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Stability Study of Self-Anchored and Arch-Suspension Combination Bridge Qiu Jing, Li Guangfeng, Shen Ruili 2012, 31(1): 1-5.  DOI: 10.3969/j.issn.1674-0696.2012.01.01 Abstract ( )   PDF (687KB) ( )   The self-anchored arch-suspension bridge is characterized by innovative structure and beautiful shape. It has great engineering significance to research on the stability of this structure that has never been built. Firstly, the dead load state and the transfer mechanism of live load were introduced in detail. Secondly, based on a self-anchored arch-suspension bridge scheme with a main span of 406 m, the universal finite element software ANSYS was adopted to study the linear elastic stability, geometrically nonlinear stability and double-nonlinear ultimate load-bearing capacity under six load cases. Also, the influence of the initial imperfection on the structure was discussed. Finally, for comparison, the deck arch bridge with the same span was studied to find out the differences of the stability between these two structures. The results show that the first-order linear elastic instability modes are both lateral flexure of the junction at mid-span for these two structures. And the load applied on the structure has a certain influence on the overall stability and failure mode. In order to analyze the ultimate load-bearing capacity accurately, the geometric and material nonlinearities need to be taken into account. At the same time, the out-of-plane initial imperfection has little influence on the ultimate load-bearing capacity for the self-anchored arch-suspension bridge. Related Articles | Metrics

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Finite Difference Method of Free Transverse Vibration Equations of Beams Du Shaohong 2012, 31(1): 6-10.  DOI: 10.3969/j.issn.1674-0696.2012.01.02 Abstract ( )   PDF (649KB) ( )   A fourth order partial differential equation which originates from the free transverse vibration of beams, was changed into a second order mixed initial boundary value problem by introducing a couple of auxiliary functions. An implicit scheme of difference was constructed by discretization of two auxiliary functions and the second order mixed initial boundary value problem in which intermediate variables were eliminated and the second order boundary value conditions derived from vanishing deflection at both ends of the beam were approximated. Numerical experiments showed that the developed implicit scheme was absolutely stable and guaranteed a very high accuracy. Related Articles | Metrics

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Element Calculation Method of Variable Cross-Section Beams Zhang Xiaoqing, Wang Jialin 2012, 31(1): 11-14.  DOI: 10.3969/j.issn.1674-0696.2012.01.03 Abstract ( )   PDF (542KB) ( )   The variable cross-section beam is widely used in bridge engineering. C++ Language was used to write a program for calculating variable cross-section beam according to the actual change rule of section, and the result was compared with that of several other softwares. The result shows that the central axis is selected as coordinate can get higher precision than other position. But in order to model conveniently, the coordinate selected in bridge deck is also an effective method. Related Articles | Metrics

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Internal Force of Double-Column Pier Coping and Prestress Tendon Zhao Jun, Xiang Zhongfu, Jiang Yu 2012, 31(1): 15-18.  DOI: 10.3969/j.issn.1674-0696.2012.01.04 Abstract ( )   PDF (579KB) ( )   The finite element of double-column coping was analyzed by MIDAS. The influence of coping height, pier spacing, and pier height on the control section internal forces of coping was compared separately, so as to provide the basis for the reasonable prestress tendon distribution under different forces of coping. Through engineering examples, the correct selection of structure calculation model lays the foundation for the number and location of prestress tendon. The analysis shows that when the distance of the pier is fixed, copping beam height has little influence on internal force; while the copping beam height is fixed, the distance of the pier has tremendous influence on internal force of the copping beam, the bending moment in the middle span increases with the pier distance, but it goes opposite in the fulcrum of copping beam. With the pier height goes down, the bending moment has the tendency of increasing in the midspan and reducing in the fulcrum. Related Articles | Metrics

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Research on Composite Pier Structural Form of Double Thin-Wall and Single Pier Li Lu, Zhou Shuixing, Jiang Xiongfei 2012, 31(1): 19-21.  DOI: 10.3969/j.issn.1674-0696.2012.01.05 Abstract ( )   PDF (499KB) ( )   The rational structure form of double thin-wall piers combined with variable cross section single pier was studied. According to combination of three load cases, the finite element software ANSYS was adopted to analyze pier’s integral stability under different structural proportion of double thin-wall piers and single pier. The analysis results indicate that the height proportion of double thin-wall piers and single pier ranged from 0.5 to 1 is better. Related Articles | Metrics

