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15 February 2010, Volume 29 Issue 1 Previous Issue    Next Issue

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Step-by-Step Algorithm of Liner Control of Arch Ribs of CFST Arch Bridges ZHAO Yang，ZHOU Shui-xing，LIU Jing 2010, 29(1): 1-3.  Abstract ( )   PDF (478KB) ( )   Aiming at the problem of height difference caused by the cable tension in segment installation of CFST arch ribs， the zero-order optimization method to calculate the pre-lift capacity and cable forces of each arch rib section in global installation is put forward，which takes the deformed arch axis caused by rib self-weight as the control objective，using the optimization theory and one-time cable tension method. Then，taking the results of global installation as objective，the pre-lift capacity and cable forces of every segment in installation are calculated by iteration algorithm，according to installation sequence of arch rib segment. The algorithm is applied to the arch axis control for New Long-men Bridge with 240m span in Wushan. It is showed that the arch axis under released cables is in well accordance with the expecting ones. References | Related Articles | Metrics

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Deviation Analysis on Construction of Steel-Concrete Composite Arch Bridges Caused by Vertical Rotation Construction WU Hai-jun，ZHU Shi-feng，ZHOU Zhi-xiang 2010, 29(1): 4-7.  Abstract ( )   PDF (507KB) ( )   A novel kind of vertical rotation construction about steel-concrete composite arch bridges is introduced. At the same time，various factors which are easy to bring in deviation in the process of construction are analyzed，demonstrated and discussed. The location deviation of the rotation axis would affect the accuracy of closure. This effect is analyzed，and the formula is derived. The mechanical behavior of arch rib under the compulsive folding is analyzed，when there is deviation in the process of folding. The result shows that the rectifying deviation method of compulsive folding has little influence on the structural stress. References | Related Articles | Metrics

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Influence of Abutment Width and Relative Rigidity Coefficients on Moment of Continuous Beam ZHANG Hua-ping，LUO Wen-hua，ZHANG Jin-hua 2010, 29(1): 8-10.  Abstract ( )   PDF (520KB) ( )   Considering the influence of abutment width B and relative rigidity coefficient α on moment value of continuous beam，the moment calculations of continuous beam under different B and α values are carried out. The peak clipping degrees of different abutment width influencing the continuous beam moment and the rule of the relative rigidity coefficients influencing moment are obtained by calculation. Wide abutment and point abutment have different reaction modes. The moment of abutment center in the section of beam caused by the reaction of abutment’s edge is the main reason which results in peak clipping of negative moment. When the relative rigidity coefficient is less than 0. 15，comparing the elastic abutment with the rigidity abutment，it is concluded that the error of moment calculations can be controlled within 5%. If the value of error is taken as the limitation criterion，the elastic abutment can be simplified into a rigid one. References | Related Articles | Metrics

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Engineering Diseases Analysis of Pre-stressed Sheet-pile Wall and Regulation Measures CHEN Hua，ZHAO You-ming，ZHANG Fa-chun 2010, 29(1): 11-15.  Abstract ( )   PDF (1262KB) ( )   The engineering diseases characteristics of the pre-stressed sheet-pile wall are summed up，which includes the partial damage，connector damage and whole damage. The partial damage is the most popular disease，which can be further divided into anchor cable damage，pile damage，shield damage and damage of rock-solid embedded. The main causes of each damage form are analyzed and the regulation measures for each kind of damage are given，which could be referenced for the design and construction of similar engineering in the future. References | Related Articles | Metrics

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Adjusting Load Process of Spandrel Construction for Large-Span Stone Arch Bridge with Deteriorated Arch Axis ZHOU Jian-ting，DENG Zhi，YUAN Rui，LAN Yong，CHEN Qi 2010, 29(1): 16-19.  Abstract ( )   PDF (372KB) ( )   Basing on the analysis of additional internal forces influencing the long-span stone arch bridge with deteriorated arch axis，spandrel construction is adjusted in steps and segments by the influence line loading method. The adjusting load process is verified by Midas /Civil structure software，and the reasonable adjusting load process of spandrel construction for long-span stone arch bridge with deteriorated arch axis is proposed. In light of engineering practice，it is showed that the adjusting load process proposed is reasonable and feasible. References | Related Articles | Metrics

