Archive

15 April 2014, Volume 33 Issue 2 Previous Issue    Next Issue

---

For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Select

FailuRe Mechanism of MasonRy ARch BRidge by Analysis Method Hong Hua，Liu Shanhong，Ma Dengyang 2014, 33(2): 1-4.  DOI: 10.3969/j.issn.1674-0696.2014.02.01 Abstract ( )   PDF (207KB) ( )   Deformation or local cracking appears in masonry arch bridge under the excessive external loadings to adjust its own constraints． The masonry arch bridge disease was studied based on Heyman analysis method，D.K.McNeely analysis method and Qian Lingxi analysis method.Three hinge failure mechanism and qualitative analysis mechanism of the pressure line were presented to determine the damage of masonry arch bridge． References | Related Articles | Metrics

Select

Development of Cable Inspection System ?ased on Image Processing Liu Chaotao, Du Zixue, Wu Wei, Xiang Zhongfu 2014, 33(2): 5-9.  DOI: 10.3969/j.issn.1674-0696.2014.02.02 Abstract ( )   PDF (418KB) ( )   A stayed cable health inspection system based on the image acquisition and processing was developed , which con sisted of robot , hosl computer , cameras and image acquisition syslem. The robot was driven with single motor and could automatically climb cables of various diameters. Omni-directional pictures of the cables were taken by the robot , and the de fects and mars were identified through the automatical recognition of the cable image. The steps of image recognition including image de-noising , image enhancement , image segmentation and feature extraclion , and lhe defecls and mars were iden tified from the features of the grayscale distributions and energy distributions in grey level histogram. References | Related Articles | Metrics

Select

Primary Analysis of The Additional Moment of Center Axis For The Whole Mechanics of Column with Reinforced around The Cross Section Wang Jun，Liu Shaoqian，Su Wenming，Zheng Gang 2014, 33(2): 10-14.  DOI: 10.3969/j.issn.1674-0696.2014.02.03 Abstract ( )   PDF (354KB) ( )   According to the theory of the basic mechanics. the mechanical mode of the concrete column with reinforced around the section was predigested. The force balance equation and torque-equilibrium equation were presented by derivation. The deviation of cenler axis in the crazing cross-section of the bridge pier in the course of earthquake was analyzed The conception of the additional moment of center axis was adopted , and the cause of the additional moment of center axis and its influence on the mechanics and the whole stiffness of column were discussed. The results show that , in a certain sense , the additional moment of center axis could offset the horizontal defoτmation of column with reinforced around the cross-section; and could restrain the cross-section to crack and defer the degradation of stiffness. And it is recommended that the additional moment of center axis should be considered in the seismic analysis of the stmcture. References | Related Articles | Metrics

Select

Damage Mechanism of Simply Supported Beam Bridges' Pier and Girder in Wenchuan Earthquake Xiao Xuhong 2014, 33(2): 15-20.  DOI: 10.3969/j.issn.1674-0696.2014.02.04 Abstract ( )   PDF (432KB) ( )   Study on damage mechanism of bridge is the important procedure which turns seismic damage investigation results into a practical technology. Some damage features of simply supported beam bridges which differ from the features in other earthquakes are shown in Wenchuan earthquake. The damage mechanism of pier and girder was simulated by FEM analysis and seismic table test. The results show that the seismic action of girder released by relative sliding between girder and bearing is why the damage of pier is reduced in Wenchuan earthquake. The displacement of girder is coordinated by continuous pavement , and the longitudinal displac&lnent is restrained by abutment , which reduces the risk of girder fell down. A complete seismic resistance system is formed by girder, pier, bearings , abutment , continuous pavement in simply supported beam bridges; the seismic action of girder is released and the risk of girder fell down is reduced by the system. References | Related Articles | Metrics