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Research on External Prestressing to Strengthen Reinforced Concrete Void Slabs Zhao Yafei, Zhou Jianting, Ning Jincheng, Tian Jinchang 2012, 31(1): 22-24.  DOI: 10.3969/j.issn.1674-0696.2012.01.06 Abstract ( )   PDF (709KB) ( )   External prestressing technique is widely used in beam bridges reinforcement for its construction convenience, economy and reliance. However, this technique has not been used in slab bridges. So it is important to investigate its applicability in slab bridges. The deflection, strain, cracking and ultimate bearing capacity of common reinforced concrete (RC) void slabs before and after the slabs strengthened by external prestressing are analyzed. The results show that the echnique can effectively improve the bearing capacity of common RC void slabs and can be widely used in engineering projects. Related Articles | Metrics

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Analysis Method of Loading Test on Xiaotangzi Wide Bridge Xu Xianfen, Lin Sheng, Wang Cheng 2012, 31(1): 25-28.  DOI: 10.3969/j.issn.1674-0696.2012.01.07 Abstract ( )   PDF (659KB) ( )   With the development of infrastructure in city, more and more bridges with wide-span ration have been constructed as well. As the lateral distribution is much more apparent in this kind of bridges compared with the common ones, there would be some deviations in calculating live load effect of bridges if they were simulated in by traditional bridge modeling. Based on the analysis of simple supported hollow slab with a 2.3 width-span ration by structural plane and space loading modeling, a comparison of deformation and stress of the bridges between the calculation value and actual surveying value after loading was made to provide a practical reference for engineering works. Related Articles | Metrics

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New Method of Reinforcing and Repairing of Stone Spandrel Zhou Zhixiang, Mao Jiuqun, Zhang Jiangtao 2012, 31(1): 29-32.  DOI: 10.3969/j.issn.1674-0696.2012.01.08 Abstract ( )   PDF (1122KB) ( )   A method to strengthen a stone spandrel arch bridge was presented according to the damage situation of the bridge. The mechanical characteristics of using reinforced concrete fringe frame to strengthen stone masonry construction was also discussed. The simplified calculation method was presented. The analysis and comparison of the structure stress state before and after reinforcement were carried out aiming at bridge engineering. Related Articles | Metrics

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Calculation on Collision Force of Vehicle Impacting on Bridge Fan Wencai, , Zhang Nan, Wang Xin, 2012, 31(1): 33-36.  DOI: 10.3969/j.issn.1674-0696.2012.01.09 Abstract ( )   PDF (516KB) ( )   Aiming directly at frequently occurred vehicle and bridge collision, the analysis model of vehicle and bridge impact dynamics was established according to falling-weight impact equipment on the reinforced concrete pier model. Based on the D'Alembert principle, the Single-Degree-of-Freedom and Two-Degree-of-Freedom models were set up for one-dimensional and double-dimensional conditions to calculate impact force. The results show that the errors of peak and average were -15.4% and 14.5% respectively. It can provide the significant reference for anti-crash of bridge. Related Articles | Metrics

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Research on Collision Force of Ship and Bridge Substructure Xiong Qian, Liu Yu 2012, 31(1): 37-40.  DOI: 10.3969/j.issn.1674-0696.2012.01.10 Abstract ( )   PDF (797KB) ( )   Recently accidents of collision between ship and bridge substructure happen frequently, which seriously threatened the safe of bridges and city traffic system. In order to reduce the loss due to ship-to-bridge collision, the collision resistance of bridge needs to be strengthened. To achieve the effect that not only protect Bridges but also safe money, the collision force between ships and the bridge must be know well. Based on the ANSYS/LS-DYNA nonlinear FEM program, the process of boat hit a bridge on different circumstances was simulated. The calculation formula of collision force was summarized and compared with the standard formula. It can provide some reference for the study direction or engineering design. Related Articles | Metrics

