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20 March 2018, Volume 37 Issue 03 Previous Issue    Next Issue
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Bridge & Tunnel Engineering
Highway & Railway Engineering
Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment
Traffic & Transportation Engineering
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Bridge & Tunnel Engineering

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Influence.Factor.Analysis.and.Curve.Fitting.of.Camber.of Continuous.Beam.Bridge.in.Cantilever.Construction WU Xiaoguang, AN Pinghe, HUANG Xuqin, ZHENG Peng, LI Yilin 2018, 37(03): 1-4.  DOI: 10.3969/j.issn.1674-0696.2018.03.01 Abstract ( )   PDF (379KB) ( )   In view of the problem of setting camber alignment of large span continuous beam bridge in cantilever construction, the influencing factors affecting the construction deflection were analyzed one by one, and the theoretical calculation formula of the camber of the continuous beam bridge in construction was calculated. For setting the camber alignment curve in construction of actual bridge, taking Juhe Bridge as an example, numerical methods were adopted for fitting. The results show that: in the engineering example, the determination coefficient of polynomial fitting is 0.844, which is generally consistent with the deflection curve of model; the determination coefficient of nonlinear fitting is 0.992 7 and the fitting results are excellent. The above two fitting methods can both be used in the calculation of the alignment of camber in construction, and the obtained results are reliable. References | Related Articles | Metrics

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Dynamic Temperature Field of Welding of Orthotropic Bridge Deck Based on ANSYS ZHANG Li 2018, 37(03): 5-8.  DOI: 10.3969/j.issn.1674-0696.2018.03.02 Abstract ( )   PDF (644KB) ( )   Considering the characteristic of the temperature dependence of the thermos-physical properties of materials, the numerical simulation of the dynamic temperature field of multi-seam welding of the orthotropic bridge deck panel was carried out on the basis of double life and death element technology, in order to discuss the distribution rule of the welding temperature field. The results show that the welding thermal-cycle curve of orthotropic bridge deck evolves according to the mode of “fast rise, fast drop and slow cooling”. The welding sequence significantly affects the dynamic change of the temperature field. The local high temperature zone near the weld seam is mainly distributed in the range of 10 mm on both sides of the weld seam, and the number of temperature peaks of different weld seams at different time is not the same. The reliability of the numerical simulation is verified by experiments, and the numerical solution is in good agreement with the measured temperature. References | Related Articles | Metrics

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Evaluation Study on Technical Status of Steel Bridge Deck Paving in Anhui Province ZHAO Yang1, ZHOU Qiwei2, HU Deyong2 2018, 37(03): 9-13.  DOI: 10.3969/j.issn.1674-0696.2018.03.03 Abstract ( )   PDF (435KB) ( )   In view of the present situation that there is no evaluation standard for the technical status of steel bridge deck paving system in the current standards, the inspection data and maintenance history of the paving layers of typical steel bridges in Anhui province over the years have been collected. Four indicators, that is, damage index, driving quality index, rutting depth index and skid resistance index of steel bridge paving system in Anhui province were put forward by mathematical statistics regression and expert scoring method. Finally, the comprehensive evaluation index, that is, the performance index of the pavement layer, was put forward according to the weight of each single index assigned by the corresponding experts. The fact shows that the evaluation standard of the technology status of steel bridge paving system fills the vacancy of the evaluation of steel deck paving condition, and lays a foundation for subsequent maintenance decision of pavement layer. References | Related Articles | Metrics

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Influence of Vehicle Headlights on the Quality of Tunnel Pavement Lighting LIANG Bo1,2, LING Chao1, LI Xiang1, ZHANG Yangfan1 2018, 37(03): 14-21.  DOI: 10.3969/j.issn.1674-0696.2018.03.04 Abstract ( )   PDF (1142KB) ( )   The results of the laboratory scale model test were used to analyze the influence of the front light source with different luminous flux on the visibility, luminance and luminance uniformity of the small target in the tunnel. The mechanism of the effect of headlights on the visibility of small targets was researched. Meanwhile, Dialux was used to simulate the influence of the headlights on the quality of tunnel pavement lighting. Research results show that: vehicle headlights can highly improve the luminance of small targets but only have a little influence on road luminance and luminance uniformity. It will reduce the small target visibility of the road, which is limited to the direct range of its exposure. The bigger luminous flux of the headlamp is, the more seriously the small target visibility will be weakened; higher road luminance and sidewall with better reflectivity can improve the small target visibility under headlights. References | Related Articles | Metrics