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Modification of Virtual Displacement Based on Unstressed State Method TIAN Wei-feng，ZHOU Shui-xing，QIN Zhen 2010, 29(1): 20-22.  Abstract ( )   PDF (370KB) ( )   The causes of virtual displacement in long-span cable-stayed bridge construction control and structural analysis have been analyzed. The calculation errors which are resulted from the virtual displacement have also been described. The error modification method based on unstressed state theory is proposed. The effectiveness of the modified method has been verified through examples. The proposed method is of reference value for FEM error analysis of bridge. References | Related Articles | Metrics

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Deformation Analysis on Large-Span Prefabricated T Beam in Storage Process Based on AEEM ZHOU Sheng-yi，ZHOU Zhi-xiang 2010, 29(1): 23-26.  Abstract ( )   PDF (632KB) ( )   Large-span prefabricated prestressed T beam has strongpoint in low costs and convenience for traffic. However， the deformation of large-span prefabricated prestressed T beam in storage process changes nonlinearly under the influence of load age，prestress loss，sectional characteristics，storage time etc，which is hard to control. According to the theory of ageadjusted effective modulus method (AEMM) with high precision，MATLAB is used to write the corresponding creep analysis module，and the best loading age and storage time are worked out; moreover，the optimal precamber alignment is recommended， which provides solutions for the complex creep problems in the storage process of beam. References | Related Articles | Metrics

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Comparison of FEM Simulation Methods of Prestressed Reinforced Concrete Members LI Ping，WANG Jia-lin 2010, 29(1): 27-29.  Abstract ( )   PDF (433KB) ( )   The modeling methods，solution thoughts and features，which apply the embedded region and the non-nodal FEM in ABAQUS to simulate the reinforced concrete members，are introduced. The shortcoming of embedded region that it can’t restrict the rotation degree is expounded. The advantages and disadvantages of the embedded region and the non-nodal FEM are expounded through three examples. Meanwhile，it is indicated that the non-nodal FEM is advantageous in dealing with reinforced concrete members. References | Related Articles | Metrics

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Local Buckling Performance of Rectangular Concrete-Filled Steel Columns CAO Yuan-jun，HUANG Ming-kui，ZHUANG Jia-zhi，YANG Jin-hua 2010, 29(1): 30-32.  Abstract ( )   PDF (288KB) ( )   The use of thin steel plates in rectangular concrete-filled steel stub columns will give rise to the local buckling that would reduce the strength，stiffness and ductility performance of the rectangular concrete-filled steel stub columns. The changes of local critical buckling stress (σcr) of the rectangular concrete-filled steel stub column under the eccentric loading are analyzed. Thus，the eccentricity is described by adopting the stress gradient coefficient φ and the formula for calculating the critical local buckling stress σcrof the rectangular concrete-filled steel stub columns is deduced by Galerkin method. From the formula，it is known that the local critical buckling stress (σcr) of steel plates of rectangular concrete-filled steel columns decreases with the increase of stress gradient coefficient φ. In addition，the axial force is disadvantageous to the local buckling of the rectangular concrete-filled steel stub columns. References | Related Articles | Metrics

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Synthetic Optimization Research of Road and Bridge Management Based on Assessment of Assets Value ZHU Jie，CHEN Zhang，SUN Li-jun 2010, 29(1): 33-37.  Abstract ( )   PDF (271KB) ( )   The corresponding synthetic optimization management of the facility in road and bridge management has become inevitable. An asset value evaluation method is proposed to link the value of the assets with the change of facilities’performance and then economic indicator is adopted to describe benefits of road and bridge maintenance uniformly. The synthetic optimization of road and bridge management，including optimum plan for maintenance，allocation of funds and optimization performance of road and bridge under the condition of fixed maintenance founds，is realized by the mathematic optimization method. References | Related Articles | Metrics

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Magnetic Measurement Method to Test Steel Bridge Welding Residual Stress LIU Xiao-yu 2010, 29(1): 38-41.  Abstract ( )   PDF (272KB) ( )   Magnetic measurement method is a new method of stress measurement，based on the piezomagnetic effect of ferromagnetic materials. Firstly，the principle of magnetic measurement method is introduced. The welding stress after completion of welding and after ultrasonic impact is tested by magnetic measurement method，in the cases of studying 3 full-scale models of Guanyinyan Yangtze River Bridge. The test results show that there is a large welding residual stress in parallel direction and the direction perpendicular to welds，and most of them are close to the yield strength of steel; local structural design is significant for the prevention of welding stress concentration; the ultrasonic impact is showed significant to eliminate welding residual stress. Experimental results show that the magnetic measurement method can effectively test the welding stress of the bridge steel members and that it is a reliable means for people to understand the weld stress distribution of the bridge. The proposed magnetic measurement method has good potential because of its high sensitivity，simple test system and the flexible operation. References | Related Articles | Metrics

