交通运输工程学报

Summary of backcalculation methods of pavement layer moduli

CHA Xu-dong

Abstract: The researches on backcalculation methods of pavement layer moduli in China and other countries were reviewed. The advantages and disadvantages of 5 kinds of backcalculation methods, nomographies and regressive equations, iterative methods, database searching techniques, genetic algorithms and artificial neural networks, were discussed. It is pointed out that initial value and local convergency, uniqueness of solution, and reasonableness of backcalculation results are the 3 key issues.More>

2002, 2(4): 1-6.

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Summary of forecasting methods of expressway settlement on soft ground

ZHOU Huan-yun, HUANG Xiao-ming

Abstract: During the building of expressway on soft ground, it is necessary to study how to accurately calculate the settlement of embankment to control the construction rate of progress and instruct the later construction plan. This paper introduces the theory and application of several forecasting methods of highway settlement on soft ground in common use, such as curve fitting method, GM (1, 1) model, artifical neural network and genetic algorithm.It offers reference for accurately forecasting settlement of soft ground.More>

2002, 2(4): 7-10.

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Application of WKL to pavement subbase

LIU Zhen-qing, HUANG Wei

Abstract: The analysis of WKL chemical and physical properties, and environment effects was carried out.The results show that it can be applied to the subbase and roadbed.By the orthogonal test method, this paper proposed the optimized mixing for WKL stabilized by use of the lime fly ash, mixture mixed into the lime fly ash and cement mixed into the lime fly ash, analyzed various factors that may influence strength of the mixture, and determines their technical parameters for road applications.In Lianyungang, the optimized mixing was applied to pave the base of 1 km test road so as to examine the practical test and analyze the application mechanism.This study can provide the feasible and rational optimized mixing for the popularization and application of this material to pavement subbase, and provide the system of feasibility and guarantee for engineering construction.More>

2002, 2(4): 11-16.

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Influence of shear deformation on deflection of box girder with corrugated steel webs

LI Hong-jiang, YE Jian-shu, WAN Shui, WU Wen-qing

Abstract: The box girder with corrugated steel webs is a new type of composite steel concrete structure. Compared with conventional box girders with concrete webs, the influence of shear deformation may be not ignored in its deflection calculation. Combining structural properties of box girder with corrugated steel webs and the theory of elementary beams, a calculation method of its deflection under flexure, which considers the influence of shear deformation on it, is provided. The results of model tests and finite element analysis further testify it. With different shear span ratios, the influence of shear deformation on the box girder deflection is different, thus a limit value of shear span ratio is suggested for considering the influence of shear deformation or not.More>

2002, 2(4): 17-20.

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Damage safety assessment and maintenance management strategy of bridges

WANG Chun-sheng, CHEN Wei-zhen, CHEN Ai-rong

Abstract: Damage cumulation in existing bridges affects not only on normal service of bridges, but also on service safety of structures. Both load carrying capacity testing and health monitoring technology could not alone identify damage cumulation, which often leads to brittle fracture of bridges. A new approach of damage safety assessment based on damage mechanism is proposed, which combines local nondestructive inspection with global health monitoring technology to identify and localize damage. On the basis of accurate damage identification, damage mechanics, fatigue and fracture mechanics, reliability theory are applied for damage safety assessment. According to the online safety assessment results and the damage characteristics of different types of bridges, maintenance management strategy is timely suggested in order to help management department to ensure the service safety of bridges. The practice application of the new method is introduced through the example of Waibaidu Bridge in Shanghai. Finally, some suggestions about damage safety assessment of bridges in the future are given.More>

2002, 2(4): 21-28.

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Dynamics performance of low wear bogie for high speed passenger car

GAO Chang-jun, FU Mao-hai, LI Fei, WANG Kai-wen

Abstract: According to the fundamental principle of self steering bogie, the paper puts forward the basic scheme of low wear bogie for high speed passenger car on the basis of the existing several self steering bogies in order to solve the problem of wheel and rail wear of high speed passenger car.The dynamics model is established, the dynamics performance is analyzed and calculated by using Simpack simulation program and compared to that of ordinary bogie.The principle analysis and calculation results show that self steering bogie may improve negotiation performance and wheel and rail wear of high speed passenger car effectively.More>

2002, 2(4): 29-33.

