2005 Vol. 5, No. 1

Display Method:
Evaluation method of asphalt aging properties
ZHANG Zheng-qi, LIANG Xiao-li, LI Ping
Abstract: In order to analyze the reasonability of rolling thin film oven test(RTFOT) on asphalt aging and the relationship between short term aging and long term aging of asphalt, tie constituent analysis, normal tests and Superpave performance-based tests were conducted on several asphalt specimens after RTFOT and pressure aging vessel(PAV). Test results indicate that the change rules of asphalt constituents in the two terms are different, while mechanical parameters values change with different magnitude, but if these asphalts are ranked according to their aging properties, the order is basically unchanged. The results show that the short term aging test is a good alternative to evaluate and select right asphalt at present time, but it can not reflect the aging properties of asphalt thoroughly.More>
2005, 5(1): 1-5.
Stress-corrosion-evaluation indices of high-property-concrete
CHEN Shuan-fa, WANG Bing-gang
Abstract: The stress-corrosion damage of concrete is the coupled action result of stress and corrosion medium, and its study is in exploratory stage. With the loading test equipment of stress-corrosion, the attenuation discipline of high-property-concrete's performance under the action of three-points loading and corrosion solution was studied, the sensitivity of testing results to the stress-corrosion-evaluation indices was analyzed. The results indicate that the loss rate of high-property-concrete's bending strength under the action of stress-corrosion is over 10%, its compression strength and quality usually have no change, the bending strength loss rate is most sensitive to the evaluation indices of concrete's stress-corrosion performance.More>
2005, 5(1): 6-10.
3-D overlay model of broken concrete pavement
LIU Ying, HUANG Xiao-ming, LIU Xiao-yao
Abstract: When reconstruct old portland-cement-concrete pavement, the old pavement needs to be broken, the regular layer's continuous model doesn't match with the broken pavement, so a (3-D) overlay structure model was developed with finite element method. In the model, the overlay and subgrade's deflection is continuous, the broken pavement deflection is not so, the deflection between upper and low layers might not be continuous. The analyzing results show that there is an empty space among the overlay, broken pavement and subgrade; the broken pavement's deflection is dual linear distribution, the low deflection basin still contains the upper deflection basin; there is a deflection difference in the two sides of the broken pavement's seam, there are moment and shear differences in the overlay. To the disconnection rigid or half-rigid subgrade pavement structure, the model is a feasible calculation method.More>
2005, 5(1): 11-13.
Conversion method of axle-load for steel bridge deck based on fatigue-equivalent
HUANG Wei, LIU Zhen-qing, QIAN Zhen-dong, CHENG Gang
Abstract: The index system of structure design was proposed according to the fatigue failure type and rutting failure type of steel bridge deck, and it was classified into two types, one is fatigue index, another is rutting index. The conversion method of axle-load was proposed based on its fatigue and rutting equivalent ruks. The conversion formulas of steel bridge deck were proposed based on fatigue equivalent ruks. The conversion exponents and coefficients of other axle-type and wheel-type of the formulas were computed according to fatigue tests and mechanical analysis. Computation results show that the conversion exponent is (4.35) for guss asphalt concrete pavement, the conversion exponent is 5.30 for modified asphalt SMA qavement, the conversion exponent is 6.25 for epoxy asphalt concrete pavement. The conversion formulas can be applied to design or check the computation of steel bridge deck pavement, and its conversion results are precise and feasible.More>
2005, 5(1): 14-18.
Theoretical models of determining tolerable differential settlement at end of bridge
ZHANG Hong-liang, HU Zhang-shun, LU Wen-jiang
Abstract: In order to determine the tolerable differential settlement between bridge abutment and approach embankment, taking into account the comfort and safety of riders, the paper put forward the riders' vibration frequency and maximum transient vibration value of acceleration as controlling indices, built-broken lines models and step models for bridge approaches with and without approach slabs respectively, suggested the tolerable differential movement of embankment/structure interface and the tolerable differential slope of approach slab as the tolerable differential settlements, selected three freedom degrees system and five freedom degrees system as the models for the roughness testing vehicle with only one wheel and the vehicle with two axles respectively, and emphasized that the inertia moment of vehicle body in five freedom degrees system couldn't be ignored. The allowable differential slope of approach slab [Δi] is (0.4%) to 0.5%. When the tolerable maximum transient vibration value was 1.0 m/s2, [Δi] is 0.42%. The result indicates that the models are reasonable.More>
2005, 5(1): 19-23.