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Analysis of Piston Wind Impact Factor in Tunnel Tian Weiming, Weng Qineng, Zhang Jianwei, Zhang Zhimin 2012, 31(1): 41-43.  DOI: 10.3969/j.issn.1674-0696.2012.01.11 Abstract ( )   PDF (546KB) ( )   The piston wind and the piston effect, which will be produced when the subway enters or leaves the subway station, have close relationship with the ventilation of railway tunnel and energy consumption of the subway. With the wide application of underground rail transit, how to save energy and money as possible, with the comfort of the stand halls and the platform layers, is a question that the construction and management apartment have to consider. Therefore, the rational utilization of piston wind has important theoretical and practical significance to achieve saving energy consumption in railway transportation. Starting from the causes of piston wind, the factors which influence the size of piston wind was studied systematically. And SES simulation was carried on to explore influencing reasons of the piston wind, and a better choice of the piston wind was pointed out. Rational utilization of piston wind is not only good to achieve further energy-saving effective way, but also provide the theoretical support and provide technical reference for subway design and operation. Related Articles | Metrics

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Establishment and Analysis of Temperature Field Model of Heat-Reflective Coating Pavement Chen Suming, Huang Wenhong, Luo Tingyi, Ding Yongjie 2012, 31(1): 44-47.  DOI: 10.3969/j.issn.1674-0696.2012.01.12 Abstract ( )   PDF (1000KB) ( )   Based on heat transfer theory and meteorology, ANSYS CFX, the finite element method, was used to study the temperature field of heat-reflective pavement, asphalt pavement and cement pavement. The results show that the higher the road surface reflectance, the lower the surface temperature of pavement is. The reflectance of heat-reflective pavement, whose reflectivity is 51%, the maximum temperature reduction value can reach 9℃ and 3℃ compared with asphalt pavement and cement pavement. The surface temperature of three types of pavement was also actually measured and the results are in good accordance with the calculating results. Related Articles | Metrics

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Effect of Wheel Pressure and Temperature on Rut Resistance of AC-20 Asphalt Mixture Sun Jishu, Chen Zhaoxia, Xiao Tian, Jin Canzhang 2012, 31(1): 48-50.  DOI: 10.3969/j.issn.1674-0696.2012.01.13 Abstract ( )   PDF (455KB) ( )   In order to investigate the effect of wheel pressure and temperature on the rutting resistance of asphalt mixture, rutting tests for AC-20 under different temperatures (40℃ to 70℃) and wheel pressures were carried out with an wheel rutting tester which can adjust the wheel pressure and test temperature. The influencing laws of wheel pressure and temperature on the dynamic stability and rutting depth of asphalt mixture were analyzed. And the formula between wheel pressure, temperature and the dynamic stability and rutting depth were proposed. The results show that wheel pressure and temperature have a significant effect on the rutting resistance of asphalt mixture. The dynamic stability will decrease about 30% and rutting depth will increase 23% to 55% as the wheel pressure rises 0.15 MPa. The dynamic stability will decrease about 37% and rutting depth will increase 10% to 42% as the temperature rises 10℃. These achievements contribute to grasp the influencing factors and laws of asphalt mixture rutting resistance. Related Articles | Metrics

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Influence of Ray Aging on Low Temperature Performance of Asphalt Mixture in Plateau-Cold Region Guo Weiwei, Zhang Zutang 2012, 31(1): 51-53.  DOI: 10.3969/j.issn.1674-0696.2012.01.14 Abstract ( )   PDF (629KB) ( )   Aiming at low temperature and strong radiation of sunlight in plateau-cold region, Xenon lamp was used to simulate the sunlight effect on asphalt mixture in order to accelerate ray aging test on these asphalt mixture. Through splitting test, beam bending test and linear contractive test for bituminous specimen, the low temperature performance of asphalt mixture under different test-time of ray aging was studied. Test results show that the influence on basic asphalt mixture is significant when experienced certain time ray aging, while the additive of SBR can improve ray aging resistance and crack resistance of asphalt mixture at low temperature effectively. The research results can be reference for selection of suitable asphalt binder and study on ray aging in plateau-cold region. Related Articles | Metrics

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Analysis of AC-13 Asphalt Mixture Permanent Deformation in Triaxial Repeated Load Test Li Jinfeng, Liang Naixing, Wang Xinyang, Lin Yuan 2012, 31(1): 54-58.  DOI: 10.3969/j.issn.1674-0696.2012.01.15 Abstract ( )   PDF (1282KB) ( )   The half sine wave of intermittent load was applied to triaxial repeated load test on AC-13 asphalt mixture by using MTS (Material Test System). The influence of the test temperature and stress level on the asphalt mixture permanent deformation characteristics was studied to obtain the permanent deformation law of AC-13 asphalt mixture at different temperatures and under different stress level. Based on the nonlinear regression analysis of the relation of permanent strain, load effect times, stress and temperature, the model which can fully reflect the asphalt mixture permanent deformation characteristics was proposed. The 3d graphics at different temperature were drawn to show the deformation features of asphalt mixture. Related Articles | Metrics

