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24 March 2025, Volume 44 Issue 3 Previous Issue   
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Transportation Infrastructure Engineering
Transportation+Big Data & Artificial Intelligence
Transportation Equipment


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Transportation Infrastructure Engineering

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Residual Traffic Reliability of Bridge Structures Subjected to Heavy-Duty Truck Collision LIU Lang1, ZHAO Yifei1, XIA Yongqing2, LUO Hao1, XU Manfei1 2025, 44(3): 1-8.  DOI: 10.3969/j.issn.1674-0696.2025.03.01 Abstract ( )   PDF (1801KB) ( )   To explore the traffic reliability of bridge structures subjected to heavy-duty truck collision, a typical reinforced concrete (RC) bridge was selected as the object and the limit state equation was developed for bridge piers being impacted by heavy-duty trucks. Considering the randomness of the main parameters in the random process of vehicle bridge collision, the failure probability of piers was calculated, and parameter sensitivity analysis was conducted on the key random variables involved. Then, collision damage indicators and residual bearing capacity reduction calculation methods for bridge piers were proposed. At end, using the standard lane and vehicle load models specified in bridge design specifications, as well as the WIM heavy-load model, different traffic parameters were set to load the bridge’s finite element analysis. The bridge traffic reliability after the collision was analyzed. Research results indicate that after being impacted by heavy-duty vehicles with 2 or 3 axles, the bridge pier still retains its ability to withstand the design load. However, after being impacted by heavy-duty vehicles with 4 or 5 axles, the bridge pier is no longer suitable for continued service. The type of passing vehicles and their position on the bridge deck significantly affect the probability of the impacted bridge pier failing to continue serving. Overall, the failure probability for the bridge pier caused by WIM heavy-load model is 1.5 to 2.0 times greater than that under the standard vehicle load specified in the specifications. When vehicles approach the centerline of the bridge pier, the probability of failure of the impacted pier is significantly reduced. References | Related Articles | Metrics

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Principle and Effect of Flexible Anti-collision Structure of Steel Enclosure-Steel Spring Sleeve Box for Cylindrical Pier SHI Yongcan1, YU Xiaohui1, ZHANG Xixiang2, YU Hongming2, LI Tijun2 2025, 44(3): 9-17.  DOI: 10.3969/j.issn.1674-0696.2025.03.02 Abstract ( )   PDF (11098KB) ( )   In order to solve the technique problem of ship collision prevention on “weak pier resisting strong collision” of weak type of cylindrical pier in bridge engineering, according to ship collision force characteristics of the weak type of cylindrical pier and “all-rounded flexible anti-collision” defects of existing anti-collision structures for cylindrical pier, a new type of attached flexible anti-collision structure of steel enclosure-steel spring sleeve box for cylindrical pier was developed and designed by adopting problem solving-method of improving “all-rounded flexible anti-collision” capacity of the anti-collision structure by its structure form innovation. On this basis, according to the structural form and functional analysis of the new anti-collision structure, the flexible anti-collision principle of the new anti-collision structure was derived. The flexible anti-collision effect of the new anti-collision structure was determined according to the results inspected by the application of the new anti-collision structure in actual bridge engineering, such as the reduction of bridge pier ship collision force, the reduction of ship collision damage and improvement of safety under accidental conditions of bridge pier ship collision. The research results show that the new anti-collision structure, relying on its “impact flexibility” structure form, has a far better flexible anti-collision effect than the conventional steel sleeve box anti-collision structure does, which can greatly reduce pier ship collision force and ship collision damage, and can significantly improve the safety of pier at ultimate limit state under ship collision action accidental condition. References | Related Articles | Metrics

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Experimental Investigation of Air-Coupled Impact Echo in Detection of Internal Defect in Tunnel Structures ZHONG Yupei1,2, XU Qipeng1,2, MA Zhanguo3, LIU Shukui3, LIU Jishun2 2025, 44(3): 18-25.  DOI: 10.3969/j.issn.1674-0696.2025.03.03 Abstract ( )   PDF (3334KB) ( )   In order to study the applicability of the air-coupled impact echo method for identifying internal defects in tunnel structures, the finite element model of internal defects in tunnel structures such as cavities, cracks and water-containing cavities was established. The response characteristics of the air-coupled impact echo under different defect conditions were analyzed. Tunnel structure models with different defect conditions were poured and experimental research on internal defect detection of tunnel structures based on air coupled impact echo method was conducted. The research results show that the air-coupled impact echo method can well identify internal defects in tunnel structures. The identified defect depths are basically consistent with theoretical values, and the numerical simulation and indoor test results are basically consistent. Whether there is water in the defect has little effect on the impact echo detection results. As the depth of the defect increases and the size of the defect decreases, the identification accuracy gradually decreases. The detection error increases from 0.05% to 3.26% as the defect depths increase from 30 cm to 50 cm, and the defect sizes decrease from 50 cm×50 cm to 10 cm×10 cm. References | Related Articles | Metrics

