Recommended articles

1 Study on Deformation Characteristics of Kaolin Under Dry-Wet and Freeze-Thaw Cycles

YANG Shang , XIAO Dingyuan

2026, 46(3):1-8. DOI: 10.14048/j.issn.1671-2579.2026.03.001

[Abstract](62) [HTML](36) [PDF 914.75 K](304)

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In seasonally frozen areas, surface soil is subjected to prolonged and drastic fluctuations in temperature and humidity, causing excessive deformation and resulting in engineering issues such as subgrade settlement and building deformation. The deformation characteristics of kaolin in seasonally frozen areas under the combined influence of freeze-thaw and dry-wet cycles were studied. Through a self-designed experimental setup, experiments with interleaved dry-wet and freeze-thaw cycles were conducted on compacted specimens, and wetting-freezing-thawing-drying cycle experiments were performed to explore the swelling-shrinkage deformation characteristics of kaolin under the combined action of different freeze-thaw and dry-wet cycles. The results indicate that intermittent freeze-thaw cycles destroy the stable strain previously achieved by kaolin specimens during dry-wet cycles, and the new stable strain achieved by the specimens during subsequent dry-wet cycles decreases; furthermore, the longitudinal strain of kaolin specimens gradually tends to a stable state after three wetting-freezing-thawing-drying cycles.

2 Comparative Analysis of Highway Carbon Emission Accounting Systems between China and Britain

LIANG Guangquan , DING Lecheng , XU Jin , REN Zhen , WANG Wei , LIU Anyang

2026, 46(2):280-288. DOI: 10.14048/j.issn.1671-2579.2026.02.030

[Abstract](156) [HTML](118) [PDF 893.24 K](911)

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With the goal of “achieving carbon peak by 2030 and carbon neutrality by 2060” proposed by China in 2020, energy conservation and carbon reduction in the transportation industry have become particularly important. As an established industrialized country, Britain started its research on carbon emission reduction in the transportation sector relatively early. This paper compared and analyzed the similarities and differences between the highway carbon emission accounting systems of China and Britain, so as to explore their respective policy backgrounds, accounting methods, and application effects and provide relevant suggestions for highway carbon emission reduction in China. Through literature analysis and case studies, the policy frameworks and implementation mechanisms of carbon emission accounting in the two countries were systematically reviewed. The results indicate that China focuses on government-led regulation and monitoring and ensures data accuracy through laws, regulations, and monitoring systems; meanwhile, Britain adopts a market-oriented flexible mechanism to encourage multi-party participation and voluntary emission reduction. This difference leads to China being rigorous in setting and implementing emission reduction targets but lacking flexibility, whereas Britain demonstrates greater adaptability in practice. Based on this, the following suggestions are proposed: China should comprehensively evaluate its accounting modules, clarify medium-term emission reduction targets, and refine them into annual operable targets; renewable energy policies should be promoted in the energy sector to reduce dependence on high-emission energy; in the transportation sector, the promotion of electric vehicles should be continuously increased, and public transportation networks should be improved. The research results can provide a useful reference for China to optimize the highway carbon emission accounting system, emphasize the importance of international cooperation and knowledge sharing in promoting low-carbon technology innovation, and provide a new perspective for the improvement of future carbon emission reduction policies and practices.

3 Analysis of Microscopic Crack Propagation in Polyurethane-Cement Stabilized Crushed Stone Based on Discrete Element Method

YU Xin , HUANG Yujie , CHEN Chen , JIANG Ziqi , WANG Min , LING Chenxin

2026, 46(2):255-271. DOI: 10.14048/j.issn.1671-2579.2026.02.028

[Abstract](142) [HTML](229) [PDF 5.24 M](1206)

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To study the effect of polyurethane grouting on the crack repair performance of cement stabilized crushed stone, a microscopic model of cement stabilized crushed stone was established by the discrete element method (DEM) in this paper. SCB fracture simulation tests were conducted on specimens with different initial notch-to-depth ratios to obtain load?displacement curves, and sensitivity analysis of microscopic parameters was performed. Then, by comparing microscopic characteristics such as crack propagation paths, crack types, and particle displacements before and after grouting, the repair effect of polyurethane grouting materials was evaluated. The results indicate that the grouting filler significantly enhances the overall stress uniformity of the specimens, expands the tension zone, and disperses internal particle displacements; after grouting, the crack propagation paths of the specimens are similar to those before grouting, but the polyurethane grouting material effectively suppresses crack initiation from the pre-cut notch; cracks mainly propagate along the aggregate?mortar interface at the bottom central axis and the mortar interface at the bottom of the loading plate; crack propagation undergoes three stages: slow accumulation, rapid propagation, and stabilization; the grouting filler significantly improves the crack resistance of the specimens, delays the time of crack generation, and suppresses the rapid propagation of cracks, among which the crack resistance is optimal when the notch-to-depth ratio is 0.4R (R is the specimen radius); tensile stress is the driving force for crack propagation, and the aggregate-mortar interface and the interior of the mortar are the main weak failure interfaces; polyurethane grouting can significantly improve the crack resistance of cement stabilized crushed stone, enhance the structural integrity of the specimens, and improve stress distribution.

4 Research on Wing-Wall-Free Transition between W-Beam Guardrail and Combined Bridge Guardrail

JIANG Guanglun , SHANG Zhongping , ZHANG Yinjiang , WU Junhong , LI Zhen , QIAN Jun

2026, 46(2):232-238. DOI: 10.14048/j.issn.1671-2579.2026.02.025

[Abstract](162) [HTML](102) [PDF 974.59 K](1068)

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To address the transition problem between the W-beam guardrail and the combined bridge guardrail during the upgrading and reconstruction of in-service highway guardrails, an SB-level wing-wall-free transition section with simple construction and high efficiency was proposed. Computer simulation technology was adopted to study the stiffness transition, height transition, and cross-section transition of the wing-wall-free transition section. The guardrail stiffness transition was achieved by optimizing the column spacing and column cross-sectional dimensions. By comparing the contact area between the vehicle and the guardrail and the vehicle redirection situation under different height differences, it was preliminarily determined that the vehicle can be safely redirected when the height difference of the guardrail is less than 15 cm. On this basis, a collision simulation analysis was conducted on the specific scheme of the wing-wall-free transition section, and its protection performance was further verified through a real vehicle collision test. The test results indicate that the structure can achieve the SB-level protection capacity stipulated by the standard.

5 Analysis of Temperature Field in Negative Temperature Tunnel Based on Material Thermal Parameter Tests

XIN Quanming , ZHANG Feng , ZHAO Zhongliang , SUN Zhenhua

2026, 46(2):201-211. DOI: 10.14048/j.issn.1671-2579.2026.02.022

[Abstract](91) [HTML](70) [PDF 1.90 M](1069)

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In view of the temperature field problem of Asia’s first four-season cross-country skiing tunnel reconstructed from an existing tunnel, based on the study of the thermal conductivity of tunnel materials by the HOTDISK method, steady-state heat transfer models under different protection conditions were established by using the finite element method and the multi-layer cylinder heat transfer theory, respectively. The temperature field distribution characteristics of the negative temperature tunnel were analyzed, and the influence laws and sensitivities of various factors were investigated. The results show that the freezing of the tunnel affects the material properties of the tunnel structure; the thermal conductivities of the saturated rock sample and concrete in the frozen state are 8%?20% higher than those in the thawed state; the thermal resistance under the protected condition increases by nearly 9 times compared with that under the unprotected condition, and the heat flow decreases to 1/10; the thermal resistance component of each material layer is inversely proportional to its thermal conductivity and increases approximately logarithmically with the thickness of the insulation layer; the tunnel temperature field has an approximate logarithmic relationship with the thermal conductivity of the surrounding rock and the thickness of the air layer and has a low correlation with the thermal conductivity of the lining; as the thermal conductivity of the insulation material increases, the insulation effect decreases rapidly. The main factors affecting the distribution of the tunnel temperature field are the thickness of the insulation layer, the thermal conductivity of the insulation layer, and the thermal conductivity of the surrounding rock. Intervals can be set in the air layer to reduce the impact of convective heat transfer, and active heating technology can be applied in the lining to prevent the freezing of the tunnel structure.