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Research on Moisture Distribution of Concrete at Early Age Zhang Yin, Zheng Dan 2012, 31(1): 59-62.  DOI: 10.3969/j.issn.1674-0696.2012.01.16 Abstract ( )   PDF (583KB) ( )   It’s important to make researches on concrete moisture distribution for better controlling cracks of concrete at early age. Based on diffusion theory and existed experiments, the factors influence concrete moisture diffusion coefficient were analyzed. The moisture distribution of concrete with different water /cement ratio was also analyzed by solving partial difference equation with Matlab. The results show that the calculation is in good agreement with the experiments. The moisture distribution calculated by the numerical method can provide references for prevented surface cracking of concrete at early age. Related Articles | Metrics

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Identification of Highway Traffic Accident Black-Spots Based on Traffic Conflict Technique Sun Lianchao, Shao Yiming, Yan Xueli, Lei Xing 2012, 31(1): 63-67.  DOI: 10.3969/j.issn.1674-0696.2012.01.17 Abstract ( )   PDF (529KB) ( )   On the basis of the existing identification methods, the grey evaluation method based on Traffic Conflict Technology was proposed to be used in highway traffic black-spots identification. The introduction of serious conflict times evaluation index improved credibility and accuracy of the data and the evaluation results. Then grey evaluation method was used to classify all sorts of gray types’ clustering values. This method provides a new idea for identification of highway traffic black-spots. Finally, the method was verified through an example and compared with other similar identification methods to obtain its superiorities. Related Articles | Metrics

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Structure Design of Double-Bar Semirigid Guardrail of Freeway Liu Jianxun, Tang Hui 2012, 31(1): 68-71.  DOI: 10.3969/j.issn.1674-0696.2012.01.18 Abstract ( )   PDF (499KB) ( )   According to the situation that highway guardrail can not meet the crash safety requirements of different vehicles in China, guardrail structure and parameters were studied. By method of energy conservation, vehicle-guardrail saddling model was established and a new double semirigid guardrail structure was presented. Through the method of uniform design, traffic composition and model shape parameters were analyzed, and the parameters of double semi-rigid guardrail was determined. The results show that the new guardrail can prevent the minicar drilling guardrail and large, heavy vehicles saddling guardrail effectively. Related Articles | Metrics

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Influencing Factors of Travelers’ Intention to Use Public Transit Bai Yufang, Li Linbo, Wu Bing 2012, 31(1): 72-76.  DOI: 10.3969/j.issn.1674-0696.2012.01.19 Abstract ( )   PDF (403KB) ( )   Factors affecting travelers’ intention to use public transport were studied according to different travelers. A travel intention survey was carried out to obtain data for analyzing and logistic models were constructed for qualitative analyses of those factors influencing travelers’ intention. The results shows: the increasing transit speed and improving transferring convenience will increase travelers’ intention to use public transport to the highest extent; the decreasing car travelling speed and parking difficulties are the main factors forcing car travelers to use public transport; however, car travelers’ intention to use public transport was relative lower compared with travelers who use public transport currently. The conclusion is that in order to improve travelers’ intention to use public transport effectively, efforts must be done from these two aspects all together: improving transit service quality and controlling car travel operation environment. Related Articles | Metrics

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Study on Sight Distance Issue in Road Safety Audit Peng Ming, Wang Zhongren 2012, 31(1): 77-82.  DOI: 10.3969/j.issn.1674-0696.2012.01.20 Abstract ( )   PDF (950KB) ( )   Sight distance is a critical review element in road safety audit. Some critical but easily neglected freeway sight distance issues were discussed. These include: the narrow-median induced sight distance insufficiency for adjacent fast lanes at horizontal curves; night time sight distance issues for vertical curves; and back of queue sight distance issues caused by operation difficulties at service area. These discussions can help improve freeway design through the road safety audit process. Related Articles | Metrics