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Aging Asphalt Regeneration Mechanism Based on Molecular Dynamics Simulation QIAO Jiangang, ZHANG Shuaize 2025, 44(3): 26-32.  DOI: 10.3969/j.issn.1674-0696.2025.03.04 Abstract ( )   PDF (13079KB) ( )   The molecular dynamics software Materials Studio was used to construct 12 component asphalt molecular models of aged and unaged asphalt, in order to study the regeneration mechanism of aged asphalt under different simulated temperatures, aging degrees, and rejuvenator dosages. The results of molecular dynamics simulation experiments were verified by asphalt dynamic viscosity experiments. The results show that as the temperature increases, the sensitivity of diffusion coefficient to temperature decreases and the growth rate slows down. The effect of rejuvenators on the increase in diffusion coefficient of aged asphalt models is significant, and the diffusion rate of rejuvenators in aged asphalt is faster. As the dosage of rejuvenator increases, the increase in diffusion coefficient of the aged asphalt model decreases. When the dosage reaches 10%, the diffusion coefficient basically no longer increases. The dynamic viscosity of aged asphalt decreases with the increase of rejuvenator dosage, indicating an increase in asphalt fluidity and improvement in diffusion performance, which is consistent with the results of molecular dynamics simulation results at the nano-micro scale. References | Related Articles | Metrics

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Shear Strength Characteristics and Prediction Model of Polypropylene Fiber Modified Red Clay under Dry-Wet Cycle MA Hongyan1, WENG Mingsheng1, HUANG Renjie1, XU Song1, ZHENG Litang2 2025, 44(3): 33-39.  DOI: 10.3969/j.issn.1674-0696.2025.03.05 Abstract ( )   PDF (3174KB) ( )   In the humid and rainy southern region, red clay roadbed was prone to diseases such as excessive settlement and uneven settlement. Polypropylene fiber was incorporated into red clay to form fiber-modified red clay, aiming to investigate its shear strength characteristics under dry-wet cycles. Direct shear test was employed to investigate the effects of fiber content (0 ‰, 2 ‰, 6 ‰, 106 ‰), fiber length (0, 3, 6, 9mm), and dry-wet cycles (0, 2, 4, 6 times) on the shear strength characteristics of red clay. The results indicate that the shear strength of red clay is significantly enhanced by the incorporation of fibers, and within the range of dosage and length studied, the shear strength increases with the increase of fiber dosage and length. Fibers have a noteworthy impact on increasing the cohesion value of red clay, while their improvement of internal friction angle is limited. When the fiber length is 6mm, the shear strength of red clay reaches its maximum value. The dry-wet cycle significantly reduces the strength of red clay and its deterioration of cohesion exceeds the internal friction angle. Under the action of dry-wet cycle, fiber and normal pressure can reduce the deterioration effect of dry-wet cycle on red clay. Based on the above experimental results, the strength prediction model of red clay under the action of dry-wet cycle is established using the back propagation (BP) neural network technique, and the relative error value of its prediction is below 10%. References | Related Articles | Metrics

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Review of Design Influencing Factors and Length Calculation Models for Highway Acceleration Lane HE Yongming1,2, WANG Fan1, SUI Shengchun1 2025, 44(3): 40-48.  DOI: 10.3969/j.issn.1674-0696.2025.03.06 Abstract ( )   PDF (892KB) ( )   The determination of the length for the acceleration lane on highway is core content of the geometric parameter design of confluence area, which directly affects the traffic efficiency and traffic safety of the confluence area. To explore the research status and development trend of the acceleration lane and rationally set up the acceleration lane, a literature review and criticism on the design of acceleration lanes, was conducted by bibliometric methods from two aspects: influencing factors and length calculation models. Aiming at different influencing factors, gap acceptance theory model, vehicle merging theory model, traffic simulation model, Breakdown probability model, reliability theory model, regression model and other calculation models of acceleration lane length were sorted out. The evaluation indexes and design problems of acceleration lanes were summarized, and the future research prospect was forecasted. The research shows that the existing relevant regulations are not comprehensive in the aspects of driving characteristics of large vehicles, driving characteristics of drivers and heterogeneous traffic flow conditions, which need to be further revised and improved. To avoid the defects of gap acceptance theory, the simple and easy-to-use Breakdown probability models and reliability theory models or highly reproducible traffic simulation models can be adopted in the future. The data-driven methods can be combined to study the acceleration lane length, so as to make it more universal and ensure the reliability of the length. The optimization of the length of the acceleration lane, the design of the gradient section and special acceleration lane for the separation of passenger and cargo, and the minimum distance between continuous entrances on the same side of the main highway are the future research directions. References | Related Articles | Metrics

