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15 January 2018, Volume 37 Issue 1 Previous Issue    Next Issue
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Bridge & Tunnel Engineering
Highway & Railway Engineering
Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment
Traffic & Transportation Engineering
Vehicle &Electromechanical Engineering


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Bridge & Tunnel Engineering

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Causes of Longitudinal Cracking of Hollow Slab Based on Management and Maintenance Data JI Bohai1, XIE Mindian1, XIE Faxiang1, CHEN Xin1,2, LEI Xiao1 2018, 37(1): 10-16.  DOI: 10.3969/j.issn.1674-0696.2018.01.02 Abstract ( )   PDF (1592KB) ( )   In order to systematically analyze the features and causes of longitudinal cracks in the slab of the pre-stressed hollow slab beam, the distribution characteristics of longitudinal cracks were summarized on the basis of the disease data of bridge management system and field investigation. On the basis of the above analysis, the influence of the prestress, vehicle load, bridge width span ratio and baseplate thickness on longitudinal crack formation was analyzed from the point of view of finite element numerical calculation. The results show that the longitudinal cracks mainly occur in the prestressed hollow slab bridge, and the number, length and width of cracks increase year by year; the Poisson effect and improper construction are the main causes of the initial micro- cracks in the slab girder, and also the important inducement of the longitudinal cracks in the operation period; the main cause of the crack initiation and propagation is the load during the operation stage;under the vehicle load, the crack propagation is extended from the upper edge to the downward edge of the baseplate;the bridge with larger width-span ratio is more likely to produce longitudinal cracks in the baseplate;the weakening of the thickness of the baseplate has a significant effect on the longitudinal crack, and the influence degree increases with the increase of the weakening degree. References | Related Articles | Metrics

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Procedure Optimization for CFST Arch Bridge with Non-uniform Cross-section during Pouring Externally Wrapped Concrete WU Haijun, WANG Miaomin, QIAN Ji 2018, 37(1): 17-23.  DOI: 10.3969/j.issn.1674-0696.2018.01.03 Abstract ( )   PDF (1119KB) ( )   Taking Guansheng-Qujiang CFST Arch Bridge in construction in Guangan as an example, to minimize the total vertical deformation of the vault in the process of pouring the second ring (variable cross-section) of the wrapped concrete, the pouring path of the second ring was optimized and the scheme of pouring path optimization was obtained by the influence factor of vault deflection and exhaustive method. The length of working face of the second ring (variable cross section) of the bridge was divided according to the principle that the length was equal and the weight of the wrapped concrete was equal. The scheme of equal length of working face and equal weight of working face were obtained respectively. Through comparing and analyzing the three schemes, it is found that the pouring path optimization scheme is better in the vault deflection, arch rib alignment, upper and lower chord stress as well as the stress of the wrapped concrete. References | Related Articles | Metrics

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Tunnel Collapse Characteristics Based on UDEC Discrete Element Method GAO Feng1, TANG Xing1, LI Xing1, CHEN Xiaoyu2, LI Yukun1, LI Juechi1 2018, 37(1): 24-28.  DOI: 10.3969/j.issn.1674-0696.2018.01.04 Abstract ( )   PDF (2623KB) ( )   UDEC discrete element method can simulate the actual tunnel collapse to a large extent by the cyclic iterative calculation of the large deformation motion of the block. Taking Ziyin tunnel collapse accident as the engineering background, the collapse process of the tunnel was simulated by UDEC discrete element method, and the correctness of the UDEC discrete element method to simulate the tunnel collapse was verified by comparing with the actual collapse situation. The collapse process of tunnel with different buried depth, different rock mass structure and different surrounding rock grade was simulated by UDEC discrete element method, and the collapse characteristics of tunnel were analyzed. The results show that the buried depth mainly affects the range of vault collapse and the rock mass structure (such as joint fissure) has a greater influence on the form of collapse; the surrounding rock parameters also affect the range and the form of collapse. References | Related Articles | Metrics