Highway & Railway Engineering

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SAC Gradation Design Based on Fractal Theory and Modified Asphalt Application YU Jiang, GUO Xin, LI Linping, HU Bangyan 2018, 37(03): 22-26.  DOI: 10.3969/j.issn.1674-0696.2018.03.05 Abstract ( )   PDF (413KB) ( )   The multi-level density built-in grading skeleton of SAC was designed by the fractal gradation theory, and different groups of SAC grades were designed through the adjustment of fractal design dimension Dc, Df and the passing percentage of demarcation size P(rDCF). The influence of fractal gradation design method on the composition structure of SAC gradation was researched by the macro index voidage, and the relativity between the fractal design index and the voidage of mixture was analyzed by the grey relational method. Using SBS modified asphalt on fractal SAC gradation, the application effect of the SAC grading modified asphalt was revealed through the indoor road performance test of the mixture. The results show that: the relativity of the 3 indexes of fractal grading design and void fraction is Dc>Df>P(rDCF); by adjusting 3 design parameters, the voidage of asphalt mixture can be effectively controlled, and the modified asphalt used with SAC grading shows excellent pavement performance. References | Related Articles | Metrics

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Experimental Study on High Temperature Performance of Nano-composite Modified Asphalt and Its Mixture at Extreme High Temperature SU Manman1, 2, ZHANG Hongliang2, LV Jianwei3, ZHANG Yongping3 2018, 37(03): 27-33.  DOI: 10.3969/j.issn.1674-0696.2018.03.06 Abstract ( )   PDF (1273KB) ( )   In order to reduce the rutting failure of asphalt pavement at extreme high temperature, the nano-ZnO, nano-TiO2 and SBS were used to compositely modify SK-70 base asphalt. According to the comparison of penetration, softening point, ductility, DSR and the results of aging tests, a nano-composite modification scheme for improving the high temperature performance of asphalt was proposed. And then the nano-composite modified asphalt mixture was prepared according to the AC-20 and SMA-13 asphalt mixture grades. The rutting tests of 5 different asphalt mixtures were respectively carried out by a Hamburger rutting tester at 60 ℃, 67 ℃ and 75 ℃. The results show that 3% ZnO +0.5% TiO2+3.7% SBS modified system has a good effect on high temperature properties of base asphalt, and can improve the aging-resistance ability of asphalt. For areas with extreme high temperature, the AC-20 asphalt mixtures with 3% ZnO +0.5% TiO2+3.7% SBS modified asphalt was recommended as a medium layer paving material to resist the shear failure of middle layer caused by extreme high temperature weather. References | Related Articles | Metrics

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Compaction Properties of Warm Mixed Non-fiber SMA Mixture XIAO Qingyi, SUN Bowei, WANG Yubao 2018, 37(03): 34-39.  DOI: 10.3969/j.issn.1674-0696.2018.03.07 Abstract ( )   PDF (533KB) ( )   The effect of bitumen aggregate ratio and molding temperature on the compaction properties of warm mixed SMA was studied by using a rotary compaction apparatus. The compaction properties of SMA were compared with those of ordinary hot mixed SMA. The results show that the compacting properties of warm mixed non-fiber SMA and ordinary hot mixed SMA are similar. In the case of reducing the temperature of 30 ℃, both the warm mixed non-fiber SMA and ordinary hot mixed SMA have good compaction performance. With the increase of bitumen aggregate ratio at 0.3% intervals, the compaction of the warm mixed non-fiber SMA shows a trend of increasing. The temperature has large influence on the compaction performance of the warm mixed non-fiber SMA. When the temperature is raised by 20 ℃ , the compaction work is reduced by about 50%, but the compaction rate tends to be balanced after 140 ℃. References | Related Articles | Metrics

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Development of Compaction Degree Management System Based on LabVIEW CAO Yuanwen，QIAO Feng 2018, 37(03): 40-43.  DOI: 10.3969/j.issn.1674-0696.2018.03.08 Abstract ( )   PDF (1406KB) ( )   Access database was used to establish a data table of the correlation between the compaction degree and the vibration acceleration under several factors. Combined with the LabVIEW virtual instrument software, the database management system of highway subgrade compaction was developed, which could retrieve and analyze the collected data more quickly. Meanwhile, a real-time analysis system of continuous detection for compaction degree was set up, which could realize the real-time call of relation formula in database, the processing and displaying of the collected signals. References | Related Articles | Metrics