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Research on Steel Element Division Method in Non-node Connectivity Modeling of Reinforced Structure PENG Yi，WANG Jia-lin，YI Zhi-jian，LI Ping 2010, 29(1): 42-44.  Abstract ( )   PDF (260KB) ( )   The non-node connectivity method provides a completely independent element modeling program for steel and concrete in reinforced structure，it allows steel element and concrete element division staggered. To the issue of steel element crossing through the concrete element in this method，the intersection location relationship between steel element and concrete element surfacse and its effect are analyzed. The mathematics model which devides the nodes of steel elements at the intersection of concrete element interfaces is established; meanwhile，the problem of coordinating the displacement between the steel element and concrete element is solved. The feasibility and effectiveness of this method is demonstrated by case study. References | Related Articles | Metrics

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Research on Interchange Density of Chongqing Ring Highway GAO Lu-bin，SUN Jia-si，ZHANG Ming 2010, 29(1): 45-48.  Abstract ( )   PDF (1350KB) ( )   There are so many interchanges on the ring highways of Chongqing that the space between interchanges becomes smaller and smaller. In order to meet the requirements of minimum space between interchanges and enable the ring highway to be made full use of，the characteristics of interchanges on the ring highway are analyzed. According to the criterion of the interchange space in“Highway Route Design Specification”(JTG D20-2006)，the interchange density of Chongqing ring highway is discussed，with the combination of successful examples of small distance interchanges built in Chongqing and other cities. Finally，preliminary measures of small distance interchanges on the ring highway are proposed. References | Related Articles | Metrics

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Rutting Caculaiton of Asphalt Pavement Based on the Johnson-Cook Viscoplastic Model HE Zhao-yi，WANG Fan，ZHU Lei，LU Zhao-feng 2010, 29(1): 49-53.  Abstract ( )   PDF (862KB) ( )   The constitutive equation of asphalt mixture is described by the Johnson-Cook model. The model parameters of base asphalt mixture and modified asphalt mixture are gained by uniaxial compression experiments of different temperatures and different strain rates. Based on the ANSYS transient dynamic theory，the effects of asphalt pavement rutting of the number of equivalent axle load，temperature and overloading are analyzed. The results indicate the anti-rutting performannce of nature rock asphalt modified asphalt mixture is 20% higher than the anti-rutting performannce of base asphalt mixture， which is consistent with the asphalt pavement rutting deformation of the actual situation. The rutting caculaiton method based on the Johnson-Cook viscoplastic model is put forward，which provides a new method for asphalt pavement rutting analysis. References | Related Articles | Metrics

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Crack Damage of Cement Concrete Pavement LV Hui-qing，ZHANG Xiang-wei，ZHANG Rong-hui 2010, 29(1): 54-57.  Abstract ( )   PDF (909KB) ( )   The crack of the cement concrete pavement(CCP)is caused by the coupling of various damage effects from macroscopic， meso，and microcosmic levels. Initially，the cement concrete pavement slabs in the test road are numbered and the crack damages of pavement are investigated in detail. The size and location of every crack in each pavement slab are measured and drawn in a plane map of cracking. Through the statistical analysis of crack distribution in every pavement slab，the distribution rule of pavement cracks under stochastic vehicle and environmental load is obtained. The physical reasons causing the cracks are discussed. With the results of crack distribution study，the theory of designing newly-constructed CCP，as well as the theory of the preventive maintenance of damaged CCP is developed and improved. References | Related Articles | Metrics

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Load Stress Analysis of Rubble Concrete Pavement HUANG Wei-rong，XU Ding-jin，HE Zhao-yi，HE Fu-yuan 2010, 29(1): 58-62.  Abstract ( )   PDF (466KB) ( )   On the basis of analyzing the characteristics of industrial rubble concrete materials，the load stress of industrial rubble concrete pavement surface is calculated by means of 3-D finite element software COSMOS. At the same time，the orthogonal design method is used to analyze the factors influencing the load stress，and the variation rule of influencing parameters is obtained. The uniform design method is adopted to arrange parameters combination; and a practical computation formula that can be applicable to the load stress calculation for rubble concrete pavement is worked out by SPSS regression analysis software. References | Related Articles | Metrics

