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Vertical Vehicle-Bridge Coupling Dynamic Analysis on Highway-Ｒailway Cable-Stayed Bridge Xie Bingmin，Xiang Zhongfu，Wang Xiaosong，Wang Shaohuai 2013, 32(4): 551-554.  DOI: 10.3969 /j.issn.1674-0696.2013.04.01 Abstract ( )   PDF (848KB) ( )   Taking a certain highway-railway cable-stayed bridge as the research object，the FEM model is established to analyze the natural frequency and mode shape characteristics，through the space bar FEM method and grillage method based on ANSYS． The coupling vibration responses of vehicle-bridge system under a running train are also calculated． Ｒesults indicate that the dynamic response between vehicle and bridge got by the proposed method is consistent with the measured results at home and abroad． At the same time，the vertical comfort and safety indicators when the vehicle is running meet the regulatory requirements． References | Related Articles | Metrics

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Finite Element Model Updating of Single Pylon Cable-Stayed Bridges Based on ＲBF-ANN Shan Deshan，Ding Dehao，Li Qiao，Huang Zhen 2013, 32(4): 555-559.  DOI: 10.3969 /j.issn.1674-0696.2013.04.02 Abstract ( )   PDF (363KB) ( )   In order to obtain the contemporary state for the cable replacement project of one certain existing single pylon cable-stayed bridge with double cable plane，a new combined method for finite element model updating is proposed． In the light of the parameterized model updating theory，the relative sensitivities of the calculated design parameters are analyzed to determine the will be modified parameters． Substructure method is introduced in the model updating process for meet the requirement of the parameter’s discreteness，and the calculated parameters in each substructure is regard as invariables． The radial basis function neural network ( ＲBF) is adopted as the optimization algorithm of model updating． Combination the substructure method and ＲBF，the intrinsic“inverse problem”of finite element model updating is transformed as the“forward problem”． The substructure partition，ＲBF neural network construction and its input and output parameters determination are discussed as well． A certain existing single pylon cable-stayed bridge is taken as the case study to verify the proposed combined model updating algorithm． The result shows that the discrepancy between the calculated value and measured valued decrease dramatically before and after the finite element model updating． References | Related Articles | Metrics

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Application of Vehicle-Bridge Coupling Vibrations Theory in the Study of Bridge Surface Ｒoughness Yi Jinsheng，Gu Anbang，Wang Xiaosong 2013, 32(4): 560-563.  DOI: 10.3969 /j.issn.1674-0696.2013.04.03 Abstract ( )   PDF (225KB) ( )   The vehicle-bridge system are considered as two separate subsystems，and the vibration equilibrium functions for double axis vehicle model and bridge are derived with the application of d’Alembert principle． And then the separate iteration method is applied in the numerical solution of vehicle-bridge coupling vibration problem． In consideration of NEWMAＲK numerical calculation principals，computational procedures for vehicle-bridge coupling vibration are compiled by use of MATLAB． Furthermore，the accuracy of this program is verified． The influence of the deck conditions and vehicle speed on vehicle-bridge system is discussed on the basis of this program． It demonstrates that the solution is accurate and the influence of the deck conditions on vehicle-bridge vibration is significant; the influence of the vehicle speed on bridge vibration depends on the force frequency caused by vehicle on the bridge． References | Related Articles | Metrics

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FEM Calculation of Space Timoshenko Beam of Large Deflection Liu Xiaohui，Wang Jialin，Yan Bo 2013, 32(4): 564-568.  DOI: 10.3969 /j.issn.1674-0696.2013.04.04 Abstract ( )   PDF (312KB) ( )   A variation principle for Timoshenko beams of large deflection with geometrical non-linearity is presented． And the space beam element stiffness matrix of large deflection can be deduced from this variation principle，considering the effect of the shear deformation． To improve the computational precision and efficiency for the large displacement and rotation of beam，a finite element method based on the moment-curvature relationship of beam section is presented． The method calculated by node coordinates of the beam element is applied to calculate the internal nodal forces． A nonlinear finite element code is then developed which considers the effects of large rotations，large displacements and shear deformations． Numerical examples are provided in order to verify the feasibility and effectivity of the presented method． References | Related Articles | Metrics

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Casting Length of Cast-in-Place ＲC Arch Ｒib in Arch Centering Zhou Shuixing，Deng Xiang 2013, 32(4): 569-572.  DOI: 10.3969 /j.issn.1674-0696.2013.04.05 Abstract ( )   PDF (390KB) ( )   The deformation law of arch centering is analyzed in the process of pouring arch concrete． A new method is proposed to determine the concrete cast-in-situ section lengths and corresponding formulas based on deformation proportion of arch centering are deduced． When the stiffness of earlier constructed concrete is ignored，all concrete is cast at the same loop，and the deflection of arch centering is a constant． According to influence line of arch centering deflection，a program which is used to calculate the cast length and arch centering deformation is developed by APDL language of ANSYS． This program could automatically calculate every casting length of arch concrete based on the assigned deformation condition． A numerical result shows that deformation proportion caused by each segment of box concrete should be controlled in range of 0． 5 ～ 0． 6，when the arch centering deformation scale is taken as the target． References | Related Articles | Metrics