Select

VibRation Analysis of BRidge undeR TRains ConsideRing TRansient Jump of Wheel Yang Hongyin，Zhang Hailong，Chen Zhijun，Huang Wen 2014, 33(2): 21-25.  DOI: 10.3969/j.issn.1674-0696.2014.02.05 Abstract ( )   PDF (468KB) ( )   The non-linear Hertz contact theory was adopted and then linearized，and a new vehicle-bridge interaction element considering the transient jump of wheel was derived，which solved the deficiency of the no-jump assumption in the traditional analysis． The dynamic equations of the interaction system were then formulated by means of the“set-in-right-position”rule for formulating matrices，and the combination method and the solution procedure were also presented． Finally the corresponding calculation program was coded，and the proposed interaction element was adopted to analyze an established railway bridge． The results demonstrate that the dynamic acceleration response of the bridge significantly increase and the results of moving loads model are safer under the vehicle-bridge resonance． The abrupt irregularity causes strongly high frequency vibration and makes the dynamic acceleration response of bridge remarkably increase． When there is no jump of the wheel， the result from the proposed method is consistent to the traditional one． But when the jump happens，the proposed method also yields a true result while the traditional one can’t，and the transient jump of wheel has been accurately simulated by the proposed method． The model considering transient jump of wheel should be adopted to analyze the vehicle-bridge interaction and the track maintenance and the deformation control of bridge should be paid more attention． References | Related Articles | Metrics

Select

Crack Width Monitoring of Concrete Structures Based on Smart Film Zhang Benniu，Fan Zhonghua，Huang Rui，Zhang Xu，Yang Guang，Li Xingxing，Wu Tao 2014, 33(2): 26-29.  DOI: 10.3969/j.issn.1674-0696.2014.02.06 Abstract ( )   PDF (315KB) ( )   Smart film monitoring method has the capability of monitoring the important features of concrete structures effectively， such as occurrence，location，shape，length and development of initial crack． Aiming to monitor the crack width of concrete structures，the improved smart film adopted several groups of bunched magnetic wires which were horizontally placed． Each group of bunched magnetic wires was composed by a few of magnetic wires with different diameters，and each magnetic wire had different ultimate tensile strain． Therefore，the direct proportion between the ultimate tensile strain of magnetic wires and the crack width of structures was verified by the theoretical derivation and experiments． And the crack width can be indirectly calculated by the ultimate tensile strain of magnetic wires． References | Related Articles | Metrics

Select

Large Span Bias Weak Surrounding Rock Double-Arch Tunnel Construction Process Gao Feng ，Xue Dianli 2014, 33(2): 30-34.  DOI: 10.3969/j.issn.1674-0696.2014.02.07 Abstract ( )   PDF (348KB) ( )   The process of the construction of the transitional joint arch tunnel of Ziyin Tunnel in Zunyi was simulated by ANSYS FEM program. The stress states of sUITounding rock , ground settlement and the change of intemal forces of tunnel support structure during each period of construction were analyzed by the analysis of 3 excavation conditions. Through the comparative analysis and the monitoring and measurement data in the field construction , it is revealed that different excavation sequences have different effects on the tunnel stlucture in biased state. References | Related Articles | Metrics

Select

Influence of Bridge Pile Construction Vibration on Adjacent Buried Pipeline She Yanhua, Su Huayou 2014, 33(2): 35-39.  DOI: 10.3969/j.issn.1674-0696.2014.02.08 Abstract ( )   PDF (379KB) ( )   Through developing field micro-seismic trial , the characteristics of vibration attenuation of bridge pile construction and sphere of inf1uence were analyzed to assess their impact on the buried pipeline nearby. It is concluded that the amplitude of vibration energy have been enlarged with the presence of the pipeline; it should make the smface peak velocity above the pipeline as the main control index in routine vibration monitoring of pile foundation construction adjacent to buried pipeline. By analyzing positioning of impacting vibration source , the rupture area of rock and soil around the pipeline caused by the vibration was determined , and the conesponding security ll1easures for pipeline protection was proposed. It provides a new trial ll1ethod of control technology for pile foundation construction. References | Related Articles | Metrics

Select

Application of Transient Electromagnetic Method in Subsidence Area of Collapsible Loess: Case Study of Chang-Yan Separate Overpass Jiang Bo，Wang Zhirong，Jia Yakun，Zhang Limin 2014, 33(2): 40-43.  DOI: 10.3969/j.issn.1674-0696.2014.02.09 Abstract ( )   PDF (318KB) ( )   For the specialties of subsidence problems of collapsible loess in West Henan，the transient electromagnetic method was applied to explore the resistivity response characteristics of the non-layered system in loess areas，including the chasm，fracture and collapse body of water． A program which could make a direct and dynamic query of soil moisture according to a visible resistivity ρ value was designed to realize the quick conversion of soil moisture information from the electric information． According to the case studies，10 percent of water content was the criterion of judging the collapsible area． The geophysical interpretation and prediction methods were proposed to deal with loess collapsibility problems in West Henan，and the exploration engineering was used to verify the effect of detection，which is a good example for the similar complex project． References | Related Articles | Metrics

