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25 December 2016, Volume 35 Issue 6 Previous Issue    Next Issue
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Bridge & Tunnel Engineering

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Reynolds Number Effect of Aerodynamic Forces of Close Range Parallel Cables of CableSupported Bridges DU Xiaoqing1, ZHANG Liping1, LIU Qingkuan2, 3 2016, 35(6): 1-5.  DOI: 10.3969/j.issn.16740696.2016.06.01 Abstract ( )   PDF (1632KB) ( )   Parallel cables with close range were used extensively in practical engineering. However, there were limited studies on the aerodynamics of parallel cables as well as their Reynolds number effects, especially at critical Reynolds regime. When Reynolds numbers were between 0.9×105~3.2×105, located in subcritical Reynolds regime and critical Reynolds regime, the aerodynamic characteristics of twin circular cylinders with close range along with their Reynolds numbers effect were investigated through a series of wind tunnel tests. Results show that the aerodynamic forces of two circular cylinders with close range have strong Reynolds number effect; with different wind attack angles, the average aerodynamic coefficients of circular cylinders in the critical regime are very different from those in subcritical regime. In the critical Reynolds number region, the mean lift coefficient of the downstream cylinder can reach more than 1.35, and the mean lift coefficient and drag coefficient suffer a discontinuous change with the change of Reynolds number, which may relate to the shift of the flow state. The mean lift coefficient of the upstream cylinder can reach more than 1.0, and the mean lift coefficient suffers a discontinuous change with the change of the Reynolds number, which may relate to the shift of the flow state of flow around twin circular cylinders. References | Related Articles | Metrics

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Mechanism of Corrosion Damage of Stayed Cable under the Effect of Acid Rain and Loading Coupling YAO Guowen1, LIU Chaoyue2, WU Guoqiang3 2016, 35(6): 6-10.  DOI: 10.3969/j.issn.16740696.2016.06.02 Abstract ( )   PDF (1406KB) ( )   By conducting the artificially accelerated corrosion test of galvanized steel cable under the effect of acid rain / load coupling, three kinds of loading patterns were applied for the stayed cable, which included alternating load, static load and no load, and the relationship between three kinds of loading patterns and corrosion rate was obtained. The characteristics and mechanism of strand stress corrosion fatigue damage were also discussed. Numerical simulation for stayed cable in different corrosion conditions was carried out by ANSYS finite element software, and the effect of the strand uniform corrosion and surface corrosion pitting depth on the steel equivalent stress distribution state was analyzed. Studies show that: the corrosion rate of the strand in accelerated corrosion test and the components under complex loads is higher in the same corrosive environment. In the preperiod of corrosion test, stress corrosion and corrosion fatigue have little effect on tensile strength; the tensile strength has no significant difference among three loading patterns. In the middle and later periods of corrosion test, the tensile strength starts a sharp decline, and the tensile strength of alternating stress loading specimens appears the phenomenon of a short increase; the more serious corrosion the strand, the greater the steel strand stress near surface corrosion pits during its service time. References | Related Articles | Metrics

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Shear Lag Effect of Box Girder with Corrugated Steel Webs FENG Tianpeng1, XU Xiangfeng2, ZHANG Feng3, JIANG Ruijuan3 2016, 35(6): 11-15.  DOI: 10.3969/j.issn.16740696.2016.06.03 Abstract ( )   PDF (1654KB) ( )   In order to study the shear lag effect of box girder with corrugated steel web plate, the longitudinal displacement warping function of box girder was established, which considered the shear deformation of corrugated steel web plate, longitudinal and inplane shear deformation of the top and the bottom flange. Based on the energy variational principle, an analytical solution was derived for the shear lag analysis of the box girder with corrugated steel webs. Results of model test, finite element analysis and variational solution method were compared with each other. Study shows that: the calculation results of the shear lag effect of box girder with corrugated steel webs are in a good agreement with those of the model test and finite element analysis; the effect area of shear lag only occurs at both sides near the loading position in a very small range; the closer the loading position near the bearing position, the more obvious the shear lag effect. The ratio of width to height has no effect on shear lag. The shear lag coefficient is linearly related with the ratio of width to span. The shear lag coefficient of box girder increases with flange width. References | Related Articles | Metrics

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Large Eccentric Compression Test of Reinforced Concrete Masonry Piers YANG Qingguo, GONG Shiwei, PAN Jianqing 2016, 35(6): 16-19.  DOI: 10.3969/j.issn.16740696.2016.06.04 Abstract ( )   PDF (1411KB) ( )   The reinforced hollow block masonry structure was used to make pier models, and the failure mode, bearing and deformation capacity of the pier models under large eccentric compression were studied. Studies show that reinforced hollow block pier has a better bearing capacity under the action of large bias, and the crack location mostly appears at the shafts of horizontal mortar joint location; there are good adhesive strength and cooperative working performance between block and steel, whose deformation is similar to the one of reinforced concrete member; the tension side of the bridge pier appears crack and steel yield, and the pressure side has masonry crushed flake without brittle failure and local failure, which is very similar to the bias damage of reinforced concrete member. References | Related Articles | Metrics