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Experimental Ｒesearch and Application of the New Welding Stirrup Liao Xiufeng，Wei Qike，Dong Mengneng，Wu Bo，Li Zhineng 2013, 32(4): 573-576.  DOI: 10.3969 /j.issn.1674-0696.2013.04.06 Abstract ( )   PDF (293KB) ( )   Compared with the traditional composite hook stirrup，the new welding stirrup saves the material of hook and the repeated part． Further more． the new welding stirrups are manufactured by the factories that assure the dimensional accuracy and quality of the stirrup． From the two aspects of the energy-saving，emission reduction and mitigation of labor shortage，economic and social benefits are very significant． The mechanical behavior and seismic performance of the new welding stirrup have been examined by the low cyclic loading experiment and axial compression test． The result illustrates the advantage of the new welding stirrup in its applicability and anit-seismic performance． References | Related Articles | Metrics

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Correcting on Bump Quality Impact on Filed Test of Natural Vibration Frequency Shi Shangwei，Xu Xuxu，Xu Peng 2013, 32(4): 577-580.  DOI: 10.3969 /j.issn.1674-0696.2013.04.07 Abstract ( )   PDF (200KB) ( )   Through the analysis on three-equal-span continuous beam jump car test，it is found that the additional quality of test truck can affect the measured bridge natural frequencies． Ｒayleigh method is used to assume the shape function of bump test; correction coefficient λ is introduced and a modified formula for the measured natural vibration frequency of three-equal-span continuous beam． The case study shows that the error of field measuring frequency reduces by 27% after correction than that before correction． References | Related Articles | Metrics

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Quick Deflection Monitoring System of Gaojiahuayuan Bridge Zhang Benniu，Cui Hongmei，Shi Lingli 2013, 32(4): 581-584.  DOI: 10.3969 /j.issn.1674-0696.2013.04.08 Abstract ( )   PDF (354KB) ( )   Through the design and installment of a quick deflection monitoring system on Gaojiahuayuan Bridge，the monitoring data after fire disaster in box beam are analyzed． Since the system performs a long term deflection monitoring for the deflection change of the bridge in a short time after fire disaster，the monitoring data could guide the research on the structure deformation of the bridge after the fire． References | Related Articles | Metrics

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Weight Determination Method of Bridge Static Parameter Monitoring Section Based on Damage Sensitivity Shi Zengchao，Wu Xiaoguang，Wang Fuyi 2013, 32(4): 585-588.  DOI: 10.3969 /j.issn.1674-0696.2013.04.09 Abstract ( )   PDF (249KB) ( )   The static measurements such as structure displacement and stress are important factors to do the safety assessment of bridge structure by the synthesized assessment method． As weight values of sections are depended on experts’judgment by giving grades or filling judgment matrix forms，this method has more subjectivity． The damage sensitivity degree of monitoring parameters at different sections of bridge is analyzed，and a damage sensitivity factor S of each monitoring section is constructed． And then the weight value is obtained by normalizing the weight eigenvectors composed by S． The proposed method effectively avoids the subjectivity of weight determination． References | Related Articles | Metrics

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Evaluation of Hazardous Materials Transportation on Super-Large Bridge Based on Set Pair Theory and Variable Weight Principle Qi Yuchao，Zhang Weigang，Lu Jian 2013, 32(4): 589-593.  DOI: 10.3969 /j.issn.1674-0696.2013.04.10 Abstract ( )   PDF (224KB) ( )   The evaluation of hazardous materials transportation on super large bridge can effectively prevent and reduce the accidents． Based on the set pair theory and variable weight principle，the hazardous materials transportation in the condition of severe weather and emergency in the Yangtze Ｒiver Delta is analyzed，and the key influence factors of operational safety are also proposed． The influence factors are analyzed respectively by the set pair theory from the perspectives of sameness，difference and reverse． Combining the set pair theory with the penalty-incentive principle of target weight，a varying weight evaluation model of the hazardous materials transportation on super large bridge is established and the maximum connection is taken as the principle to judge the security of the project． Through the case study，it is indicated that the application of this evaluation method is effective，which can offer reference for the bridge operator． References | Related Articles | Metrics