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Reasonable Spacing of Closely Spaced Tunnels with Large Cross-Section WU Heng-bin，ZHANG Xue-fu，ZHOU Yuan-fu，LIU Jia-xiang 2010, 29(1): 63-68.  Abstract ( )   PDF (1375KB) ( )   The closely spaced tunnels with large cross － section have large excavation span，low flat rates and significant effect of two holes. The mechanical behavior and stress mechanism of closely spaced tunnels with large cross-section are more complicated than those of normal tunnels in construction. Based on the engineering project of Chaoyangsi tunnel which underpasses the Yu-Ling expressway，the deformation characteristics of supporting structure and the rock surrounding tunnel are obtained. Then the concept of close proximity to yielding degree is adopted to make an evaluation of the mechanical characteristics in supporting structure and the rock surrounding tunnel. Finally，the changing rule of the closely spaced tunnels with large cross-section during excavating is discussed. The research results show that the reasonable distance between two tunnels should be 1D ～ 1. 2D. Their deformation and mechanical characteristics of the surrounding rock in the naked tunnels are obtained by the strength reduction method. These calculated results are in accordance with the foregoing results. So a new reasonable distance of the closely spaced tunnels with large cross-section is proposed. The research findings would provide some references for the design and construction of similar tunnels. References | Related Articles | Metrics

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Cracking Recognition of Pavement Surface Based on Wavelet Technology SUN Bo-cheng，QIU Yan-jun，LIANG Shi-qing 2010, 29(1): 69-72.  Abstract ( )   PDF (1038KB) ( )   The image decomposition and reconstruction programs based on wavelet transform are applied to the detection and recognition of pavement cracking. Firstly，2-D discrete wavelet multi-resolution decomposition is carries out on the image of the pavement. The location of the edge is determined by the size of two components，that is，the phase (gradient direction) and local modulus maxima of the wavelet transform at different decomposition levels. The wavelet decomposition coefficients are further transformed to remove noises and to enhance the edges of cracks. Then，effects of different wavelet bases， different multi-resolution levels，the decomposed sub-images used in reconstruction on the segment of pavement image cracks are discussed and analyzed through experiments. Finally，simple threshold technology is used to generate binary image， which can discriminate cracks against background regions in the reconstructed images. References | Related Articles | Metrics

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Portfolio Analysis on Construction Equipments in Uninterrupted Road Retreading CAO Yuan-wen，MA Li-ying，CHEN Peng-peng 2010, 29(1): 73-75.  Abstract ( )   PDF (1376KB) ( )   In order to retread the cement concrete pavement with uninterrupted use，taking Frankfurt (FRA) airport runway renovation as a case study，the portfolio analysis on construction technology and construction equipments are carried out，in accordance with the special requirements of construction equipments，construction time，and construction technology. The results show that the continuously uninterrupted mechanization construction technology have realized the retreading of the old cement concrete pavement，eliminated the original defects，and ensured the uninterrupted use of the airport. References | Related Articles | Metrics

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Safety Analysis on Lining Structure of Long-Span Shed-Tunnel alongside Mountain PAN Shi-qiang，LI Yi-wei 2010, 29(1): 76-79.  Abstract ( )   PDF (421KB) ( )   The plane analysis is mainly used in previous finite element analysis of shed-tunnel’s structure. Although the plane analysis is simple，they cannot analyze the safety of lining structure at cross-section of span. The load structure method is applied to calculate the internal force of each element in 3-D shed-tunnel lining structure，furthermore，the safety calculations is also carried out according to its lining structure reinforcement. The numerical simulation shows that the maximum axial force of shed-tunnel lining appears in the sidewall of the foundation along the mountain; the maximum positive moment appears in the central region of curved wall and that most positive moment appears in the central region of the left board. The lining structure safety coefficients of mid-span section are slightly higher than those of the support saddle section， and the safety coefficients of whole lining structure satisfy the requirements of“Road and Tunnel Design Specification”( JTG D 70—2004). References | Related Articles | Metrics