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Determination of Undrained Shear Strength of Clayey Soil in Ningbo Based on CPTU LI Xuepeng1, 2, YANG Xiaojuan3, CAI Guojun1, 2, LI Biao4, LIN Jun1, 2 2016, 35(6): 20-23.  DOI: 10.3969/j.issn.16740696.2016.06.05 Abstract ( )   PDF (1214KB) ( )   The undrained shear strength is an important physical property of clayey soils and is also very valuable to the design of subway. According to the difficulty and cost constraint of obtaining the undisturbed samples of high quality, a modern insitu test was commonly applied to evaluate the undrained shear strength. In the case study of Ningbo Subway, the piezocone penetration test (CPTU) was used to test and evaluate the clayey soil. Firstly, the basic operation principles of piezocone penetration test were introduced. Secondly, according to the pore pressure cone coefficient (NΔu) obtained from the inversion of field vane shear test, the relationship between undrained shear strength and excess pore pressure was analyzed, and the relationship between the pore pressure cone coefficient and pore pressure parameter ratio was also discussed. Moreover, the results of undrained shear strength based on the piezocone penetration test were contrasted with the results obtained from laboratory test. It is shown that piezocone penetration test can be used for effective evaluation of undrained shear strength of clayey soil; the undrained shear strength obtained from field vane shear test has a good relevance with the excess pore pressure obtained from piezocone penetration test; and the pore pressure cone coefficient and pore pressure parameter ratio have some corresponding relation with each other. References | Related Articles | Metrics

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Indoor Model Test of Pulling Anchor Supporting Structure WU Shuguang1, 2, PENG Peng2,3, HAN Peiyu1, 2, ZHENG Huajing1, 2 2016, 35(6): 24-29.  DOI: 10.3969/j.issn.16740696.2016.06.06 Abstract ( )   PDF (1605KB) ( )   In view of little theoretical and experimental research on pulling anchor supporting structure currently, the indoor model test of the pulling anchor supporting structure was designed and completed independently. Analysis of the test results reveals that the maximum values of internal force of pile and the displacement at the top of the pile both appear in the construction process, rather than the completion of the construction. Different time of excavating and supporting has great influence on the internal force of pile and the distribution of soil pressure. The distribution characteristics of the internal force, the soil pressure and the soil pressure of the baffle in the pulling anchor supporting structure are concluded. References | Related Articles | Metrics

Highway & Railway Engineering

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Overloading Effect on Concrete Pavement Deflection and Stress Analysis XIN Qin1, SUN Jishu1, REN Xiaojun2, ZHANG Xiaoran1 2016, 35(6): 30-33.  DOI: 10.3969/j.issn.16740696.2016.06.07 Abstract ( )   PDF (1447KB) ( )   ANSYS software was used to establish 3D entity model of the pavement structure, and sine load was used to simulate the random load movement of the vehicle. The vertical displacement and stress change of the pavement structure under overloading were simulated and analyzed respectively. And then the effect of overloading rate and cavity size were also analyzed. The conclusion shows that: in the case of dynamic load, the panel deflection value and the bottom maximum tensile stress increase with the increment of the cavity size of the bottom plate board of concrete pavement; moreover, with the higher of overload rate and the larger of void area, the increase of the vertical deflection and tensile stress is greater. References | Related Articles | Metrics

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StressStrength Ratio of Cement Pavement at Early Age Based on Base Temperature ZHANG Yancong1, GAO Lingling2 2016, 35(6): 34-37.  DOI: 10.3969/j.issn.16740696.2016.06.08 Abstract ( )   PDF (1173KB) ( )   In order to explore the effect of base temperature on early cracking of concrete pavement slabs, the cement concrete surface was paved in the same construction environment on six kinds of bases whose temperature was 10, 15, 20, 25, 30, 35 ℃, and the development rules of flexural tensile strength and maximum principal stress of concrete slabs within 72 h after the pavement were calculated respectively based on the software Hiperpav. And the risks of cracking were also compared. The results show that: the higher the base temperature, the faster forming of slab flexural tensile strength and the earlier the structure stress; moreover, the strength and stress of slab in higher temperature are greater than in lower temperature; so, it is better to pave cement concrete surface when the base temperature is lower. Within 48 hours after paving, the impact of base temperature difference on structure stress is much greater than flexural tensile strength; so, the outside curing in this period should be paid attention in order to reduce the risk of cracking caused by the high base temperature. The stressstrength ratio reaches the first peak when the surface concrete is finally coagulated; and then, the ambient temperature replaces the base temperature and gradually becomes the dominant factor affecting the stressstrength ratio. Therefore, the control measures against the cracking caused by base temperature difference should be applied before the final coagulation. References | Related Articles | Metrics