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Longitudinal Slope at Super-Elevation Sections of S Curve Considering Flow Path Length Zhang Zhuo，Gao Jianping 2013, 32(4): 594-596.  DOI: 10.3969 /j.issn.1674-0696.2013.04.11 Abstract ( )   PDF (174KB) ( )   It is easy to have water at super-elevation section of S curve in rain，which affects the traffic safety． According to the difference of super-elevation gradient direction，the gradient sections are divided into the same change direction and the opposite of cross slope． The calculation models for flow path length of super-elevation section are established by dynamics and FDM． Considering the vehicle in hydroplaning danger state，the control length of flow path is obtained． Taking S curve of highway arch as the research object，flow path length of transition section whose super-elevation value is from -2% to 2% is analyzed，with 3 different types of lane numbers and 7 different types of longitudinal slopes． The results show that when longitudinal slope is increased from 0． 5% to 6% ，the average flow path length increases 2． 83 times; the larger longitudinal slope，the longer of flow path length; when longitudinal slope is greater than 4% ，the prescribed values of different lanes all exceed． Taking the flow path length as the control index，the proposed maximum longitudinal slope values at super-elevation section of S curve with different lanes are put forward． References | Related Articles | Metrics

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Influence Factors of Frost-Salt Ｒesistance of Cement Concrete Zhang Hui，Pan Yonqiang，Zhang Jian，Zhu Lei 2013, 32(4): 597-600.  DOI: 10.3969 /j.issn.1674-0696.2013.04.12 Abstract ( )   PDF (278KB) ( )   The influence factors on frost-salt resistance of cement concrete including air void systems，surface conditions and loads are studied by indoor test． The results show that the spacing factor has more impact on frost-salt resistance of concrete than air content does． The frost-salt resistance of concrete is not so sensitive if the air content is beyond 6% or the spacing factor is less than 0． 18mm． Ｒesults also indicate that different surface properties have influence on frost-salt resistance of concrete． Improper operation and surface weeping of concrete will lower the frost-salt resistance of cement concrete by lowering the strength of concrete and degrading the air void structural parameters． And the coupling interaction of load and freezedeicer scaling cycle will greatly accelerate the frost-salt scaling of concrete． And the general laboratory tests may overrate the frost-salt resistance of concrete in practical engineering． References | Related Articles | Metrics

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Effects of Compound Curing Agent on Structure and Properties of Epoxy-Asphalt Zhou Wei,Zhao Hui,Wen Jun,Cai Fangchang,Jiang Tao 2013, 32(4): 601-605.  DOI: 10.3969 /j.issn.1674-0696.2013.04.13 Abstract ( )   PDF (476KB) ( )   Methyl-tetrahydrophthalic anhydride ( MeTHPA) or tung oil anhydride ( TOA) is added in decanedioic acid，which is taken as the epoxy-asphalt curing agent． Tensile strength，penetration，DSC，DMTA，torn section microscopy photos and SEM analysis are used to investigate the mechanical properties，thermodynamic behavior，and micro-structure of epoxy-asphalt curing systems under different curing agents． The results show that: the compound curing agent can make strength and surface hardness of the epoxy-asphalt curing system effectively improved，the induction period of the curing reaction shorten，and the curing reaction mechanism turn to one-step reaction from two-step reaction; the compound curing agent can make the glass transition temperature of asphalt phase and epoxy phase simultaneously increased，and high-temperature damping performance also improved，but the particle size of asphalt dispersed in epoxy resin become uneven，and the curing system become semi-brittle from toughness． Compared with compound TOA，the effects of MeTHPA in decanedioic acid are more obvious． References | Related Articles | Metrics

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Ｒesearch on Fatigue Properties of Ｒeclaimed Asphalt Pavement Dong Lingyun，He Zhaoyi，Huang Gang，Wang Guowei，Hou Jun 2013, 32(4): 606-609.  DOI: 10.3969 /j.issn.1674-0696.2013.04.14 Abstract ( )   PDF (319KB) ( )   Aiming at ＲAP ( reclaimed asphalt pavement) of Yu-Chang freeway，the indirect tensile fatigue tests are carried out between a fresh asphalt mixture of AC-16 and the reclaimed AC-16 with ＲAP mixing amount 10，30，and 50 respectively，before and after the long-term aging． The fatigue life ratio Nf( k / n) and fatigue life loss ratio F ( k) are introduced to systematically analyze the variation of the fatigue properties of the reclaimed asphalt mixture． Test results show that: with the increase of ＲAP amount，the reclaimed asphalt mixture fatigue life ratio decreases; meanwhile，the age of fatigue life ratio of the reclaimed asphalt mixture is less than that before aging，and the fatigue life loss ratio increases． References | Related Articles | Metrics