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Mechanical Characteristics of Foundation Pit Retaining Structure of Adjacent Buildings with SMW Method XIE Tingwei1, 2, ZUO Dianjun3, 4, WANG Xufeng5, AN Xiaoyu3 2018, 37(03): 44-50.  DOI: 10.3969/j.issn.1674-0696.2018.03.09 Abstract ( )   PDF (1945KB) ( )   Based on the excavation of basement close to the Europe-International Business Pedestrian Mall located in Binhai newly developed area in Tianjin, the bearing performance of excavation retaining structure reinforced by SMW method was investigated by the finite element software ABAQUS. Meanwhile, the effect of the interaction between section steel and cement on the pile constructed by SMW method was discussed. The results show that the horizontal displacement of the top of the pile constructed by SMW method is about 4.53mm, indicating that the influence of the adjacent building on the excavation retaining structure conducted by SMW method is small; the horizontal displacement value, shear value, and moment value of the pile constructed by SMW method are less about 25%~35% than those calculated by the existing codes after considering the stiffness of cement; the impact of the interaction between section steel and cement soil on the stress and strain of pile is large; with the decrease of the interaction between the section steel and the cement soil, the bond strength of the cement soil to the section steel becomes smaller, and the stress and deformation of the section steel become larger. References | Related Articles | Metrics

Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment

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Parameter Sensitivity Analysis on Pulling Anchorage Supporting Structure in Neighboring Foundation Pits WU Shuguang1,2, HAN Peiyu3, SONG Kang1,2, PENG Peng4 2018, 37(03): 51-57.  DOI: 10.3969/j.issn.1674-0696.2018.03.10 Abstract ( )   PDF (2681KB) ( )   The sensitivity analysis of parameters was carried out by FLAC3D software, considering the influence of 6 factors such as the cable vertical spacing, pile diameter, spacing of neighboring foundation pits, anchorage prestress, pile spacing and pile embedding fixation length on the cable supporting structure performance, specifically for 3 aspects such as the bending moment of the pile body, the axial force of the anchorage cable and the displacement of the soil after the pile. The analysis results show that: the bending moment of the pile looks like a wave locally because of the setting of the prestressed anchor cable, however, this characteristic of the bending moment of the pile is gradually weakening with the increase of the pile diameter. The effective bending length of pile becomes longer with the increase of pile diameter. By increasing the prestress, the control bending moment of the pile can be reduced significantly, and thus the reinforcement of the pile can be reduced and the cost of the project can be saved effectively. The bending moment along the pile looks like the letter S in the whole, and the control bending moment is located in the embedded section. When the embedded length meets a certain depth, the change of the embedded length has no effect on the bending moment of the pile, the axial force of the prestressed anchor cable and the soil displacement after the pile. References | Related Articles | Metrics

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Undrained Strength Characteristics of Silt in the Yard MEI Ling1, ZHU jie1, WANG Nanjiang2, SUN Yunliang3 2018, 37(03): 58-63.  DOI: 10.3969/j.issn.1674-0696.2018.03.11 Abstract ( )   PDF (1226KB) ( )   The newly filled silt has the characteristics of high water content and low permeability, and the shear strength is very low. In order to study the influence of deposition time on the shear strength of the dredged silt in the yard, the deposition process of silt in the yard was simulated by a settlement column. 3 groups of tests of indoor sedimentation columns at different time were carried out, and the micro-cross plate was used to carry out the undrained strength test after reaching the set deposition time. The test results show that: under the influence of deposition time, the undrained strength increases with the increase of the deposition time in the case of the same water content; under the influence of the initial water content, the undrained strength-effective stress curve shows a shape of concave, which is inconsistent with the linear relationship considered in general case. References | Related Articles | Metrics

Traffic & Transportation Engineering

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Evaluation of Traffic Information Release Mode Based on Guidance Terminal Combination CHENG Zeyang, WANG Wei, QU Xin 2018, 37(03): 64-70.  DOI: 10.3969/j.issn.1674-0696.2018.03.12 Abstract ( )   PDF (513KB) ( )   In order to improve the service level of urban traffic information, the characteristics of traffic information release and the travelers' demands were analyzed, and every two guidance terminals were combined as a group. Based on the above, the evaluation system of traffic information release mode was proposed. Firstly, the index weights were obtained by the combined method of analytic hierarchy process and entropy value method. Secondly, the final evaluation model based on an improved osculating value algorithm was presented. Results of the case study show that: the results of the improved osculating value algorithm are lower than the traditional value; at the same time, the evaluation errors are lower than those obtained by TOPSIS method and the multi-attribute utility method. It is indicated that the improved osculation value algorithm is a relatively effective evaluation method of traffic information release mode. References | Related Articles | Metrics

