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中文核心期刊
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中国科技核心期刊
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    Bridge & Tunnel Engineering
    Automatic Meshing of Box Girder Based on TetGen 3D Tetrahedral Element
    WANG Jialin,DUAN Hongjun
    2016, 35(5): 1-4.  DOI: 10.3969/j.issn.1674-0696.2016.05.01
    Abstract ( )   PDF (1155KB) ( )  
    Based on VC++ platform, the tetrahedral mesh generation interface software—TetGen was used to study high quality tetrahedral element generation method of box girder with varied cross section of generation single box with single cell. The girder cross section was described with facet of multiply connected plane polygon and letter and symbol string function was used to describe coordinate variation at respective feature points on the box girder cross section. First of all, it was mapped from plane cross-section facet to space cross-section facet. Secondly the connected facet of adjacent space facet was generated automatically, thus spacial polyhedron of box girder was achieved. The tetrahedral mesh generation interface software—TetGen was used to subdivide spacial polyhedron. High quality tetrahedron element was generated automatically. The network data was written in inp document which was subscribed in software Abaqus which allowed for visual inspection and verification of effectiveness of this grid.
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    Dynamic Reliability Analysis of Serviceability State for RC Beam Bridges Strengthened with CFRP Sheet
    CHEN Qiang
    2016, 35(5): 5-8.  DOI: 10.3969/j.issn.1674-0696.2016.05.02
    Abstract ( )   PDF (1941KB) ( )  
    The model simulating the mean and standard deviation of load effects for serviceability limit state of RC beam bridge strengthened by CFRP sheets were developed, and then the fuzzy equivalent method was used to convert deflection equivalent under serviceability limit state of bridge in service into equivalent uniform-distribution function in a certain range. On basis of this, the formulation for serviceability limit state of RC beam bridge strengthened with CFRP sheets was formulated. Combined with an actual bridge strengthened with CFRP, the JC checking point method was employed to calculate the dynamic reliability index of serviceability limit state at the completion of reinforcing works and in some time after such strengthening work done. The study findings show that after the bridge being reinforced with CFRP, #1 girder still fails to satisfy the required normal serviceability and #2 girder, and after being reinforced and serving over 30 years still fails to satisfy the required normal serviceability, both of which indicate the defect of the currently applied CFRP in respect of reliability of normal serviceability of bridge strengthened with CFRP.
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    Study on the Crack Pattern of RC Beam Bridge Based on Gold-division Ratio Model
    SONG Jun, ZHOU Jianting, WANG Mingbin, JIANG Rui
    2016, 35(5): 9-12.  DOI: 10.3969/j.issn.1674-0696.2016.05.03
    Abstract ( )   PDF (1224KB) ( )  
    A gold-division ratio was first introduced as a new approach to evaluate the crack distribution pattern for RC beam bridge.The crack opening and space of cracked concrete was predicted by establishing a concrete “single rebar tension model” and by compiling procedures and finally the accuracy of the obtained parameters were verified by conducting model experiment and numerical simulating. The results of above study show that application of gold-division ratio in analyzing crack opening and space of cracked concrete is of profound physical significance and the research results also reveal that crack spacing of concrete beam is of size effect. The significance of this given method lies that scale model can be used to predict the crack distribution pattern of large bridges and thus provides guidance to safety assessment of concrete bridge.
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    The System Design of Cable Cranes Applied in Erection of Long-span Suspension Bridge in Mountainous Region
    CHANG Wen, ZHU Dongsheng, LIU Dejing, LIANG Jingda, LI Qingda, QIU Dayan
    2016, 35(5): 13-16.  DOI: 10.3969/j.issn.1674-0696.2016.05.04
    Abstract ( )   PDF (1233KB) ( )  
    The salient features of the cable crane for suspension bridge erection were introduced and in combination with the design of cable crane with thousand-meter scale and large tonnage capacity for Longjiang River Bridge design key points and common forms for such major components or configurations as cable crane,tower support on top of bridge tower, cable support, anchorages of main cables were addressed.The results of analysis can be reference to the cable crane design for suspension bridges erection.
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    Sensitivity Analysis of Influences on Internal Force of Soil Tunnel Lining under Frost Heave Force
    HUANG Jie,SHI Yalong,LIU Zhiqiang
    2016, 35(5): 17-21.  DOI: 10.3969/j.issn.1674-0696.2016.05.05
    Abstract ( )   PDF (1458KB) ( )  
    The influences of tunnel lining internal forces (bending moment, axial force and maximum tensile stress) on soil frost heave ratio, frozen ring thickness, lining thickness and rock elastic modulus were simulated, calculated and analyzed by use of finite element numerical model and then the relations between them were also analyzed. The results indicate that the free frost heaving ratios of surrounding rock affected tunnel lining moment, axial force and tensile stress significantly while tunnel lining moment had small influence on ground elastic modulus and tunnel lining internal forces were notably influenced by depth of frozen ring while lining thickness had relatively weak influence on lining internal forces. It is thus suggested that thermal insulation be provided in seasonably frost soil zone and grouting injected in certain area behind the lining.