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Two-Stage Design Method for the Evotherm Warm-Mix Asphalt Mixtures Li Zhengzhong，Wei Ｒuxi，Song Xiaoyan，Ma Tao 2013, 32(4): 610-613.  DOI: 10.3969 /j.issn.1674-0696.2013.04.15 Abstract ( )   PDF (300KB) ( )   By analyzing the principle of Evotherm warm-mix technology and the current situation of design method for warmmix asphalt mixtures，it is the first time to propose the two-stage design method． Based on two-parameter system including asphalt content and test temperature，the components of Evotherm warm-mix asphalt mixtures are optimized，considering the design data of hot-mix asphalt mixtures． The control temperature is determined according that the volume parameters of specimen are basically equal． Based on the two-stage design method，GTM molding method is used to design Evotherm warmmix SBS-modified-asphalt mixtures． The test results show that the pavement performance of Evotherm warm-mix modified-as-phalt mixtures are superior to that of hot-mix mixtures，and the two-stage design method can make the materials design for Evotherm warm-mix asphalt mixtures combine with corresponding hot-mix mixtures，which can effectively avoid the risk of current design method，and provide universal significance for other warm-mix technologies References | Related Articles | Metrics

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Application of Orthotropic Unit to Simulating the Interlayer Contact Situation of Asphalt Pavement Fan Ling，Yuan Meijun 2013, 32(4): 614-617.  DOI: 10.3969 /j.issn.1674-0696.2013.04.16 Abstract ( )   PDF (209KB) ( )   Based on the measured strain at the bottom of the layer in pavement，the orthotropic unit is adopted to simulate the complicate contact situation between asphalt surface layer and base layer． Through adjusting corresponding unit parameters，the calculation results are consistent with the measured data． The proposed method can improve the reliability of theoretical calculation of the pavement structure，and provide a new theoretical approach for in-depth study of other mechanical indicators of pavement structure． References | Related Articles | Metrics

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Checking and Evaluating Method of Fill Ｒoad Subgrade Sedimentation Based on AＲ Model Zeng Shan，Xu Xi 2013, 32(4): 618-620.  DOI: 10.3969 /j.issn.1674-0696.2013.04.17 Abstract ( )   PDF (280KB) ( )   The sedimentation situation of fill road subgrade is checked and evaluated by the application of AＲ model in mathematical theory． Meanwhile，the completing quality of the project is also evaluated． Furthermore，the sedimentation extent and trend in future is forecasted． Ｒesearch shows that the application of mathematical theory could make the process have a better commodity，reliability，initiative，and clearly active / advanced characteristics． References | Related Articles | Metrics

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Elasto-Plastic Seismic Ｒesponse Analysis on Pile-Soil-Structure Interaction Wu Liming，Wang Zijian 2013, 32(4): 621-624.  DOI: 10.3969 /j.issn.1674-0696.2013.04.18 Abstract ( )   PDF (519KB) ( )   The resulting internal forces and displacements are multiplied by reduction factors to obtain the design load． This paper deals with an investigation of the elasto-plastic dynamic characteristics of the superstructure for a frame structure under horizontal seismic excitations where the pile-soil-structure interaction is considered． The results of the investigation indicate that whether or not considering the pile-soil-structure interaction in elasto-plastic seismic response analyses has a great effect on the calculation results． With the consideration of the pile-soil-structure interaction results，the column stresses have amplification on different floors of the building． Therefore，the method using reduction factors to consider the pile-soil-structure interaction is not always safe or reasonable． So the elasto-plastic seismic response should be fully taken into account in design． References | Related Articles | Metrics

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Stability Analysis of Perilous Ｒock Considering Lunar Tide-Generating Force and Temperature Difference between Day and Night Chen Hongkai，Tang Lan，Zhu Xiuzhu 2013, 32(4): 625-629.  DOI: 10.3969 /j.issn.1674-0696.2013.04.19 Abstract ( )   PDF (426KB) ( )   Taking astronomy and impact of temperature difference in one day into account，the mechanism of perilous rock is analyzed． According to solid tide theory，the characteristics that moon’s gravitation results in gravity of perilous rock changing between day and night are analyzed，and the calculation method of moon’s gravitation for perilous rock is also proposed． Furthermore，the effect of temperature difference between day and night on the characteristics of filling in control fissure expanding after sopping up is analyzed． Hereby，basing on the moon’s gravitation and swelling force of filling，the stability calculation method of perilous rock is revised． At last，taking Wanzhou Taibaiyan perilous rock as an example，the stability coefficients are calculated and the stability coefficients are reduced from 0． 96% to 6． 73% ，considering the moons gravitation and swelling force of filling in control fissure． The research results are of positive significance for studying failure mechanism of perilous rock． References | Related Articles | Metrics

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Anti-Seismic Ｒesponse Characteristics of Vault in the Double Holes Tunnel Entrance Based on Fractal Theory Shu Xiaohong 2013, 32(4): 630-632.  DOI: 10.3969 /j.issn.1674-0696.2013.04.20 Abstract ( )   PDF (234KB) ( )   Based on the test data of anti-seismic response of vault in the double holes tunnel entrance，the anti-seismic response characteristics of vault are explored from the perspective of fractal dimension． The results show that: the anti-seismic response of vault in the double holes tunnel entrance does exist fractal phenomenon; the dimension can reflect the uniformity of vault curve of seismic response，and the greater dimension，the more uniform of vault curve is． That is，the anti-seismic effect is not good． The structure of vault in the double holes tunnel entrance has a certain anti-seismic effect on the dynamic response under anti-seismic layers． The vault of the tunnel can still achieve the purpose of monitoring through calculating the size of the fractal dimension after setting up anti-seismic layers． References | Related Articles | Metrics