6 Study on Calculation Method for Deflection of PC Beams Subjected to Local Corrosion

YAO Shuhao , YAO Yan , PENG Jianxin , XIAO Junyi , ZHAO Yang

2026, 46(2):117-124. DOI: 10.14048/j.issn.1671-2579.2026.02.013

[Abstract](98) [HTML](82) [PDF 1.10 M](1039)

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To reasonably evaluate the increase in deflection of PC beams after local corrosion, a calculation method for deflection of corroded PC beams based on the stress and strain model of corroded reinforcement was proposed by considering the beam-arch effect formed by reinforcement corrosion and the degradation of bond strength between reinforcement and concrete. Bending tests on a batch of locally corroded PC beams were carried out to verify the calculation method, and a parameter analysis on the corrosion rate and corrosion position was conducted. The results show that the load?deflection curves obtained by the calculation method are in good agreement with the experimental results. When the corrosion rate is less than 5%, the bending stiffness of the PC beams basically does not change; when the corrosion rate exceeds 5%, the weakening degree of the corrosion rate on the bending stiffness of the PC beams gradually increases, and the deflection of the corroded beams increases significantly with the increase of the corrosion rate. The influence of the corrosion position on the deflection is related to the corrosion rate; when the corrosion rate is relatively low, the change of the corrosion position has little influence on the deflection; when the corrosion rate exceeds 10%, the influence increases, and the mid-span is the most unfavorable.

7 Advances in Properties of Construction Waste Mixtures and Recycling Technologies for Road Construction

LIU Yuanqiang , DAI Wenbin , JIAO Weili , XU Bin

2026, 46(2):48-58. DOI: 10.14048/j.issn.1671-2579.2026.02.006

[Abstract](137) [HTML](199) [PDF 799.80 K](1226)

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Resource utilization of construction waste is an important approach for the sustainable development of infrastructure. To improve the diversified recycling system of construction waste in China and resolve the contradiction between the yield of construction waste and lagging treatment technologies, the physical-mechanical properties, modification methods, and pavement performance of construction waste were systematically summarized in this paper. Firstly, by analyzing the sources and treatment processes of construction waste, material variability was clarified as the key factor restricting its high-value application. Secondly, the application characteristics of construction waste mixtures in the subgrade, base, and asphalt surface layer of road engineering were comprehensively analyzed, and their pavement performance characteristics and process parameters were discussed layer by layer. Finally, the economy and feasibility of the pavement technology of recycled construction waste mixtures were clarified through typical engineering cases, and the significant environmental benefits provide technical support for the construction industry to achieve the carbon neutrality goal. The results indicate that the strength of recycled construction waste mixtures can be effectively improved by addressing the weak interface between old mortar and aggregates, while the low-temperature cracking resistance of asphalt mixtures of construction waste for road use needs to be broken through. It is suggested that research on the effect of low-temperature asphalt modifiers on the performance of construction waste mixtures should be carried out. Meanwhile, the pavement performance of construction waste materials is significantly influenced by the construction compaction process, and conducting research combining material design and process is more conducive to guiding engineering practice.

8 Study on Influence of UDL Hydraulic Parameters on Anti-Seepage Performance of Slope Treated with Cover Layer

XIAO Jie , YAN Dongqing , CHEN Guanyi , HU Linjie , CHANG Jin

2026, 46(2):1-13. DOI: 10.14048/j.issn.1671-2579.2026.02.001

[Abstract](135) [HTML](118) [PDF 1.32 M](1512)

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To explore the influence of hydraulic parameters of the drainage layer (UDL) on the anti-seepage performance of the capillary barrier cover (CBC) layer, the VG model was adopted to fit the soil-water characteristic curve and permeability function of soil based on the principle of unsaturated seepage in this paper. A simplified model of “fine-UDL-coarse”-type CBC layer containing a UDL was established using Geo Studio finite element software. By carrying out the numerical simulation of seepage of expansive soil slope treated with the cover layer under heavy rain conditions, the influence rules of different hydraulic parameters of the UDL on the anti-seepage performance of the CBC layer were systematically analyzed, and the reasonable hydraulic parameter values of the UDL were determined. The results show that the optimal values of hydraulic parameter n, saturated permeability coefficient k_s, and air-entry value a of the UDL are 3.5, 5.79 × 10^?4 m/s, and 9 kPa, respectively. For the UDL, increasing n, k_s, and a can all effectively extend the effective drainage length of the UDL under long-term rainfall conditions, reduce the volume of water breaking through from the sand layer to the gravel layer, and significantly reduce the range of the saturated zone of expansive soil. Therefore, when the “UDL CBC”-type cover layer is adopted in practical engineering applications, various hydraulic parameters of the UDL should be comprehensively coordinated to improve the anti-seepage performance of its CBC layer. The research results can provide a reference basis for material selection in the design of expansive soil treatment engineering using the CBC layer.

9 Environmental and Economic Benefits of Brick Aggregate for Road Applications in Bangladesh

LIU Zhifang , LIU Gang , XU Jinlong , ZHANG Jingbo

2026, 46(1):275-280. DOI: 10.14048/j.issn.1671-2579.2026.01.030

[Abstract](210) [HTML](207) [PDF 527.11 K](2238)

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In response to the shortage of stone materials in Bangladesh, which leads to higher costs for road construction due to reliance on imports, this study investigated the significant potential of utilizing brick slag aggregate and recycled aggregate as substitutes for graded gravel. This approach was particularly relevant given the country’s large production of clay-fired bricks and substantial construction waste. Using a life cycle analysis (LCA) method, the study established environmental impact inventories for graded gravel, brick slag aggregate, and recycled aggregate. The BEPAS model was employed to quantitatively analyze the environmental impacts of the two alternative solutions, providing a comprehensive evaluation of their environmental and economic benefits. The results show that the environmental benefit-to-cost ratio for brick slag aggregate is 0.017, while for recycled aggregate it is 3.762. This indicates that the environmental benefits of brick slag aggregate are far lower than the environmental costs incurred, whereas the environmental benefits of recycled aggregate are clearly higher than the associated environmental costs, demonstrating notable environmental advantages. In terms of economic benefits, the use of brick slag aggregate in pavement construction reduces costs by 28.40%, while costs for recycled aggregate can be further decreased to below 10%, delivering even more significant economic benefits.

10 Research on Carbon Emission Accounting for Road Engineering Foundation Reinforcement

YANG Penghui , LIU Rui , WAN Chuanfeng , ZHANG Haixiao , ZHOU Yefei , LU Chunying

2026, 46(1):268-274. DOI: 10.14048/j.issn.1671-2579.2026.01.029

[Abstract](244) [HTML](226) [PDF 581.30 K](2232)

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To cope with the increasingly serious global warming and implement China’s carbon peak and carbon neutrality goals, the promotion of energy conservation and emission reduction in the construction industry should be accelerated. Starting with the foundation treatment project in road engineering, this study used the carbon emission factor method. According to the budget consumption quota of the project, the carbon emissions of each sub-project in the project were calculated. Then, the cost of each sub-project was calculated based on the engineering cost standard. From the perspectives of carbon emissions and engineering costs, data analysis was conducted to explore the project’s emission reduction potential. The results indicate that materials are the primary source of carbon emissions in foundation reinforcement projects, mainly from high carbon emitting materials such as cement and steel bars. For sub-projects, the proportion of emissions from compacted pile engineering is the highest (72.6%). By comparing the relationship between costs and carbon emissions, it is found that the ratio of engineering costs to carbon emissions of replacing sand, stone chips, and crushed stone projects is the highest. To economically and efficiently control carbon emissions in foundation reinforcement projects, priority can be given to sub-projects with a low ratio of engineering costs to carbon emissions and low carbon emissions, such as compacted pile engineering, replacement soil engineering, and cement stabilized soil engineering. The proposed energy conservation and emission reduction measures based on the analysis results can provide method references and data support for carbon emission accounting in road engineering.

11 Research on Multi-Object Detection Algorithm for Routine Highway Inspection Based on UAV

MA Tao , TIAN Meijuan , WANG Zhipeng , DONG Jiazhi , ZHU Junqing

2026, 46(1):229-239. DOI: 10.14048/j.issn.1671-2579.2026.01.025

[Abstract](385) [HTML](579) [PDF 2.20 M](2946)

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To address the problems of insufficient detection accuracy and poor real-time performance caused by small detection objects, complex backgrounds, and large calculation volume in routine highway inspection tasks using unmanned aerial vehicles (UAVs), this paper proposed an improved UAV-based routine highway inspection algorithm relying on YOLOv11n, YOLOv11-UR. The algorithm incorporated the multi-level channel and attention (MLCA) mechanism into the backbone network to fuse channel and spatial dimension information, integrate local and global receptive fields, and effectively enhance feature expression capability. It achieved a significant improvement in detection accuracy with only a small increase in parameters. In the Neck part, GSConv was introduced to replace standard convolution, making the output of the convolution calculation as close as possible to standard convolution while reducing computational costs. VoVGSCSP was introduced to replace C3k2, reducing the model parameter volume and computational complexity while enhancing feature extraction capability. Experimental results show that the YOLOv11-UR algorithm has significant advantages in UAV-based routine highway inspection. It effectively reduces the parameter volume and computational overhead of the model without losing much inference speed. The model detection precision (R_P) and mean average precision (m_AP) reach 78.26% and 73.34%, respectively. The improved algorithm balances detection accuracy and inference efficiency and can better meet the needs of UAV-based routine highway inspection.