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Construction Land Assessment for Rural Highway Based on Sustainable Development Theory LIU Yan，JIANG Mei-sheng，LIU Jian-feng，DENG Ke-rong 2010, 29(1): 80-84.  Abstract ( )   PDF (234KB) ( )   The sustainable development theory is introduced to make an assessment of land consuming in rural highway construction. Through analyzing the nature of the sustainability of the land consuming in rural highway construction，a sustainable assessment indicator system of land consuming in rural highway construction is established firstly; and then，an exponential model of growth curve of land consuming in rural highway construction is set up，which coordinates the development of society，economy，resources and environment，making use of the method named same indefinite-contrary order in set pair analysis (SPA); furthermore，the proposed model is applied in construction land assessment for rural highway. The result shows that the assessment model based on the relative degree and same indefinite-contrary order is convenient and practical in calculation and assessment; the assessment result is of better objectivity and reasonability. References | Related Articles | Metrics

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Causes Analysis and Control Measures of Waduan Village Landslide on Feng-Yun Expressway in Chongqing WANG Hong，ZHONG Ning，WANG Zhi-chao 2010, 29(1): 85-89.  Abstract ( )   PDF (559KB) ( )   With the rapid development of western highway construction in recent years，the disasters frequently occur along the roads. It is necessary to study the disasters and implement corresponding control measures. According to the analysis on engineering geological and hydrological conditions，geological structures and landslide characteristics of Waduan village landslide on the expressway from Yunyang to Fengjie in Chongqing，the formation mechanism of the landslide is summarized. Finally，the cause analysis of the landslide is carried out，and the prevention plan and treatment measures are proposed to provide reference for the renovation of expressway landslide in the future. References | Related Articles | Metrics

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System of Self-Protection and Self-Coordination of Anchor-Hold Structure XU Xi-bin，YE Xiao-ming，DENG Ji-hui，CHU Guang-hui 2010, 29(1): 90-92.  Abstract ( )   PDF (259KB) ( )   The basic principles of a new method of supporting slope—system of self-protection and self-coordination of anchor- hold structure are introduced. The system is composed by the self-protection technology of anchor-hold structure and the unit structural system，which is a complete set of new technologies to support slope. A plastic deformation device has been used in this technology to prevent the overloading rather than increasing the amount of material used，which can implement self-protection and self-coordination in the case of overloading. This technology is suitable to be applied to support slope in complex environment and earthquake region. References | Related Articles | Metrics

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Risk Zoning Assessment of Geological Hazard at Nanshan Scenic Spot YANG Jun，TANG Hong-mei，LUO Hong 2010, 29(1): 93-97.  Abstract ( )   PDF (898KB) ( )   Nanshan scenic spot is the area where geological hazard is rather developed in the urban of Chongqing. Based on field observation and investigation，six risk factors resulting in geological hazard includes: terrain slope，formation lithology combination，geological structure，the thickness of accumulation body，groundwater and engineering activities. The value assignment of index is obtained through expert system，and the weight of index is determined by analytical hierarchy process (AHP); the risk zoning assessment model of geological hazard is established. Hereby，based on GIS platform，the risk zoning of geological hazard of Nanshan scenic spot is identified，including slight hazard area，medium hazard area，high hazard area，extremely hazard area. They take up 65. 2%，18. 1%，13. 2% and 3. 5% respectively in area; and these data are consistent with those of actual situation. The research results can provide certain scientific basis for the comprehensive development of land and resources as well as the environmental protection in scenic spot. References | Related Articles | Metrics

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Method and Application of Debris Flow Hazard Assessment Based on SIGA-BP Neural Network GU Xiu-zhi，CHEN Hong-kai，LIU Hou-cheng 2010, 29(1): 98-102.  Abstract ( )   PDF (268KB) ( )   The risk degree of debris flow is determined by dangerous factors of the debris flow. The dangerous factors are divided into primary and secondary factors. It is difficult to choose the most dangerous factor. BP neural network is optimalized by self-adaptive immune genetic algorithm (SIGA)，and seven dangerous factors of Yunnan province are obtained. SIGA-BP neural network is also established，which is applied to forecasting data of 10 groups’debris flow，and more accurate forecasting results are obtained. References | Related Articles | Metrics

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Boundary Conditions of Engineering Implementation at Zone of Exit Ramp of Elevated Road CHEN Ying-xue，WU Bing 2010, 29(1): 103-105.  Abstract ( )   PDF (398KB) ( )   Currently，some exit ramps of elevated roads in Shanghai are so crowd at peak time that they face to be taken of engineering measures. Boundary conditions of engineering implementation at zone of exit ramp of road are studied by using VISSIM software to model. Firstly，the evacuation capability of the exit (the largest traffic volume to leave the ramp and to get through the intersection ahead) is determined on the condition that the queue length of vehicle at the zone of exit ramp does not go back to the main line，which establishes theoretical foundation for the control and organization of exit ramp. Then，with the combination of existing traffic demand，the sufficient conditions and necessary conditions of engineering implementation are determined quantitatively，which can provide a theoretical basis for the engineering implementation at zone of exit ramp of elevated roads in Shanghai or other cities in China. References | Related Articles | Metrics