Bearing property of large-diameter over-length nonplacement pile
FENG Zhong-ju, XIE Yong-li, LI Zhe, ZHANG Hong-guang
Abstract: Based on the field test of pile foundation in Zhichuan river bridge, the bearing property of large-diameter over-length nonplacement pile in the area of powder sandy soil was studied, a comparison was made between the test result and the calculation value of empirical formula. It is pointed that there is a remarkable difference between the bearing property of large-diameter over-length nonplacement pile and that of medium length or short ones, when powder sandy soil is in different depth underground, its lateral resistance is different significantly, the bearing capacity difference of experimental piles and normalized formula is over 50%. The results show that the limiting lateral resistances of powder sandy soil of different depth are different, the normalized formula is not suited to evaluate the bearing capacity of large-diameter over-length nonplacement pile.More>
2005, 5(1): 24-27.
Comprehensive evaluation method of bridge strengthening effectiveness
WU Tong-le, XU Yue
Abstract: In order to evaluate bridge strengthening effectiveness, the paper put forward the conception and content system of post-evaluation of bridge strengthening effectiveness, based on the conventional success-degree evaluation method, set up the comprehensive success-degree evaluation model of bridge strengthening effectiveness. In the model, the evaluating indices system of success-degree for bridge strengthening was established by analytic hierarchy process, the indexing set of evaluating indicators was determined with the merits of Delphi method, and it was optimized according to the different types of indicators, hence comprehensive appraisal matrix was formed, the matrix operator of fuzzy theory was improved. Computation result of bridge evaluation is 0.46, comprehensive evaluation is part success, which accords with the bridge real situation, the model is feasible.More>
2005, 5(1): 28-32.
Time-varying model of railway tangent track spatial vibration
CENG Zhi-ping, CHEN Xiu-fang, ZHAO Guo-fan
Abstract: In order to analyzing the vehicle-track coupling vibration character of infinite length track, a time-varying model of railway tangent track spatial vibration was presented. With finite element method, both the sleeper and the rail were divided by linear viscoelastic discretely supported beam element. The vibration equation group of the model were formulated using the principle of total potential energy with stationary value in elastic system and the "set-in-right-position" rule for formulating matrixes. Using the technique of track being "added and cut down", the mass matrix, damp matrix, stiffness matrix and force vector of the model became time-varying. With the existing vehicle dynamics model and the measurement parameters, 4 km track was applied to calculate the dynamic responses of vehicle-track coupling vibration. The maximum values of!rail displacement, wheelset lateral force and carbody acceleration between calculation and measurement results are very close, which demonstrates the feasibility of the presented model.More>
2005, 5(1): 33-35.
Dynamic inverse analysis for vibration-load history of high-speed railway
JIN Liang-xing, ZHANG Jia-sheng, NIE Zhi-hong
Abstract: On the basis of the solution for dynamic equilibrium equation utilizing the Newmark method, the formulas for calculating vibration load were derived, the dynamic finite element method for calculating vibration-load history using the measured vibration-acceleration history was put forward. Combined with the vibration-acceleration history of the field measurement in Qinhuangdao-Shenyang dedicated passenger line, the vertical vibration-load history curves were calculated when train speeds were 230 km/h and 265 km/h. It is pointed that the maximum vertical vibration load increases by 16.34 kN when train speed increases by 35 km/h. The results indicate that vibration-load history could be obtained with the measured vibration-acceleration history, the method is feasible.More>
2005, 5(1): 36-38.
Transverse vibration analysis of two maglev trains passing by in open air
LIU Tang-hong, TIAN Hong-qi
Abstract: Using the 3-D compressible N-S equations and dynamic mesh, the train passing pressure pulse of Shanghai maglev train at the relative speed of 860 km/h was analyzed in order to know the aerodynamic force's influence on the stability of maglev train. A detailed dynamic model was established, where the carbody was considered as elastic body while the suspension system was considered as spring-damp element. The transverse vibration considering the train passing pressure pulse was calculated. The results show that the difference of the maximal pressure pulse between numerical calculation and real car test is less than 6%, and the transverse vibration only arosed by the irregularity of rail track is little. It is great if the influence of train passing pressure pulse is considered, and the underframe's maximal transverse acceleration is 1.5 m/s2. The suspension bogies' acceleration reduce to 0.7 m/s2 under secondary suspensions' buffer action.More>
2005, 5(1): 39-44.