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Stiffness Damage Model of Small Beam in Strain Fatigue Test DING Biao1, ZHENG Chuanchao2, PENG Zixin3, CHEN Tuanjie1 2018, 37(1): 29-34.  DOI: 10.3969/j.issn.1674-0696.2018.01.05 Abstract ( )   PDF (747KB) ( )   In order to study the stiffness damage of the small beam in the strain fatigue test of asphalt mixture, the stiffness damage model of the small beam was established on the basis of the relative theory of materials mechanics. The damage laws of the stiffness of the small beam when the damage was developed from the lower part of the cross-section to the top and from the upper and the lower sides to the middle part were studied respectively. The results show that when the damage of small beam develops from bottom to top, the distance between neutral axis and top edge of the beam decreases firstly from the initial 0.5h, then increases gradually, and finally goes back to the initial position. Meanwhile, the stiffness attenuation of the small beam also passes through 3 stages: the stiffness decrease is significant firstly, and then becomes stable, and decreases sharply lastly. When the damage of the small beam extends from the upper and the lower sides to the middle, the position of the neutral axis remains unchanged, and the stiffness of the small beam decreases greatly at the initial stage, then decreases gradually, and finally tends to be stable. References | Related Articles | Metrics

Highway & Railway Engineering

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Comparative Study on HMA Elastic Modulus Based on Different Predicting Methods ZHANG Haitao, MA Shengsheng, YU Tengjiang 2018, 37(1): 35-39.  DOI: 10.3969/j.issn.1674-0696.2018.01.06 Abstract ( )   PDF (349KB) ( )   Through the comparative analysis on the different predicting methods of HMA elastic modulus, the most reasonable method of fast prediction was found. BP neural network was used to predict HMA elastic modulus at different temperatures, and the relationship between Et/E20 and temperature of HMA elastic modulus was established. On this basis, it was compared with other forecasting methods. The research contents included: the data investigation and the influence factors analysis of HMA elastic modulus, the prediction results of HMA elastic modulus based on different prediction methods, and the prediction results of BP neural network as well as the comparative analysis on other methods. Through the comparative analysis on different predication results, the scientific rationality of BP neural network method was demonstrated. The research shows that BP neural network method can accurately predict HMA elastic modulus at different temperatures; it has a certain advantage compared with other methods. References | Related Articles | Metrics

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Climate Zoning for Asphalt Pavement Based on Cluster Analysis Method YANG Yanhai1, DONG Shuai1, HOU Bo2, ZHANG Huaizhi1 2018, 37(1): 40-45.  DOI: 10.3969/j.issn.1674-0696.2018.01.07 Abstract ( )   PDF (976KB) ( )   In order to make the structure of the asphalt pavements more adapt to the climate of a certain region to achieve the purpose of extending the service life of the road and keeping the road performance, the main damage forms of asphalt pavement, the causes of damage and the main climatic factors affecting the performance of main road in Liaoning province were elaborated in detail. The climate of the asphalt pavements in Liaoning province was divided into five areas according to the clustering methodology by three zoning indexes such as the annual extreme maximum temperature, the annual extreme minimum temperature and the extreme precipitation. The above five areas included the water stability area (I), the low temperature anti-cracking area (II), the high temperature stability and low temperature anti-cracking area (III), the high temperature stability area (IV) as well as the high temperature stability and water stability area (V). Combined with the regional administrative boundaries, the climate zoning map of the asphalt pavements in Liaoning province was drawn on ArcGIS platform, and the numerical distribution of each regional index was obtained. References | Related Articles | Metrics

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Automatic Crack Detection Algorithm Based on 3D Virtual Pavement PENG Bo, CAI Xiaoyu, LI Shaobo, ZHANG Youjie 2018, 37(1): 46-53.  DOI: 10.3969/j.issn.1674-0696.2018.01.08 Abstract ( )   PDF (2670KB) ( )   In order to detect cracks accurately, precisely and completely with the consideration of stereoscopic features of pavement, an automatic parallel crack recognition algorithm based on 3D virtual pavement was proposed. Firstly, 3D virtual pavement was established by hiding processing and illumination model processing on 1mm/pixel pavement depth images, and four projection images, Ω1~Ω4 , were generated via stereoscopic projection at four angles over it. Then, dimension reduction, crack recognition (intensity verification, symmetry check) and crack connection were conducted on Ω1~Ω4 respectively. Correspondingly, shadowed crack images Ωs1~Ωs4 and reflection crack images Ωr1~Ωr4 were obtained. At last, the crack information of Ωs1~Ωs4 and Ωr1~Ωr4 were fused, examined by depth verification and filtering denoised, yielding the final crack image. Test results based on 255 images (4 096×2 048) show that, the proposed algorithm achieves relatively high precision (averaging 80.34%) and recall rate (averaging 83.89%). It outperforms ADA3D algorithm with an F score of 80.47%. Furthermore, the parallel framework of the proposed algorithm helps parallel programming, which can improve computation speed effectively. References | Related Articles | Metrics