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Short-Time Traffic Flow Prediction Based on Information Fusion of Wavelet Denoising and Optimal Weight GAO Wei，LU Bai-chuan，HUANG Mei-ling 2010, 29(1): 106-109.  Abstract ( )   PDF (281KB) ( )   Since the actual transportation system features in complex time-varying changes and uncertainty of traffic flow changes，the wavelet analysis theory is applied to denoise the original traffic data，which makes the data after denoising is better to reflect the nature of traffic flow and its changing rule. Information fusion technology is able to do integrated treatment of different sensor data，to remove redundancy，to overcome the ambiguity，so it can obtain more comprehensive， more accurate and reliable information than any single data source do. Considering the accuracy and reliability of real-time road traffic prediction，the information fusion prediction method based on wavelet denoising and optimum weight is proposed， using the thought of integrating denoising technology based on wavelet analysis and modern information; furthermore， the experimental results are verified by case studies. Empirical results of the analysis show that the method proposed can improve the accuracy of traffic flow prediction effectively. References | Related Articles | Metrics

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Analysis on Short-Term Traffic Flow Characteristics Based on Nonlinear Time Series Analysis XU Lun-hui，TANG De-hua，ZOU Na，XIA Xin-hai 2010, 29(1): 110-113.  Abstract ( )   PDF (1375KB) ( )   The qualitative and quantitative analysis of short-term traffic flow characteristics are made，which is based on nonlinear time series analysis in time dimension. At first，recurrence plot and recurrence quantification analysis are briefly introduced; the dynamic characteristics of field traffic flow is visualized by the qualitative analysis of recurrence plot，which takes 1-minute interval data of filed traffic flow as example and selects four different parts of one day. And then the quantitative values of each part are obtained by utilizing the recurrence quantification analysis; furthermore，the recurrence variables are analyzed. The result indicates that short-term traffic flow is non-linear and non-stationary and shows randomness， chaos and uncertainty at different periods，which would be valuable in theoretical and practical application of short-term traffic flow forecast. References | Related Articles | Metrics

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Algorithms of Schedule-Based Transit Flow Assignment LIU Zhi-qian，SONG Rui 2010, 29(1): 114-120.  Abstract ( )   PDF (613KB) ( )   Transit flow assignment models proposed presently are mainly frequency-based，which has poor schedule information. Aiming at improving the research on schedule-based transit flow assignment，the modified Logit model that adopts transit route independence system in the traditional Logit model is established，avoiding the mutual influence of similar routes. At the same time，a volume restrained ＆ timetable based stochastic user equilibrium (VRT-SUE) model is established， which considers the limitation of vehicle capacity and realizes the flow assignment on transit network using SUE model. The case study result of transit network flow assignment shows that the improved Logit model has better effects than traditional Logit model does; VRT-SUE can satisfy the constrain of vehicle capacity，meanwhile the flow assignments can achieve an equilibrium state in network. Both of the proposed models could be applied to the design and operation management of urban transit network. References | Related Articles | Metrics

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Correlation Analysis on Driver’s Human Factors and Accident Hazard in Road Traffic Accidents AO Gu-chang，YANG Li 2010, 29(1): 121-124.  Abstract ( )   PDF (497KB) ( )   The vehicle driver’s human factor is one of the most important aspects in road traffic accidents trigger and formation. In order to analyze the relations between the driver’s human factors and the accident hazard，the statistical indicators of regional road traffic accidents，including death number，casualties，and direct economic losses etc. ，are utilized as the referential sequences; the statistical number of road accidents caused by vehicle driver’s human factors is taken as the comparison sequence; and then the grey relation model between the vehicle driver’s human factors and the accident hazard can be established. And combination with the case studies，the human factor of vehicle driver’s influence on the extent of accident hazard caused by different types of road traffic can be identified and evaluated，which is based on quantitative analysis on gray relational matrix. The results can provide references for the corresponding departments to take more effective safety management and prevention measures. References | Related Articles | Metrics