Controller design of hydrofoil catamaran with dynamical output-feedback H scheme
REN Jun-sheng, YANG Yan-sheng
Abstract: This paper studied the attitude controller design for a kind of fully-submerged hydrofoil catamaran with output-feedback H scheme by using Matlab's simulink toolbox and LMI control toolbox, this research was based on the boat's simulation platform. The linearization of nonlinear mathematical model of hydrofoil catamaran at design speed, was implemented, and the state-space model was obtained. With hydrofoil catamaran "HC200B-A1", simulation was carried out to demonstrate the controller design. It's pointed out that output-feedback H attitude controller for hydrofoil catamaran is efficient to suppress the wave-induced motions, the controller has good performance with only partially observed system's state information.More>
2005, 5(1): 45-48.
Multi-layers and multi-objects fuzzy optimization model of main target ship
LIU De-xin, WU Zhao-lin, JIA Chuan-ying
Abstract: To solve the problem of intelligential decision-making on multi-ships collision avoidance in the field of automatic collision avoidance, a multi-layers and multi-objects fuzzy optimization model of main target ship was designed. The collision risk degree and the difficulty degree of collision avoidance on judging main target ship were studied, the objects were separated into interrelated parts to make the problem consecutive, the model was established using fuzzy optimization theory, every layer cell system was calculated by inputting the output of lower layer into higher layer. Using pricing vectors, the sequence of all target ships was arranged, the optimal selection for main target ship was performed. The pricing vectors were calculated while own ship encounters with seven target ships at the same time. Computation results show that the tactic sequence of all target ships and the selected main target ship are conforming more exactly to practical forecast result, the model is feasible.More>
2005, 5(1): 49-52.
Stability improvement of vehicle's anti-overturn with semi-active suspension system
YU Qiang, MA Jian
Abstract: In order to improve the stability of vehicle's anti-overturn in curve driving and sudden turning at high speeds, which affect vehicle driving safety, this paper put forward the semi-active suspension system (SASS) to replace the passive suspension system with poor anti-overturn stability, established the models of SASS and control system. Its suspension damping force was adjust by controller in order to improve the vibration stability of vehicle. Simulation results show that the effective roll angle of vehicle with SASS decreases by 60.9% in sudden turning at high speed, the effective roll angle acceleration and anti-overturn factor decrease by 64.6% and 35.2% respectively. The results show that the SASS can effectively reduce the roll angle and roll angle acceleration in nonlinear driving, improve the anti-overturn stability. SASS is a reasonable solution to improve vehicle safety in nonlinear driving.More>
2005, 5(1): 53-56.
Fuzzy optimum decision-making model of airfield minimum operating strip
XU Wei
Abstract: This paper studied the evaluation of minimum operating strip(MOS) in the procedure of airfield rapid repair by fuzzy optimum decision-making theory, put forward a fuzzy optimum decision-making model of MOS. Applying the model, an example was analyzed. It is pointed that the final value of measuring best MOS increases from 0.83 to 0.98 only considering repair-time. The result indicates that the model is feasible, and can reasonably describe the result of evaluation.More>
2005, 5(1): 57-60.
Conjecture method of dynamic flying track
PENG Ying, HU Ming-hua, ZHANG Ying
Abstract: This paper studied the algorithm of flying track conjecture by using the principium of garden line and angle line conjecture combined with the dynamic data of radar and flight telegraph, calculated the flying track and fix point time of aerocraft, and estimated air traffic flow by the method, the result was compared with that by experience time add-up method with the flight plan data of airport ZGGG. It is pointed that dynamic flying track conjecture method has high sensitivity, its error is within ±0.5 min, it accords with fly rules, and can revise the fly route in real-time. The results indicate that dynamic flying track conjecture method could estimate the flow of airspace more accurately, is an effective measurement for tactical air traffic flow management.More>
2005, 5(1): 61-65.
Integrated prediction method of nonlinear-seasonal passenger traffic income of airlines
WANG Fei-feng, WANG Kun, DENG Xue-jun
Abstract: Passenger traffic income of airlines has a dual trend of growth and seasonal fluctuation, which makes the income demonstrate a complicated nonlinear characteristic. A prediction model, based on the theory of grey prediction model GM (1, 1), was introduced to reflect the characteristic of its growth trend, a seasonal change prediction model was employed to reflect the characteristic of its seasonal fluctuation, an integrated nonlinear-seasonal prediction model of passenger traffic income of airlines was proposed. Prediction results show that the error rate of actual value and test value is less than 1%, the model is feasible.More>
2005, 5(1): 66-69.
Crane dynamic deployment model of container storage yard
LI Jian-zhong
Abstract: In order to optimize the dynamic deployment for rubber tyred gantry crane, this paper constructed a nonlinear multi-objective programming model. In the model, the minimum time of uncompleted workloads and the minimum wasted time of workloads were optimal objects, the problem was solved by Lagrangian algorithm based on heuristic method. Computation results show that the average duality gap is within 1%, the average computation time is 4 min, which demonstrates the model is feasible.More>
2005, 5(1): 70-74.