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Design and Realization of Wireless Synchronized Traffic Control System Based on ZigBee Technology Cui Lizhen, Yu Quan 2012, 31(1): 83-85.  DOI: 10.3969/j.issn.1674-0696.2012.01.21 Abstract ( )   PDF (568KB) ( )   The ZigBee agreement and the Wireless Sensor Network synchronization control algorithm were studied. A Traffic Control System based on ZigBee technology is proposed. The hardware node was designed based on ATmega128L microcontroller, CC2420 RF transceiver and other chips. A wireless traffic system was improved to collect the information of the vehicle, and transfer data to traffic control center. The traffic control center sent data packets through the sink node to the wireless traffic lights. Testing results demonstrate that the system design has a good practical value. Related Articles | Metrics

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CVM Assessment of Social Utility of Chongqing Rail Transit Liu Rong, Liu Lang 2012, 31(1): 86-89.  DOI: 10.3969/j.issn.1674-0696.2012.01.22 Abstract ( )   PDF (602KB) ( )   Taking Chongqing Rail Transit as the research object, the econometrics test was used to inspect the evaluation result, and CVM was applied to assess social and economic benefits of Chongqing 700km rail line network . The results of the assessment method prove the validity of CVM. Related Articles | Metrics

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Mystery of Earthquake-Induced Tsunami Xiao Shengxie ,Tao Qingdong 2012, 31(1): 90-93.  DOI: 10.3969/j.issn.1674-0696.2012.01.23 Abstract ( )   PDF (427KB) ( )   A concept of “hydraulic jump” with a turning directing effect on tsunami wave was introduced based on the sustainable tracking analysis idea integrating “energy”, “dynamic wave” and the evolution of “medicating carrier” which are all the core concerns in the research of earthquake-induced tsunamis. It provides a system theory and approach for quantitative analysis to explain the driving direction shift and destructive power of tsunamis, as well as a traceable way of “chain-cutting disaster mitigation” for reducing the damages of tsunamis. Related Articles | Metrics

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Impact Study of Sediment on Pollutants in Rivers Luo Qiu, Cheng Changhua, Jiang Bin 2012, 31(1): 94-97.  DOI: 10.3969/j.issn.1674-0696.2012.01.24 Abstract ( )   PDF (371KB) ( )   The categories and sources of pollutants in the river which are oxygen-consuming organics, heavy metal and organic poison, were briefly described. The influence mechanism of sediment on these pollutants was summarized. Experiments both in laboratory and in field should be combined properly to know better the impacts of sediment on pollutants with consideration of multi-factor at the same time. Related Articles | Metrics

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Application of High-Density Electrical Method in Surveying Cavity Deng Diping, Wang Junjie, Deng Wenjie, Yao Yongsheng 2012, 31(1): 98-102.  DOI: 10.3969/j.issn.1674-0696.2012.01.25 Abstract ( )   PDF (1055KB) ( )   Along the middle highway, Haikou to Tunchang in Hainan Province, there is 7-kilometre across the basalt region, in which geological situation is complex, and rock melt hole are developed. Finding out the distribution and the size of underground cavity is the base to proceed the engineering treatment, and it is of great importance to ensure the quality of the engineering constructions. Because of the differences between underground cavity resistance and surrounding rock resistance, it was feasible that the high-density electrical method was used to detect the underground cavity and the distribution of the underground cavity was judged by the resistivity data image which showed the high impedance. The field testing results are identical to the field survey results, so it indicates that the high-density electrical method is suitable for detecting the cavity in basalt area. Related Articles | Metrics

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Analysis on Future Climate Change Impact on Inflow of Three Gorges Reservoir Wang Miaolin,, Hou Baojian, Fu Hua 2012, 31(1): 103-105.  DOI: 10.3969/j.issn.1674-0696.2012.01.26 Abstract ( )   PDF (403KB) ( )   Based on the output of the atmospheric general circulation model, the distributed monthly hydrological model was used as a tool to analyze the possible change trend of runoff under future climate scenarios in the upper reaches of the Yangtze River, and then the future change trend of the inflow of Three Gorges Reservoir was analyzed. The HadCM2 model was selected as the future climate scenarios. A large scale distributed monthly water balance model was developed and applied in the upper Yangtze River. The developed model was able to reproduce the historical streamflow record with the average Nash-Sutcliffe efficiency value of 85.34%. Based on the future climate scenarios from the HadCM2 model, using the precipitation and average temperature as the model input, the impacts of climate change on the changes of runoff generation in the upper Yangtze River basin was analyzed. The result shows that, influenced by climate change, the inflow of Three Gorges Reservoir will slightly decrease during the next 30 years, and then tend to increase after 60 years. Related Articles | Metrics