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Coordination and Control Method for Y-Shaped Intersection-Group Using Double-Cycle Green Wave XU Jianmin1, 2, ZHAN Junjie1, JING Binbin1, MA Yingying1 2018, 37(03): 71-75.  DOI: 10.3969/j.issn.1674-0696.2018.03.13 Abstract ( )   PDF (608KB) ( )   To solve the problem of traffic safety, traffic inefficiency and other issues that caused by the traffic flow intertwined with each other at Y-shaped intersection-group in urban area, a double-cycle green wave coordination and control model was established, which was on the basis of the time-space diagram and had a target of maximizing the two-way bandwidth of green wave. The proposed model could separate the two traffic flows coming from upstream intersections in time sequence and make them pass through the downstream intersections respectively, so as to solve the problems of safety and efficiency caused by the interweaving of vehicles. The actual case study and simulation results show that: compared with the single point signal timing scheme, the proposed model has significant effect on reducing vehicle delay time, reducing vehicle parking number and improving traffic safety. It is showed that the proposed model has a significant effect on improving the traffic efficiency and traffic safety of the Y-shaped intersection-group, and has a certain theoretical and practical value. References | Related Articles | Metrics

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Lane-Changing Traffic Flow Characteristics of the Urban Multi-road Merging Region Affected by Speed-Change Ramp MA Xinlu, WANG Di, HU Yuehao, HE Yuanyuan 2018, 37(03): 76-87.  DOI: 10.3969/j.issn.1674-0696.2018.03.14 Abstract ( )   PDF (2390KB) ( )   According to the analysis of the measured data, the driving behavior features and traffic flow characteristics of the multi-road merging section in urban were obtained; by introducing the drivers' character parameter and the probability of lane changing considering the drivers' psychology, the cellular automaton (CA) of multi-road merging section in urban was established. Through the verification of JAVA numeral simulation and model, the traffic flow characteristic parameters for both types of speed- changing ramp, the direct type and the parallel type, were acquired. The results indicate that: the direct type is not conducive to the main line and ramp vehicles, and vehicles on the right ramp have severe interferences on the middle ramp; a too long parallel speed-changing ramp exacerbates the conflictions between the main and middle ramp, meanwhile, increases the effect of the middle ramp on the right ramp. In addition, the direct type increases the traffic congestion of the merging region, and by contrast, the length of parallel speed-changing ramp within a certain range can clearly improves traffic conditions of the merging region, but too long parallel speed-changing ramp leads to the counterproductive result. References | Related Articles | Metrics

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Access Spacing of Suburban Highways Based on Maximum Entropy QIAO Jiangang1, TIAN Yalei1, CHEN Luogang1, DAI Changyong2 2018, 37(03): 88-91.  DOI: 10.3969/j.issn.1674-0696.2018.03.15 Abstract ( )   PDF (569KB) ( )   Access spacing has a great influence on traffic safety and traffic capacity of suburban highway. Through the survey on the suburban highway, the definition of the access spacing was put forward on the basis of the data such as the running speed and traffic volume in the field. Based on the collected data, the model was established by the maximum entropy principle. MATLAB software was used to solve the equation, and the reasonable spacing of suburban highway access was determined. Taking the delay, the number of parking and the average speed as the evaluation index, the distance between different access ports was simulated and checked by the simulation software Synchro, which provided a new way to solve the problem of traffic safety. References | Related Articles | Metrics

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Reversing Obstacle Detection Based on Binocular Vision Image LIU Yugang1,2, WANG Zhuojun1, LIU Yanfang1, ZHANG Zutao3, XU Hong4 2018, 37(03): 92-98.  DOI: 10.3969/j.issn.1674-0696.2018.03.16 Abstract ( )   PDF (3253KB) ( )   According to the problem of false matching and obstacle detection range of binocular vision image obstacle detection in the course of reversing, a reversing obstacle detection method based on binocular stereo vision was proposed. Firstly, dilation and erosion algorithms were implemented in the disparity map to connect discontinuous region and remove small noise points. Binaryzation processing of parallax images was adopted to control the detection range of obstacles, which realized the detection of obstacles based on distance. Then the connectivity region marking algorithm based on travel was used to mark all connected regions. Finally, the area of the above regions was calculated. The region with too small area was removed as hot pixel, and the remaining area was proposed as an obstacle. The experiment results demonstrate that the proposed detection method of reversing obstacle based on binocular vision image can effectively detect the obstacle area of the post-car image. References | Related Articles | Metrics