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3-D parametric CAD system of locomotive with streamline surface

MOU Bing-rong, XIAO Shou-ne

Abstract: At high speed, locomotive must be designed with streamline surface. The 3 D parametric surface modelling CAD system is the key technique for designing locomotive. Based on the platform of Auto CAD 2000, an integrate CAD system named LSurfCAD was developed with ObjectARX 2000 and VC ⁺⁺ 6 0. The main function and interface of the system were described.More>

2002, 2(4): 34-37.

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Finite element analysis for resilient wheelset

SUN Ming-chang, CENG Jing, WEN Ze-feng

Abstract: The resilient wheelset has been widely used in light rail transit abroad. The practices indicate that it is of advantage to reduce wheel/rail noise, dynamic wheel/rail force and improve passenger ride comfort. In this paper, stresses, deformations and modalities of the resilient wheelset are analyzed by using the finite element analysis program ANSYS. The calculative results are compared with the results of the rigid wheelset. The studies on the influence of constitutive parameters of rubber on static strength of the resilient wheelset are also presented. The results indicate that the maximum equivalent stresses of the resilient wheelset and the rigid wheelset appear at the wheel spoke attached to the axle, and the peak value of the resilient wheelset is larger than that of the rigid wheelset. The material parameters of the rubber have large effects on stresses and strains of the rubber. It is necessary to select the optimum parameters. It is also acquired that the low inherent frequencies of the resilient wheelset is less than those of the rigid wheelset, which determines that the resilient wheelset has high efficiency in reducing vibrations.More>

2002, 2(4): 38-42.

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New measuring method of smoke emission for diesel vehicle

WANG He-wu, LIU Hao-xue

Abstract: Based on the chemical reaction of fuel with air in internal combustion engine and the elementary equilibrium before and after combustion, the relationship of the quantity of total exhaust gas with the fuel consumption and with the quantity of each exhaust composition was analyzed, and a new model/method was set up for measuring the smoke emission under on road conditions. The precision of the model/method was validated by an engine bench test. The smoke emission of a diesel vehicle running on road was measured using this method.More>

2002, 2(4): 43-45.

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Effect of road gradient in highway tunnel on smoke emission of diesel vehicle

LIU Hao-xue, WANG Sheng-chang, WANG He-wu, ZHANG Qing-yu, MA Zhi-yi

Abstract: A engine bench test is carried out by means of exhaust gas recirculation, and a certain proportion of exhaust gas is mixed with inlet air to monitor the effect of the environment in the highway tunnel on smoke emission. The effect of road gradient on the smoke emission is modified. A road test is achieved at different gradient. The test results show that the smoke emission increases remarkably with the increasing of road gradient and vehicle speed, the smoke emission increases 70%~120% when gradient degree in highway tunnel raises 1%.More>

2002, 2(4): 46-48.

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Scientific installation of static traffic signs on expressway

ZHENG An-wen, NIU Zhuo-min

Abstract: With the development of expressway, the installation of static traffic signs is very important for driving safety. According drivers' receiving information process and their reaction regular, how to scientifically installate the static traffic signs along expressway was discussed.More>

2002, 2(4): 49-53.

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Competitive location model of logistics distribution center

SUN Hui-jun, GAO Zi-you

Abstract: This paper, on the basis of more than one existing distribution centers, discusses how to make an effective decision of location for a new distribution center in order to reap maximum market share, set up a location model and regard location decision as a problem of non constraint non linear programming. An iterative solution algorithms and a numerical example are given, the model is extended to multiple factors and distribution centers location problem.More>

2002, 2(4): 54-57.