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Research on New Wharf Structure in Fluctuant Backwater Area of Three Gorges Reservoir Weng Zhenyan, Wu Deyong, Wang Duoyin, Yang Yang 2012, 31(1): 106-109.  DOI: 10.3969/j.issn.1674-0696.2012.01.27 Abstract ( )   PDF (573KB) ( )   After the Three Gorges Project impounding to 175 meters, the terminals construction environment are long-lasting large water depth, large water level difference and large water flow. So the traditional suspended vertical wharf structure before the Three Gorges Reservoir impoundment is not suitable. Taking the Naxigou project for an actual example, a new structure of pier beam slab terminal was proposed and its mechanical properties were analyzed. The results show that the pier beam slab terminal can adapt to long-duration deep water after the Three Gorges impoundment. This terminal structural, on the one hand, help to improve the construction level; on the other hand, it can increase the bent spacing and improve the stability of terminal, in order to achieve all-weather construction of terminal. It can be widely used as a new terminal structure in fluctuating backwater area of Three Gorges Reservoir Area. Related Articles | Metrics

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Research on Scour Ability of Dredging Pipeline Installations Dai Jun 2012, 31(1): 110-115.  DOI: 10.3969/j.issn.1674-0696.2012.01.28 Abstract ( )   PDF (662KB) ( )   Dredging pipeline installations system on the bottom of the pool is mainly applied to deal with soil problems of marginal quay. This equipment’s structure mainly includes the sequential arrangement of the pipe nozzle, scour pipe, piping systems and power facilities. According to experimental results, the basic components of the system namely Nozzle design and the selection of optimal pipeline parameters were mainly discussed. The feasibility and the capacity of dredging pipeline system were analyzed. The application and layout of the dredging pipeline installations system were introduced. The main characteristic of dredging pipeline installations system on the bottom of the pool is taking full advantage of river transport for dredging work itself. The dredging technical can be a technical measure of solving the sedimentation problem of shore wharf basin and other specific areas. Related Articles | Metrics

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Reliability Analysis of Overhead Vertical Pier on Horizontal Loading Huang Ran 2012, 31(1): 116-120.  DOI: 10.3969/j.issn.1674-0696.2012.01.29 Abstract ( )   PDF (504KB) ( )   The response surface function which replaced the real limit state curved surface was fitted at the design checking calculation point by using the response surface numerical simulation technology. And the reliability of the overhead vertical pier’s pile structure was analyzed by the MATLAB program coded through first order and second moment (FOSM) method. The result indicates that it’s feasible to calculate the reliability of large scale structures based on the response surface method. Related Articles | Metrics

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Application of Vertical Two-Dimensional Dam Break Simulated by SPH Method Miao Jilun, Zhao Wanxing, Huang Chenglin 2012, 31(1): 121-123.  DOI: 10.3969/j.issn.1674-0696.2012.01.30 Abstract ( )   PDF (1126KB) ( )   Smoothed particle hydrodynamics (SPH) is a Lagrange meshless method, which has been developed mature recently. The basic principle, kernel function, discretization of governing equations and boundary treatment were introduced. Based on the numerical flume model, the vertical two-dimensional dam break flow was simulated. The computational results were compared with the VOF results and experimental measurements. It shows that the SPH method can capture the fluid fragment and coalescence, and is available to simulate the mechanics problems with instantaneous very large deformation. Related Articles | Metrics

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Optimization and Simulation Analysis of Vehicle Powertrain Mounting System Li Nan， Jian Xiaochun， Zhang Chao 2012, 31(1): 124-127.  DOI: 10.3969/j.issn.1674-0696.2012.01.31 Abstract ( )   PDF (419KB) ( )   Abstract：The energy decoupling has directly effects on the vibration isolation of the powertrain mounting system. Taking mounting position and stiffness as parameters, the energy decoupling was optimized. The impact of constrained range of mounting position on optimized system’s energy decoupling was analyzed. The result indicates that the decoupling of main vibration direction is improved. It also shows that a higher system’s energy decoupling can be obtained by increasing the constrained range of mounting position at a less price of vehicle’s compactness. Related Articles | Metrics