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    Numerical Simulation of Single Crack Propagation and Damage Evolution Mechanism of Rock Specimens
    ZHAO Cheng, LIU Fengming, YANG Lei, TIAN Jiashen
    2016, 35(5): 22-27.  DOI: 10.3969/j.issn.1674-0696.2016.05.06
    Abstract ( )   PDF (1475KB) ( )  
    The whole process of crack initiating, propagation and through of rock specimen with single crack at various preset inclination angles under single axial compression was simulated by use of extended distinct element method (EDEM) and the stress variation in crack spreading stages was investigated and explored and the mechanism of single crack spreading with various preset inclination angles was analyzed. The results show that with the increase of inclined angle α of preset crack, the crack—starting stress of new cracks and compressive strength of the specimen are in overall tendency of increasing and sharp change occurred when α=30°. The crack developed most rapidly when α=30° . When α=15°, 45°, 60°, 75°, the crack expanding speed reduced progressively in order. When α=15° and α=30° , the new crack started expanding from the two wings of tip end of the pre-existing crack. When α increased from 45° to 75° , the new crack expanded gradually toward vertical depth along bilateral sides of the pre-existing crack. α=45° is the inclined angle at the transition of the two different crack expanding patterns.
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    Simulation Research on BOTDR-based Monitoring over Temperature Field of Water Inrushing from Coal Floor
    ZHANG Pingsong, , SUN Binyang, XU Shi’ang
    2016, 35(5): 28-31.  DOI: 10.3969/j.issn.1674-0696.2016.05.07
    Abstract ( )   PDF (2165KB) ( )  
    During the process of floor water inrushing on coal face, abnormal responses of corresponding temperature field occured. Therefore, the sensitiveness of distributed fiber testing technology was used to test the changed temperature field. Through designing the sensor for detecting optical fiber floor temperature field, a geo-physical model was developed to test the geology and the earth a simulation test was conducted to simulate and analyze the rock stratum temprature field variation induced by inrush on coal face. The result indicates that the distributed fiber testing technology can well identify the temperature variations induced by water temperature change in process of floor water rising and can determine water bursting area quickly and effectively.
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    Highway & Railway Engineering
    A Design Scheme to Improve the Safety Performance of Corrugated Beam Crash Barrier on the Freeway
    LI Xia, TIAN Yuan, CUI Hongjun, ZHAO Zhiqiang, ZHANG Zhilei
    2016, 35(5): 32-37.  DOI: 10.3969/j.issn.1674-0696.2016.05.08
    Abstract ( )   PDF (1233KB) ( )  
    Aiming at the inadequate safety performance of the corrugated beam crash barrier in highway rehabilitation and expansion program, in light of the design principle of referrable utilization of existing crash barrier to greatest extent, an innovative scheme of improving existing corrugated beam crash barrier was proposed for the first time. This scheme proposed not only upgraded the bending shear resistance of the crash barrier but also a cross beam was designed in compliance with the requirement on material workability and standard construction. By investigating the resistance of soil and road shoulder, the penetration depth of vertical post was calculated to improve the crash barrier’s bearing capacity against uplifting. For purpose of the properties of shear force and bending moment distribution in the standing post in moment of collision between the post and vehicle out of control. Reinforcement arrangement in the steel tubular post of crash barrier was designed in accordance with “ uniform theory” to improve shear and bending resistance properties of the crash barrier. Finally mechanical simulating software of LS-DYNA was applied in simulating test on the corrugated beam crash barrier. The experiment results show that under similar colliding conditions, the upgraded crash barrier can effectively impede the vehicle beyond control and the maximum displacement of the corrugated beam with its impact capacity improved in big magnitude meets the specifications.
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    Effect of SBR on the Rheological Properties of Emulsifed Asphalt
    CHANG Runtian, DU Sujun, PEI Qiang, GUO Yingying, PANG Jinyu
    2016, 35(5): 38-41.  DOI: 10.3969/j.issn.1674-0696.2016.05.09
    Abstract ( )   PDF (1184KB) ( )  
    Effect of emulsified SBR content on emulsified asphalt was investigated by measuring general performances and rheological properties of asphalt emulsion evaporation residue. The results show that, in the high temperature and the low frequency region, SBR improved elasticity of asphalt in certain extent and with the increace of SBR addition this improvement effect is enhanced slightly, which is consistent with the test results on the three major indices including ductility at 5 ℃ penetration at 25 ℃ and softening point. The overall analysis results show that the optimal dosage of SBR is 3%.