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Mechanical Characteristic Analysis of Systematic Anchor in Loess Tunnel under Drawing Force Li Qiang，Su Zhongming 2013, 32(4): 633-635.  DOI: 10.3969 /j.issn.1674-0696.2013.04.21 Abstract ( )   PDF (270KB) ( )   Based on the displacement solution of Mindlin problem，the elastic solution to the distribution of shear stress and axial force is deduced under the drawing load for mortar anchor in loess tunnel． The ultimate drawing load of systematic anchor in the sidewall is measured by means of field test based on a certain loess tunnel in Kelan-Linxian Expressway，and the forcing characteristics of the anchor are analyzed． The distribution forms of the shear stress and axial force are also discussed in different soil characteristics． The obtained results will offer the theoretical basis for the design and optimum of systematic anchor in loess tunnel，which has the guiding significance in the design and construction． References | Related Articles | Metrics

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Partial Expansive Load Induced by Shield Tunneling in Expansive Ground Fang Yong，Cui Ge，Fu Yapeng，He Chuan 2013, 32(4): 636-641.  DOI: 10.3969 /j.issn.1674-0696.2013.04.22 Abstract ( )   PDF (357KB) ( )   The equation of additional load caused by partial ground expansion is deduced theoretically． The influence of partial expansion at various positions with different range on the contact pressure of tunnel structure is studied by numerical method． The results show that expansion load is related with the expansive force，stress，ground resistance and material parameters of expanded soil． Generally，the load of partial ground expansion added to the pressure on tunnel structure is less than the expansive force obtained by indoor test． Water swelling of the soil will significantly reduce the ground resistance and influence the load distribution of shield tunnel structure around expansion zone． Small expansive force will reduce the load on tunnel structure because of strong softening and weak expansion after the saturation． References | Related Articles | Metrics

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Construction Method of Lajishan Tunnel Entrance Yan Pengfei，Yao Kun 2013, 32(4): 642-646.  DOI: 10.3969 /j.issn.1674-0696.2013.04.23 Abstract ( )   PDF (485KB) ( )   The methods of tunnel entrance construction in the soft ground at home and abroad are introduced． Based on numerical analysis，the construction planning of Lajishan Tunnel entrance is studied and CＲD method is chosen as the construction method，and the construction process of Lajishan Tunnel is determined． The site displacement monitoring data show that: the displacement of crown settlement is no more than 9cm with the CＲD method construction，which ensures the safety of the construction process． Compared the monitored value with the calculated value，it is indicated the use of the CＲD method in construction is appropriate． References | Related Articles | Metrics

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Adaptive Partition Evaluation of Shallow Geothermal Energy in Urban Area of Chongqing Zhang Furen，Zhu Fangyuan，Peng Qingyuan，Zhu Yongqin，Liu Xianyan 2013, 32(4): 647-651.  DOI: 10.3969 /j.issn.1674-0696.2013.04.24 Abstract ( )   PDF (241KB) ( )   Based on comprehensive evaluation theory，an evaluation model of adaptability division about shallow geothermal energy in urban area of Chongqing is established; meanwhile，the factors and corresponding weights of the evaluation are identified． Then with the comprehensive index method，through the MAPGIS 6． 7 software，the partitioning total score about the grid points is calculated in the studied area． And the four levels adaptability division results figure about the development and utilization of shallow geothermal energy in urban area of Chongqing． And the adaptability division provides a reference value for the rational development and utilization of shallow geothermal energy in urban area of Chongqing． References | Related Articles | Metrics

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Classification of Urban Expressway Traffic Flow Situation Based on Fuzzy Clustering Yin Junjie，Ding Hongfei，Bo Wu，Zhong Mei 2013, 32(4): 652-655.  DOI: 10.3969 /j.issn.1674-0696.2013.04.25 Abstract ( )   PDF (164KB) ( )   In order to solve the problem of urban expressway traffic flow situation judgment，an improved algorithm which uses fuzzy C-means clustering method is proposed． Based on the combination of FCM algorithm and hierarchical clustering algorithm，the hierarchical clustering algorithm is firstly used to get the number of cluster type and initial cluster centers; then Ｒelief F algorithm is used to calculate the weights of the chose features，which affects the division of the traffic conditions;at last FCM is used to perform the cluster to obtain the division results of traffic conditions． A simulation is performed by software VISSIM to confirm the proposed methodology． Through the comparative analysis，it is obtained that the propose method can improve the classification results of urban expressway traffic flow situation． References | Related Articles | Metrics