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Effect of DCLR and TLA on Adhesion Characteristics of Asphalt and Aggregate JI Jie1, 2, MA Rongda1, ZHENG Wenhua1, SUO Zhi1, XU Ying2 2018, 37(1): 54-61.  DOI: 10.3969/j.issn.1674-0696.2018.01.09 Abstract ( )   PDF (471KB) ( )   In order to study the effect of direct coal liquefaction residue (DCLR) and Trinidad lake asphalt (TLA) on the adhesion characteristics of asphalt and aggregates, based on the theory of surface free energy, SK-90 asphalt, limestone and granite were used as the matrix asphalt and aggregate respectively. Sessile drop method was adopted to measure the surface free energy of the modified asphalt with different dosages of DLCR and TLA content respectively (0%, 2%, 4%, 6%, 8%, 10%, the mass ratios of DCLR/TLA and SK-90). Parameters were calculated, including the cohesion work of asphalt, and the adhesion work, the flaking work and the water stability evaluation parameter of asphalt-aggregate system. The results show that with the increasing dosage of DCLR and TLA, the surface free energy and cohesion work of asphalt, the adhesion work and water stability evaluation parameter of asphalt-aggregate system are all increasing, which indicates that adding DCLR and TLA can improve the adhesion ability of the asphalt-aggregate system and the water stability of the asphalt mixture. The effect of improving the surface free energy of asphalt, the adhesion ability and water stability of asphalt-aggregate system by DCLR is better than TLA at the same dosage. References | Related Articles | Metrics

Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment

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Z-Q Relationship Curve Analysis for the Lower Reaches of the Yangtze River in the Case of Continuous Flood in Flood Season YANG Qingwei, LIAO Xiang, BAO Wenjun, PENG Huiling 2018, 37(1): 62-65.  DOI: 10.3969/j.issn.1674-0696.2018.01.10 Abstract ( )   PDF (388KB) ( )   Generally, for one mono flood, the water level-flow relationship (Z-Q) curve normally presents a shape of counterclockwise loop. However, the Z-Q curve is unknown when continuous flood occurrs. Based on the measured data of the water level and flow from Datong Hydrological Station of the lower Yangtze River in June to August in 2016, and applying the Least Squares Method, the curve relationship between Z and Q was studied in the present research. The results show that, in 2016, the flooding of the lower Yangtze River can be qualitatively classified as classical basin flood. The counterclockwise-clockwise-alternating loop curve is found for a general flood, while single clockwise loop curve is found for the catastrophic flood. Additionally, the order of characteristic value for the general flood is the maximum flow, the maximum water level; and an inverse order, namely, the maximum water level-the maximum flow for the catastrophic flood. The above analysis indicates that: during the flooding period from June to August in 2016, the serious channel and bank erosion occur; some necessary measures should be conducted to improve the stability of the bank and slope. References | Related Articles | Metrics

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Improvement of Ultra Soft Soil by Vacuum Preloading Combined with Water Bag Method of Sand Free Cushion WANG Haijian1，YANG Jiangui2，CAO Jianyong1，TIAN Yanmei3，PENG Jie3 2018, 37(1): 66-71.  DOI: 10.3969/j.issn.1674-0696.2018.01.11 Abstract ( )   PDF (2280KB) ( )   Combined with the actual project, the effect of ultra-soft foundation reinforced by vacuum combined with water bag preloading method of sand free cushion was studied by the tests. The experiment results show that the proposed method can effectively improve the bearing capacity of foundation. Compared with the conventional vacuum preloading method, the reinforcement effect of the proposed method is better, and it can increase the thickness of the hard shell layer and the effective reinforcement depth of the soil. The vacuum film surface overlying water preloading method was compared and analyzed, and its defects and failure especially in the case of “cyclic water” were discussed. References | Related Articles | Metrics

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Numerical Simulation on the Bending Properties of Micro CFST Members CHEN Zaiqian, PU Shutao, GUO Guo, SHUAI Shijie 2018, 37(1): 72-79.  DOI: 10.3969/j.issn.1674-0696.2018.01.12 Abstract ( )   PDF (2513KB) ( )   Concrete strength grade, thickness of steel pipe, diameter of the piles and yield strength of steel are the main factors to affect the bending strength of micro CFST members. In order to research the influence of the above four factors on the bending properties of micro CFST members, the finite element software ABAQUS was adopted and the numerical simulation was carried out. The research results show that: the bending strength of micro CFST members is increased with the increase of concrete strength grade, but the growth rate gradually decreases; the bending strength of micro CFST members is increased with the increase of the thickness of steel pipe, and their relation is almost linearly; the bending strength of micro CFST members is increased with the increase of diameter of the piles and the growth rate is increased with the increase of diameter of the piles; the bending strength of micro CFST members is increased with the increase of yield strength of steels. In addition, based on the results of finite element numerical calculation, the expression of ultimate flexural capacity of micro CFST members was proposed finally, and compared with the experimental results, they corresponded well. By comparing with the norms, the calculation method of flexural bearing capacity proposed in this paper is more suitable for micro CFST members. References | Related Articles | Metrics