Combined assessment model of harbour navigation environment safety assessment
CHEN Wei-jiong, HAO Yu-guo, QIN Ting-rong, LI Fei, WANG Kai-yuan
Abstract: In order to solve the assessment diversity on the same thing caused by different assessment methods, combined assessment model(CAM) was proposed. 10 seaports of China were used as a sample case of safety level ordering assessment of navigation environment. The methods of principal component analysis(PCA), factor analysis, TOPSIS, fuzzy aggregate assessment, gray aggregate assessment were employed to the case separately, and 5 different group results were obtained. The theory of serial number summation and mode theory were adopted to coordinate the results of the 5 methods, and come to an only ordering conclusion. The conclusion based on CAM is much close to the fact, excelled to any result of single method, and generally accepted by senior master mariners.More>
2005, 5(1): 75-77.
Dimension analysis theory in traffic flow analysis
OU Zhong-hui, WU Zheng, TAO Ming-de
Abstract: According to the multiformity of traffic flow models and the measure value variety of the same parameter, this paper analysed the modeling principles and the consistent of measure and statistics methods. In the light of the physical magnificence of model parameters, applying the dimension analysis method, the paper studied several traffic flow models and their parameters, and deduced the basic results about the similarity of these models and the function formulas of their parameters. The dissipation procedure of traffic flow density wave was analyzed by dimensionless theory, and the analytic conclusion can explain the dimensional counterpart of high velocity and low velocity traffic flow models. The dimension analysis method has theoretical and practical value for further developing traffic flow theories.More>
2005, 5(1): 78-81.
Ideal decision-making method of urban public traffic line network optimization
HU Qi-zhou, SHI Qin, ZHANG Wei-hua, ZHANG Ai-ping
Abstract: On the basis of considering each factor of urban public traffic line network, the optimization function expression and the restricted conditions of urban public traffic line network were presented. Based on ideal scheme's definition, the schemes were arranged in simple order according to the distance between each scheme and ideal scheme, so the decision-making model for the optimization of urban public traffic line network was presented. Applied results indicate that the method improve the used ratio of urban public traffic line network, optimization results accord to the real situation, the method is feasible.More>
2005, 5(1): 82-85.
Comprehensive evaluation on original and terminal stations of urban public transport
LI Tie-zhu, LIU Yong, LU Can, SHEN Li-fang, WANG Chao-yang
Abstract: In order to evaluate the layout, operation and service level of urban public transport original and terminal stations, and to optimize planning schemes, according to the five principles, such as comprehensiveness, practicability, comparability, independency and compatibility, ten evaluation indices were given respectively based on planning harmony, operational efficiency and environmental sustainability. The comprehensive evaluation system was conceived with AHP theory. In practical engineering, the indices were defined, their calculating methods and grade values were presented, the comprehensive evaluation method based on systemic clustering analysis theory was brought forward. The applied results indicate that this evaluation system could reflect comprehensively the layout, operation and environment impact of public transport original and terminal stations, and has extensive applicability and good operability, and could be used to plan and manage the original and terminal stations system of urban public transport.More>
2005, 5(1): 86-91.
Optimal path algorithm of road network with traffic restriction
WANG Feng-yuan, PAN Fu-quan, ZHANG Li-xia, ZOU Xu-dong
Abstract: Based on the principle of the shortest path algorithm in graphic theory, this paper described the optimal path solution in practical urban road network, which includes traffic control signal. The characteristics of road network with restricted routes were analyzed, the corresponding mathematic model was constructed to convert it into another road network with free routes. The relationship of road network joints was expressed, the traditional Dijkstra algorithm was optimized by dynamic adjacent node relation matrix and adjacent node weight matrix, the corresponding algorithm was constructed. A vehicle guidance system was developed with the optimized Dijkstra algorithm to find the optimal routes in the network. The results indicate that the system can reduce the computation nodes of road networks.More>
2005, 5(1): 92-95.
PPSA algorithm of strategic inventory routes
YE Zhi-jian, DU Wen, YE Huai-zhen, ZHOU He-fang
Abstract: In order to amend the shortcomings of replenishment period short of Larson's SIRSA heuristic algorithm, the paper set up PPSA heuristic algorithm, in which the inventory replenishment period and inventory replenishment phase are variables. The computational results show that when the vehicle is large enough to replenish several customers in a single trip and there is significant variation in the maximum inter-replenishment intervals of the customers, the vehicle demand of SIRSA algorithm is larger than that of PPSA algorithm.More>
2005, 5(1): 96-101.