Select

Influence of Interlayer Contact on the Mechanics Behavior of Semi-rigid Asphalt Pavement Li Xing , Liu Zhifang , Song Xiaoyan 2014, 33(2): 44-48.  DOI: 10.3969/j.issn.1674-0696.2014.02.10 Abstract ( )   PDF (366KB) ( )   Based on the typical multilayer elastic layered system , the asphalt pavement structure was divided into top surface layer , middle surface layer， bottom surface layer , semi-rigid base and soil base. Considering the contact between layers of the structure , a three dimensional finite element interlayer-contact model was established and the contrast analysis with the interlayer-continuous model was conducted by ABAQUS. In two different finite element models , the deflection values of the pavement with the vehicle load , the max principal stress of asphalt surface and semi-rigid base , the min principal strain of top soil base and the max shearing stress of the structure layer were presented. The results show that the designed value for the thickness of semi-rigid pavement based on interlayer-continuous model is smalL lt causes damages in the early operation stage of asphalt pavement. And the interlayer-contact model is in line with the real working state of the pavement layer bet ter. The interlayer-continuous model is suggested to use in the designing of thickness for semi-rigid pavement References | Related Articles | Metrics

Select

Impacts of Base Parameters on Mechanical Properties of Cement Pavement Considering Interlayer Contact Zhang Yancong , Zhao Duijia , Liu Shaowen , Shen lunmin 2014, 33(2): 49-52.  DOI: 10.3969/j.issn.1674-0696.2014.02.11 Abstract ( )   PDF (368KB) ( )   Three-dimensional structure model with Winkler foundation situation was established considering interlayer contact. The effects of base modulus , thickness , interlayer contact situation between slab and base on the maximum stre岛s of slab and base , shear stress between slab and base , warping of slab were calculated. The results show that interlayer contact status has great influence on slab stress and warping. Maximum stress of slab bottom decreases while bonding status decreases , slab warping and warping scope increase obviously while bonding status decreases. Base modulus is the key factor for base stress. Maximum stress of base increases while modulus increases , and decreases while bonding status decreases. Interlayer shear stress occurs mainly at slab edge , and decreases while the bonding status weakens. It has no variation with the changing of base modulus and thickness. References | Related Articles | Metrics

Select

Ring Test Research of the Permanent Deformation on Flexible base Precast Block Pavement Wang Huoming, Ling Tianqing , Zhou Gang , Wang Xiu 2014, 33(2): 53-57.  DOI: 10.3969/j.issn.1674-0696.2014.02.12 Abstract ( )   PDF (337KB) ( )   The permanent deformation characteristics of the graded gravel f1exible base precast block pavement were tested by the full-scale indoor ring road tes t. And the inf1uence of joint width , sand cushion thickness , block thickness and loading times on the precast block pavement permanent deformation was also analyzed. The results show that the absolute value of the joint width variation is less than 2 mm under the load; there is a positive correlation between joint width and final permanent deformation; the right joint width is 3 - 8 mm; in the case of the same joint width , the thickness of the sand cushion inserts for precast block paving squeeze have no impact on the formation of the state , but have impact on the size of permanent deformation for the final pavement. Then the appropriate sand cushion thickness is 2 - 5 cm. Block thickness has little inf1uence on pavement permanent deformation. And the relationship between permanent deformation L and load times N for the precast concrete block pavement was then established. References | Related Articles | Metrics

Select

Applicability of Fly-Ash for High Embankment in Widening Engineedng Zhang Xiaolei , Hu Haiyan 2014, 33(2): 58-62.  DOI: 10.3969/j.issn.1674-0696.2014.02.13 Abstract ( )   PDF (334KB) ( )   Based on the field tests and theoretical analysis , the applicahility of f1y ash as fillers in the subgrade widening construction was analyzed. The mechanical responses of two parts which were separately filled by the fly ash and soil with geogrid were compared. The settlement rules of the suhgrade and foundation in the suhgrade widening construction filled by f1y ash and reinforced by geogrid were studied. The rationality and applicability of f1y ash in filling the high embankment were also analyzed References | Related Articles | Metrics