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Macro Aging Characteristics of Asphalt under Heat and Light Coupling Condition CHEN Long1, CHEN Songmin2, HE Zhaoyi1 2016, 35(6): 38-44.  DOI: 10.3969/j.issn.16740696.2016.06.09 Abstract ( )   PDF (1459KB) ( )   Through the indoor experiments on several technical performance indicators (including penetration, viscosity, softening point, rutting factor) of two kinds of matrix asphalt and four kinds of modified asphalt, the macro aging characteristics under different coupling condition of heat and light were compared. The results show that: for matrix asphalt, the antithermal aging performance of ZH asphalt is obviously superior to that of SK asphalt when the light intensity is constant; the antilight aging performance of SK asphalt is obviously superior to that of ZH asphalt when the temperature is constant. For the modified asphalt, the ability of linear modified asphalt to resist heat and light coupling is better than that of star type modified asphalt. When the single factor and couple factors change, the matrix asphalt and the modified asphalt have a strong correlation with antiaging properties which is reflected by penetration ratio; in addition, there is minor correlation with antiaging properties which are reflected by viscosity ratio, softening point ratio and shear rheology coefficient. Therefore, penetration ratio is recommended for the index to evaluate the aging degree of asphalt and antiaging properties. The variance analysis results of couple factors show that the temperature is more significant than light intensity in the light and heat coupling effect. References | Related Articles | Metrics

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Cooling Effect of Different Warm Mix Asphalt ZHANG Yiluo, WANG Tao, LI Chen 2016, 35(6): 45-50.  DOI: 10.3969/j.issn.16740696.2016.06.10 Abstract ( )   PDF (1142KB) ( )   The organic additive Sasobit and artificial zeolite were chosen as two kinds of warm mix agents, and Donghai 70# asphalt was adopted as the preparation of warm mix asphalt, and AC13 mineral aggregate gradation was selected to mix the asphalt mixture. The optimum content of two kinds of warm mix agents was determined respectively by the volume indicators of viscositytemperature curve and Marshall specimen. Under the condition of optimal dosage, the change rule of voidage was observed by forming Marshall specimen and gyratory compact specimen with different temperature, to study the cooling effect of two kinds of warm mix asphalt. The results show that both of two warm mix agents can reduce the high temperature viscosity of asphalt, and its viscosity decreases with the increase of the dosage of warm mix agent; the optimal dosage of Sasobit is 3% (the ratio to asphalt), and WMA molding temperature with Sasobit added decreases by 14 ℃ under the condition of Marshall compaction, compared with that of HMA; the optimum content of artificial zeolite was 0.3% (the ratio to mixture), and WMA molding temperature with artificial zeolite added decreases by 20 ℃ under the condition of Marshall compaction, compared with that of HMA; in the case of gyratory compaction, the temperature of the both above reduces by nearly 30 ℃. References | Related Articles | Metrics

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RealTime Monitoring and Assessment of Vibration Compaction Quality of Highway Water Stable Layer LIU Donghai, LIN Min, LI Zilong 2016, 35(6): 51-56.  DOI: 10.3969/j.issn.16740696.2016.06.11 Abstract ( )   PDF (1658KB) ( )   The commonlyused inspection method of water stable layer compaction quality relies on spot sampling tests at current time. However, this method not only damages the pavement structure and interferes with subsequent construction operations, but also has a certain deviation, because of using the limited test pit samples to show the compaction quality of the whole road. Therefore, a realtime monitoring system for vibration compaction quality of highway water stable layer was developed, and a quality assessment model between the realtime monitoring compaction values (CV) and the compactness of water stable layer was established. Then, a fast compaction quality assessment method of water stable layer was proposed to analyze the compaction uniformity and judge the weak area of compaction. The proposed method realizes the realtime monitoring and feedback control of the water stable layer compaction quality with 100% coverage of construction zone, and provides a new technical measure to ensure the construction quality of highway water stable layer. References | Related Articles | Metrics

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Experimental Research on Influences of Water Content and Soil Samplies of Different Directions on SoilWater Characteristic Curves of Intact Unsaturated Loess LIANG Yan, DU Xin, HUANG Fubin, LI Wenlin 2016, 35(6): 57-59.  DOI: 10.3969/j.issn.16740696.2016.06.12 Abstract ( )   PDF (1082KB) ( )   The desorption process experimental research on undisturbed unsaturated loess Q3 with different initial water contents and different seepage directions was conducted by using the pressure plate extractor, and the effects of them on the soilwater characteristics were analyzed. The test results show that under the condition of the same initial water content, the influences of the matrix suction on different water seepage directions are almost the same; under the condition of the same seepage direction, volume water contents gradually reduce with the increase of matrix suction; when matrix suction increases to a certain degree, the influences of different initial water contents on soilwater characteristic curves are nearly the same. References | Related Articles | Metrics

