwards gathers in the range from 0 to 8 h. The results indicate that the waiting time at locks has relation to the actual operation and the transit capability of locks, so the service level of locks can be evaluated from the view of waiting time combined with the actual transit capability of locks.More>
2003, 3(3): 117-121.
Analysis model of supply, demand and price of container shipping market
HOU Rong-hua
Abstract: The shipping velocity and cell capicity are two key factors for container shipping. A production function for container shipping was presented. In the function, the fuel per slot and per day and slots number were chosen as variables. According to this production function, the unit total cost and marginal cost of supplier can be calculated, so the supplier can adjust the supply according to the change of market. The results show that at a wide range, marginal cost is relatively insensitive to demand, the transport price is relatively stable, but when the fleet is fully utilized, the marginal cost and transport price will increase quickly.More>
2003, 3(3): 122-126.