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    Pavement Performance Research of Chongqing Broken Pebble and Its Cement Stabilized Material
    LIU Ke,YANG Xiwu
    2016, 35(5): 42-49.  DOI: 10.3969/j.issn.1674-0696.2016.05.10
    Abstract ( )   PDF (1514KB) ( )  
    The production, pavement performance and cement stabilized broken pebble(CBP) technical features of pebble produced in the main city of chongqing river were researched by factory investigation, laboratory experiments, field tests, mechanical analysis. The results show that the size of material plants is small, and products of single material plant are difficult to synthesize all required grading of pavement layers. Since the rough stone size was smell,mainmarn diameter of broken pebble was 26.5 mm. Because of gradation characteristics,CBP production should be at least 4 specification aggregates. Broken pebble crushed values was about 1/2 of local limestone gravel, and acicular flakiness content was less than 15% which was linear increase with crushed values, sand equivalent of pebble chips associated with 0.3 mm passrate was greater than 60%. Ash dosage, compaction degree were critical to CBP 7 day compressive strength (R7d), and the less gravel content generated the higher R7d.Structural differences between crushed gravel and cement mortar and the smooth interface was the main cause of worse R7d of CBP than cement stabilized limestone. In case of high ash dosage,structural bearing capacity quals to that cement stabilized limestone. Rubber tire rolling was critical to CBP compaction degree and optimum process was "(one weak vibration rolling+3 times rubber tire rolling)×2". Water content and delay in time affected compaction degree significantly. Poor curing CBP layer rolled by material trucks would result in damages due to shear, bending pull and edges thrust displacement. When lower layer modulus was higher, shear failure was main damage of poor curing CBP layer.Shear stress limit is about 0.5 MPa.
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    Effects of RAP on the Fatigue Life of Asphalt under Different Strain Levels and Loading Frequencies
    CAO Yi,YU Huan
    2016, 35(5): 50-53.  DOI: 10.3969/j.issn.1674-0696.2016.05.11
    Abstract ( )   PDF (2151KB) ( )  
    This study examines the effects of RAP, loading frequency and strain level on the fatigue properties of asphalt mixtures and binders. In addition, the relationship between the fatigue lives of asphalt mixture and binder is determined. Beam fatigue tests were conducted to compare and analyze the fatigue properties of two asphalt mixtures: one with RAP and the other without RAP. To evaluate binder’s fatigue behavior, binders were extracted and recovered from these two mixtures respectively , on which TS tests were conducted. Results show that presence of RAP in mixture causes a decrease in the mixture’s fatigue life, and an increase in the fatigue life of binder. An increase in loading frequency results in an increase in the fatigue lives of asphalt mixture as well as binder; increase in strain level causes a decrease in the fatigue lives of both mixtures and binders.
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    A New Evaluation Method of Oil Corrosion for Asphalt Mixture
    LI Shanqiang,LI Hao,
    2016, 35(5): 54-57.  DOI: 10.3969/j.issn.1674-0696.2016.05.12
    Abstract ( )   PDF (1128KB) ( )  
    The major factors influencing rationality and accuracy of asphalt mixture oil corrosion test are test container, oil sample amount, oil corrosion mode and oil corroding duration. By designing uniform testing container for test, oil amount and oil corroding way, the three elements, oil corroding duration of 24 hours was the determined to be the reasonable for oil corrosion test according to the laws of the oil corrosion test. The results show that the oil corrosion Cantabro quality loss can evaluate the oil corrosion effect more accurately by comparative analysis of Cantabro quality loss and oil corrosion Cantabro quality loss of asphalt mixture under 20 ℃ and 60 ℃ in the diesel fuel and engine oil. The new asphalt mixture oil corrosion test method can evaluate oil corrosion phenomenon more reasonably and accurately.