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Experimental Study on Navigable Ship Model in Bifurcated River of Yuanshui Taoyuan Junction CAI Chuang, LI Ke, LI Lin, WANG Duoyin, XU Guangxiang 2025, 44(3): 49-56.  DOI: 10.3969/j.issn.1674-0696.2025.03.07 Abstract ( )   PDF (8594KB) ( )   In order to put forward a more scientific and reasonable overall layout scheme of ship lock, the navigation safety of left and right bank schemes of the second-line ship lock expansion project of Yuanshui Taoyuan Junction was studied by self-propelled ship model test. By using 1∶100 integral physical model test and small-scale ship model technology, the arrangement and navigation conditions of avionics junction on bifurcated river were studied. The navigation parameters of ship model such as rudder angle and speed under different flow rates were analyzed, and the navigation conditions of ships with locks arranged respectively on the left and right banks were compared according to the flow conditions of the left and right branches. The navigation scheme of the right bank was proposed as the overall layout scheme of the newly built second-line lock. The small-scale ship model test shows the sailing conditions of ships in different branches directly and provides technical support for solving the problem of choosing navigable branches in this kind of engineering. References | Related Articles | Metrics

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Mechanical Properties and Micro-mechanism of Rice Husk Charcoal Lime Composite Soil HU Huimin1, GUO Lei1, WANG Bo2 2025, 44(3): 57-64.  DOI: 10.3969/j.issn.1674-0696.2025.03.08 Abstract ( )   PDF (4984KB) ( )   The rice husk charcoal (RHC) and lime, by-products from biomass gasification, were used to conduct composite modification of roadbed soil. The unconfined compressive strength and dynamic rebound modulus of RHC-lime composite soil was tested, and its strength characteristics and mechanism were analyzed by Fourier transform infrared spectroscopy (FTIR), XRD, and SEM. The results show that the addition of rice husk charcoal significantly improves the unconfined compressive strength of soil. The strength of composite soil with different rice husk charcoal and lime dosages varies significantly, and the combined addition of rice husk charcoal and lime is superior to the addition of rice husk charcoal alone. According to the strength, energy-saving and carbon reduction effects, the recommended dosage of rice husk charcoal+lime is 2%+2% (2L+2R). Composite soil exhibits early strength, with slow later improvement. The predictive formula for compressive strength changing with age has been derived. Rice husk charcoal enhances the toughness of composite soil, and as the dosage increases, the failure mode transitions gradually from brittle to plastic. Additionally, the dynamic rebound modulus of the composite soil positively correlates with confining pressure, cyclic stress, and age. The addition of rice husk charcoal increases the dynamic rebound modulus of composite soil, and the established multi-state dynamic rebound modulus prediction model exhibits high accuracy. It is revealed that the volcanic ash reaction between SiO2 and lime in rice husk charcoal is the main reason for the rapid increase in the strength of composite soil, and age-related strength variations stem from the quantity and form of C-S-H generation. References | Related Articles | Metrics

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Green Coupling Efficiency of “Roadbed-Environment” of Mountain Railway BAO Xueying, SHEN Duhua, LI Yajuan, HE Zhenxia, ZHANG Chenghao 2025, 44(3): 65-72.  DOI: 10.3969/j.issn.1674-0696.2025.03.09 Abstract ( )   PDF (3030KB) ( )   When green construction of railway embankments is carried out in mountainous areas, it is necessary to consider not only avoiding environmental damage caused by roadbed construction activities but also minimizing the costs of engineering investment. Its green coupling efficiency can help to rationalize the allocation of engineering investment and to promote the high-quality development of “roadbed-environment” green construction. Firstly, the green coupling efficiency was defined and a “roadbed-environment” input-output black box model was proposed to construct a basic framework for analyzing green coupling efficiency. Then, a network DEA model was used to compare and evaluate the green coupling efficiency of roadbed engineering and the efficiency of each sub-stage. Moreover, the entropy weighted TOPSIS model was combined to analyze the coupling status of roadbed engineering. Finally, the key factors that affected the green coupling efficiency were analyzed and mined by the obstacle degree model, which provided theoretical reference for improving the green and efficient coordination status of roadbed engineering. The results indicate that the green coupling efficiency of mountainous roadbed engineering is not high, and there is a certain waste of design resources. The low efficiency of the construction impact stage is the main factor affecting the overall coupling efficiency. The green coupling efficiency and input-output superposition relationship present three states: “low, high, high”, “high, high, high”, and “low, low, high”. Most roadbed sections are in a green low efficiency coupling state. The reasons that affect the green coupling efficiency of “roadbed-environment” in mountainous areas are different. The obstacle degree model can be used for differentiation analysis to obtain rational suggestions. References | Related Articles | Metrics