12 Smoke Control Wind Speed of Transversal Double-Source Fire in Road Tunnel Sections

GAO Hengchao , TAO Jiaqing , CHEN Xun , WANG Feng

2026, 46(1):205-212. DOI: 10.14048/j.issn.1671-2579.2026.01.022

[Abstract](153) [HTML](250) [PDF 937.82 K](2239)

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The numerical calculation method was adopted to conduct an in-depth analysis of the control wind speed, smoke back-layering length and smoke temperature of dual-source fire in road tunnel sections and thus study the smoke control method of dual-source fire in road tunnel sections. The results show that under the dual-source fire scenarios, due to the dispersion of fire sources, the critical wind speed is mainly controlled by two fire sources. When the power of the two fire sources is the same or similar, there is a certain superposition effect between the two fire sources, with the critical wind speed subject to the joint influence of the two. When the power of the two fire sources is different, the critical wind speed mainly depends on the fire source with larger power, and the role of the fire source with smaller power is not obvious. The critical wind speed of dual-source (5 MW+5 MW) fire is 2.5 m/s, and the critical wind speed of dual-source (20 MW+20 MW) fire is 3.3 m/s, increasing to a certain extent compared with the same power of the single fire source. In contrast, the critical wind speed of dual-source (20 MW+5 MW) fire is 3.2 m/s, which is the same as that of the single-source 20 MW fire. The smoke temperature is affected by the power of the two fire sources, as is the critical wind speed. The smoke back-layering length is controlled by the fire size, and at the same ventilation speed, the smoke back-layering length increases with the growing fire size, which is not related to the power of the two fire sources.

13 Influence Mechanism of Maintenance Rails on Vortex-Induced Vibration of Twin Steel Box Girders

SUN Hongxin , HU Lei , CHEN Wei , HUANG Wenjun

2026, 46(1):122-129. DOI: 10.14048/j.issn.1671-2579.2026.01.013

[Abstract](138) [HTML](211) [PDF 1.62 M](2449)

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Maintenance rails are an important passage for the safe operation and maintenance of bridges, significantly affecting the vortex-induced vibration (VIV) performance of main girders. A twin steel box girder cable-stayed bridge with the main span of 658 m was taken as the engineering background to investigate the influence mechanism of maintenance rails on the VIV performance of twin steel box girders. Combined with section model wind tunnel tests and two-dimensional fluid-structure interaction CFD numerical simulations, the vertical VIV performance of the main girder sections with and without maintenance rails was studied, and the mechanism of maintenance rails’ influence on VIV performance was analyzed. The results show that large vertical VIV occurs in main girder sections with maintenance rails, while the vertical VIV amplitude of the sections without maintenance rails decreases by more than 40%, indicating that maintenance rails significantly influence the VIV performance of the twin steel box girders. Periodic vortex shedding occurs on the upper and lower surfaces of main girder sections with maintenance rails, which results in a large pressure difference between the upper and lower surfaces of main girders, thus generating periodic vortex-induced force and causing large-amplitude vertical VIV of main girders. After removing the maintenance rails, the periodic vortex shedding pattern on the upper and lower surfaces of main girder sections with maintenance rails is disrupted, thereby suppressing the VIV amplitude of main girders.

14 Review of Study on Performance of Interlayer Bonding of Concrete Bridge Pavements

LYU Songtao , YANG Dingling , LU Weiwei , DUAN Haihui

2026, 46(1):45-62. DOI: 10.14048/j.issn.1671-2579.2026.01.005

[Abstract](227) [HTML](319) [PDF 1.52 M](2457)

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To clarify how interlayer bonding performance of cement concrete bridge decks affects the durability of bridge deck pavements and to identify the technical methods, research challenges, and future development trends for improving interlayer bonding performance, the research progress on the interlayer bonding performance of bridge deck pavements in China and abroad was reviewed. First, the characterization models and bond failure modes of the existing interlayer bonding state of bridge deck pavements were summarized, and the influencing factors of interlayer bonding performance and their working mechanisms were analyzed. Second, current evaluation methods and indices for interlayer bonding performance were discussed, and their limitations were pointed out. Finally, effective measures for improving interlayer bonding performance are outlined, and future research directions are proposed. The results show that the current interlayer contact models are relatively simple and have difficulty accurately characterizing complex interlayer bonding states. Temperature and interlayer interface roughness are the key factors affecting interlayer bonding performance. Existing interlayer bonding performance evaluation methods mostly rely on destructive shear tests, and the development of repeatable and rapid non-destructive testing technologies is an important trend. At present, there is no unified evaluation standard or specification for interlayer bonding performance at home and abroad, and the consistency among different evaluation indices is insufficient. It is recommended that the evaluation of interlayer bonding performance be incorporated into the bridge deck pavement design system to improve pavement durability and ensure the long-term service performance of bridges.

15 Review of Research on Ecological Protection Technologies for Highway Subgrade Slopes

ZHANG Rui , LI Wangjun , GAO Qianfeng , CHEN Bo , GONG Yi , HOU Yudong , ZHANG Xiwei

2026, 46(1):1-20. DOI: 10.14048/j.issn.1671-2579.2026.01.001

[Abstract](464) [HTML](759) [PDF 2.69 M](3663)

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Safety, durability, and green low-carbon performance are key requirements for the development of highway slope engineering. Given the shortcomings of conventional masonry slope protection and vegetation-engineering composite systems with respect to construction duration, construction safety, and environmental impacts, this paper presents a systematic review of ecological protection technologies for highway subgrade slopes. The working mechanisms of typical ecological protection technologies, such as plant slope protection and attached-type slope protection, were systematically analyzed. Important Chinese and international research results on these technologies were summarized. The slope protection performance of different ecological protection technologies was discussed in depth, and future development trends of ecological protection technologies for highway subgrade slopes in China were prospected. Comprehensive analysis indicates that currently, there are no scientific and systematic guidance methods for plant selection and configuration in plant slope protection technologies; regarding vegetation blanket protection, the effects of blanket structural layer thickness, grid shape, and stitching pile arrangement on protection effectiveness require further in-depth study; the quality of ecological bags directly affects their protection effect, thus ecological bags with high water permeability and soil retention capabilities should be developed; the durability of ecological concrete and the potential impact of porous concrete on slope ecology require continuous research and evaluation; geocell slope protection faces problems such as geocell deformation caused by cultivated soil compression and water accumulation inside the cells during rainfall, which need to be solved urgently; for three-dimensional network plant protection technology, standards are lacking regarding material selection, net type selection, and substrate development, and research on the synergistic mechanism among plants, cultivated soil, and the three-dimensional network is insufficient. Currently, there are no unified standards for the design and evaluation indices of ecological protection technologies, and practical applications mostly rely on field experience. Therefore, future theoretical and application research should be conducted in the aforementioned areas to identify the most suitable ecological protection technologies to replace skeleton-plant slope protection, providing guidance for promoting the development of ecological protection technologies for highway subgrade slopes in China.

16 Bending Capacity and Strengthening Design with Bonding Steel Plates of Concrete Sections in French Standards

WU Zi

2025, 45(6):287-292. DOI: 10.14048/j.issn.1671-2579.2025.06.033

[Abstract](141) [HTML](262) [PDF 18.76 K](2770)

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In the French general technical clauses widely used in Francophone African countries, only the calculation principles for the bending capacity of normal concrete sections are provided, with explicit formulas not listed, and the strengthening design of structures is not involved. According to the fundamental principles of concrete structures and French standard regulations, the calculation formulas for the bending capacity of normal concrete sections were derived. On the basis of the assumptions of strengthening design, calculation formulas for strengthening with bonding steel plates were derived. Through practical engineering calculations conducted on the VDN Expressway project in Senegal, the applicability and reliability of the proposed formulas were verified. This study can offer a reference for the design and strengthening of normal concrete sections in similar overseas engineering projects.

17 Object Detection and Tracking Based on Fusion of Radar and Camera on Highway Side

ZENG Yongqiang , ZHANG Yonghua , ZHAO Hui , LIU Xin , XU Mingsheng , SHEN Jianwei , HU Zhiwei , CHEN Zhenquan

2025, 45(6):261-267. DOI: 10.14048/j.issn.1671-2579.2025.06.030

[Abstract](191) [HTML](290) [PDF 30.02 K](2833)

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Camera is the most widely used sensor in intelligent transportation systems (ITS), but the decline of detection and positioning accuracy caused by target occlusion and external environment interference has always been an important factor restricting the development of ITS. In order to solve this problem, a multi-mode fusion target detection and tracking method based on millimeter-wave radar (MWR) and camera on highway side was designed. Compared with cameras, high-resolution MWR had better measurement accuracy and weather robustness, serving as a better complement to camera perception. The proposed method used the center point-based radar and camera fusion algorithm for target detection and adopted the greedy algorithm for target association. The test results show that on the public dataset nuScenes and the self-built multi-modal dataset of highway side, the proposed method achieves an A_MOTA (multi-object tracking accuracy) performance of 69.1% on the nuScenes dataset, outperforming all visual-based 3D tracking benchmark methods; the self-built dataset verifies its good applicability and accuracy, and the processing time for a single image is 35 ms.