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Damage Types and Activity Characteristics of Debris Flow along Highway after Wenchuan Earthquake XIANG Lingzhi 1, 2, CUI Peng3, CHEN Hongkai2, FAN Weijia1, 2 2016, 35(6): 60-67.  DOI: 10.3969/j.issn.16740696.2016.06.13 Abstract ( )   PDF (1369KB) ( )   Sixty debris flow gullies along the main highway (DujiangyanWenchuan highway and provincial highway 303) in Wenchuan County were chosen as the research objects. Through multiple field surveys and laboratory tests, the formation conditions, damage types and activity characteristics of debris flow after Wenchuan earthquake were analyzed. The analysis results show that, the instability of the geological landform and the material foundation of the rock and soil after earthquake, as well as the interaction between the high intensity rainfall and debris material source area is the main condition for the debris flow after earthquake. 3 main damage types of debris along highway include the damage or bury of highway, the plugging or squeezing of the river and the forming of disaster chain. After earthquake, the critical rainfall is reduced; debris flows occur in small watershed, most with viscous fluids and with the characteristics of high frequency and group outbreak. References | Related Articles | Metrics

Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment

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Research on Incipient Velocity of Fine Sediment in Three Gorges Reservoir LI Wenjie1，ZHAO Chang1，YANG Shengfa1，WANG Tao2 2016, 35(6): 68-72.  DOI: 10.3969/j.issn.16740696.2016.06.14 Abstract ( )   PDF (1480KB) ( )   Since Three Gorges Reservoir operated, there have been a large amount of fine sediment deposition with 0.01 mm medium size. The basis to address this issue lies on the study on the fine sediment incipient velocity. The existing representative incipient velocity formula was verified with the collected lab experiment data, and the result turned out that the incipience of fine sand was influenced by water depth and dry bulk density, in addition that the accuracy of existing formula was insufficient. The new incipient velocity formula was established based on the stress principle of sediment particle, and the fitted parameters were obtained by using large amount of measured data and previous works. It turns out that the calculated values of the new formula are in good agreement with the measured values, namely, it has a relative low error ratio. References | Related Articles | Metrics

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Stability of Solidified Cement Sea Mud Cofferdam Considering Spatial Variability ZHANG Rongjun, CHENG Yushi, ZHENG Junjie, CHEN Yaohui 2016, 35(6): 73-76.  DOI: 10.3969/j.issn.16740696.2016.06.15 Abstract ( )   PDF (1923KB) ( )   As a kind of the filling material for the cofferdam, the strength of cement Stabilized Dredged Fill (SDF) has spatial variability. The insite data of SDF strength of Tekong Island reclamation project was collected to analyze the probability characteristics of the strength and conduct the simulations of random fields that fitted the strength distribution of SDF. The numerical models of cofferdam were respectively established under the condition of random field and uniform field, and the stability analysis was conducted by Monte Carlo method. The results show that the high spatial variability of SDF has a significant effect on the stability of SDF cofferdam, which makes the design of practical engineering conservative. References | Related Articles | Metrics

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Weathering Degree of Gneisses and Their Acoustic Emission Characteristics LIU Chuanxiao1, LIU Xinghui2, DONG Xiaohua3, LI Maotong1, ZHOU Tong1 2016, 35(6): 77-80.  DOI: 10.3969/j.issn.16740696.2016.06.16 Abstract ( )   PDF (1248KB) ( )   As a foundation building material, Taishan gneiss was shallowly buried and had obviously regional characteristics. The influence of weathering degree of gneiss on the stability of civil engineering was extensive and complex. Test on the relationship of strain and stress presents that five groups of gneiss specimens have been subjected to no weathering, middle weathering, strong weathering and full weathering respectively. Synchronous acoustic emission signals of gneisses with different weathering degrees have been tested in mechanical test, which indicates that ringing counting rates present evident downtrend with the increase of weathering grades of gneiss. The highest ringing counting rate of no weathering and middle weathering gneisses can reach 2 500 per second and their energy is cumulative and releases centrally, which determines their obvious brittleness. Strong weathering gneiss is of typical ductility and its acoustic emission signals are concentrated, whose average ringing counting rate is about 200 per second. That average ringing counting rate of full weathering gneiss is only 15 per second and its discrete and irregular acoustic emission signals indicate that it is the same as a disperse medium. Partial quantization rules between weathering degree of gneiss and its acoustic emission signal have been obtained. The established relationship between weathering degree of gneiss and its acoustic emission signal may be useful for the treatment of weathered gneiss and looking for the replacement materials of the foundation. References | Related Articles | Metrics

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Experimental Research on Sintering Ceramsite of Dredged Saline Sediment from Seaport LI Mingdong1, 2, XIA Ting3, LIU Yangyang3, ZHANG Zhifeng4, TIAN Anguo2 2016, 35(6): 81-85.  DOI: 10.3969/j.issn.16740696.2016.06.17 Abstract ( )   PDF (1131KB) ( )   Dredged sediment from Lianyungang port was selected as an example, and its basic performances and chemical composition were tested. Experiments were carried out to test the expansion and compound sludge of sintered ceramic, and the basic properties and soluble salt content of the ceramic were tested. The results show that: the main chemical compositions of Lianyungang dredged sediment are SiO2, Al2O3 and Fe2O3, and its physical compositions are tiny particles with high liquid limit, plastic limit and plasticity index, which are suitable for sintering ceramsite. Ceramsites, whose density is less than 600 kg/m3 and cylinder compressive strength reaches 3.8 MPa, are successfully sintered from the mixture of Lianyungang dredged sediment and 35% sludge. Moreover, the best sinterswelling temperature is 1 020 ℃. Soluble salt content of the sintered ceramsite is extremely low, which means that there is no problem of moisture absorption, scum, corrosion or heavy metal pollution for the produced ceramsite. References | Related Articles | Metrics