Traffic & Transportation Engineering

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Influence of Curb Parking Behavior on Traffic Capacity of Basic Road Section SHAO Changqiao, YANG Qiaoqiao 2018, 37(1): 80-84.  DOI: 10.3969/j.issn.1674-0696.2018.01.13 Abstract ( )   PDF (702KB) ( )   Based on the investigation of curb parking in Beijing residential, official and commercial areas, a quantitative study of the impact of curb parking on the traffic capacity was carried out. The survey data was analyzed and processed by SPSS and the time distribution characteristics of curb parking affecting the traffic flow and its influencing factors were obtained.A quantitative relationship model between vehicle input, output frequency and influence time was established. The traffic capacity was reduced from 3 aspects: lane width, lateral clearance as well as vehicle entering and leaving frequency; and a relationship model between curb parking and traffic capacity of road section was obtained.Finally, the relationship model was simulated and verified by VISSIM.The research results show that:it is more convenient to quantitatively describe the influence of traffic frequency on the traffic capacity by using the relationship between the vehicle input and output frequency as well as the influence time. References | Related Articles | Metrics

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Lane Allocation of Highway Toll Gate Based on Cost Analysis JI Yangbeibei, ZHOU Jinfeng 2018, 37(1): 85-91.  DOI: 10.3969/j.issn.1674-0696.2018.01.14 Abstract ( )   PDF (1335KB) ( )   From the angles of construction operation cost and delay cost, a cost model to minimize the total costs was established, combined with the queuing theory. Taking Chenhai toll gate as an example, the reasonable construction scheme of the toll gate was discussed in the case of different arrival flow and ETC vehicle proportion, and the minimum cost values under different conditions were obtained. The relationship between the total cost, the construction operation cost, the delay cost and ETC vehicle proportion as well as the arrival flow was also studied. The results show that increasing the proportion of ETC can effectively reduce the total cost and the delay cost, and when the proportion of ETC remains at a high level (＞70%), the measures of increasing the proportion of ETC can also reduce the cost of construction and operation. References | Related Articles | Metrics

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Multi-goal Optimization Design on the Point-to-Point Emergency Evacuation Organization Based on Minimum Risk ZHAO Xueyu1,2,YANG Jiaqi2 2018, 37(1): 92-98.  DOI: 10.3969/j.issn.1674-0696.2018.01.15 Abstract ( )   PDF (827KB) ( )   According to the problems of the point-to-point emergency evacuation organization in current research, the influence of different emergency evacuation objectives on the total emergency evacuation efficiency was analyzed in the view of multi-goal optimization. Two targets of emergency evacuation organization were focused, that is the minimum distance and minimum risk.The multi- goal optimization model for the point-to-point emergency evacuation organization was established in accordance with its network features and constraint conditions.Meanwhile, the NSGA-II algorithm was proposed to solve the multi-goal optimization model.By increasing the risk values of each section of the emergency evacuation network, the case studies were designed and solved, which reflected a more objective and effective emergency evacuation strategy. References | Related Articles | Metrics

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Deceleration Landscape Design of Tunnel Entrance Based on Visual Illusion CHEN Liuxiao1, LIU Tangzhi2, DUAN Mengmeng1 2018, 37(1): 99-103.  DOI: 10.3969/j.issn.1674-0696.2018.01.16 Abstract ( )   PDF (1910KB) ( )   In order to reduce the probability of accidents at tunnel entrance, a kind of space visual illusion deceleration landscape was designed, which was based on the theory of road space and color visual illusion. Three kinds of landscapes, that is green, yellow and red were designed at the tunnel entrance, and the spacing of each scheme was set with 10m×4+7m×5+5m×5. Combined with simulation experiment and real vehicle experiment, the driving comfort, the warning effect and the deceleration effect of the three spacious deceleration schemes were evaluated. The results show that the plant landscape with gradually diminished spacing at the tunnel entrance has a certain deceleration effect. The green space deceleration landscape is likely to cause driver visual fatigue. The red deceleration landscape has larger color contrast to the surrounding and it has strong visual impact, which is likely to cause driver a certain psychological burden. The yellow space deceleration landscape’s warning effect and deceleration effect are the best, and it can meet driver’s driving comfort. Therefore, it is recommended to set a yellow space deceleration landscape with gradually diminished spacing at the tunnel entrance to improve the traffic safety. References | Related Articles | Metrics