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Method to Analyze Behavior Safety of Vehicle Group in Virtual Condition JI Ting-ting，CHEN Shao-jun，CHEN Yu-ren 2010, 29(1): 125-128.  Abstract ( )   PDF (323KB) ( )   The moving characteristics and rule of vehicle group are studied in the virtual condition，which includes the framework of the software and hardware，the experiment process，the data collection，analysis and calculation，as well as the data reliability analysis. In the experimentation，15 drivers simulate driving in one scene，meanwhile，the moving parameters of vehicles are collected respectively，including the running track，all kinds of velocity and acceleration，and the use of brake and steering wheel of the vehicles etc. Fuzzy neural network and risk probability matrix are used to analyze the data mentioned，and the risk probability of the vehicle group is calculated; furthermore，the method to study behavior safety of vehicle group is proposed. References | Related Articles | Metrics

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Appraisal on Automobile Emission Intensity of Typical Urban Roads in Hangzhou CAO Xiao-chun，WU Liu-liu，MA Lin-cai 2010, 29(1): 129-132.  Abstract ( )   PDF (260KB) ( )   Three typical roads’traffic conditions of urban district in Hangzhou are investigated. It is showed that the saloon car current capacity is the biggest one，occupying 74% ～ 81% of the total flow; and the average vehicle speed is excessively low in some sections，only up to 18. 54km/h. According to the results of traffic investigation，total emission intensities of the three roads are calculated and finally obtained. The results show that the emission intensity of urban road in Hangzhou is unoptimistic. It is suggested that the sections where automobiles are always at a low speed should be renovated immediately; secondly，the emission of saloon car in urban district should be controlled，and the frequencies of public buses in some sections should be increased simultaneously; thirdly，the routes of public buses should be optimized or some special automobiles should even be forbidden in some sections. References | Related Articles | Metrics

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Regulation Measures of Tonggu Beach at Upstream of Yangtze River YANG Xiang-fei 2010, 29(1): 133-137.  Abstract ( )   PDF (754KB) ( )   Tonggu Beach is located in the transition section of two reverse rivers. The upstream of the beach can’t satisfy the requirements of water level in dry season; the middle section is the navigation channel with small bending radius; and the down section is of high flowing speed and disordered flow pattern，which is dangerous to navigate. The regulation treatments of dangerous shoal and building structures are discussed through the analysis of the evolution rule and hindering mechanism of the beach based on experimental results of relative models. Furthermore，the effect of regulation treatment is evaluated. The method proposed provides certain references for the regulation treatment of similar beaches of rivers at the mountainous area. References | Related Articles | Metrics

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Ship Motion Model and Simulation Study in Bridge Navigable Waters of Three Gorges Reservoir Area LIU Yuan-feng，YANG Du-jun，CHEN He，LIU Xi-hua 2010, 29(1): 138-141.  Abstract ( )   PDF (992KB) ( )   After the construction of Three Gorges Reservoir，river-crossing bridges in construction at the reservoir area become more and more. In order to reduce or avoid the ship-bridge collision，the mathematic model of ship’s off-course influenced by the wind and stream in bridge navigable waters is established，from the perspectives of ship driving and collision avoiding. Zhongxian Yangtze River Bridge located in Shi-Zhong highway is taken as the research object and the ship controlling theory is used in this model. And the ship motion track in the bridge navigable waters is simulated by the simulation technology，which shows three-dimensional view of ship getting through the bridge. The proposed mathematic model provides theoretic basis for river-crossing bridges in Three Gorges Reservoir area to take the initiative measures to prevent collision. References | Related Articles | Metrics

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Calculating Method of V-Shaped Drainage Channel in Debris Flow SUN Xiao-yong，CHEN Hong-kai 2010, 29(1): 142-146.  Abstract ( )   PDF (415KB) ( )   The drainage engineering is widely-used in the civil engineering measurement against debris flow. In particular， the V-shaped drainage channel has played a significant role in draining the solid materials of debris flow. Based on the loading models of V-shaped drainage channel and the boundary conditions，a method of calculating the slide wall and the bottom of V-shaped drainage channel is put forward，by utilizing the theory of Rankine’s earth pressure and the calculating theory of elastic foundation beam. The case studies have been carried out in the engineering measurement against debris flow of Santan in the line of Chengdu-Kunming Railway and Pingliao Station in the line of Yidu-Liuzhou，which include the calculation of channel bottom displacement，sub-grade reaction and internal force of the V-shape channel. References | Related Articles | Metrics