18 Evaluation Method for Nighttime Visual Space Improvement on Mountain Roads

ZHAO Yan , CHEN Yanli , CHEN Jiale

2025, 45(6):254-260. DOI: 10.14048/j.issn.1671-2579.2025.06.029

[Abstract](164) [HTML](310) [PDF 25.99 K](2823)

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To address issues such as poor visual guidance, narrow field of view, and short sight distance during nighttime driving on mountain roads, this study proposed a visual space enhancement evaluation method applicable to mountainous roads at night. By integrating active and passive traffic safety facilities, a visual space enhancement strategy adapted to the nighttime environment of mountain roads was proposed. A multidimensional evaluation indicator for visual space was established based on co-simulation. The effectiveness of the strategy was verified from the perspectives of visual space expansion and driving safety improvement by taking a trunk highway in the Qinling mountainous region as a case study. The results show that the proposed visual space enhancement measures can significantly increase effective sight distance and improve driving safety, especially on high-risk road sections such as complex curves and steep longitudinal slopes, where they can effectively reduce the risk of traffic accidents.

19 Wind Tunnel Test Study on Wind-Resistant Performance of Shuangliu Yangtze River Bridge

LI Xiukun , WU Xuewei , YANG Can , PENG Xiaobin , HUANG Zhiwen

2025, 45(6):127-136. DOI: 10.14048/j.issn.1671-2579.2025.06.015

[Abstract](213) [HTML](295) [PDF 38.26 K](3121)

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The main bridge of Shuangliu Yangtze River Bridge on the Xingang Expressway in Wuhan City is a single-span suspension bridge with a main span of 1 430 m and a bridge tower of 272.75 m. The stiffening girder is in the form of a closed flat steel box girder with a width of 50.5 m. In order to study the wind-resistant performance of the bridge during operation, the performance of vortex-induced vibration of the girder was tested through wind tunnel tests of section model with two different geometric scales of 1∶60 and 1∶30, respectively. The sensitivity of the vortex-induced vibration response to the structural damping ratio was analyzed, and the effect of installing a guide vane inside or on both sides of the maintenance rail on the performance of vortex-induced vibration was evaluated. The flutter performance of the bridge was tested in a wind tunnel by using the 1∶60 geometrically scaled section model, in which the effect of the guide vanes on the flutter performance was analyzed. Finally, the flutter performance of the bridge was tested through wind tunnel tests of the full-bridge aeroelastic model with a scale ratio of 1∶205. The results show that the bridge shows good flutter performance under the wind angle of attack from ?3° to +3°, and the critical flutter wind speed at each angle of attack is more than 20% higher than the tested flutter wind speed. The vortex-induced vibration response is significantly affected by the structural damping ratio. When the vertical bending and torsional damping ratios are 0.136% and 0.048% respectively, significant vertical and torsional vortex phenomena were observed in the large-scale wind tunnel test of the section model. However, if the former damping ratios are increased to 0.217% and 0.164%, respectively, the vertical vortex-induced vibration and torsional vortex-induced vibration almost disappear. Installing the guide vane on the maintenance rail can suppress the vortex-induced vibration under a small structural damping ratio, and has little influence on the flutter performance of the bridge.

20 Mechanical Properties of Transition Section of Cable-Stayed Bridge with Kilometer-Scale Steel-UHPC Composite Girders

LI Qiu , ZHI Haitao , PENG Yanqing , PENG Jianxin , YUAN Qin , WU Xuewei

2025, 45(6):119-126. DOI: 10.14048/j.issn.1671-2579.2025.06.014

[Abstract](152) [HTML](387) [PDF 38.29 K](3122)

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To study the mechanical properties of the steel-concrete composite section between steel box girders and steel-ultra-high performance concrete (UHPC) composite girders, the Guanyinsi Yangtze River Bridge with a main span of 1 160 m was used as the background. Through refined finite element modeling, the stress characteristics under the most unfavorable load conditions and transmission mechanism of the steel-concrete composite section were analyzed, and the main factors affecting the stress of the composite section were discussed. The results indicate that under the most unfavorable load conditions, the stress of each component in the steel-concrete composite section is within 160.4 MPa, which is lower than the material strength design value, and there is sufficient safety reserve. Along the longitudinal direction of the bridge, the influence of the composite section on the force transmission of the bottom plate and middle web of the steel box girder is relatively small, and the stress generally shows a downward trend from the steel box girder to the composite girder direction, with a variation amplitude within 20 MPa. The stress levels of the top plate, web plate, and bottom plate of the steel lattice chamber decrease by 25.6%, 73.3%, and 35% near the bearing plate, respectively. In the process of transmission force through shear nails, the proportion of force transmitted by shear nails of the top plate in the steel lattice chamber is the highest, and a closer proximity to the end of the composite girder indicates a higher proportion, with a maximum of 57%. Increasing the thickness of concrete filled in the composite section can reduce the structural stress, and a thickness of 350 mm–400 mm can achieve the optimal stress of the structure. A longer composite section is more conducive to the stiffness transition of the shear nails.

21 Research on Pavement Roughness Evaluation Method Based on Smartphones

SIRIGULENG , YILIGUOQI , ARONG , GUO Guoying , WANG Jing

2025, 45(6):58-66. DOI: 10.14048/j.issn.1671-2579.2025.06.007

[Abstract](152) [HTML](259) [PDF 43.63 K](3029)

Abstract:
To address the low efficiency and high cost of current detection methods, as well as the insufficient accumulation of pavement damage data on rural low-grade roads, this study developed a vehicle vibration data acquisition application based on smartphones and proposed a conversion method for calculating an index equivalent to the international roughness index (I_IRI). Vertical acceleration signals collected during vehicle travel were proposed through high-pass filtering and denoising to calculate the vertical displacement, from which a converted IIRI' was derived. Experimental results show that although the data collected by smartphones has slightly lower accuracy than that collected by professional detection equipment, the proposed IIRI' exhibits a high correlation with the traditional IIRI', effectively reflecting pavement roughness characteristics. This method provides an economical, efficient, and convenient solution for roughness detection on low-grade roads, with significant application value for large-scale pavement condition monitoring and preliminary screening.

22 Reflection Cracking Resistance and Fatigue Performance of Super-Flexible FMA Mixture

LAN Yong , DENG Xinghe , ZHANG Zida , WU Kuanghuai , DING Weizhe , GUAN Xuebing , PENG Tiekun

2025, 45(6):45-57. DOI: 10.14048/j.issn.1671-2579.2025.06.006

[Abstract](152) [HTML](252) [PDF 35.14 K](3207)

Abstract:
To investigate the fatigue performance and reflection cracking resistance of super-flexible fluid mastic asphalt (FMA) mixtures, this study designed a super-flexible FMA-13 mixture by the mastic flow for filling (MaFF) method. The effects of temperature and maximum horizontal tensile displacement on the cracking resistance of both FMA-13 and GAC-13 (as the control) mixtures were explored via the Overlay Tester. Additionally, small-scale accelerated pavement loading tests were conducted to analyze the effect of load cycles on the rebound modulus of the FMA-13 mixture. A nonlinear fatigue damage model was employed to predict the fatigue life of both mixtures. The results indicate that when the temperature decreases from 25 °C to 0 °C, the load loss rate of the FMA-13 mixture increases from 63.2% to 72.5%, while that of the GAC-13 mixture significantly rises from 82.8% to 94%. Temperature has a significant effect on the reflection cracking resistance of the GAC-13 mixture, while the maximum horizontal tensile displacement does not significantly affect the reflection cracking resistance of the FMA-13 mixture. When the number of load cycles increases from 0 to 1 million, the rebound modulus of the GAC-13 mixture decreases by 32%, whereas the FMA-13 mixture experiences only a 24% decrease. Furthermore, the fatigue life of the FMA-13 mixture far exceeds that of the GAC-13 mixture. These experimental results demonstrate that FMA mixtures possess superior crack resistance and fatigue performance, enabling them to be used as functional pavement materials in stress-absorbing layers. They can address issues such as reflection cracking in pavements, offering broad application prospects.