Select

2D and 3D DEM Numerical Research on the Conventional Triaxial Test Zhou Jie 2014, 33(2): 63-67.  DOI: 10.3969/j.issn.1674-0696.2014.02.14 Abstract ( )   PDF (423KB) ( )   The conventional triaxial test was simulated by DEM software PFC2D and PFC3D， and the inf1uence of model di mension on DEM studies was analyzed from the macro mechanical behaviors and the micro fabric characteristics. Numerical simulation results indicate that , stress-stain curves of densest 2D and 3 D numerical specimens both show obvious softening characteristics , the slrains cOlTesponding to the peak strength of 3D specimens are 75% smaller than that of 2D specimens. The peak strenglhs of both specimens iricrease with confining pressure , and the peak strength of 3D specimen under high confining pressure becomes larger than that of 2D specimen. The shapes of macro shearing band of 2D and 3D numerical specimens are different under the same confining pressure level , which are determined by the distribution of tangential contact force between particles. The increase of the confining pressure makes the distribution of tangential contact force between particles of the DEM specimens tend to the contact normal distribution , which is in the form of concentrated shear band of speclmen m macro. References | Related Articles | Metrics

Select

Test Study on Interface Properties of Geogrids Reversely Packaging Retaining Wall Surface Layer Made by Ecological Bags Wei Junyang, Wang Baotian, Zhang Haixia, Lan Riyan 2014, 33(2): 68-71.  DOI: 10.3969/j.issn.1674-0696.2014.02.15 Abstract ( )   PDF (310KB) ( )   Through the ecological bag intelface direct shear test and the drawing lest by choosing two kinds of warp knitted polyester geogrid with the same grid size and different strength reversely package retaining wall surface layer made by ecological bags , the intelface properties of different kinds of geogrid reversely packaging retaining wall surface layer made by ecological bags was studied. The test results show that: the shear fl~ction strength between ecological bags bagged with clay and the drawing test strength of geogrid reversely packaging ecological bags both increase with the normal stress increasing , and both of their strength envelopes are straight lines; the reverse drawing test strength is greater than the shear friction strength; the average friction coefficient and cohesion of reverse package drawing test are greater than the shear test , but the friction angle is opposite; and the peak value may not appear in drawing strength-displacement curve; the strong geogrid reverse drawing test strength is stronger than the weak geogrid reverse drawing test , and the cohesion , friction angle and the average friction coefficient have the same rules. In the engineering construction , it is recommended to choose high-strength geogrid to stiffen the stability of earth-retaining wall surface. References | Related Articles | Metrics

Select

Development Progress and Prospects of Overhead Upright Wharf Structure Dai Jun，Wu Linjian，Guo Chengxin，Peng Huajun，Shu Dan 2014, 33(2): 72-75.  DOI: 10.3969/j.issn.1674-0696.2014.02.16 Abstract ( )   PDF (396KB) ( )   The construction of the three gorges project brings unprecedented opportunities for inland waterway, But it make the wharf construction in reservoir faced a new challenge. At the same time, it also promote a breakthrough development of the wharf structure in reservoir .This paper reviews the commonly used wharf structure, Detailed describe the Structure, advantages and disadvantages. Focus on the analysis of the development progress and the development trend of the new Wharf structure type——vertical-faced frame container wharf. Put forward the idea that optimizing the Wharf structure by Rock-socketed pile fork and raking pile, provide some reference to the development of wharf structure type in the three gorges reservoir area. References | Related Articles | Metrics