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Regional logistics information platform and resource planning

DONG Qian-li

Abstract: The manner for third-part logistics provider to integrate social logistics resources was studied.Integrated logistics information system is divided into two tiers as micro(enterprise)and macro(region)to be built.The paper analyses logistics information needs and features for industrial and commerce enterprises, third-part logistics(TPL)providers and the departments of government based on regional logistics information platform and social logistics resource integration, discusses the functions and operation mechanism of regional logistics information platform, and puts up the theater model of regional logistics information platform.According to the theater model, it is important for TPL to build up the capacities of supply chain solution design, integration management and consultation from the concept of fourth-part logistics.Only by this way, TPL providers can use regional logistics information platform to improve the competence of integrating logistics resource, and last to implement the thoughts and ways to integrate logistics resource on society.More>

2002, 2(4): 58-62.

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Reasonable distance of pedestrian crossing facilities

LU Jian, YE Hui-qiong, YAO Dong-lei

Abstract: Pedestrian transportation is a key part of urban transportation.On the basis of pedestrian flow characteristics, through the analysis of pedestrian psychology, vehide driving and street capacity, the method of setting the distance of pedestrian crossing facilities can be decided. The paper calculates the reasonable distance of pedestrian crossing facilities in urban central business district and normal district. The recommend values of the corresponding pedestrian crossing facilities distance are put forward.More>

2002, 2(4): 63-67.

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An improvement on fuzzy comprehensive evaluation method and its use in urban traffic planning

LIANG Jun, JIANG Wei, LI Xu-hong

Abstract: For the fuzzy comprehensive evaluation method has a shortcoming that the weights of indexes usually are decided by experts, hence the conclusion is not so objective. In order to make the conclusion more objective, a new method that combines the concept of entropy and relevance rate was presented.Based on this new method, a model of evaluating traffic planning of urban key area was developed. Some values of parameters were put forward, and tested by an example.More>

2002, 2(4): 68-72.

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Generalized planning system of provincial expressway network based on traflic engineering

WANG Jian-jun, YAN Bao-jie, CHEN Kuan-min

Abstract: Modern expressway must possess scientific and advanced engineering facilities system, so the generalized planning of expressway network based on traffic engineering plays an important role in constructing engineering facilities system.On the basis of summarizing and analyzing generalized planning reports of some provincial expressway network in China, some creationary planning contents and methods are proposed.Its main contents, including expressway network analysis, management system, toll system, surveillance, control and communication system, emergency rescue system, power distribution and lighting system, safety installations system, service area and maintenance division, environmental protection, industrial belt along the expressway line, system evaluation, are examined.More>

2002, 2(4): 73-79.

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Effect of left-turning traffic signal lights on vehicle motion delay at intersection

YUAN Yi-wu, DONG Li-yun, DAI Shi-qiang

Abstract: In recent years, left turning traffic signal lights have been installed at some main intersections in big cities in China. A model describing the delay in vehicle motion at an intersection with left turning lights is established, and the stochastic processes in the cases of the uniform distribution and negative binomial distribution for the vehicles passing through the stop line are analyzed. The model was examined with a typical intersection in Shanghai. The comparision of the presented model with the stop line model and the conflicting point model proves that the present model is applicable. The results show that the application of the left turning signal lights could enhance the traffic capacity and to reduce the conflicts or accidents at intersections.More>

2002, 2(4): 80-85.

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Traffic guide simulation system with four intersections

WANG Jin-mei, LI Qing-feng, YANG Jian-guo

Abstract: The urban road traffic jam mainly occures at some representive intersections.The paper brings forward the traffic guiding simulation system model framework in which four intersections are taken into account as the objects.The factors that affect the choosing of intersection are discussed.If the traffic flow at each intersection is regarded as queue affair, the conflict should take place between the traffic flows at different intersections.The expert system polls the traffic flow queue affairs at the intersections one by one by combing the event driven state transfer with expert system technology to resolve the affairs conflicts.Meanwhile, the objectives and functions of simulation system modeling, and system state such as intersections, lanes, phases and cycle length are described.More>

2002, 2(4): 86-89.