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Influence Factor Analysis on Cyclotella Bloom of Jialing River Estuary in Chongqing WANG Min1, YUAN Shaochun1, XU Wei1, ZHANG Tengcan2 2016, 35(6): 86-90.  DOI: 10.3969/j.issn.16740696.2016.06.18 Abstract ( )   PDF (1142KB) ( )   The quantity of cyclotella in the estuary area of Jialing River was continuously monitored and analyzed from 2010 to 2013, in order to study the occurrence rule of cyclotella bloom in the estuary area of Jialing River in chongqing. It is indicated that cyclotella asterocoststs are dominant species in the estuary area of Jialing River and show an annual periodic outbreak. Water bloom occurs in early spring every year (from late January to early March), and cyclotella asterocoststs occupy 85%～94% of the total algae density during water bloom. Correlation between a variety of physical and chemical indicators and the quantity of cyclotella asterocoststs are analyzed by SPSS18.0 software, and it is shown that there is a significant positive correlation between the water temperature and the quantity of cyclotella asterocoststs (r = -0.450, p = 0.004 <0.01). Total nitrogen (TN), total phosphorus (TP), flow velocity (v), light intensity, and other physical and chemical factors have no significant correlation with cyclotella asterocoststs blooms, but according tor＞r偏, it is illustrated that the interaction of other physical and chemical factors has a promoting effect in cyclotella asterocoststs blooms. So, spring is a suitable growth environment of cyclotella asterocoststs. The lower surveyed water temperature (8.5～11.5 ℃), slow flow rate (0.01～0.29 m /s), enough light (11.25 h) and a reasonable distribution of nutrients may promote cyclotella asterocoststs blooms. References | Related Articles | Metrics

Traffic & Transportation Engineering

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Traffic Flow Model of Signalized Intersections Considering Effect of Brake Lights PENG Yong1,YAN Guangcong1,JIANG Ruyan2,NIE Huadong1 2016, 35(6): 91-94.  DOI: 10.3969/j.issn.16740696.2016.06.19 Abstract ( )   PDF (1155KB) ( )   The front vehicle’s brake lights would influence the rear vehicle on the actual road. Based on the improved brake lights model, a cellular automaton model of signalized intersections was established, and the relationships among the traffic flow speed, the density, the queue length and the green time were studied. The proposed model was compared with the one without consideration of brake lights. The research shows that considering the effect of the brake lights or not, the relationships among traffic flow speed, the density, the queue length and green time are alike. However, the traffic flow of signal intersection is affected by the brake lights, so the effect of brake lights should be considered in the analysis on the variables of the signalized intersection traffic flow. References | Related Articles | Metrics

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Identification Method of Traffic State and Its Authenticity Combined with Signal Control CHEN Zhaomeng, LIU Xiaoming, WU Wenxiang, TANG Shaohu 2016, 35(6): 95-100.  DOI: 10.3969/j.issn.16740696.2016.06.20 Abstract ( )   PDF (1454KB) ( )   Abstract： Oversaturated traffic state identification is the first condition of the oversaturated traffic signal control. The identification method of traffic state and its authenticity combined with signal control optimization was proposed, which avoided the “false saturation” due to the unreasonable traffic signal control, especially the unreasonable coordination control. The headway variance and time occupancy were used as identification parameters, combining with the departure of queue vehicles in a cycle to identify the traffic state. Through analyzing a numerical example and simulation, it is indicated that the proposed method can accurately and effectively judge the oversaturated traffic state. References | Related Articles | Metrics

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Calculation Model of Taxi Passenger’s Waiting Time under Information Condition LV Ming1, CAO Yi2, LUO Xia2 2016, 35(6): 101-104.  DOI: 10.3969/j.issn.16740696.2016.06.21 Abstract ( )   PDF (1072KB) ( )   The operation characteristics of urban taxis were distinguished from those of traditional cruise mode with the information provided by taxihailing apps. In order to accurately calculate the average passenger’s waiting time in each zone, the traffic zones were divided into saturation zone, instauration zone and equilibrium zone according to the relationship of arrival and departure quantity of load taxis firstly. And then, the distribution matrix of vacant taxi could be forecasted, considering the effect produced by information condition on searching behavior. Finally, the model of passenger’s average waiting time in each zone was established, according to the equilibrium relationship between taxi single vacant time and passenger’s single waiting time. In the numerical experiment, comparing with the equilibrium model in traditional background, the influence of taxihailing apps on the passenger’s waiting time in different zone was different in the same network. The passenger’s single average waiting time was reduced by 65% in saturation zone and equilibrium zone. However, it was increased by 23% to 58% in instauration zone; meanwhile, taxi unloaded ratio in this zone was reduced. The calculation results reveal that taxhailing apps contribute to information transparency, reduce taxi unload ratio and have certain effect on passenger’s waiting time, which could offer some beneficial guidance and theoretic basis to the planning and management of urban taxihailing apps. References | Related Articles | Metrics