23 Influence Mechanism of Static and Dynamic Loading on Adsorbed Bound Water and Deformation in High Liquid Limit Soils

FANG Zhongwang , ZHOU Shijie , XIAO Yupeng , PENG Xin , ZHANG Rui

2025, 45(6):17-24. DOI: 10.14048/j.issn.1671-2579.2025.06.003

[Abstract](191) [HTML](227) [PDF 31.15 K](3213)

Abstract:
In order to reveal the evolution law of adsorbed bound water and the deformation characteristics of high liquid limit soil under static and dynamic loading, Hainan high liquid limit soil and Hunan clayey sand were selected as comparative samples. Through consolidation, consolidation-creep, and dynamic triaxial tests, the deformation patterns of high liquid limit soil under different loading conditions were obtained. By combining nuclear magnetic resonance tests, the variation pattern of adsorbed bound water content in specimens before and after the consolidation and dynamic triaxial tests was studied. The results show that under static loading, the compression coefficient of high liquid limit soil meets the requirements of the Specifications for Design of Highway Subgrades (JTG D30—2019) for subgrade fill materials. The adsorbed bound water content is basically stable, and the consolidation-creep deformation is small. Under dynamic loading, the elastic strain and permanent axial strain of the specimen increase with increasing loading amplitude. Dynamic loading significantly reduces the adsorbed bound water content in the high liquid limit soil, leading to the large plastic cumulative deformation of the soil under cyclic loading. The study can provide a reference for the engineering application of high liquid limit soils as lower embankment fill.

24 Shaking Table Test and Numerical Simulation of Seismic Response Characteristics of Rock Slope with Muddy Interlayer

DUAN Chenggang , FANG Yanlin , TIAN Yeqing , ZHOU Zhijun

2025, 45(6):1-9. DOI: 10.14048/j.issn.1671-2579.2025.06.001

[Abstract](242) [HTML](427) [PDF 31.60 K](3514)

Abstract:
In order to study the seismic macroscopic failure process and dynamic response characteristics of rock slope with muddy interlayer and reveal the influence of muddy interlayer on slope stability, a similar slope model with concave and convex slope types was designed, and shaking table test was carried out; finite element analysis was used for numerical modeling analysis, and the results obtained by the two models were compared. The results show that: ① The macroscopic deformation and failure process of the model slope is divided into three stages. Muddy interlayer dislocates, and cracks occur; mud interlayer slips, and cracks expand; slope collapses; ② The seismic load has a decisive influence on the stability of the slope. With the increase in the seismic acceleration amplitude, the slope damage becomes more serious; ③ Muddy interlayer is the weak part of the slope. Under the influence of the earthquake, tension cracks first appear, which is a key factor in triggering the instability of the slope; ④ The seismic acceleration response characteristics of the two slopes are as follows: with the increase in seismic load, the peak ground-motion acceleration (PGA) amplification coefficient first significantly increases and then slowly decreases. The curve trend of the PGA amplification coefficient of the two slopes is basically the same. The values near the third interlayer and at the slope shoulder are significantly higher than other measurement points. The PGA amplification factor of the concave slope is slightly larger than that of the convex slope, and the trend of the broken line is more tortuous, showing a more complicated amplification effect; ⑤ Numerical simulation results show that when the seismic acceleration amplitude reaches 0.6g, the slope undergoes instability and failure. The failure modes of concave and convex slopes are slightly different. The failure mode of concave slopes is as follows: Slope shoulder collapse, with sliding failure near the point of gradient change. The failure mode of a convex slope is mainly the line of gradient change failure. Overall, the seismic stability of a convex slope is slightly better than that of a concave slope.

25 Research on Enhancement of Toughness Performance in Polyurethane-Modified Epoxy Asphalt

LIANG Bo , LIAO Xintao , LIAO Wei , JIANG Hui , QIN Ruiming

2025, 45(5):102-112. DOI: 10.14048/j.issn.1671-2579.2025.05.011

[Abstract](231) [HTML](741) [PDF 1.04 M](3691)

Abstract:
To solve low toughness and high brittleness of epoxy asphalt under low-temperature conditions, in this study, polyether-type polyurethane (JMPU) and polyester-type polyurethane (JZPU) were employed to prepare modified epoxy asphalt. Firstly, the Brookfield viscosity test, infrared spectroscopy test, and fluorescence microscopy were utilized to characterize the curing process. The curing time and curing temperature of JMPU and JZPU modified epoxy asphalt were 3 h/140 °C and 4 h/150 °C, respectively. With styrene-butadiene-styrene block copolymer (SBS), a common modifier, as the control, the performance changes of epoxy asphalt before and after modification with different toughening agents were evaluated through mechanical tensile test, rheological property test, multiple stress creep recovery (MSCR) test, and storage stability test. The research findings indicate that the polyurethane system can effectively enhance the elongation at break, low-temperature performance, and storage stability of epoxy asphalt by forming an interpenetrating network structure (IPNs) with epoxy asphalt, while maintaining excellent high-temperature performance. The elongation at break of JMPU-modified epoxy asphalt and its low-temperature creep stiffness at ?12 °C can reach 233% and 169 MPa, respectively. Results of an aging test on the toughened and modified epoxy asphalt show that the incorporation of JMPU and JZPU effectively mitigates the adverse effects of aging on epoxy asphalt performance, evidenced by lower creep stiffness aging index and rutting factor aging index, as well as higher creep rate aging index. Therefore, the addition of the PU system as a toughening agent improves the toughness of epoxy asphalt and enhances its compatibility and anti-aging performance.

26 A Review of Pavement Condition Evaluation Index Systems in China and Abroad

CHEN Leilei , YANG-LI Wenyun , LI Wei , Muhammad Thlha , QIAN Zhendong

2025, 45(5):61-74. DOI: 10.14048/j.issn.1671-2579.2025.05.007

[Abstract](258) [HTML](941) [PDF 855.40 K](3888)

Abstract:
With the increasingly complex operating conditions of roads, it has become a consensus among countries to improve the accuracy and systematicness of maintenance decisions. Since the pavement condition evaluation index system is the core tool supporting the judgment of schemes, its construction method and applicable ability directly affect the maintenance efficiency and resource allocation level. Based on the construction logic of the index model, the scoring mechanism of grade division, and the conditions of road grade adaptation, the characteristics of the evaluation index systems in typical countries in China and abroad were compared and sorted out. The internal causes affecting the characteristics of the index system were discussed from in-depth perspectives such as management concepts and institutional arrangements. Research findings show that some systems abroad emphasize hierarchical structural response or public experience, while in China, unified deployment and hierarchical downward management are emphasized. In China’s case, the system has a certain foundation in terms of universality and standardization, but there are obvious shortcomings in threshold adjustment, scene adaptation, and system integration. Therefore, suggestions are proposed including setting dynamic thresholds in combination with maintenance goals, enhancing the adaptability to various types of road operating environments, and promoting the effective integration of evaluation results with the actual management process, which provides ideological support for the structural optimization and institutional coordination of the evaluation system.

27 Pavement Performance Prediction Based on Integrated Particle Swarm Optimization-Gray Back Propagation Neural Network Model

LI Xuelian , HUANG Yan , LI Xiong

2025, 45(5):46-52. DOI: 10.14048/j.issn.1671-2579.2025.05.005

[Abstract](205) [HTML](531) [PDF 696.34 K](3837)

Abstract:
The existing performance prediction model of asphalt pavements is limited by low accuracy and a lack of historical measured data. To address this issue and maximally optimize the pavement maintenance decision, a pavement performance prediction model integrating particle swarm optimization (PSO), gray model (GM), and back propagation neural network (BPNN) was proposed based on network management. Meanwhile, the model was compared with the GM(1,1) model, support vector regression (SVR) model, BPNN model, and PSO-BPNN model. Then, the prediction accuracy of the models was evaluated by the mean absolute error (E_MAE), the root mean square error (E_RMSE), and the mean absolute percentage error (E_MAPE). The fitting results of the PSO-gray BPNN model were assessed by the R-squared (R²). The results indicate that by optimizing the BPNN model with the PSO algorithm and the GM model, the accuracy of the PSO-gray BPNN model is significantly improved. Based on the performance data of 14 expressways in Hubei Province, a high correlation between the predicted values of the model and the measured data is found. For the I_PCI index, the value of E_MAE, E_RMSE, and E_MAPE is reduced to 1.721 8, 2.296 8, and 1.897 1, respectively. The value of R² could be up to 0.919. Compared to the other four models, the PSO-gray BPNN model has the smallest values of prediction error for I_PCI, I_RQI, I_RDI, and I_SRI, fully showing the superiority of the model. With higher prediction accuracy, the proposed PSO-gray BPNN model has prediction results more consistent with the actual situation, providing an accurate and reliable technical support for the prediction of pavement performance at the network level.