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Track Prediction Based on Neural Networks and Genetic Algorithm TAN Wei，LU Bai-chuan，HUANG Mei-ling 2010, 29(1): 147-150.  Abstract ( )   PDF (973KB) ( )   Genetic algorithms are applied to the optimal design of BP neural network. And a predictive model of tracking forecast of moving object based on genetic BP neural network is established. The model overcomes the defects of trapping into local optimal point that ordinary neural network algorithms in the training process are easily to be trapped; and higher accuracy and faster convergence speed are obtained. Finally，the model is analyzed and verified by the filed measurement data. The results show that the neural network forecasting model based on genetic algorithm is better than the single neural network forecasting model in prediction accuracy，which can be used to track forecasting. References | Related Articles | Metrics

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Global Asymptotic Stability of Cellular Neural Networks with Time-Varying Delays HU Chun-yan，YANG De-gang，HU Zhi-qiang 2010, 29(1): 151-156.  Abstract ( )   PDF (416KB) ( )   The global asymptotic stability of cellular neural networks with time-varying delays is investigated. A novel sufficient judging criterion of the equilibrium point of global asymptotic stability of cellular neural networks with time-varying delays is given. First，the cellular neural network model with time-delay is proposed，the conditions for the system to activate the function and the lemma would be used are introduced. Then，the system under study carries out the“linearization” through an equation. The global asymptotic stability of cellular neural networks with time-delay is discussed by utilizing Lyapunov- Krasovskii functional method and the linear matrix inequality (LMI) technique，on the basis of defining a mapping operation system associated with the system. The results obtained are associated with the time-delay. Finally，a numerical example is given to verify the effectiveness of the proposed method. References | Related Articles | Metrics

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Study on Thermal Oxidative Aging Kinetics of SBS CAO Xue-juan，LEI Yun-bo 2010, 29(1): 157-161.  Abstract ( )   PDF (1251KB) ( )   The thermal oxidation process of SBS is tracked by in-situ FTIR; meanwhile，the reaction parameters of SBS oxidation kinetics are calculated by thermal analysis kinetics. The results show that there is no chain scission and degradation occurred in nitrogen atmosphere below 160℃; while，in oxygen atmosphere，thermal oxidative degradation and random chain scission occur in PB segment of SBS; PS segment of SBS has excellent anti-oxidation performance and it can’t be oxidized when temperature is below 300℃. The α-H beside the double-bond has great activity，which is easy to be oxidized. The results also show that both of chain scission and de-polymerization occur in the thermal oxidation reaction. Auto-oxidation is the main feature of SBS thermal aging oxidation process. The mechanism of the reaction is freely-chained reaction， which includes chain initiation，chain growth and chain termination. After the reaction experiences the induction period of initial free radical，SBS is oxidized rapidly and degraded severely. References | Related Articles | Metrics

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Traffic OD Data Collection Technology Based on Mobile Phone Location HUANG Mei-ling，LU Bai-chuan 2010, 29(1): 162-166.  Abstract ( )   PDF (818KB) ( )   Origin destination (OD) traffic data is one of the most important basic data in the traffic planning. Although the traditional traffic inquiries with pen，paper，telephone etc. are simple，they also have many limitations. With the development of information and mobile communication technologies，it is a hot issue to collect traffic data by mobile phone location technology. The consecutive location of travelers is traced by CDMA communication network and gpsOne technology. Then the information of beginning and end points location is extracted by data processing. Combining with the given traffic region division，the OD data of travelers can be obtained by area-judgment calculation，which is a part of the algorithm between point and polygon. Finally，the proposed method is used to make an OD survey at the area of Yangjiaping in Jiulongpo District in Chongqing，and topics of OD centralized occurrence and OD-line are obtained. References | Related Articles | Metrics

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Reduce Form and Fundamental Domain of a Class of Second-Type Fuchs Groups CHEN Bo，XIA Xing-wu 2010, 29(1): 167-170.  Abstract ( )   PDF (260KB) ( )   A class of second-type Fuchs group is defined，which is an important generalization of classical modular form. q is acted as a nature number which has no square factor. In the case ofq > 4 ，G(槡q) is defined as the group consisting of matrices in the form of a b槡q 槡( ) c q d ∈SL(2，R) . Then the reduce form of all real positive quadratic form P2 under the action of G(槡q) is discussed. Finally，the relationship between the set of all reduce forms and the fundamental domain under the action of G(槡q) onP2 is given. References | Related Articles | Metrics