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Reliability Study on Waiting Time for Regular Bus Based on Passenger Perception FENG Shumin, ZHANG Gui’e 2016, 35(6): 105-108.  DOI: 10.3969/j.issn.16740696.2016.06.22 Abstract ( )   PDF (1105KB) ( )   In order to make more passengers choose bus travel, the multiple linear regression model of passenger perception on the waiting time for vehicle was established, on the basis of the survey data of Harbin bus station passenger perception. The probability density function of passenger perception on the waiting time was derived by risk functions and the reliability model of the waiting time at regular bus station based on passenger perception was deduced. The case study was carried out to verify the model. The results show: the difference between model results and actual survey results is in the range of 2%, and the model is of high accuracy. References | Related Articles | Metrics

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Classification of Passenger’s Travel Behavior Based on IC Card Data LI Jun, DENG Hongping 2016, 35(6): 109-114.  DOI: 10.3969/j.issn.16740696.2016.06.23 Abstract ( )   PDF (1398KB) ( )   To obtain the data of the spatial and temporal patterns of public transit passengers, the first step was to infer the alighting stop for each cardholder based on trip chain method, and then a full data framework was established for describing each passenger’s travel behavior in several days. Meanwhile, three types of travel were defined derived from passenger’s different types of activity in terms of temporalspatial characteristics, including the commuting travel type, the ordinary type and the random travel type. Finally, each passenger’s travel was classified into the above three types according to travel frequency and the standard deviation of departure time. The result of classification shows that about 39.1% of total passengers have the commuting type or ordinary type and these passengers generate about 76.4% of total passenger flow; about 60.9% of total passengers only have random travel type and these passengers only generate about 23.6% of total passenger flow. It is possible to obtain the public transit passenger’s travel pattern and demand at a much more detail level by classifying each passenger’s multiday travel behavior. References | Related Articles | Metrics

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Correlation Analysis of Accident Characteristics on Multilane Highway MA Zhaoyou1, 2, FANG Shouen1, WANG Changjun2 2016, 35(6): 115-119.  DOI: 10.3969/j.issn.16740696.2016.06.24 Abstract ( )   PDF (1231KB) ( )   On the basis of analyzing the highway safety of current China, the correlation rules were used to deeply analyze the main characteristics of 90 traffic accidents mortality on a multilane highway. Several rules were elaborated, such as: the first and the fourth lane were accident prone; accidents mortality of heavy semitrailer trains and minibuses was high; the driver and passengers without wearing a seatbelt and flying out of the vehicle died more; the death toll from fatigue driving was the most. The results show that: in highway management, to reduce the occurrence of casualty accidents, the control of heavyduty semitrailer trains and minibuses should be focused; the behavior of the driver or passengers without wearing seat belts and the illegal activities of fatigue driving should be severely investigated; and the traffic behavior of the personnel off the vehicle should be regulated. References | Related Articles | Metrics

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Safety Risk Investigation of Spring Festival Travel Rush Return by Motorcycle and Its Countermeasures CHEN Fujian, XIE Songfei, DENG Weijian, ZHONG Zhao, WU Zhentuan, DENG Wenli, CHEN Qiong 2016, 35(6): 120-126.  DOI: 10.3969/j.issn.16740696.2016.06.25 Abstract ( )   PDF (1383KB) ( )   In order to make safety management countermeasures against the serious traffic safety hazard caused by the Spring Festival travel rush return by motorcycle, its safety risk investigation was carried out. Based on the statistically sampling theory, transportation system analysis method and the road traffic safety, various investigation measures were carried out, such as onsite survey, direct observation, vehicle speed detection, paid contact card of safe round trip, telephone interview and web searching. The traffic safety risk of Spring Festival travel rush return by motorcycle was respectively investigated from traffic system aspects of ridermotorcycleroadenvironmentmanagement and the inductive analysis on the survey results was conducted. Based on the above, the countermeasures to improve the riding safety were presented from 3 aspects of the highway department, the traffic police department and the cycling people. References | Related Articles | Metrics

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Calculation Model of Service Area’s Land Based on Drivinginto Rate LI Xia1, LI Lin1, CUI Hongjun1, REN Xilong2, LI Hao3 2016, 35(6): 127-130.  DOI: 10.3969/j.issn.16740696.2016.06.26 Abstract ( )   PDF (1124KB) ( )   The influence of service area’s space information, service level, and freeway topographic conditions on service area’s land was considered in the distribution function of vehicle continuous driving time, and the calculation method of service area’s drivinginto rate based on vehicle continuous driving time was put forward. Considering the composition of main line’s traffic volume and the service demand characteristics of different types of vehicles, the service traffic volume and the passenger flow volume of service areas were calculated; at the same time, the land of parking lots, public toilets, acceleration lane and deceleration lane, restaurants and other facilities were calculated respectively, and then the calculation model of service area’s land was determined. Finally, referring to OD survey data of Hengshui—Daming section on DaqingGuangzhou Expressway in the stage of engineering feasibility study, the calculation of the drivinginto rate and the reasonable land of each service facility in each service area along the expressway was completed, and the reasonable land of each service area was obtained. References | Related Articles | Metrics