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Remolding Process and Characteristic Analysis of Dredged Hard Clay ZHENG Lu 2025, 44(3): 73-78.  DOI: 10.3969/j.issn.1674-0696.2025.03.10 Abstract ( )   PDF (2129KB) ( )   With the continuous increase of shipping demand and the deepening promotion of the concept of smart waterway, the task of waterway construction and maintenance becomes increasingly complex and challenging. In channel dredging engineering, the quality of soil has a significant impact on engineering quality and investment. Especially, the presence of hard clay can easily cause difficulties in excavation, pilling and pipe blockage. Statistical analysis was conducted on hard clay encountered in domestic and foreign projects, and typical mechanical indicators of hard clay were obtained. The impact compaction combined with electro-osmotic consolidation method was used for remolding, and the large-scale experimental soil similar to natural hard clay was obtained, which played a certain role in the research of dredging equipment and technology for hard clay. Analysis results show that the combined remolding method can effectively prepare hard clay in a short period of time, and the standard penetration test (SPT) blow of the remolded soil can reach 20 blows. The electro-osmotic method can further enhance the consolidation effect of the soil, with the intermittent reversal voltage method showing optimal results. It is essential to fully consider the influence of overlying stress and water level changes on the standard penetration test blow of the remolded soil during the experiment. References | Related Articles | Metrics

Transportation+Big Data & Artificial Intelligence

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Infrared Ship Target Detection Algorithm Based on YOLO-IST CHEN Lili1, YANG Weichuan2, ZHANG Chengwang2, ZHAO Xin2 2025, 44(3): 79-87.  DOI: 10.3969/j.issn.1674-0696.2025.03.11 Abstract ( )   PDF (5902KB) ( )   Aiming at the problems of blurred target features, complex background and missed detection of small targets in infrared ship images, a detection algorithm YOLO-IST (YOLO for infrared ship target) for ship targets in maritime traffic was proposed based on YOLOv8. Firstly, the C2f_DBB module and CPCA attention mechanism were introduced into the backbone network of the baseline model, and the recognition ability of the model to the target was improved by adding the feature extraction layer. Then, the C2f_Faster_EMA module was used to replace the C2f module in the neck network to improve the detection accuracy and speed of model. Finally, the multi-attention dynamic detection head, that is Dynamic Head, was used to optimize the model framework and enhance the detection effect of the model to small ship targets. The experimental results show that Recall, Precision, Map@50、Map@50-95 and F1score of YOLO-IST are 89.7%, 90.5%, 94.7%, 66.6% and 90.1%, respectively, which are improved by 4.5%, 3.8%, 4.4%, 4.7% and 4.2%, respectively, compared to the baseline model YOLOv8.The proposed model has a wide application prospect in maritime intelligent transportation. References | Related Articles | Metrics

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The Impact of Urban Built Environment on Bicycle Travel Time under Different Trip Purposes ZHU Zhenjun1, ZHANG Ruijia1, HAN Ji1, TANG Chao2, GUO Xiucheng3 2025, 44(3): 88-95.  DOI: 10.3969/j.issn.1674-0696.2025.03.12 Abstract ( )   PDF (4790KB) ( )   Travel time is an essential factor for residents to choose their traffic modes. In order to explore the differences in the impact of urban built environment on bicycle travel time under different travel purposes, based on multi-source data such as Shantou residents travel survey data, road network data, and interest points, the impact of built environment on commuting and non-commuting bicycle travel time was analyzed by the extreme gradient boosting model and SHAP algorithm. The research indicates that the extreme gradient boosting model fits better than the multiple linear regression model. The importance of built environment variables on commuting and non-commuting bicycle travel time is different, and there is a nonlinear impact. The population density has the highest importance for commuting bicycle travel time, while the normalized difference vegetation index (NDVI) has the highest importance for non-commuting bicycle travel time. The influence of population density on the two types of bicycle travel time is V-shaped, while the density of bus-stops and road network is inverted V-shaped. NDVI, the number of office facilities and the mixing degree of land use have opposite effects on the two types of bicycle travel time. References | Related Articles | Metrics