Select

Sediment Physical Model Research at the Area of Lao-Mu-Kong Reservoir Ni Zhihui，Yi Jing ，Zhang Xujin，Du Zongwei，Wang Yunli 2014, 33(2): 76-80.  DOI: 10.3969/j.issn.1674-0696.2014.02.17 Abstract ( )   PDF (468KB) ( )   After the running of the Lao-Mu-Kong hub, the water level in the reservoir area increased, flow rate generally decreased, the slope of the river became gentle, the capacity of sediment transport decreased, the sediment occurred cumulative siltation. In order to study the impact of siltation at the Le-Shan Giant Buddha in Le-Shan City, the sediment physical l model of river siltation at the reservoir area in reservoir area is created. Quantitative analysis of the amount of river siltation and sediment deposition distribution within 20 years, and predicted the river siltation at reservoir area. The results show that the sediment mainly siltation in perennial backwater area, but siltation little in fluctuating backwater area at the end of hub run 20 years. For all levels of frequency flood, flood level has not been more than the natural flood level of the same frequency before the construction after siltation at the reservoir area, so it has little effect on Le-Shan Giant Buddha and Le-Shan city. References | Related Articles | Metrics

Select

Damage of Highways Caused by Debris Flow and Disaster Prevention after Earthquake Liu Cuirong, Yao Lingkan,Du Cui 2014, 33(2): 81-85.  DOI: 10.3969/j.issn.1674-0696.2014.02.18 Abstract ( )   PDF (410KB) ( )   The typical damage events of highways along rivers caused by debris flow in Wenchuan earthquake areas were studied. Four disasler models of highways along rivers caused hy debris flow were concluded , deposit , erosion , impact and damming-river. According 10 the phenomenon Ihat Ihe most serious damage 10 highways along rivers was caused by dammingriver by debris flow , the disaster prevention mode of making greatesl use of Ihe maximum capacity of canying sediment of Ihe main river was proposed. Based on the calculation equation of head 四water level and criteria of disaster at the opposite river bank caused by debris flow river-blocked , the method of determining the maximum capacity of canying sediment of main riv er was then presented. References | Related Articles | Metrics

Select

Activity Intensity Assessment Method of Landslide Geohazard Caused by Earthquake Dang Jie，Chen Jun，Yang Shengyuan，Guo Guo 2014, 33(2): 86-89.  DOI: 10.3969/j.issn.1674-0696.2014.02.19 Abstract ( )   PDF (319KB) ( )   The geological hazards caused by the earthquake have a characteristic of gregariousness. Since there is no unified activity intensity assessment method, it’s very hard to horizontally analysis the different between all the seismic geological disasters. On the basis of the energy released by geological disasters for the strength evaluation, using the physics principle of friction works convert the mechanical energy into internal energy, put forward the assessment indicators and methods of activity intensity for landslides geological disasters caused by earthquake. Taking a typical landslide geological disaster occurred within the region of Yunnan-Guizhou "9.7" earthquake in Guizhou as an example, provide reference and help for quickly and easily assessing the energy of geological disasters. References | Related Articles | Metrics

Select

Characteristics and Application of Electrical Resistivity of Soil-Stone Composite Medium Wang Kui, Zhao Mingjie 2014, 33(2): 90-94.  DOI: 10.3969/j.issn.1674-0696.2014.02.20 Abstract ( )   PDF (397KB) ( )   The earth-rock particles features , rock content , Illoisture content and cOlllpaction degree of the Illultiphase soi\ - stone composite medium have a great illlportant effect on lhe electrical resistivity characteristics. Because of the correlation between each faclor , the conductivity of Illultiphase soil-stone cOlllposite medium becallle cOlllplicaled. Based on the current electrical resistivity models of unsaturated and pure soil ancl rock meclia , the physical Illoclel of the concluctivity for Illulti 田 phase earth-rock composite mecliulll was establishecl , ancl the theoretic relationship between electrical resistivity ancl the physical characteristic parameters was presentecl. Accorcling to the research , the feature parameter of earth-rock cOlllposite mecliUlll is proposecl in clifferent neecls basecl on resistivity testing technique. References | Related Articles | Metrics

Select

Assessment of Geological Environment Carrying Capacity of Fengjie County Based on AHP Yang Le，Peng Haiyou，Zhou Molin，Xie Hongbing，Luo Zhenfu，Tan Liang 2014, 33(2): 95-99.  DOI: 10.3969/j.issn.1674-0696.2014.02.21 Abstract ( )   PDF (442KB) ( )   Considering the geological and regional feature，the assessment system of geological environment bearing capacity was established，and the weights assessment indexes were presented by Analytic Hierarchy Process ( AHP) ． Through extracting， analyzing and processing the assessment indexes by means of GIS，the zone map of geological environment bearing capacity of Fengjie County was obtained． The results provide a scientific evidence for the construction plan for Fengjie new town and provide a reference for the relocated cities of similar reservoir areas and city construction of hilly and mountainous areas． References | Related Articles | Metrics