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Simulation Analysis on Dynamic Loads of Heavy-Duty Semitrailer Model Based on ADAMS Huang Xuejiao, Cao Yuanwen, Li Shifeng 2012, 31(1): 128-132.  DOI: 10.3969/j.issn.1674-0696.2012.01.32 Abstract ( )   PDF (1639KB) ( )   The heavy-duty semi-trailer model was set up by ADAMS/Car. The pavement surface was imitated by using sine curve based on the measured data of Qijiang-Wansheng highway pavement roughness. The simulation analysis of the vehicle dynamic loads of every wheel, at different speeds and loads was conducted. In addition, the live loads on vehicle model with different wave-lengths and amplitudes were also investigated. The simulation result provides some reference for analyzing the interaction between vehicle and pavement surface. Related Articles | Metrics

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Vibration Property of Dependent Suspension Based on MATLAB Hu Qiguo, Wang Wenjing, Sun Baoxian, Lei Xudong 2012, 31(1): 133-136.  DOI: 10.3969/j.issn.1674-0696.2012.01.33 Abstract ( )   PDF (627KB) ( )   A simplified 4-degree-of-freedom 1/2 body equation of linear vehicle active suspension was established for studying the influence of the external environment on the vibration response when the dependent suspension was on the road. Based on the random vibration theory, taking the power spectral density of road surface undulation as the input, road roughness degree, vehicle speed and body mass effect on body vibration were analyzed. Through the MATLAB example, the result indicates that body vibration increases with speed and road roughness degree, and it’s beneficial to reduce body vibration by adding weight without overloading. Related Articles | Metrics

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Research and Design of Location Service for Urban Vehicular Ad Hoc Network Li Xiuming, Li Shuai, Yang Luxia, Fang Zhen 2012, 31(1): 137-140.  DOI: 10.3969/j.issn.1674-0696.2012.01.34 Abstract ( )   PDF (614KB) ( )   The urban vehicular Ad Hoc network has many features such as driven-slowly vehicular and many stopped vehicular when vehicular travels to the intersections. Taking the aforementioned features into account when designing the location service, we proposed a general design of location services for urban vehicular Ad Hoc networks, which was integrated into geographic routing protocols such as stateless routing GPSR. We implemented the location service under network simulation platform NS2 and provided an extensive simulation in a wide of urban scenarios. Simulation results show that ILSV (Intersection Location Service for VANET) achieves good results in terms of query success ratios and remarkable scalability compared with GLS and HLS. Related Articles | Metrics

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Application of Correspondence and Cluster Analysis in Competitiveness Evaluation of Construction Enterprise Dong Zhiqing, Huang Julin 2012, 31(1): 141-143.  DOI: 10.3969/j.issn.1674-0696.2012.01.35 Abstract ( )   PDF (421KB) ( )   The competitiveness of 17 listed construction enterprises from China was evaluated by using correspondence analysis methods. The most information of samples and indexes were showed by the least dimensions. The differences of the competitiveness of the construction enterprises can be exhibited by the method of correspondence analysis. Through the figure of correspondence analysis, the advantage and disadvantage of competitiveness can be revealed distinctly. Meanwhile, in order to make up for the rigor of the corresponding chart in the subjective judgments of distance, the method of cluster analysis was used, and the performance of the corresponding analysis was further validated. The competitiveness of enterprises was evaluated objectively and the right direction of enhancing competitiveness was available. Related Articles | Metrics

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Land Use Change of Different Districts in Ha Noi City, Vietnam PHAM Thi-mai, Mu Fengyun, TRAN Phong-vu 2012, 31(1): 144-148.  DOI: 10.3969/j.issn.1674-0696.2012.01.36 Abstract ( )   PDF (564KB) ( )   The LUCC single dynamic index model and comprehensive dynamic index model and matrix analysis were used to study the LUCC space pattern change and the land-use dynamic change in urban of Ha Noi, Vietnam. The results show that from 2000 to 2010, the land-use changed greatly caused by some apparent changes including: the special facilities area were changed into residential land and other kinds of land; the agricultural land area changed greatly and actively; the woodland area and unused land area were reduced. By contrast, the other agricultural land, aquatic land, urban land, faith-religion land, graveyard, waters and other non-agricultural land increased. As to the comprehensive land use dynamic degree, it was more active from 2000 to 2005 compared with the period from 2005 to 2010. The number of comprehensive land use dynamic degree index is 0.8246% actually in 2000-2005. It has decreased to 0.59781% during 2005-2010. Related Articles | Metrics