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Pricing Model of Three-Class Parking Facilities under User Equilibrium Conditions Fan Wenbo 2013, 32(4): 656-658.  DOI: 10.3969 /j.issn.1674-0696.2013.04.26 Abstract ( )   PDF (181KB) ( )   In order to capture the competing operational behaviors ( pricing) of operators of multiple parking facilities as well as users’responses to the pricing decision，a three-class parking ( i． e． ，curb parking lot，off-street parking lot，and parkand-ride facility) pricing model is established based on user equilibrium conditions． The upper-level is an optimization model which simulates the parking operators’pricing decisions with objective of maximizing their profits; the lower-level is a user equilibrium model that describes users’travel behaviors，e． g． ，mode choice，path choice，and parking facility choice，under the principle of personal travel cost minimization． The proposed model is a non-linear programming problem，which is resolved by a sensitivity analysis based algorithm． A numerical example is presented to testify the validity of the proposed model and algorithm，and the results show that the competition of multiple parking facilities has significant influences on the optimal solution of parking pricing，and may lead to generally lower pricing level and better effectiveness of TDM ( e． g． ，reduced congestion costs per person trip and improved park-and-ride mode share) ． References | Related Articles | Metrics

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Mountainous Expressway Mobile Meteorological Monitoring System Liu Juntao，Zhang Yang 2013, 32(4): 659-662.  DOI: 10.3969 /j.issn.1674-0696.2013.04.27 Abstract ( )   PDF (256KB) ( )   The mobile meteorological monitoring system，integrated visibility collection，wind direction and wind intensity collection，temperature and humidity collection，as well as variable message are introduced in detail; GSM and GPS technology are used to realize mobile meteorological monitoring and field data collection． Meteorological indicators are evaluated by matter-element evaluation method，according to the points and road segments． The meteorological information analysis and processing system are realized by the use of C / S modeling． References | Related Articles | Metrics

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Study on Silt-Sand’s Sediment Carrying Capacity He Yang，Yang Shengfa，Zhang Shuaishuai，Wang Xiao 2013, 32(4): 663-667.  DOI: 10.3969 /j.issn.1674-0696.2013.04.28 Abstract ( )   PDF (286KB) ( )   Aiming at the special deposition of silt in Three Gorges Ｒeservoir perennial backwater region，the silt-sand’s sediment carrying capacity is studied through the following test works in 6 m-length flume． The research results indicate that the sediment carrying capacity calculated from the formula of Zhangruijing，Shayuqing are larger than the experimental data，but that from ЭаМаРин is close to the experimental data． According to the formula mode of ЭаМаРин and dimensional analysis，the sediment carrying capacity formula mode is deduced． Based on the experimental data，the sediment carrying capacity formula is fitted by using multiple linear regressions． References | Related Articles | Metrics

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Experiment of Flow Ｒesistance in Compound Channel with Vegetated Floodplain Fang Chunyan，Luo Xian 2013, 32(4): 668-672.  DOI: 10.3969 /j.issn.1674-0696.2013.04.29 Abstract ( )   PDF (285KB) ( )   The influences of floodplain vegetation to the flow resistance are experimentally studied． The experimental data of local flow velocities at different vertical measurement lines are obtained by the Micro-ADV． The effects of flow height，vegetation density，submerged or emerged vegetation to the resistance coefficient are discussed． When the vegetation is planted on the floodplain，the vertical velocity is not following the logarithmic distribution and the value which is affected heavily by the vegetation density can be regarded as a constant in the vertical direction． The roughness coefficient changes slightly with the flow height in the case without vegetation while its value increases significantly with the increasing depth of water and vegetation density in the vegetated ones． Though the resistance coefficient rises with the climbing water level when the vegetation is submerged on floodplain，its value is relatively small，comparing with the emerged case． References | Related Articles | Metrics

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Ｒiverbed Evolution and Water Flow Characteristics of Tangtuba Ｒeach in the Upper Stream of Yangtze Ｒiver Li Shuangjiang，Xie Long 2013, 32(4): 673-676.  DOI: 10.3969 /j.issn.1674-0696.2013.04.30 Abstract ( )   PDF (294KB) ( )   Through the analysis on Tangtuba upstream volumetric coming water and sediment conditions，it is showed tat this reach is the part of the typical mountainous river; the banks are of relative rigid composition; the riverbed deformation is mainly the mass movement of traction load; and the annual coming water and sediment volume of the reach has little change．Combination of the change of water and sediment condition and the field terrain materials after Three Gorges dam water storage，the riverbed evolution law of Tangtuba reach is analyzed thoroughly，and the bottomland evolution tendency is also forecasted，which provides theorectic basis for the channel maintenance and management． References | Related Articles | Metrics