Select

Heavy Metal Pollution Level of Urban Soil ?ased on Two Models Gong Jie，Zhang Min，Lei Lin 2014, 33(2): 100-102.  DOI: 10.3969/j.issn.1674-0696.2014.02.22 Abstract ( )   PDF (228KB) ( )   A comprehensive pollution index model was established by the fuzzy mathematical analysis method. Carmelo inclex model was established by the use of discrete mathematical principles. And then the degree of heavy metal contamination of urban soils was analyzed and evaluated by the two models mentioned above. The results show that in Nan' an District , the pollution level of traffic areas is the highest; the industrial parks are in a cordon grade; the utility area and the agricultural area is in light degree of contamination and clean grade respectively. It is consistent with the actual situation and the models are reliable. References | Related Articles | Metrics

Select

Minimum Spacing between Successive Exits Terminals in Interchange Ramps Gao Jianping，Liao Li 2014, 33(2): 103-107.  DOI: 10.3969/j.issn.1674-0696.2014.02.23 Abstract ( )   PDF (371KB) ( )   The minimum spacing between successive exit terminals in interchange ramps, a index when planning and designing, has an important effect on traffic operation. Firstly, the effect of traffic volume, operating velocity, layout of traffic sign on minimum spacing was analyzed. Secondly, lane-change behaviors in ramp successive exit area was studied based on investigation, composition of minimum spacing was analyzed on different types of lane-change, which was conducted traffic safety evaluation with traffic conflict technique. Furthermore, according to traffic sign recognition distance, the required minimum safe distance of lane-change and the length of deceleration lane, the model of minimum spacing between successive exit terminals in interchange ramps has been established based on drivers’ behavior theory and the gap acceptance theory. At last, the reliability of the minimum spacing model was verified by using an example application, and furthermore, it proved that the model can provide technical reference for interchange planning and designing in mountain city. References | Related Articles | Metrics

Select

Spacing and Function Configurations of Service Facilities Based on the Demand Characteristics of Drivers and Passengers Cui Hongjun，Xing Xiaogao，Liang Guofeng，Zhu Minqing 2014, 33(2): 108-112.  DOI: 10.3969/j.issn.1674-0696.2014.02.24 Abstract ( )   PDF (248KB) ( )   The demands and the toleration elasticity of drivers and passengers were investigated and analyzed． And according to the spacing setting of the service facilities in home and abroad，it is concluded that more attention should be paid to the construction of the parking area in the highway construction，and the service facilities reasonable spacing should be controlled in the range of 15 km． According to the quantity of the service facilities on the freeway and the total demands of various types，the service facilities spacing and function configurations method was proposed based on the total demands and the toleration elasticity of drivers and passengers． References | Related Articles | Metrics

Select

Reconstruction of Pedestrian-Vehicle Collision Accident Based on PC-Crash Zhu Lusheng，Pan Gongyu，Zhang Xuerong 2014, 33(2): 113-117.  DOI: 10.3969/j.issn.1674-0696.2014.02.25 Abstract ( )   PDF (336KB) ( )   A real vehicle-pedestrian crash case study was performed to establish the field model for vehicle-pedestrian crash accident by PC-Crash，according to the relevant information collected from the accident site． Then the orthogonal test was utilized to analyze the weights of various parameters and simulate the reconstruction of the vehicle-pedestrian crash in the assistance of analysis results． Vehicle-pedestrian position value and dynamic response on pedestrian’s head and chest were consistent with the measured vehicle-pedestrian position value and the pedestrian’s head and chest damage． It indicates that the orthogonal test is able to effectively assist PC-Crash to select parameters in the accident simulation to obtain the reasonable results． References | Related Articles | Metrics