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Octopus Wave Energy Conversion System Based on Linear Generators Wu Linjian, Zheng Xueqin, Yang Yang, Gao Wu, Zhang Wenjing, Zhu Di 2012, 31(1): 149-153.  DOI: 10.3969/j.issn.1674-0696.2012.01.37 Abstract ( )   PDF (706KB) ( )   On the basis of existing offshore wave energy technologies, a new wave energy conversion system named Octopus, which based on linear generators, was introduced. A case study in Zhejiang was presented, in which the power of antenna was 10 kW, the average water depth was 10 m, and wave energy was collected over a 100 m long range. The results show that the theoretical wave energy efficiency of five Octopus systems was about 63%. Octopus system shows advantages in terms of its simple structure, high efficiency, and easy installation and maintenance. The system can provide a promising way in offshore wave energy development. Related Articles | Metrics

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Economic Evaluation of Taiwan Strait Passenger & Freight Ro-Ro Vessel Form Based on Fuzzy Matter Element Chen Jihong, Zou Yu, Zong Beihua 2012, 31(1): 154-157.  DOI: 10.3969/j.issn.1674-0696.2012.01.38 Abstract ( )   PDF (503KB) ( )   With the stable development of cross-strait relations, the Taiwan Strait passenger and freight ro-ro transport gets good development opportunities and potential. For the multi-criteria, multi-objective decision-making problem of economic evaluation of the Taiwan Strait passenger & freight ro-ro vessel form, fuzzy matter element theory was used to propose a reasoning method and models of the Taiwan Strait passenger & freight ro-ro vessel form. The empirical research was also conducted. Empirical study results show that the fuzzy matter-element theory used for decision making is feasible. This evaluation method combined qualitative and quantitative analysis is very practical, convenient, and objective. Related Articles | Metrics

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Exploration of DV-Hop Location Error Model Hou Zhongwei, Xu Dengyuan, Liu Chunxiao 2012, 31(1): 158-162.  DOI: 10.3969/j.issn.1674-0696.2012.01.39 Abstract ( )   PDF (629KB) ( )   DV-Hop is a typical location technology in wireless sensor network. Building a location error model and analyzing the location error quantificationally in DV-Hop are in favor of improving location accuracy in WSN. Firstly the relationship of the location error and the coverage from the angle of the theory were analyzed, and then the relationship of the relative location error and the coverage under the Restricted Communication Radius through the simulation experiment was discussed, and the corresponding mathematical model was given. The experiment shows that this model can estimate the location error based on local area effectively. Related Articles | Metrics

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Research Progress in Test Case Generation Based on Petri Nets Mu Xiaoling, Ding Xiaoming, Zhang Wang 2012, 31(1): 163-167.  DOI: 10.3969/j.issn.1674-0696.2012.01.40 Abstract ( )   PDF (390KB) ( )   Test case generation is the key step in software test and it has an important impact on the automation of software test. The tested object was modeled, and then test sequences were generated according to the model. The research status and the problem of test case generation based on Petri nets were described. Related Articles | Metrics

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Optimization of Effect Factors on Technology of Magnesium Ammonium Phosphate Tang Qi, Luo Guyuan, Tang Jin 2012, 31(1): 168-172.  DOI: 10.3969/j.issn.1674-0696.2012.01.41 Abstract ( )   PDF (319KB) ( )   The sequence of factors affecting the removal ratio of NH3-N and PO43—-P is as follows: concentration>pH> Mg∶N >P∶N> reaction time, through orthogonal experiment. The regress equation of the quantity of PO43—-P and NH3-N in the treated water is as follows: y(PO43—-P)=-3 041.57-2.76z1+2 307.2z2+3 075.5z3-2 310z2z3 (z1=pH，z2=Mg∶N，z3=P∶N), y(NH3-N)= 1 104.84-50.76z1-45.5z2-515.5z3, through once regress orthogonal experiment. The regress equation has high notability. When NH3-N is 1400 mg/L, the best treatment condition is as follows: pH=9.5, Mg∶N=1.2，P∶N=1.03, when reaction time is 30min, and stirring speed is 200r/min. On these treatment conditions, the removal ratio of PO43— is 99.73%; the quantity of PO43—-P in the treated water is 8.66 mg/L; the removal ratio of NH3-N is 98.83%; the quantity of NH3-N in the treated water is 16.45 mg/L. Related Articles | Metrics