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Compaction Key Technology of Thick Layer and Large Diameter Ｒock-Filling Embankment Zhu Genqiao，Zhu Xiaoxia，Li Xia 2013, 32(4): 677-680.  DOI: 10.3969 /j.issn.1674-0696.2013.04.31 Abstract ( )   PDF (375KB) ( )   As a result of the limits of loose laying depth and maximum particle size in the specifications for design of highway subgrades，a large amount of stone excavations and tunnel wastes cannot be used as roadbed filler in the construction of highway in mountain areas，causing damage to the environment and increasing the engineering costs． Based on a large amount of field compaction tests and quality detections with large diameter cemented rockfill，combining with the existing construction machine and milling method，the suitable laying depth，maximum size limit，rolling machine and the combination，compaction times of big diameter stone are preposed． References | Related Articles | Metrics

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Experimental Study on the Effect of Cross-Sectional Shape of Transition Section on the Transverse Slope in Successive Bends Jing Xiaoju，Zhao Zhizhou 2013, 32(4): 681-686.  DOI: 10.3969 /j.issn.1674-0696.2013.04.32 Abstract ( )   PDF (594KB) ( )   Taking the Xu-Yu section of Yangtze Ｒiver as the prototype，the generalized model with successive bends has been established，and the fixed bed water flow test has been carried out． The results show that the boundary conditions of the transition section has significant influence on the distribution of transverse gradient in successive bends． The distribution of transverse gradient in the successive bends within compound section is the form of non-full symmetry，which is different from the full symmetry distribution of the curved roof in the single rectangular bend． The transverse gradient of export is bigger than that of entrance in the successive bends． The formulas of maximal transverse gradient and the distribution of transverse gradient in the whole successive bends are built，where the morphology factor of side shoal is reflected． References | Related Articles | Metrics

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Waterway Ｒegulation of Xiaobaita Beach in Lancang Ｒiver Jiang Ziwei，Xu Guangxiang，Tong Sichen 2013, 32(4): 687-691.  DOI: 10.3969 /j.issn.1674-0696.2013.04.33 Abstract ( )   PDF (553KB) ( )   In view of the problems appeared in Xiaobaita beach of Lancang Ｒiver，such as insufficient local water depths，irregular bilateral shorelines of the dredged channel，poor water flow state，flow velocity and gradient ratio exceeding the hydraulic parameters of rapids abating，etc． ，channel regulation is studied through a plane two dimensional numerical model．The channel regulation scheme adopts solving waterway scale，improving flow state，relieving rapids programs，etc． ． The results show that the regulation measures of cut-off works and reef explosions can smooth the shorelines and improve the flow state; the channel scales of the beach after engineering regulation can meet the grade requirements of channel planning． References | Related Articles | Metrics

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Novel Optimization Structure of Inland Ｒiver Overhead Upright Wharf Dai Jun，Yang Bo，Yuan Zhaolong，Zhang Shaobo，Ma Guoqi 2013, 32(4): 692-695.  DOI: 10.3969 /j.issn.1674-0696.2013.04.34 Abstract ( )   PDF (345KB) ( )   Aiming at the complicated geological environment and using conditions faced by large inland wharf construction，a new type of inland river overhead upright wharf structure based on the thought of structural optimal principle and the most provinces project cost was put forward，which was named by“space triangle frame pier + large span bent which taking slant supports”． And then the characteristics of the proposed wharf structure and its stability were analyzed． The proposed new optimization structure was applied to the wharf structure of CuntanⅠ，Ⅱ project，meanwhile，the engineering costs were calculated． And then the engineering costs of Cuntan wharfⅠandⅡ project after the optimization were compared with the engineering costs before the optimization． Ｒesearch shows that the construction of the proposed new structure is of concision，reasonable force，less underwater workload and economy． References | Related Articles | Metrics

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Structural Optimization Design of Vehicle Steering Column Based on Its Crashworthiness Song Xiaohua 2013, 32(4): 696-700.  DOI: 10.3969 /j.issn.1674-0696.2013.04.35 Abstract ( )   PDF (530KB) ( )   The drivers are always hurt by vehicle steering column in a frontal collision easily，so the steering column with well energy-absorbing is very useful for the drivers． To solve this problem，the crashworthiness of the vehicle steering column is studied according to the explicit dynamics finite element analysis method and the finite element software named ANSYS / LS-DYNA is used． The finite element model of steering column is proposed． The steering column with different cross sectional shape and thickness is investigated． The deformation pattern，displacement，velocity and energy absorption are analyzed． The results show that the crashworthiness including deformation pattern，displacement，and velocity as well as energy absorption of the vehicle steering column with circular section are better than square and hexagonal section． In addition，the increase of the thickness of the column helps to improve its crashworthiness． It also shows that the proposed method provides a new approach for improving its optimization design and crashworthiness． References | Related Articles | Metrics