Hybrid algorithm of vehicle's optimal route
YANG Rui-chen, ZHOU Yong-fu, YUN Qing-xia
Abstract: Ant-colony-system was improved in three aspects, such as visibility, trail update and parameters calculation. Its visibility was calculated according to the saving value and distance, its trail update was connected with several best solutions, its parameters was determined according to the generation. Hybrid algorithm was founded after adding 2-option (2-opt) to finish local search. The algorithm was applied to solve vehicle routing problem, so as to find the best path. Taking 5 vehicles model as an example, its total route is 855.68 km after calculation with the algorithm, its accuracy is better than one of genetic algorithm.More>
2005, 5(1): 102-105.
Models for determining minimum distance of ramps on urban expressway
LONG Ke-jun, YANG Xiao-guang, WANG Yue-hui, ZHOU Zhi-gang
Abstract: The distance of ramps is the key for designning road route, it has a big effect on the mainline traffic flow of urban expressway. According to the ramps features of urban expressway, the driving at the ramps of urban expressway was simulated with drivers behavior theory. In order to determine the minimum distance of ramps the lane lengthes for acceleration and deceleration were calculated under different ramp structures, and the calculating formulas were given. The model for determining the minimum distance of ramps was developed. An example shows that when the distance of ramps is less than the minimum distance, the vehicle's speed will be cut down, the service level of ramps will be reduced.More>
2005, 5(1): 106-110.
Model of pedestrians crossing time at signalized intersection
XU Liang-jie, WANG Wei
Abstract: In order to analyze the influence of turning vehicles on pedestrians crossing time, and to provide rational pedestrians control signal, the pedestrians number of crossing and waiting-crossing crosswalk were calculated, by using the conflict theory and the critical-gap accepted theory the models of pedestrians crossing time were built up. The absolute error and relative error of pedestrians crossing average time, are respectively 0.452 7 s and 4.15%, the absolute error and relative error of 85% pedestrians crossing average time are respectively 0.206 5 s and 1.57%; the absolute error and relative error of 90% pedestrians crossing average time are respectively 0.401 2 s and 2.84%. Computation results show that the precision of the models is high, the models are feasible for the pedestrians phase setting at signalized intersection.More>
2005, 5(1): 111-115.
Freeway integrated traffic control system based on multi-agent
HUANG Zheng, ZOU Qun, ZOU Guo-ping
Abstract: Freeway integrated traffic control system(FITCS) is a distributed-nonlinear-dynamic-complex-huge system. According to the hierarchical structure of intelligent control system, the distributed hierarchical architecture of FITCS was presented, and the multi-agent system(MAS) model of FITCS was constructed by taking agents as intelligent controllers of the distributed hierarchical control system. The agent construction model, constructing method, communication and cooperative mechanism in the MAS model were studied. The study of the system provides theory and method aguide for real application system development.More>
2005, 5(1): 116-119.
Travel choice characteristics of transportation corridor of Europe-Asia
PENG Hui, CHEN Kuan-min, WANG Jing-wei, WANG Yu-ping
Abstract: In order to estimate the travelers demand construction of comprehensive transportation corridor, the travelers structure of Europe-Asia transportation corridor(EATC) in China was investigated. 20% of the whole travelers are administers, most of other travelers are workers, peasants and businessmen. The income of highway travelers is below 1 000 Yuan, and the income of airline travelers is more than 2 000 Yuan. More than half of the whole travelers are businessment and visitors. Travelers will choose highway travel if the travel distance is within 200 km, and will choose plane travel if the travel distance is further than 1 500 km. Nearly 60% of the whole travelers would like to choose safety transport modes. Analyzing results indicate that the transport market will be expanded, the demands of travelers will be more diverse than ever with the development of the various transport modes.More>
2005, 5(1): 120-123.
Influence of adverse weather on vehicle trip at freeway
WANG Hai-yan, XIANG Qiao-jun, LU Jian, REN Ying-wei
Abstract: In order to analyzing the relations of vehicle trip probability with weather condition, trip distance and transportation safety facilities, the paper surveyed the number of vehicle trip at Shang-Kai freeway in severe weather, set up the regress models of vehicle trip probability with weather condition and trip distance. The complex correlativity coefficient of the models is 84%. Based on the influence of transportation safety facilities on the models, the paper summarized a compositive math model of vehicle trip probability. The results indicate that the vehicle trip probability has a direct proportion relation with trip distance and inverse proportion relation with severe weather condition, their influence degrees are 10%~50%.More>
2005, 5(1): 124-126.