28 Mesoscopic Simulation Study on Fatigue Performance of Asphalt Mixture Based on Discrete Element Method

MAO Quan , ZHENG Junqiu , MA Hui , WANG Min

2025, 45(5):19-26. DOI: 10.14048/j.issn.1671-2579.2025.05.002

[Abstract](249) [HTML](378) [PDF 1.51 M](3792)

Abstract:
Asphalt pavement is prone to fatigue cracking during long-term service, which can lead to secondary diseases and weaken the structural durability. For in-depth revelation of the fatigue damage behavior of asphalt mixtures, in this paper, a semi-circular bending (SCB) mesoscopic model was established based on the discrete element method. The fatigue fracture behavior of three typical asphalt mixtures in Jiangsu Province’s expressways, including SMA-13, SUP-20, and SUP-25, was simulated under different stress ratio conditions. The fatigue damage mechanism and evolution law of asphalt mixtures were analyzed from the aspects of fatigue life, crack propagation, and residual strength. The results show that all three mixtures exhibit typical three-stage fatigue damage characteristics, and the increase of stress ratio will significantly shorten the fatigue life and accelerate the crack development. SMA-13 shows excellent fatigue resistance due to its dense skeleton and modified asphalt mortar, followed by SUP-20, while SUP-25 performs the worst due to insufficient skeleton constraint and low mortar toughness. Meanwhile, the crack propagation paths and residual strength attenuation laws of different mixtures are significantly different, further revealing the key role of skeleton structure and asphalt mortar performance in the fatigue damage mechanism.

29 Research and Application Progress of RAP Plant-Mixed Hot Recycling Based on Oil-Stone Separation

YU Xin , GAO Yuchao , ZHOU Jie

2025, 45(5):1-18. DOI: 10.14048/j.issn.1671-2579.2025.05.001

[Abstract](413) [HTML](721) [PDF 1.37 M](4226)

Abstract:
Driven by global sustainable development strategies, China, as a major infrastructure nation, faces multiple pressures from resource constraints, environmental challenges, and its dual carbon goals. The efficient recycling of recycled asphalt pavement (RAP) has become a core issue for the green development of road engineering. Traditional recycling technologies struggle to overcome the 30% blending bottleneck due to issues such as high RAP agglomeration rates and significant gradation variability. Oil-stone separation technology deconstructs RAP to a near-virgin state through physical crushing, offering a novel pathway for high-ratio (≥30%) and even ultra-high-ratio (≥50%) RAP recycling. This paper critically reviewed systematic research on RAP material properties, oil-stone separation technology, and plant-mixed hot recycling applications by comparing domestic and international progress. It focused on exploring agglomeration mechanisms, causes of variability, and control strategies, while analyzing the root causes of performance controversies in recycled mixtures. Finally, the paper identified current research gaps in mechanism depth, technological intelligence, standard systems, and long-term performance validation, proposing future research directions to provide theoretical guidance for advancing asphalt pavement recycling technology toward high efficiency, high value, and low-carbon development.

30 Reference and Inspiration from Low-Carbon Development Experience of Foreign Highway Infrastructure

LU Chunying , GAO Shuohan , DU Xueyuan , JIAN Li , WANG Xinjun , KONG Yaping

2025, 45(4):233-242. DOI: 10.14048/j.issn.1671-2579.2025.04.029

[Abstract](207) [HTML](639) [PDF 669.58 K](3947)

Abstract:
In order to provide support for the scientific formulation of low-carbon highway infrastructure development policies in China, empirical analysis, comparative analysis, and other methods were utilized, and the construction goals and action strategies of low-carbon highway infrastructure in the United Kingdom, the United States, and Australia were sorted out. Advanced experience in the development of low-carbon highways abroad was summarized. On this basis, combined with the current situation and existing problems of low-carbon development of China’s highway infrastructure, the following countermeasures and suggestions were proposed: ① strengthening top-level design and formulating low-carbon development goals and paths; ② implementing the concept of life cycle and strengthening the research and promotion of low-carbon technologies; ③ carrying out carbon emission management on highways and establishing a dynamic management mechanism; ④ coordinating the entire process of highway construction and promoting green procurement work; ⑤ building a charging infrastructure network and promoting the development of electric vehicles; ⑥ conducting pilot demonstration work and orderly advancing the construction of low-carbon highways.

31 Research on Automatic Review Method of Highway BIM Based on Knowledge Graph

WANG Wuyu , SHAO Kebo , ZHANG Feng

2025, 45(4):197-202. DOI: 10.14048/j.issn.1671-2579.2025.04.024

[Abstract](270) [HTML](605) [PDF 551.62 K](3795)

Abstract:
Building information modeling (BIM), characterized by multi-dimensional modeling and multi-source data integration, is becoming a key technology to promote the innovation and digital transformation of the highway design industry. Taking BIM as the design deliverable is an inevitable trend in the future development of highway engineering design. However, the current highway BIM review is mainly conducted manually, which brings about problems such as low efficiency, susceptibility to errors, and high subjectivity. This makes it difficult to adapt to the review requirements of the three-dimensional (3D) digital design mode. To this end, this study proposed an automatic review method of highway BIM based on a knowledge graph. By constructing the knowledge graph covering multi-dimensional knowledge such as highway design standard specifications, a semantic database, and meta-structures in the field of highway engineering, natural language processing (NLP) technology was used to structurally process the review rules of design standard specifications and provisions. Then, by taking a component entity of industry foundation classes (IFC) as the object, the Cypher query language was used to realize the review of attribute information completeness, data accuracy, and design compliance of highway BIM components. The results show that the graph database based on the knowledge graph technology can provide technical methods for the review of highway BIM design results, further significantly improving the quality and review efficiency of highway 3D design results.

32 Study on Mechanical Effect of Backfill Construction in Orthogonal Underpass Section of an Open-Cut Interchange Tunnel

LI Qingda , LI Dexing , YU Tingshun , HAN Xi , LIU Jiansong

2025, 45(4):184-196. DOI: 10.14048/j.issn.1671-2579.2025.04.023

[Abstract](223) [HTML](284) [PDF 1.66 M](3929)

Abstract:
This study investigated the mechanical effects of backfill construction in the orthogonal underpass section of a full-section complex open-cut interchange tunnel. The research was based on the small-clear-distance interchange tunnel project at the extension section of Jinzhou Avenue and Xingguang Avenue in Chongqing. A combined approach of numerical simulation and on-site in-situ test measurement was adopted to analyze the influence of different backfill materials, tunnel cross-section types, and complex construction procedures on the mechanical behavior of the underpass tunnel. The mechanical effects of backfill construction in the orthogonal underpass section were determined. The following findings are revealed: During the backfill construction process, the displacement and internal force of the underpass tunnel increase gradually, with abrupt changes occurring at the end stages of the overlaying tunnel construction and the lateral backfilling. Significant stress changes are observed at the haunches and footings of the underpass tunnel. Subsequently, replacing the interface fill with C15 concrete forms a stable composite system between the upper and lower tunnels, effectively inhibiting drastic stress fluctuations in these critical zones. The displacement and internal force of the underpass tunnel structure exhibit longitudinal maxima, extending from the intersection interface toward the adjacent section. Upon completion of construction, the peak values of displacement and internal force are transmitted from the intersection interface to the longitudinal adjacent section at y = 6 m.

33 Analysis and Control of Impact of Wide Waterway Excavation on Adjacent Bridge Pile Foundations

ZHANG Peisheng , QIAO Lyu , SHENG Jianchao , SHENG Haoxiang , LIU Hanchen , WANG Zhe

2025, 45(4):144-151. DOI: 10.14048/j.issn.1671-2579.2025.04.018

[Abstract](213) [HTML](321) [PDF 1.14 M](3908)

Abstract:
When excavating a waterway beneath an existing bridge, the pile foundations are subjected to unloading from excavation and the loading from the superstructure, which may lead to excessive displacement and potential safety hazards. Based on the underpass project of the Desheng Expressway Bridge along the Zhejiang section of the Beijing?Hangzhou Canal, this study established a three-dimensional finite element model (FEM) and combined it with field monitoring to investigate the impact of wide waterway excavation on adjacent bridge pile foundations and corresponding control measures. A novel combined control method involving a retaining wall with supporting piles and fully enclosed isolation piles was proposed. The results show that this combined support scheme exhibits the best control performance. The maximum horizontal displacement of the pile foundation is 7.43 mm, representing a 26% reduction compared to the deformation observed under the single-side isolation pile control scheme. When the insertion ratio of the retaining wall is not less than 1.2 and the thickness exceeds 0.8 m, a favorable deformation control effect is observed. Increasing the depth of isolation piles from 15 m to 27 m reduces the horizontal displacement induced by waterway excavation by 32.56%, although the rate of reduction diminishes with increasing depth.