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Simulation of Automobile Stability Control Based on Sliding Mode Control Chen Song，Xia Changgao，Sun Xu，Yao Wenjun 2013, 32(4): 701-704.  DOI: 10.3969 /j.issn.1674-0696.2013.04.36 Abstract ( )   PDF (315KB) ( )   Vehicle reference model and vehicle model with the nonlinear two degree of freedom are set up by using the MATLAB / Simulink，which includes“Magic Formula”tire model． Using sliding mode control principle to direct at the nonlinear，time varying characteristics of ESP system，a controller of yaw rate based on sliding mode has been designed． By simulation results of J-turn lane change on slippery road surface，it is demonstrated that the present stability control system based on the yaw rate is effective on maintaining the yaw rate and the sideslip angle within the optimal range，which can improve the vehicle stability． References | Related Articles | Metrics

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Hybrid Braking Technology for Hybrid Electric Vehicle Yu Jianbo，He Ｒen 2013, 32(4): 705-711.  DOI: 10.3969 /j.issn.1674-0696.2013.04.37 Abstract ( )   PDF (232KB) ( )   In order to improve the safety of brake，stability and energy recovery of braking for hybrid electric vehicle，the structure and work principles of hybrid braking system are introduced． And the key techniques of hybrid braking system are also analyzed． Then the present key tasks of hybrid electric vehicle are pointed out． Finally，the future trend of hybrid braking system is discussed． References | Related Articles | Metrics

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Analysis of Transmission Characteristics of HMCVT Gao Xiang，Zhu Zhen，Zhu Yu 2013, 32(4): 712-716.  DOI: 10.3969 /j.issn.1674-0696.2013.04.38 Abstract ( )   PDF (1312KB) ( )   The appropriate planetary gear differential train and hydrostatic units are chosen to constitute the hydro-mechanical continuously variable transmission to give the transmissive schemes of HMCVT，which suits the transmission of vehicle． The transmission characteristics of rotary speed ratio，power ratio and rotary torque ratio of HMCVT of the non-road separated torque ratio-fixed speed ratio with the range of ( 3 + 1) are analyzed． The results show that: the scheme can be better adapt to the hydraulic mechanical transmission requirements of off-road vehicle． References | Related Articles | Metrics

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Dynamic Influence of Distress Ｒunway Pothole on Aircraft Ｒunning Hu Chunfei，Han Qing’ai，Lv Yaozhi 2013, 32(4): 717-720.  DOI: 10.3969 /j.issn.1674-0696.2013.04.39 Abstract ( )   PDF (257KB) ( )   The simplified vibration model of the aircraft-pothole based on 1 /4 double degree of freedom vibration model is established． The allowable depth calculation method of the pothole is studied from passengers comfort，pavement bearing capacity and likelihood to produce leaps and bounds． It is found that frame vibration acceleration increases with the increase of the pothole depth，while it decreases with the increase of velocity; dynamic load coefficient increases with the increase of the pothole depth，while it decreases with the increase of velocity． For a practical aircraft，the allowable depth values for the potholes located on different runway positions are obtained by the proposed method，which provides a theoretical reference for the airport authority in estimating the operation applicability of distress runway． References | Related Articles | Metrics

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Image Ｒegistration Algorithm of SIFT Based on Edge and Corner Point Zhao Mengmeng，Cao Jianqiu 2013, 32(4): 721-724.  DOI: 10.3969 /j.issn.1674-0696.2013.04.40 Abstract ( )   PDF (278KB) ( )   SIFT is composed of feature extraction，feature descriptor representation and feature matching，which has a huge quantity in feature extraction and a high computational complexity in descriptor representation． So this algorithm is of low efficiency． In order to solve this problem，a kind of algorithm which is named SEC ( SIFT-Edge-Corner) is proposed． Corner points instead of SIFT feature points are extracted in image scale space． According to the theory that corner is the extreme curvature of edge，SEC constructs edge-of-Gaussian pyramid by canny operator before extracting corner points，and then the scales are selected． The experimental results show that SEC improves the feature extraction efficiency at the premise of ensuring high accuracy． References | Related Articles | Metrics

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Clustering Algorithm for High Dimensional Data Stream Based on Projection and Density Wang Ｒenhong，Wang Jiawei，Liang Zongbao 2013, 32(4): 725-728.  DOI: 10.3969 /j.issn.1674-0696.2013.04.41 Abstract ( )   PDF (311KB) ( )   A clustering algorithm for high dimensional data stream based on the projection and density ( HpDenStream) is proposed，which is based on the classical data stream clustering algorithm． This algorithm combines with the sliding window technical，and it uses the projection clustering algorithm to reduce the data dimensionality of dimensional data streams and then adopts the density clustering algorithm to detect the anomaly data detection． The simulation results show that the algorithm not only takes up smaller storage space and less workload，but also improves the efficiency of the implementation of the algorithm． References | Related Articles | Metrics