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Evaluation of Railway Emergency Plans Based on Improved Fuzzy Analytic Hierarchy Process TANG Zhaoping1, LIU Huan2, SUN Jianping2 2016, 35(6): 131-135.  DOI: 10.3969/j.issn.16740696.2016.06.27 Abstract ( )   PDF (1186KB) ( )   Improved fuzzy analytic hierarchy process was used to evaluate the quality conditions of railway emergency plans. Based on the analysis of railway emergency plan in current research and combining with the field investigation, an evaluation index system consisting of 4 firstlevel indicators and 13 secondary indicators was designed by the method of clustering analysis, from the perspective of comprehensiveness, practicality, operability and scalability of the plan. Using the theory of fuzzy analytic hierarchy process and the 0.1 ~ 0.9 nine scaling method, a method of “twice scale conversion” was proposed to get the more fair and accurate index weight, and a fuzzy comprehensive evaluation model of railway emergency plan was also established. Taking a special emergency plan of one railway bureau for example, empirical analysis was carried out and some corresponding suggestions were proposed for the improvement and adjustment of the emergency plan. References | Related Articles | Metrics

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Fleet Deployment for Liner Ship Based on Biobjective Programming PAN Jingjing1, 2 2016, 35(6): 136-140.  DOI: 10.3969/j.issn.16740696.2016.06.28 Abstract ( )   PDF (1162KB) ( )   In order to optimize the allocation of resources of liner ship companies, a fleet deployment model based on biobjective programming was established to minimize the total costs of shipping operation and carbon dioxide emissions in the planning period. And then the model was solved by Gurobi. The feasibility and effectiveness of the model was verified by numerical experiments. Computational results show that comparing with ones with smaller capacity, the ship with large capacity is more competitive in single box cost and generates less carbon dioxide emissions, which will be better for the environment protection. Three methods of ship capacity structure, such as reducing the ship’s fuel consumption constants by improving the ship technology, slow steaming and the main configuration of large ship, are effective measures to significantly reduce ship operation costs and carbon dioxide emissions. References | Related Articles | Metrics

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Location Selection of LNG Powered Ship Bunkering Station in Main Line of Yangtze River YANG Yongsheng, ZHOU Yamin, XU Bowei 2016, 35(6): 141-147.  DOI: 10.3969/j.issn.16740696.2016.06.29 Abstract ( )   PDF (1421KB) ( )   Aiming at the location of LNG powered ship bunkering station in the main line of the Yangtze River, the improved ant colony algorithm (considering genetic variation) and the clustering analysis were combined. The clustering analysis can solve the problem of uncertainty and ambiguity in location selection, and the ant colony algorithm with genetic variation can effectively solve the problem of local optimal solution, due to the improper selection of the initial point in the traditional clustering analysis. The case studies show that comparing with the general ant colony clustering analysis, the ant colony clustering based on genetic variation shortens the number of iterations and reduces the amount of calculation; it is much closer to the global optimum, comparing with the traditional clustering analysis. References | Related Articles | Metrics

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Multifractal Research on Congestion Index of Chinese and Brazil Port LIN Guolong, MA Libo, ZHANG Chenyan, HE Hongdi 2016, 35(6): 148-152.  DOI: 10.3969/j.issn.16740696.2016.06.30 Abstract ( )   PDF (1162KB) ( )   The multifractal detrended fluctuation analysis method (MFDFA) and multifractal detrended fluctuation cross correlation analysis method (MFDCCA) were used to study the congestion index of ETA (Etimated Ttime of Arrival) capesize in Chinese ports and in Brazil ports, which were components of GPCI (the global port congestion index). It is found that generalized Hurst index of ETA capesize in Chinese ports and in Brazil ports in time series and MFDCCA generalized Hurst index are both monotonically decreasing and the range of their values is between 0.5 and 1; scaling index shows a concave function and fractal spectrum shows a intensive bell shaped distribution. Research results show that the two groups of experimental time series both have obvious multifractal characteristics and also have a long memory and multimarked degree; moreover, the two multifractals are crosscorrelated, and their performances are mutually influenced in a longterm. References | Related Articles | Metrics

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A SemiActive Control Strategy of MR Damper Suspension JIANG Kang1, ZHANG Teng1, FENG Zhongxiang1, ZHANG Mengya2 2016, 35(6): 153-157.  DOI: 10.3969/j.issn.16740696.2016.06.31 Abstract ( )   PDF (1368KB) ( )   An adaptive neuro fuzzy inference system (ANFIS) was used to establish the inverse model of magneto rheological (MR) damper. With the overall consideration of vehicle ride comfort and handling stability, a fuzzy hybrid control strategy was proposed on the premise of the characteristics of the damper control of skyhook and groundhook as well as fuzzy TS system. In MATLAB/Simulink, the MR damper model, the inverse model, the fuzzy hybrid controller and the random road excitation were established respectively, and they were cosimulated with the one quarter vehicle suspension model that was built in ADAMS/View. The results of cosimulation indicate that the fuzzy hybrid control strategy could improve the sprung mass acceleration, suspension dynamic travel and tire dynamic deformation effectively, comparing with the control strategy of skyhook and groundhook. References | Related Articles | Metrics