34 Effect of Granite Machine-Made Sand Properties on Concrete Performance

WANG Jiliang , WEI Xinyuan , YU Bo

2025, 45(4):59-67. DOI: 10.14048/j.issn.1671-2579.2025.04.008

[Abstract](319) [HTML](860) [PDF 609.24 K](3919)

Abstract:
As an important stone resource in China, granite is widely used in the preparation of machine-made sand and other building materials due to its stable physical properties and favorable mechanical performance. In order to promote the better application of granite in machine-made sand for cement concrete, this paper analyzed the mineral composition, particle grading, and mica content of granite machine-made sand. It systematically summarized the influence of these characteristics on the mechanical properties, durability, and volumetric stability of concrete. The results show that the concrete performance declines with increasing mica and stone powder content in granite machine-made sand. Properly limiting their content can improve the mechanical properties and durability of concrete. Based on existing research, this paper also discusses problems such as excessive mica content in granite machine-made sand, providing a reference for its further application in cement concrete.

35 Research on Crack Identification Technology Based on Sobel + Matched Filter Joint Algorithm

WEN Yan , GUO Xiaoqian , TANG Youzhi , YANG Enhui , QIU Yanjun

2025, 45(4):33-41. DOI: 10.14048/j.issn.1671-2579.2025.04.005

[Abstract](280) [HTML](376) [PDF 1.12 M](3860)

Abstract:
To address the problems of hollow recognition results, high noise, and poor crack continuity in pavement crack identification using the Sobel algorithm, this paper proposed a joint algorithm combining the Sobel algorithm and matched filter for three-dimensional crack recognition of asphalt pavement. A matched filter in the form of a sine function was designed, and the matched filter was used to extract crack features from the results of the Sobel algorithm. The matched filter results were subjected to threshold filtering and connected domain analysis to effectively solve the hollow recognition problem, while also reducing noise and improving crack continuity. The test results show that the Sobel + matched filter joint algorithm can achieve 84.72% accuracy, 95.32% recall, and 89.44% F-value, and its performance is better than that of the Sobel algorithm and the Sobel + morphological closing joint algorithm.

36 Study on Chloride Ion Diffusion Behavior in Cracked Cement Mortar with High Fly Ash Content

LIU Yang , MAO Shengzhe , LU Naiwei

2025, 45(4):25-32. DOI: 10.14048/j.issn.1671-2579.2025.04.004

[Abstract](259) [HTML](357) [PDF 965.84 K](4013)

Abstract:
In order to explore the diffusion behavior of chloride ions in cracked cement mortar with high fly ash (FA) content, this study fabricated cement mortar specimens with different FA contents and crack widths by artificially prefabricating cracks. The chloride ion content in cracks was measured after natural soaking for 30 days and 60 days. The results show that the cracks accelerate the diffusion of chloride ions in cement mortar. The increase in the diffusion coefficient caused by 0.05 mm and 0.1 mm cracks is similar, while that caused by a 0.2 mm crack is significantly higher. After 30 days of soaking, the chloride ion content of the FA50 group decreases significantly with increasing depth beyond 10 mm. After 60 days of soaking, the chloride ion content of all specimens decreases significantly with increasing depth. When the fly ash content is not more than 40%, the chloride ion resistance of the mortar improves with increasing FA content. However, at 50% FA content, the chloride ion resistance sharply decreases. The relationship between crack width and the chloride ion diffusion coefficient follows a linear function, while the relationship between fly ash content and chloride ion diffusion coefficient can be described by a cubic function. A diffusion coefficient model considering both fly ash content and crack width has been established, and the validity of the model is verified by comparison between experimental values and fitted values.

37 Settlement Calculation Method for Composite Foundations Reinforced with Geo-Encased Stone Columns

LONG Jun , TAN Jingpeng

2025, 45(4):1-7. DOI: 10.14048/j.issn.1671-2579.2025.04.001

[Abstract](400) [HTML](322) [PDF 682.17 K](4303)

Abstract:
Geo-encased stone columns (GESCs), known for their cost-effectiveness and simple construction, are widely employed in the reinforcement of soft soil foundations in practical engineering, and the analysis of their settlement serves as a crucial foundation for the design process. However, existing research mainly focuses on experimental and numerical methods, with relatively limited progress in theoretical calculations. Based on the load transfer mechanism of GESC-reinforced composite foundations and the bulging deformation of the pile body within a certain depth of the pile top under vertical loading, the reinforced zone was divided into a bulging section and a non-bulging section, and the total settlement of the pile was regarded as the sum of the compression in these two sections. A settlement calculation formula for the GESC-reinforced composite foundation was derived with consideration of the deformation compatibility between the pile, the geosynthetic encasement, and the soil. To verify the feasibility of the proposed method, a practical engineering case was analyzed using the formula. On this basis, parameter analysis was conducted. The results show that the load–settlement curve obtained from the theoretical calculation closely matches that from the field test, confirming the feasibility of the proposed method. The settlement of the GESC-reinforced composite foundation decreases with the increase in encasement strength, encasement depth, soil cohesion around the pile, and area replacement ratio, but it increases with the increase in pile-soil stress ratio. Moreover, there exists an optimal encasement depth; when the encasement depth exceeds the optimal value, increasing the encasement length has little effect on reducing the settlement of the composite foundation.

38 Comparative Study on Differences in Asphalt Pavement Design between China and Southern Africa

WANG Qing , LIN Yangyang , YAN Hongxiang , ZHAO Bin , XIA Moxuan , LI Ning , SI Wei

2025, 45(3):240-250. DOI: 10.14048/j.issn.1671-2579.2025.03.029

[Abstract](360) [HTML](1349) [PDF 979.75 K](4776)

Abstract:
To facilitate the successful implementation of projects in the Southern Africa region and promote the application and internationalization of China’s standards, this study compared the asphalt pavement design systems, construction materials, design parameters, and structural design methods of both regions based on the main asphalt pavement design specifications currently in use in China and Southern Africa. The results show that among Southern African countries, South Africa has a comprehensive and widely applied standard system, while other Southern African countries adopt more varied and less theoretical standards. In contrast, China’s standard system is complete and highly practical. Due to differences in regional climates, the selection principles and mechanical requirements for construction materials differ between China and Southern Africa. There are also differences in the values and calculation methods of design parameters between the two regions. The pavement structure design methods in Southern Africa are more diverse, while China follows a predetermined process, with the main difference in the application of the comprehensive catalog method. The study summarized the main differences in standards between China and Southern Africa, providing reference to support the internationalization of Chinese standards and guide technical personnel in highway engineering projects in Southern Africa.

39 Research on Parametric Method of Highway BIM Based on Digital Delivery

LI Jinlong , WANG Xinnan

2025, 45(3):215-220. DOI: 10.14048/j.issn.1671-2579.2025.03.026

[Abstract](317) [HTML](635) [PDF 573.60 K](4756)

Abstract:
By analyzing the application points and the current situation of digital delivery in each stage of highway engineering construction, this study found that the lack of parameter management and definition in the modification and refinement process of building information modeling (BIM) source files at each stage led to difficulties in the splitting and refinement of BIM at each stage and even the need for reconstruction. To this end, a method for strengthening the overall planning of the whole life cycle was proposed. By clarifying the demand for model parameters according to the application points of each stage, a mechanism for parameter reservation and classification was developed. The parameters, including “overall description”, “local description”, “section description”, and “model element”, were proposed, and the use scenario and classification principle of each parameter were specified in detail, so as to address parameter redundancy and repeated definition caused by parameter reservation. The study shows that the method achieves a clear definition and orderly management of model creation parameters, improves the efficiency of model creation and modification and parameter use, and provides a solution for the parameterization of BIM application in the whole life cycle.

40 Intelligent Vehicle Path Tracking Control Integrating Road Adhesion Constraints

ZHANG Zhiguo , WANG Pu , ZHANG Xinglong , WANG Yan

2025, 45(3):199-207. DOI: 10.14048/j.issn.1671-2579.2025.03.024

[Abstract](376) [HTML](622) [PDF 1.18 M](4994)

Abstract:
In the field of fault-tolerant control for intelligent vehicle path tracking, the existing methods based on model predictive control (MPC) have limitations. They often assume that the vehicle model parameters are fixed and ignore the impact of dynamic changes in model parameters, which are caused by factors such as vehicle load changes and external environmental interference, on the path tracking accuracy. When the steering system fails, the front wheel steering angle commands calculated by MPC cannot be directly executed and need to be converted into yaw moment control. Although the existing sliding mode yaw moment control methods have strong robustness, the chattering problem affects the stability and execution effect of the control system. To address these issues, this paper proposed a fault-tolerant control scheme for path tracking that integrated MPC with online model parameter updating and adaptive sliding mode control. By updating the MPC model parameters online, the adaptability to the dynamic characteristics of the vehicle was improved. The adaptive sliding mode control was used to reduce the impact of chattering, and the driving torque distribution was optimized in combination with road adhesion constraints to achieve path tracking. The research results show that the tracking accuracy of the proposed algorithm is better than that of the traditional MPC algorithm, and it can achieve more accurate and stable path tracking control, providing new ideas and methods for the development of intelligent vehicle path tracking control technology.