Select

Drivers' Visual Characteristics and Mental Load Based on Entropy Rates Peng Jinshuan，Gao Cuicui，Guo Yingshi 2014, 33(2): 118-121.  DOI: 10.3969/j.issn.1674-0696.2014.02.26 Abstract ( )   PDF (313KB) ( )   In order to analyze the influence of driving experience on drivers' visual characteristics and mental load , appropr: iate drivers were selected in the test , and driving behavior extraction experiments in urban road environment were designed. The interest areas were rationally divided , and the concept of fixation entropy rate was also introduced. The inf1uence of proficiency level and different pass modes at the intersections on drivers' visual characteristics was analyzed , and the impact of driving experience on drivers' mental load was then discussed. Results show that: the experienced drivers' visual search frequency is higher than the unskilled dri vers; during different passing modes at the intersections , visual search frequencies of left tum modes are remarkably higher than those of straight-going and right tum; in similar driving environment, the experienced drivers' mentalload is lower than unskilled counterparts. Research conclusions provide theoretical guidance to drivers' proficiency evaluation and dr:iving suitability test and it is practical and useful. References | Related Articles | Metrics

Select

Route Optimization of Multi-Trip Single Vehicle ?ased on Real Time Road Network Peng Yong，He Junsheng 2014, 33(2): 122-125.  DOI: 10.3969/j.issn.1674-0696.2014.02.27 Abstract ( )   PDF (257KB) ( )   The route optimization of multi-trip single vehicle was studied considering the vehicle speed changed with the time and route in real time road network. A multi-trip single vehicle route model based on the real time road network was established to find the shortest route between any two customers. A Dijkstra-GA algorithm was proposed to find the shortest route between any two customers by the Dijkstra algorithm; and the genetic algorithm is used to optimize the customer distribution sequence. The numerical examples demonstrate the Dijkstra-GA algorithm is effective and it is important to consider the vehicle speed changing with time when vehicle route schedule is made. References | Related Articles | Metrics

Select

Similar Particle Swarm Optimization Algorithm for the Optimization of Container Loading Model Lian Zhigang，Lin Weitian，Cao Yu，Ji Chunle 2014, 33(2): 126-130.  DOI: 10.3969/j.issn.1674-0696.2014.02.28 Abstract ( )   PDF (439KB) ( )   When the goods were loading into container with the limited size and weight in different ways , there were great differences in the capacity utilization. Through the detailed analysis， a mathematical model error of container loading case in operations research was presented. A case study was conducted to find that when the loading goods can' t be defonned , the model solution was wrong. The mathematical model which corresponded with the fact of container loading was established , and similar particle swarm optimization algorithm (SPSO) was used to achieve the maximum use of the container' s volume and weight. It is indicated that the SPSO is feasible and efficacious. References | Related Articles | Metrics

Select

Determination of Reasonable Ownership Scale for Urban Taxicab System Wang Ying，Su Jie，Hou Jing 2014, 33(2): 131-134.  DOI: 10.3969/j.issn.1674-0696.2014.02.29 Abstract ( )   PDF (298KB) ( )   Based on the theory of supply-demand balance and utility, the model of rational urban taxicabs developing scale is constructed according to the analysis of urban taxicabs supply-demand, Operation profits and passenger utility. A numeral example about Xi’an shows the model is reasonable and feasible. References | Related Articles | Metrics

Select

Vehicle Emission Inventory in Urban Areas of Chongqing Based on IVE Model Feng Xiao，Wang Tingli，Zhao qi 2014, 33(2): 135-137.  DOI: 10.3969/j.issn.1674-0696.2014.02.30 Abstract ( )   PDF (191KB) ( )   The IVE model was introduced and analyzed． And a case study relating the urban areas of Chongqing was conducted． The survey method of the main data and the calculation method of emissions amounts of IVE model were presented． Finally， the vehicle emission inventory at the urban areas of Chongqing in 2011 was established by the IVE model． It provides a good preparation for the treatments of traffic environment at Chongqing urban areas． References | Related Articles | Metrics

Select

Extrapolation Method of Motor Load Characteristic Based on Isoparametric Transformation Interpolation Method Zhu Jiangsu, Gang Xianyue, Chai Shan 2014, 33(2): 138-141.  DOI: 10.3969/j.issn.1674-0696.2014.02.31 Abstract ( )   PDF (273KB) ( )   The experimental data of engine load characteristics were important parameters for motor load characteristics. By using the experimental data of load characteristics , the mathematical modal of isoperimetric transformation interpolation method was established , and the vehicle load characteristics in the arbitrarily condition were calculated (including the fuel properties and emission characteristics of the load). Using the fuel consumption rate of the engine in the unit Lime in the idling condition , the values of fuel consumption rate in the idling condition and in the condition that the output torque was zero were obtained by extrapolation method. The validit)' of the calculation model' s deduce and establishment was verified by the case study. References | Related Articles | Metrics