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Algorithm of controller for lane-following based on basic road facilities

WANG Chun-yan, WANG Xiao-jing, LIU Zuo, WU Chao-zhong, WANG Qin, WANG Wei

Abstract: Lane following, based on basic road facilities, is one of the core research items in the field of intelligent highway system (IHS).In June 2001, the controller designed by authors finished the task of lane following on IHS testing course, and the testing result had reached/surpassed the requirement of NP17361 Lane Departure Warning System made by ISO/TC204 WGI4.This paper described the controller architecture, deduced its analytic formula, given its parameters, drawn the control error curves and analyzed the testing results.More>

2002, 2(4): 90-94.

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Evaluation of maintenance cost for commercial aircraft

LIANG Jian, ZUO Hong-fu

Abstract: In recent years, the operation of airline companies was in difficulties. An economical evaluation for commercial aircraft to reduce its maintenance cost is very important. The evaluation method and its mathematical model were introduced and developed. As an example, the maintenance of aircaft engine was analyzed. The results show that the evaluation of maitenance cost is a key work.More>

2002, 2(4): 95-98.

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Runway capacity probility model and capacity curve

YU Jiang, WANG Da-hai, PU Yun

Abstract: Runway capacity can be presented by capacity curve, which reveals the interdependent relationship between landing and departure.From the viewpoint of controller, this paper establishes a runway probility capacity model based on ASAC model, presents capacity analysis and calculation result based on the data from an operational airport. The model considers following parameters: ATC regulation, approach (departure) speed, position uncertainty, wind speed, runway occupation time, traffic mix etc.More>

2002, 2(4): 99-102.

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Database security in air transportation information system

WANG Guan-zhen, XIA Hong-shan

Abstract: Database security in management of civil aviation demands both secrecy and share, which must be guaranteed by a series of security strategies. In order to solve the problem, the paper discusses the method of establishing a set of database security strategies in air transportation information systems. The content and the basic conceptions for establishing a set of database security strategies were put forward. With the advantages of DBMS, the identification, backup, and transaction log based on an airport transportation information management system were implemented. The practical value of the set of database security strategies described in the paper is examined.More>

2002, 2(4): 103-107.

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Application and design of miniature solid state heading measuring system

LUO Jie, HUANG Sheng-guo

Abstract: With the rapid development of science, heading measuring system is becoming increasingly pint sized and intelligent. Miniature HPR 1 magnetic heading measuring system is just researched and developed in such background. It consists of HMR3300 digital compass, which is manufactured by Honeywell corporation, employed SCM and external hand held display controller. This system can not only complete the real time collection of such signals as heading, pitch, roll and deviation, but also provide users numeral and analog output after the error compensation. The experimental results show that it is accurate, reliable and flexible in operation. It can be used not only in unmanned aerial vehicles (UAV), but also in other fields such as cars and ships.More>

2002, 2(4): 108-111.

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Application of three-tired structure technology in WebGIS

ZHONG Tao

Abstract: In order to find a plan to build the GIS that is suitable for civil aviation transportation, several current building plans for GIS and the characteristics of WebGIS were introduced and compared with each other. Three main methods for WebGIS building were analyzed. It is decided to take the three tired structure client/server model as the fundamental frame of the civil aviation transportation geographic information system (CATGIS). The three tired structure model was described. This model is realized in CATGIS. Through the practice, though the system has some disadvantages, but its advantages, such as less maintenance, simpler operation, lower requirement for users and easier allocation of loads, make it be an ideal scheme for building CATGIS, which meets the needs of civil aviation transportation.More>

2002, 2(4): 112-115.

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Sea bottom detection technique using multi-subarrays in swath bathymeter system

CAO Hong-ze, ZHU Qi, XU Xin-sheng

Abstract: A bottom detection method used in the multibeam bathymeter sonar is introduced. The method is based on the separate aperture method, which is associated with phase information. As the generalization of the separate aperture method, multi subarrays can be used to estimate DOA of bottom echoes, and the depth is calculated by image transform using phase information. This technique was simulated by computer and tested with experimental data. The results show that this method can improve measurement accuracy of large angles of incidence, efficiently advance depth measurement precision and solve the problem of relative big measurement errors using amplitude based method when angles of incidence is large.More>

2002, 2(4): 116-120.

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2002 Vol. 2, No. 4

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