Vehicle & Electromechanical Engineering

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Effect of Front Wall Styling on Aerodynamic Characteristics of A Coach PENG Qian1, HU Hanqiao1, HUANG Hongwu1, HAN Fenggang1, Emmanuel Matsika2,ZHANG Gang3 2016, 35(6): 158-162.  DOI: 10.3969/j.issn.16740696.2016.06.32 Abstract ( )   PDF (1401KB) ( )   In order to assess the effect of styling parameters of front wall on the aerodynamic characteristic of a coach, The validity of the numerical simulation was verified based on Ahmed model and the relevant wind tunnel testing. According to a 12 m coach model, the local features of front wall were evaluated, which included the influence rule of arc radius of front roof, arc radius of front side and front spoiler angle on the drag factor and lift factor of a coach. The results indicate that the drag factor and lift factor of the coach respectively reduce and go up when arc radius of front roof, arc radius of front side and front spoiler angle increase; the influential sequence of the above factors on the drag factor is arc radius of front side > arc radius of front roof > front spoiler angle, whereas there is no significant difference on the effect of the lift factor. References | Related Articles | Metrics

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Effect of MnCe/γAl2O3 Catalysts on Catalytic Combustion Performance of Diesel Engine Soot LEI Lili1, YIN Junchen1, SONG Jin’ou2, LUO Peng1, WANG Pan1 2016, 35(6): 163-167.  DOI: 10.3969/j.issn.16740696.2016.06.33 Abstract ( )   PDF (1226KB) ( )   In order to investigate the effect of MnCe/γAl2O3 catalysts on catalytic combustion performance of soot, a series of xMnyCe/γAl2O3(x=4, 6, 8, 10, y=10) catalysts with different ratio of Mn and Ce were prepared by an acidaided solgel method. The effect of metallic Mn and Ce on their microstructure and catalytic properties was investigated by Xray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscope (TEM) analysis. According to the analysis results, it is indicated that the diameter variation range of MnO2 and CeO2 is from 5 nm to 20 nm. Mn appears as MnO2 in the catalyst. Some Mn2O3 disperses on the catalyst surface, when the value of x is 6 or higher. The grain size and dispersion of CeO2 are the best, when the value of x is 8. Effect of the catalysts on combustion performance of soot is analyzed by TG (thermal gravimetric analyzer). Test results show that: with the increase of x, the temperature of the catalyst T10 decreases firstly and then increases; T10 temperature of 8Mn10Ce/γAl2O3 catalyst is the lowest among the catalysts, that is 320.9 ℃, which can significantly reduce the ignition temperature of soot and have the best catalytic combustion performance of soot. References | Related Articles | Metrics

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Competition Strategy of DualChannel Supply Chain Considering Consumer’s LowCarbon Preference LIU Yunlong1, HUANG Chengfeng1, 2, HOU Zhongwei3 2016, 35(6): 168-170.  DOI: 10.3969/j.issn.16740696.2016.06.34 Abstract ( )   PDF (1047KB) ( )   In the dual channel of internet direct marketing and traditional distribution marketing, consumer’s lowcarbon preference restraints the decision of dual channel supply chain. Through introducing the lowcarbon preference parameter and establishing the game model, the market demand and price decision were studied. The research results show that in the dualchannel supply chain, manufacturer’s revenue, acceptance of internet direct marketing and consumer’s lowcarbon preference are positively correlated; retailer’s revenue, acceptance of internet direct marketing and consumer’s lowcarbon preference are negatively correlated. Optimal equilibrium price and market demand exist in dualchannel supply chain. References | Related Articles | Metrics

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Network Optimization of Fruit and Vegetable Supply Chain Considering Carbon Trading YAN Nannan, ZHU Lishan 2016, 35(6): 171-176.  DOI: 10.3969/j.issn.16740696.2016.06.35 Abstract ( )   PDF (1152KB) ( )   Based on the supply chain network, the impact of carbon trading policy on the total cost of fruit and vegetable supply chain was researched, and a supply chain cost function was established, which included product cost, transport cost, storage cost, rot cost and carbon trading cost. In order to minimize the total cost and carbon emissions, a multiobjective integer programming model was established. For the balanced and optimized model with the lowest total cost, the particle swam optimization was used to solve, and the sensitivities of parameters such as carbon trading price, vehicle capacity and unit fuel consumption were analyzed. The case study proves the feasibility of the supply chain network model and the algorithm. The experiment results show that fewer increase of the cost can greatly reduce the carbon emissions to realize the harmonious development of economy and environment. References | Related Articles | Metrics