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    Different Aggregate Polished Value Effect on the Swing Value of Asphalt Pavement
    ZHANG Weiren,ZHANG Yaodong,WANG Yongping
    2016, 35(5): 58-64.  DOI: 10.3969/j.issn.1674-0696.2016.05.13
    Abstract ( )   PDF (1197KB) ( )  
    Wearing and smoothening resistance of aggregates was the primary factor out of many factors affecting anti-skiding performance of asphalt pavement. Through experimental research, it was found that after 700 000 times wearing and smoothening, the polished value became basically stable and the polished values of the main three types of aggregates were decreased in exponential scale with polished value in order of: basalt crushed rock >crushed limestone >broken pebble. In-house simulating test was conducted with selected grading of AC-13C, by use of MMLS3 acceleration loading meter and under fixed testing condition. After 2million times of wheel loading were performed ,the swing value almost came to stabilization with its size relationship as:basalt gravel asphalt mixture >crushed pebble asphalt pavement >crushed limestone asphalt pavement. Software SPSS was used to data analysis and the results show that the asphalt surface slip resistance attenuation is in a logarithmic form and anti-sliding performance attenuation of three types of asphalt pavement with gravels is similar to polish value attenuation of the aggregates, which indicated that anti-wearing and polishing performance of aggregate is the main influence on anti-skiding performance of asphalt pavement and crushed basalt can more suitably serve as the surface of asphalt pavement.
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    Relationship between the PCI and the BBR about Old Cement Concrete Pavement
    LU Zhaofeng , SHI Xiaofu,HE Zhaoyi,WEN Jingli
    2016, 35(5): 65-69.  DOI: 10.3969/j.issn.1674-0696.2016.05.14
    Abstract ( )   PDF (1329KB) ( )  
    Based on the measurement data of 109 sections of 6 main old cement concrete pavements, the relationship between the plate method PCI and the area method PCI was studied. The classification criteria of the plate method PCI was recommended. The linear relationship mode between the plate method PCI and the bad board rate (BBR) was established. The mode accuracy is verified by the measurement data of S208(Bicheng-Dingjia) old cement concrete pavement.
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    Study on Establishment of Conversion Model for Joint Faulting of Cement-concrete Pavement
    CHEN Fuqiang, CHEN Fujian, HUANG Hui
    2016, 35(5): 70-73.  DOI: 10.3969/j.issn.1674-0696.2016.05.15
    Abstract ( )   PDF (2096KB) ( )  
    In order to find solutions to such key technical problems that a model on long term performance of pavement is difficult to set up due to the difference of faulting data collecting and recording methods in different time periods in China and difficult control of pavement as asset. Based on one real expressway project of Guangxi, by collecting large number of faulting inspection data and by use of SPSS analysis method , a conversion model among different formed faulting data was established. The results show that the linear and non-linear conversion models converting among faulting data collected and recorded by different ways possess higher corelation factor, among which the multi-element linear mode considering introduction of accumulated loading times in combination with lane and direction of traffic flow is more reasonable and no multi-collinearity problem exists and besides, the model shows higher fitness. The establishment of conversion model for pavement joining data conversion provides an important theory basis for accurate precautious maintenance timing selecting and thus is of significance and value to actual engineering application.
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    Influence of Beam-slab(Column) Stiffness Ratio on Internal Force of Subway Station Structure
    LI Juhong,WU Minghui,LI Junyao,TAO Xi
    2016, 35(5): 74-78.  DOI: 10.3969/j.issn.1674-0696.2016.05.16
    Abstract ( )   PDF (2345KB) ( )  
    For purpose of current situation that in current subway station structural design, the structural sectional rigidity variation influences internal force of the station structure and such influence principle calls for further investigation. By taking one real subway station for example, finite element model was built to simulate the station space by use of ANSYS 13.0. By adjusting the structural beam-slab rigidity ratio and slab-column rigidity ratio, the structural internal force distribution law of subway station was explored. Following conclusions are drawn as follows: With the increase of beam-slab rigidity ratio, the transverse maximum bending moment of slabs at all levels decreas is while the transverse maximum positive bending moment of side walls increasis and the maximum bending moment of slab longitudinal beams at all levels all increasis and column maximum axial force decreasis. With the increase of beam-column rigidity, the maximum bending moment of slab longitudinal beams at all levels and maximum shear force and column maximum axial force all showed signs of first increase then decrease or remaining unchanged, but increase is dominating.
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    Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment
    Finite Element Analysis on Working Behavior for Group Pile Foundation in All-Vertical-Piled Wharf in Offshore Deep-Water
    HE Linlin,LIU Yang,DENG Xiao
    2016, 35(5): 79-84.  DOI: 10.3969/j.issn.1674-0696.2016.05.17
    Abstract ( )   PDF (2572KB) ( )  
    A 3D elastic-plastic finite element model was established to simulate the interaction between all-vertical piled wharf structure and the ground. Pile load sharing ratio in the group pile foundation, bending moment distribution of pile bodies, soil pressure on pile lateral sides, characteristic of effect of group piles and the critical penetration depth of piles were investigated thoroughly and overall by using the finite element method. The results show that, it is obtained that the group pile effect can be ignored for all-vertical-piled wharf in deep water offshore, that provides basis for ignoring group pile effect in this structural stability calculation and the critical penetration depth of the horizontal bearing group pile in all-vertical piled wharf in deep water offshore.