Select

Strength and Vibration of One-Way Fluid-Solid Coupling Turbocharger Impeller Du Zixue，Han Shanhe，Liu Yaqian，Zha Lei 2014, 33(2): 142-145.  DOI: 10.3969/j.issn.1674-0696.2014.02.32 Abstract ( )   PDF (294KB) ( )   In order to acquire the more real and detailed stress status of a centrifugal compressor impeller with splitter blade , three-dimensional entity model was established. One-way fluid-solid interaction analysis was canied out by the fluid dynamics and the finite element method. The three-dimensional flow field model of one-tvvay passage and the stmcture finite element model for the impeller were established. The interfaces belween the software were used 10 realize the pressure dala transfer between flow field and stmcture field. Maxi flmm stress and strain distribution of the impeller , which was gained by the simultaneous effect of the centrifugal and aerodynamic force , were acquired. And lhe analysis and calculation of lhe stalic strength of the impeller was finished and the reliability of impeller strength of was proved. The modal analysis was caITied out on the static results. The influence of rotation speed on natural frequency was analyzed , and a resonance point at the common rotation speed was also presented. References | Related Articles | Metrics

Select

One Dimensional Numerical Simulation of Hydrogen-Enriched HCNG Engine An Na, He Yituan, Qiao Haijiang, Su Zhikai, Shao Yiming, Xie Fei 2014, 33(2): 146-149.  DOI: 10.3969/j.issn.1674-0696.2014.02.33 Abstract ( )   PDF (282KB) ( )   To prevent backfire in a hydrogen-enriched HCNG engine and improve the accuracy of simulation model, a simple one-dimensional simulation model for hydrogen-enriched HCNG engine was built up based on the engine specifications in the software of AVL BOOST. The model was applied to various parametric studies , including compression ratio and valve timing .The results show that the increasing in compression ratio improves the power and fuel economy of the engine .The charging efficiency，power and fuel economy of the engine are reduced because of decreasing of the valve overlap. Improving compression ratio and reducing valve overlap can avoid backfire in hydrogen-enriched HCNG engine. References | Related Articles | Metrics

Select

Design of Drive Mechanism with Large Steering Angle for Electric Car Ji Congdong，Ge Ruhai，Wang Bin，Liu Defang 2014, 33(2): 150-153.  DOI: 10.3969/j.issn.1674-0696.2014.02.34 Abstract ( )   PDF (380KB) ( )   An independent drive mechanism that could achieve the large angle steering was presented． The maximum steering angle of the proposed mechanism was approaching ± 90℃． The drive motor and steering motor were arranged on the frame of the vehicle，which reduced the un-sprung mass and improved the ride performance of the electric car． The speed control algorithm for drive motor of the mechanism in different steering modes was analyzed theoretically． The 3D model of the mechanism was established by NX software． Finally，a case study relating the left front wheel was conducted to verify the correctness of the control algorithm through the simulation analysis． References | Related Articles | Metrics

Select

Reduction and Improvement Strategy of Training Sample Set for SVM Based on Class-Center Pang Shouyan，Chen Song，Wei Jianmeng，Zhang Yuansheng 2014, 33(2): 154-158.  DOI: 10.3969/j.issn.1674-0696.2014.02.35 Abstract ( )   PDF (164KB) ( )   SVM has practical applications in many fields for its superior performance at present． However，it has become a bottleneck to use SVM due to the problems including slow learning speed，large save requirement，and low generalization performance． Then an improvement reduction strategy was proposed based on the class-center，which significantly cut the amount of training samples and improved the training speed by determining the boundary training sample set． In addition，for the question that in the nonlinear space the center of the feature space class can not be directly obtained by calculating，an alternative strategy was proposed． In the alternative strategy，the sample spots that could generate the smallest hypersphere in the feature space which approximately substituted the center of feature samples were found． It improves the learning speed without reducing the classification accuracy． References | Related Articles | Metrics