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Passenger Flow Distribution Model for Urban Rail Transit Based on BP Neural Networks WENG Xiaoxiong, WANG Zhoupan 2018, 37(1): 104-108.  DOI: 10.3969/j.issn.1674-0696.2018.01.17 Abstract ( )   PDF (1184KB) ( )   The essence of fare clearing is the distribution problem of passenger flow in different lines. Thus, a kind of passenger clearing model for rail transit based on BP neural network was proposed, with the full consideration of passenger travel route choice on the basis of multi-factor.The multiple factors that influenced route choice of passengers were route choice were divided into quantified and uncertain factors. By training the inhibitory coefficient and the excitation coefficient of the sample, the results were transmitted to the output layer to output by combining with the transformation function.Compared with the traditional model, the proposed model was more consistent with the multi-factor psychology of passenger travel choice. Finally, by comparing the actual investigation of passenger flow and Logit model, it showed that without the interference of other factors, the proposed method can realize the passenger clearing in different lines well. References | Related Articles | Metrics

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Optimal Design of Hub-and-Spoke Container Shipping Network Based on Node Restriction ZHANG Qi,PENG Yun,WANG Wenyuan,SONG Xiangqun,GUO Zijian 2018, 37(1): 109-115.  DOI: 10.3969/j.issn.1674-0696.2018.01.18 Abstract ( )   PDF (1219KB) ( )   With the developing trend of larger container ships, hub-and-spoke container shipping network was established by more and more liner shipping companies to improve the service efficiency and reduce the unit operation cost. Therefore, a non-linear hub-and- spoke container shipping network optimization model considering the port throughput capacity was proposed. The purpose of the proposed model was to minimize the total cost of container shipping network. Then, a hybrid optimization algorithm combining Q-learning method with chaos optimization algorithm was used to solve the problem of reasonable container shipping route and suitable ship deployment. A case study was carried out to assess the effectiveness of the proposed model. The results show that the hybrid optimization algorithm can efficiently solve the problem of container shipping route optimization and ship deployment. Besides, comparing with the direct transportation, the transportation cost of the hub-and-spoke network can be reduced by 10%. References | Related Articles | Metrics

Vehicle &Electromechanical Engineering

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Rear Engine Drive Module Development Based on ADVISOR FENG Guosheng1, QIAN Chao1, JIA Sumei1, ZHI Yahui1, ZHANG Xiaorong2 2018, 37(1): 116-120.  DOI: 10.3969/j.issn.1674-0696.2018.01.19 Abstract ( )   PDF (2622KB) ( )   In order to develop HEV bus based on HB6732, the redevelopment of the rear engine drive module was carried out on the ADVISOR platform. The vehicle model of HB6732 was established, and the rear axle driven model of bus was established by MATLAB/Simulink. The model was embedded in ADVISOR, and HB6732 bus parameters were used to simulate the performance of the whole vehicle. The simulation results were compared with the experimental values. The results show that the simulation results and experimental results are basically consistent. The established vehicle model and the redeveloped rear axle drive module have better simulation accuracy, which could be applied to the subsequent development of HEV bus. References | Related Articles | Metrics

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Energy Consumption Analysis and Parameters Optimization of Hydraulically Interconnected Suspension CHEN Long, ZHANG Chenglong, WANG Ruochen, YE Qing 2018, 37(1): 121-126.  DOI: 10.3969/j.issn.1674-0696.2018.01.20 Abstract ( )   PDF (2035KB) ( )   Taking hydraulically interconnected suspension as the research object, the energy consumption model of each element in the hydraulic system was established from the perspective of energy consumption. The simulation analysis under three common urban road conditions was carried out.In allusion to the high proportion of energy consumption of damper valve,the influence of its pore size on energy consumptionand dynamic performance of the interconnected suspension was studied. On this basis, a multi-objective optimization model for hydraulically interconnected suspension was established, and then NSGA-Ⅱ algorithm was employed to obtain the optimal solution. The results show that the optimized suspension can guarantee the vehicle dynamic performance and effectively reduce the energy consumption of the damping valve, which realizes the function of energy conservation and emission reduction. References | Related Articles | Metrics