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    Research on Application of New Technology of Internal Force Measurement in Cast-in-place Concrete Pile Test
    YANG Xiong,HE Zhongyi,QI Changguang
    2016, 35(5): 85-91.  DOI: 10.3969/j.issn.1674-0696.2016.05.18
    Abstract ( )   PDF (2327KB) ( )  
    In cast-in-place concrete pile test, the new technology, combining with the system of bore-forming digital logging and principle of sliding micrometer, was introduced, and applied in quality inspection of bore forming and measurement of internal force in pile. In vertical static load test, based on the measured data of pile diameter from the system of bore-forming digital logging, the measured strain values obtained from sliding micrometer were modified by the section method; thus, the relationship between elastic modulus and strain magnitude can be calculated according to the smooth regression; therefore, the axial force of pile, skin friction of pile, and tip resistance can be figured out. In horizontal static load test, based on the measured strain values from sliding micrometer, the point of maximum bending moment and value of ultimate lateral load can be gained according to the analysis of tensile strain curve in bearing surface and compressive strain curve behind the back of bearing surface.
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    Preliminary Analysis on the Cause of Leakage of a Concrete Face Rock-fill Dam
    MA Xingdong
    2016, 35(5): 92-96.  DOI: 10.3969/j.issn.1674-0696.2016.05.19
    Abstract ( )   PDF (1688KB) ( )  
    After studying such features as underdeveloped kast in junction region and fault in river direction, on the left bank of seepage control engineering development of monoclinic and reverse mainly of phyllite stratum, new micro—fresh phyllite permeable, by reviewing the geological conditions of the early stage and under the excavation in conjunction with assessment of rock peameability in junction region,it was judged that the possibility of deep percolation and concentrated leakage path was small, But the water pressure data show that the bottom of the curtain was still developing highly permeable rock, in view of the engineering geological complexity, the possibility of slight leakage along the local highly permeable rock mass still exists. Through a comprehensive analysis by various means and methods it is considered that dam leakage is most likely at the superficial local defects of shallow surface and water leakage from inside to outside of the tunnel on left bank.
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    Study of Penetration Test and Compression Test on Core Material of Different Gravel Amounts
    SUN Liping,QI Junxiu
    2016, 35(5): 97-102.  DOI: 10.3969/j.issn.1674-0696.2016.05.20
    Abstract ( )   PDF (1189KB) ( )  
    The experience of similar projects in China were consulted and many tests conducted on the different mixed gravel. In addition, research on the permeability and compression performance of the key proportion of soil materials were carried out simultaneously. Test results show that: When the proportion of gravel in the range of 35%~55%, compression performance index are improved greatly with the antiseeping criterion up to the design requirements.When the compressive stress is 3.2 MPa, the compression modulus increased from 46.2 MPa to 92.5~95.6 MPa, which is 2 times more than that of the original. Thus, the suggested proportion of the gravel in this project be no more than 50% and the final proportion applied is 45%.
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    The Effect of the Leeward Wall Heat Flux on the Particle Concentration Distribution of the Buildings
    ZHANG Furen, HE Xiaonan, LI Na ,TAO Jiaxiang, ZHU Shibao
    2016, 35(5): 103-109.  DOI: 10.3969/j.issn.1674-0696.2016.05.21
    Abstract ( )   PDF (2401KB) ( )  
    A physical model was established by choosing some residential area as example to study the pollutant of fine particles existing in vehicle exhaust gas. Based on three-dimensional turbulant model and by use of CFD software, air flow field surrounding window-opened building under such conditions of different leeward wall surface heat flow density, under different wind velocity and different wind loading cases was simulated and calculated by numerical model.The law of the particle concentration distribution under different situations was analyzed. The results show that for the window-opened building with its leeward wall surface with heat flow, yaw wind facilitates more in transporting the particle pollutants along with the wind from interior of building street to outside the building area. A certain critical value exists for wind effect in diluting particles at different locations and any exceeding of the critical value will block the spreading of the particles. The thermal effect field formed by leeward wall surface heat flux and impact on pollutants vary depending on wind speeds. In case of smaller wind speed, the spreading of particle pollutants primarily is driven by thermophoretic force, while for greater wind speed, the wind field dominats.