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Calculation Model of Travel External Loss Cost under Heterogeneous Traffic Flow Condition CHEN Fujian1, FENG Feiyu1, SU Lifeng2, XU Peipei1 2018, 37(03): 99-105.  DOI: 10.3969/j.issn.1674-0696.2018.03.17 Abstract ( )   PDF (475KB) ( )   In order to provide a new thought for the quantification analysis for traffic external costs in the management and pricing of transportation, the computation model of travel external loss cost based on system engineering was established. The interrelation of system cost factors was revealed by the application of system analysis principle, and the external cost of traffic travel was divided into 3 system cost factors: time loss cost, accident risk cost and environmental cost. On the other hand, the traffic flow theory was used to analyze the differential traffic flow with the mixed multiple travel modes, and the sub model of the cost factors was established with the velocity and flow of the differential traffic flow as the random variable. A sample case of survey data of a road section in Guilin was introduced to explore the application of computation model for traffic external loss cost and to calculate the price of traffic external costs. The results of the case study show that: the accident risk cost is very high in the traffic external loss cost, about 92.6%, and the traffic external loss cost also accounts for a large proportion of the cost of traffic travel. References | Related Articles | Metrics

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Container Terminal QC & IT Integral Scheduling Model for Multi-Vessel Operation under Double-Cycle Strategy LIANG Chengji, YANG Quanye 2018, 37(03): 106-114.  DOI: 10.3969/j.issn.1674-0696.2018.03.18 Abstract ( )   PDF (1031KB) ( )   Aiming at the simultaneous loading and unloading activities of many large and small ships, the blind implementation of operation surface scheduling will cause complex management difficulties, which will lead to the increase of ship handling time. Based on this problem and the influence of ship distance on integrated truck scheduling mode, the concepts of the decentralized truck group and the integrated truck group were introduced, which was the mixed loading and unloading mode for operation line and surface. The mixed integer programming model of QC and IT joint scheduling was established. According to the constraint conditions and features involved in the process of QC and IT scheduling, the adaptive genetic algorithm (AGA) method with matrix coding mode was used to solve the above problem. The results show that: when the distance between ships reaches a certain degree, the decentralized truck group outperforms the integrated truck group in the operation time and travel distance. References | Related Articles | Metrics

Vehicle &Electromechanical Engineering

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3D Visual Scene Simulation of Inland Waterway Navigational Environment TIAN Yanfei1, 2, HUANG Liwen1, 2, CHEN Yaojie1, 2, TAN Tianli1, 2 2018, 37(03): 115-120.  DOI: 10.3969/j.issn.1674-0696.2018.03.19 Abstract ( )   PDF (1344KB) ( )   Based on the development directions and requirements of navigation simulation, 3D visual simulation of inland waterway navigation environment was taken as the research object, in order to expand the practice area and improve the simulation accuracy at the same time. Elements composing the scenery of inland waterway navigation environment were deeply analyzed and divided into two categories: topographic and geomorphic features, surface and offshore targets. The mainstream software in scene simulation field such as 3D MAX and Multigen Creator were adopted for 3D modeling of the composing elements. Under the environment of VC++, the open source software OpenSceneGrap (OSG) was chosen as the driving platform to realize data fusion of 3D model of inland waterway navigation environment and strengthen simulation authenticity with meticulous rendering. Simulation shows that the constructed 3D models of inland waterway navigation environment are of higher precision, and its driving scenario is of verisimilitude, which can meet the navigation simulation requirements and can be recommended for development of large ship handling simulator. References | Related Articles | Metrics

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Establishment and Analysis of Constitutive Equation of Q345D Ship Steel during Medium Temperature Plastic Forming ZHANG Jixiang, JIANG Fei, YANG Pan, TANG Bo 2018, 37(03): 121-126.  DOI: 10.3969/j.issn.1674-0696.2018.03.20 Abstract ( )   PDF (447KB) ( )   With a SANS-CMT universal material testing machine, the tensile test of Q345D steel plate specimen was carried out in the temperature ranging from 473 K to 973 K and the strain rate ranging from 0.001 s-1 to 0.1 s-1, and the stress-strain test data were analyzed. The results show that the temperature has a greater influence on the medium temperature plastic forming of Q345D steel, but the strain rate has less effect on the forming. The material yield strength σs and tensile strength σb decrease linearly with the increase of temperature, and the obvious yield platform appears in the tensile stress-strain curve at lower temperature. The hardening phenomena of Q345D steel are obvious in the process of plastic deformation, and the hardening exponent n decreases with the increase of temperature. With the temperature increasing, the elongation rate δ increases linearly but the strain rate sensitivity coefficient m decreases linearly. References | Related Articles | Metrics