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Nonlinear Effects of Weather and Built Environment on Passengers’ Bus Commuting Time LI Xiaowei1, LIU Qian1, SHI Lanxin1,2, LI Haotian1, CHEN Jun1, SHI Zongqi3 2025, 44(3): 96-104.  DOI: 10.3969/j.issn.1674-0696.2025.03.13 Abstract ( )   PDF (3475KB) ( )   Revealing the mechanism of the influence of built environment and weather on passengers’ bus commuting time is the key to optimize passengers’ commuting time and improve bus sharing rate. Taking Weinan city in Shaanxi as an example, the variables such as passengers’ commuting time during evening peak hours, weather, and the built environment of the origin and destination were extracted through the fusion and mining of multiple sources of spatiotemporal big data. The CatBoost model and SHAP were used to analyze the feature importance and nonlinearity influence of the built environment and the weather on passengers’ bus commuting time during the evening peak hours. The research results show that CatBoost model has good fitting and prediction performance, which is significantly better than XGBoost, KNN, LR and Bayesian Ridge. The significance influencing factors in descending order are: origin science and education density, origin residential density, destination life service density, origin diversity, origin road density, destination residential density, destination diversity, temperature, and precipitation. Among them, the residential density of origin and destination, origin diversity, origin road density have a significant negative impact on the commuting time of passengers during the evening rush hour, while the increase of destination diversity and the rise of the temperature will potentially increase the bus commuting time of passengers during the evening rush hour. The origin science and education density, destination life service density have a significant nonlinear influence on the commuting time of residents. References | Related Articles | Metrics

Transportation Equipment

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Calibration Accuracy Based on Virtual Proving Ground Simulation Technology HE Wei1, ZHANG Chengwei1, CAO Huihuang2 2025, 44(3): 105-111.  DOI: 10.3969/j.issn.1674-0696.2025.03.14 Abstract ( )   PDF (8604KB) ( )   The durability performance simulation is strongly correlated with the accuracy of the input load. The output load of the traditional road spectrum iteration can meet the accuracy requirements of endurance performance development, but the iteration relies on the real vehicle for road spectrum acquisition, which takes a long period of time, and cannot provide a strong reference for structural design in the early stage of project development. Virtual proving ground (VPG) can extract loads as the input of durability development, and its efficiency and economy are far beyond the reach of traditional fatigue load iteration. However, whether the accuracy of VPG meets the durability development needs to be studied. Therefore, based on VPG technology, a whole vehicle dynamics model was established in ADAMS, and VPG calibration was carried out on the basis of road spectrum data and suspension K&C test data collected from real vehicles. Through the analysis of calibration results of twisted road and Belgian road, it is verified that VPG can provide accurate and reliable load input for the development of fatigue durability performance in the early stage of vehicle development. References | Related Articles | Metrics

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Influence of Service Environment and Its Critical Value on Lubrication Performance of Main Bearing LYU Xiuyi1, ZHAO Bin2, LONG Honglian1,2, QU Chuanbo2 2025, 44(3): 112-118.  DOI: 10.3969/j.issn.1674-0696.2025.03.15 Abstract ( )   PDF (4101KB) ( )   Low-speed two-stroke diesel engines occupy more than 90% of the main engines of ocean-going ships, and the crankshaft/main bearing is one of the most critical and typical friction pairs. Taking the main bearing of a certain low-speed machine as the research object, firstly, based on hydrodynamic lubrication theory and classical Reynolds governing equation, the lubrication numerical simulation model suitable for the main bearing of low-speed machine was established by comprehensively considering its dynamic characteristics, geometric structure, service environment and other factors. Secondly, the influence of service environment factors such as different radius clearance, journal inclination and relative speed on main bearing lubrication performance was investigated respectively, and it was concluded that the inclination angle was a significant factor affecting the lubrication performance of main bearing. Then, based on Pearson correlation coefficient theory, the influence of inclination angle on lubrication performance was quantitatively analyzed. The research results indicate that the critical value of inclination angle is 0.024 2°. If the inclination angle exceeds this critical value, the maximum oil film pressure will suddenly change, and the oil film high pressure area will concentrate towards the bearing end face, affecting the safe operation of the ship. References | Related Articles | Metrics