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    Traffic & Transportation Engineering
    Safety Assessment for Long Downgrade of Expressway in Mountainous Area by Method of Accident-prediction
    ZHOU Weidong,WU Hongbo,LIAO Junhong
    2016, 35(5): 110-114.  DOI: 10.3969/j.issn.1674-0696.2016.05.22
    Abstract ( )   PDF (1139KB) ( )  
    Based on collection of relevant materials domestic and abroad, alignment factors affecting the safety performance of long downgrade of expressway in mountainous area were analyzed. The traffic accident prediction model for long downgrade was developed by collecting and analyzing traffic accident and alignment data from several typical expressways in domestic mountainous area. The assessment standard and procedure based on accident prediction was proposed and applied in practice. The case analysis results show the good applicability of this given model.
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    Music Rhythm Effect on the Safety of Monotonous Driving on Highway
    LU Zhangping, ZHANG Mingming, LI Rui, HE Ren
    2016, 35(5): 115-119.  DOI: 10.3969/j.issn.1674-0696.2016.05.23
    Abstract ( )   PDF (1129KB) ( )  
    In order to study the influence of music rhythm on the safety of monotonous driving on highway, 6 drivers were selected to receive 4 groups of actual road driving tests. The corresponding music environments to the 4 group tests in the said experiment contained 4 situations as no-music, slow rhythmic music, moderate rhythmic music, fast rhythmic music. After driving for 8 minutes, the experimenter started playing music and meanwhile recording the driver’s EEG signals. Based on the ratio of EEG power spectrum(α+θ)/β and SMR wave amplitude, its changes were analyzed to research the influence of music on driving safety. The results show that the musical rhythm exert a significant effect on the driver fatigue state and the attention level when the driver is driving monotonously for 80 minutes up to the passive fatigue time limit on highway.
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    Adaptive Traffic Signal Control on Urban Intersection by Waiting-to-cross Pedestrian Detection
    XIAO Mei,LIU Kai,ZHANG Lei,ZHANG Huiming,WANG Xing
    2016, 35(5): 120-126.  DOI: 10.3969/j.issn.1674-0696.2016.05.24
    Abstract ( )   PDF (1346KB) ( )  
    To optimize the time distribution from traffic signal at urban intersections with unstable crowd density, an adaptive traffic signal control system based on pedestrian request was developed. This adaptive signal control system consisted of image sequence capture by video, pedestrians’ detection and signal phase transition modules. Image sequence was captured by sequence capture unit. In pedestrians’ detection algorithm, a background reconstruction technology was applied to build background of scene, and then the waiting pedestrians were acquired in real-time through background subtraction. The pedestrians’ green phase was determined based on the number and associated waiting time of pedestrians in the waiting area. The effectiveness of algorithms was tested in a real road intersection. The mean delay of pedestrian and vehicle are 5.62 s/veh and 15.99 s/ped in low pedestrians peak. While the pedestrians are in high peak, the mean delay of vehicle is 52.13 s/veh and the mean delay of pedestrian is 8.35 s/ped.
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    Analysis on Reliability of Road Network Structure by Traffic Allocation due to Limited Capacity Using Ant Colony Algorithm
    XU Xu, ZHENG Weishun
    2016, 35(5): 127-132.  DOI: 10.3969/j.issn.1674-0696.2016.05.25
    Abstract ( )   PDF (1189KB) ( )  
    The influence of traffic volume allocation due to limited capacity on the reliability of road network structure was analyzed in order to achieve the combination of the reliability of road network structure with the reliability of road network. The capacity reliability was achieved by traffic statistics and the capacity reliability of 0.4 was taken as criterion for traffic volume allocation. Based on the idea of ant-cycle algorithm and by method of traffic allocation due to capacity constraint and based on Ant-Cycle model, the parameter of impedance function of the road network under test was set anew for purpose of allocation of the road traffic volume. The reliabilities of pavement structure before and after allocation due to limited capacity were achieved by the self-prepared software of Monte Carlo MATLAB program to as to achieve the reliabity of corresponding whole network. The comparative analysis based on a real road network in Shanghai shows that although the reliability of related congested road section can be improved by means of traffic volume allocation according to limited capacity, the reliability of the road which received the allocation may decrease , which finally give rise to the reduced reliability of whole road network structure.
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    Study on Multi-Level Transit Network Design Based on the Coordination between the Demand and Supply of Mountainous Group City
    MENG Jingyun,WANG Yugang,CHENG Bing ,QU Xinming,ZHANG Dongdong
    2016, 35(5): 133-139.  DOI: 10.3969/j.issn.1674-0696.2016.05.26
    Abstract ( )   PDF (2430KB) ( )  
    In order to alleviate the three major traffic problems caused by the urban traffic system, adapt to the development of urban traffic and seize the new opportunities for the further development of urban traffic, based on the supply-demand internal relationship for transit network, a supply-demand coordination model at three levels of micro, moderate and macro levels were established and the designs involve bus stops rating classification, transit network intercooperation and coordination and macro assessment of transit network by taking Chongqing central downtown district as example for verification analysis. Through study and research, a design method for transit network of mountainous and hilly cities is proposed and applied to guide the optimization design of transit network of mountainous and hilly integrated cities.
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    Scheduling Optimization Model of Intelligent Public Transport System Based on MAST
    CHEN Jian,LI Wu,WU Dan,XU Zhiman
    2016, 35(5): 140-145.  DOI: 10.3969/j.issn.1674-0696.2016.05.27
    Abstract ( )   PDF (1129KB) ( )  
    In order to solve the problems that traditional static operation mode of transit bus was single and passenger’s demands could not be met timely the system frame of MAST(mobility allowance shuttle transit) intelligent public transport was proposed. Based on model optimization for static dispatch of public bus and in combination with the characters that intelligent public transit system allows for route and station alteration as appropriate for timely meeting traveller’s demand, the optimized model on dynamic dispatch of public bus was established. Then bus route #357 in Nanan district, Chongqing was taken as real example to apply and verify the said optimized dynamic operation mode. The relevant operating parameters of intelligent public transit system was calculated and compared with the traditional bus operation mode.The results show that within similar peak time period and by the intelligent mode, increment of 5.81% of total delivered passenger counts, average increment 6.12% of passenger count per bus and 2.86% increment of economic benefits are achieved.
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    Simulation and Intelligent Assessment of Marine JUE-75C Inmarsat-C System
    REN Hongxiang, YU Caorong
    2016, 35(5): 146-150.  DOI: 10.3969/j.issn.1674-0696.2016.05.28
    Abstract ( )   PDF (1228KB) ( )  
    In order to solve the problems of high cost, inefficiency, and easy triggering of false alarms when using actual equipment to do GMDSS training, it is necessary to develop a GMDSS simulation equipment. After analyzing the system composition and work flow of Inmarsat-C ship station, the entire framework of Inmarsat-C simulation system was built. And then the Inmarsat-C ship station (JUE-75C) was developed by using the C++ programming language, on the platform of Visual Studio 2010, which included the simulations of the terminal display equipment, the adjustment of ship-shore communication states, the message editing, the special effects, the record of operating steps and so on. Based on this, an evaluation model for operating the Inmarsat-C ship station was developed, followed by the development of the evaluation system. Simulation results show that the system has the advantages of high simulation, friendly interface and other advantages.
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    Analysis of AGV Dispatching and Configuration Simulation of Automated Container Terminals
    HAN Xiaolong,FAN Jiawei
    2016, 35(5): 151-154.  DOI: 10.3969/j.issn.1674-0696.2016.05.29
    Abstract ( )   PDF (2060KB) ( )  
    To analyze the efficiency of automated container terminal handling operation system under different AGV (automated guided vehicle) dispatching rules and configuration,the simulation software eM-Plant was used to build a container terminal simulation model which included quay crane,AGV, yard crane,and yard resource.The analysis of simulation data shows that different dispatching rules and configuration of AGV have a great influence on the whole efficiency of terminal operation system. Finally, some strategies and recommendations on AGV dispatching and configuration optimization were suggested for optimization of automated container terminals.
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    The Dynamic Allocation of Continuous Berth and Quay Cranes in Container Terminals
    LIANG Chengji , XIA Sang , LU Bo
    2016, 35(5): 155-159.  DOI: 10.3969/j.issn.1674-0696.2016.05.30
    Abstract ( )   PDF (1963KB) ( )  
    In order to mitigate the reality that berths and quay cranes were in short in container terminals, improve port operation efficiency and achieve collective assignment of berths and quay crane in ports, based on the time-dependent dynamic change of berth and quay crane quantity and after considering the continuity of berth and vessel berthing preferences one mixed integer linear programming model was established for the purpose of minimizing the sum of remaining workload of vessels, the distance between preference berth and the actual berth of vessels, the quay cranes’ shifting times. By this model vessel was allowed to depart as soon as possible ensuring vessel departure by latest allowable departure time. Then according to an actual port’s data in Shanghai, CPLEX was used to solve the model and an optimal solution was achieved. Finally, the computational result confirms the feasibility of this model in solving the joint allocation of berth and quay cranes in container terminals by analyzing the numerical example.
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    Study on Evaluation of Land Intensive Use of Railway Comprehensive Hub
    YIN Yong,ZHANG Yue
    2016, 35(5): 160-164.  DOI: 10.3969/j.issn.1674-0696.2016.05.31
    Abstract ( )   PDF (995KB) ( )  
    The meanings of land integrated use by means of railway comprehensive hub were defined and an overall evaluation system on integrated use of urban land by building comprehensive railway hub was established. The level of integrated use of urban land by building Chongqing Shapingba comprehensive railway hub was evaluated by entropy weight method TOSIS. The results show that the level of integrated use of urban land by building the railway comprehensive hub demonstrates a distinc advantage yet improved in strength is still required.
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    Vehicle & Electromechanical Engineering
    Performance Simulation and Analysis of the United Braking System of Tractor Semi-trailer
    HE Ren,SHEN Xiaomin
    2016, 35(5): 165-173.  DOI: 10.3969/j.issn.1674-0696.2016.05.32
    Abstract ( )   PDF (2046KB) ( )  
    To analyze the performance of united braking system of tractor semi-trailer,first, several models were established including a seven DOF dynamic model of tractor-semitrailer, a nonlinear tire model and a brake system model. Simulations were carried out to research the influences of hydraulic retarder and united brake system on the brake stability of a tractor-semitrailer under different working conditions. From the simulation results, several conclusions are obtained as follows.The higher adhesion coefficient is, the better brake stability hydraulic retarder is achieved.Hydraulic retarder should be used with caution on slippery road. Higher gear of the hydraulic retarder cannot be used directly when the tractor-semitrailer is on a high speed in order to prevent over impact on the tractor caused by the semitrailer, or it will lead the tractor to sideslip and the semitrailer to fold. Higher gear of the hydraulic retarder cannot be used when the tractor-semitrailer is under unloaded condition in order to prevent lock of drive shaft and occurring instability.First gear of the hydraulic retarder can be directly used under full load condition and higher gear can be used when the speed is not too high.The united brake system can effectively improve brake efficiency and maintain favorable brake stability when the demand for brake intensity is normal. The hydraulic retarder will not significantly improve brake efficiency and will aggravate instability of the tractor-semitrailer under emergency brake condition.
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    Based on External Rotor Switched Reluctance Motor’s Parameter Optimization Analysis
    JIANG Baojun,ZHOU Lin,ZHANG Dongsheng,LUO Tengke
    2016, 35(5): 174-179.  DOI: 10.3969/j.issn.1674-0696.2016.05.33
    Abstract ( )   PDF (3015KB) ( )  
    A switched reluctance motor based on simulation platform of ANSOFT MAXWELL 2D was introduced for problem of torque ripple of switch reluctance hub motor with external rotor in high speed operation.By static and transient simulation analysis,a three-phase 12/8 switched reluctance motor was analyzed as the prototype machine to obtain motor’ all kinds of characteristic curves.When motor working in high speed, it could recede torque ripple by optimized turn-on angle, turn-off angle and magnetic pole structure of stator,with referring to these features.These optimization could provide a more smooth output torque of switched reluctance hub motor.
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    orhters
    Location Selection for Logistics Network for Recycled Scraped Motorcar Based on Low-carbon Principle
    YAN Nannan, LI Ming
    2016, 35(5): 180-184.  DOI: 10.3969/j.issn.1674-0696.2016.05.34
    Abstract ( )   PDF (1100KB) ( )  
    Thus the location selection for reverse logistics network for the recycled scraped car in compliance with low-carbon principle became a topic of study. A mathematical model was firstly established based on multi-level logistics network in an effort to achieve the minimum objective of minimum total cost and minimum carbon discharge as target function and then the location and quantity of various facilities in the reverse logistics network for scraped motorcar. LINGO software was used in the model for analysis and computation and finally check calculation was performed to verify the effectiveness of the model. As a result , low carbon based economic development is realized.
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    Others
    Hand Segment Using Multi-feature Fusion Method in Unmarked Hand Gesture Recognition
    ZHANG Shengjun, WU Shixun, WANG Honggang, XU Dengyuan, HUANG Darong
    2016, 35(5): 185-192.  DOI: 10.3969/j.issn.1674-0696.2016.05.35
    Abstract ( )   PDF (1506KB) ( )  
    Identification of non-mark gesture movement was studied by multi-algorithms. Gaussian skin model was used to model human complexion accoding to human comlexion distribution properties. HSV color space was applied to represent different skin colors. For in hand movement process, background information was incorporated in hand, algorithm of Haar-like which described hand characters by removing background was applied. Meanwhile AdaBoost classifier was explored to classify characters. The results of experiment show that in non-mark hand segmenting, multi-feature combination method can achieve better segment results.
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