41 Research on Influence of Shield Synchronous Grouting Parameters on Surface Deformation

LUO Xu , ZHANG Shaofeng , FU Helin , CAO Guiqian , ZHAO Chuanming

2025, 45(3):172-182. DOI: 10.14048/j.issn.1671-2579.2025.03.021

[Abstract](371) [HTML](679) [PDF 1.99 M](5188)

Abstract:
In order to determine reasonable grouting parameters, control surface settlement, and reduce the risk of excessive surface settlement caused by irrational synchronous grouting parameters, this study studied the shield tunnel project between maglev T2 station and maglev T3 station. A numerical simulation method was adopted to study the influence of grouting pressure, grouting volume, and the elastic modulus of slurry on surface deformation. The results show that the tunnel synchronous grouting has a significant effect on surface settlement control. A greater grouting pressure, equivalent grouting layer thickness, and elastic modulus of slurry mean a smaller surface settlement. As the three parameters increase, the variation range of surface settlement decreases and gradually stabilizes, indicating that the grouting effect tends to saturate. By considering both grouting effectiveness and economic efficiency, it is recommended to adopt a grouting pressure of 200?250 kPa, a grouting volume of 5.4 m³ per ring, and an elastic modulus of slurry between 200 and 250 MPa. The on-site application has verified the rationality of this parameter combination. The research provides a reference for grouting reinforcement in similar shield tunnel projects.

42 Research on Evaluation Index of Low-Temperature Semi-Circular Bending Test of Asphalt Mixtures

LYU Songtao , CHEN Qi , LU Weiwei , ZHAO Pei , WANG Jinping

2025, 45(3):25-36. DOI: 10.14048/j.issn.1671-2579.2025.03.004

[Abstract](669) [HTML](1276) [PDF 832.18 K](5532)

Abstract:
This article aims to investigate the low-temperature crack resistance performance of asphalt mixtures under different aging conditions and loading rates and select appropriate indicators to accurately characterize and quantify their performance. Based on the semi-circular bending test, the influence of different aging degrees (unaged, short-term aged, long-term aged for three days, and long-term aged for five days) and loading rates (50 mm/min, 5 mm/min, 0.5 mm/min, and 0.1 mm/min) on the low-temperature performance of asphalt mixtures was investigated. The evaluation effect and applicable range of five crack resistance performance indicators, namely fracture energy (G_f), stress intensity factor (K_IC), flexibility index (I_FI), crack resistance index (I_CRI), and balanced cracking index (I_BCI), were studied through variance analysis and variability analysis. The results indicate that aging significantly decreases the low-temperature performance of asphalt mixtures. After short-term aging, G_f decreases by approximately 26%, and as the degree of aging deepens, it continues to decrease at an attenuation rate of about 3%. As the loading rate increases, the evaluation effectiveness of I_FI and I_BCI deteriorates. Conducting the semi-circular bending test at a loading rate of 0.1 mm/min provides a more comprehensive evaluation of the low-temperature performance of asphalt mixtures. The results of variance analysis and variability analysis indicate that G_f and I_CRI can significantly characterize the influence of aging and loading rate on the low-temperature performance of asphalt mixtures. The variability of I_FI and I_BCI is significantly higher than that of the other three indicators. Hence, it is recommended to adopt G_f and I_CRI from the semi-circular bending test as more reasonable indicators for evaluating the low-temperature performance of asphalt mixtures.

43 Overview and Prospect of Engineering Practice of Permanent Floating Bridge Structures

ZENG Zhuo , ZHENG Honggang , XIANG Sheng , CHENG Bin

2025, 45(2):264-272. DOI: 10.14048/j.issn.1671-2579.2025.02.030

[Abstract](757) [HTML](2243) [PDF 1.32 M](6377)

Abstract:
As the bridge construction goes forward to the deep-water environments, the permanent floating bridge structures have attracted more and more attention from international scholars. The project cases of worldwide representative permanent floating bridges were presented. The structural systems of the built permanent floating bridges were summarized. The research and application advances regarding the mechanical features, the construction process, and the special configurations of the permanent floating bridges were introduced. Finally, from the perspectives of the engineering economy and environment applicability, the development prospect of permanent floating bridges was analyzed. The research shows that the permanent floating bridge structure has been applied in engineering around the world and has two types of structural systems, which are the continuous pontoon system and the discrete pontoon system. The permanent floating bridges adopted in deep-water environments have shown superior engineering economy. Based on further research and verifications, the permanent floating bridge structures can be applied in deep-water crossing projects.

44 Preparation and Performance Study of Asphalt Modified by Polyphosphoric Acid/Desulfurized Crumb Rubber

YUAN Jianbo , YIN Chan , FENG Xinjun , YU Fan

2025, 45(2):90-98. DOI: 10.14048/j.issn.1671-2579.2025.02.010

[Abstract](658) [HTML](1478) [PDF 1.13 M](6370)

Abstract:
To improve the comprehensive performance of desulfurized rubber asphalt, the asphalt was modified by using desulfurized crumb rubber and polyphosphoric acid. Based on the response surface method, the preparation parameters of the composite modified asphalt were optimized. In addition, four types of modified asphalt were prepared by using ordinary rubber, desulfurized rubber, composite polyphosphoric acid/ordinary rubber, and composite polyphosphoric acid/desulfurized crumb rubber. Their performance was compared. The results show that compared with ordinary rubber asphalt, the asphalt modified by desulfurized rubber has lower viscosity, significantly lower mixing and compaction temperatures, and more stable compatibility between rubber powder and asphalt in the system, which facilitates the preparation, storage, transportation, and construction process of rubber asphalt. In terms of road performance, the high-temperature deformation resistance of asphalt modified by polyphosphoric acid/desulfurized crumb rubber shows a level similar to that of ordinary rubber asphalt, and its creep ability is more excellent in low-temperature environments. Among the four types of modified asphalt, the asphalt modified by polyphosphoric acid/desulfurized crumb rubber has more obvious performance advantages and is suitable for promotion and application.

45 Review of Intelligent Construction Development of Highway Infrastructures and Its Prospects

ZHENG Jianlong , CHEN Mengjie , LIU Chaochao

2025, 45(2):1-20. DOI: 10.14048/j.issn.1671-2579.2025.02.001

[Abstract](1925) [HTML](3600) [PDF 1.98 M](7629)

Abstract:
With the rapid advancement of intelligent construction, intelligent development of highway infrastructures has emerged as a key research focus. This paper focused on the whole life cycle of intelligent construction of highway infrastructures and provided a comprehensive analysis of its current status, challenges, and future directions. The discussion was organized into five key areas: intelligent material design, intelligent structural design, intelligent construction management, intelligent inspection and monitoring, and intelligent maintenance management. In intelligent materials, the paper explored the application and recent advancements of the pavement material genome program. Regarding intelligent structures, the role of computer-aided design (CAD) in pavement structural design was emphasized. For intelligent construction management, the importance and impact of intelligent monitoring systems throughout the pavement construction process were examined. In the area of inspection and monitoring intelligence, the current development and potential of embedded sensing units in pavements were discussed. Finally, in intelligent maintenance management, the paper evaluated the effectiveness and potential of ground-penetrating radar (GPR) non-destructive testing technology in highway quality assessment. The findings reveal that although intelligent construction technologies have made progress in highway infrastructures, challenges remain, including incomplete technical systems, limited data integration, and high technical costs. The future of intelligent highway infrastructure construction should focus on standardization, technological innovation, and cross-domain collaboration, so as to establish an efficient, safe, and sustainable intelligent highway infrastructure system.

46 Mechanism of Mud Pumping on Plateau Highway under Traffic Loads and Its Treatment Strategy

ZHANG Junhui , CHEN Zhide , GAO Feng , NA Qicai , MA Pengfei , XIAO Lin

2025, 45(1):1-10. DOI: 10.14048/j.issn.1671-2579.2025.01.001

[Abstract](917) [HTML](1276) [PDF 1.65 M](7010)

Abstract:
The dynamic hydraulic response and particle migration of subgrade structures under traffic loads are fundamental to reveal the formation and development mechanisms of mud pumping. The driving mechanism of fine particle migration in the mud pumping state was explored by conducting laboratory tests on layered gravel-sandy silt columns under dynamic loads. The results show that the slurry sloshing causes alternating positive and negative pressure gradients within the gravel layer. This oscillating pressure gradient enhances the pore permeability in the underlying sandy silt layer, providing the necessary hydrodynamic conditions for fine particle migration. Fine particle migration increases the slurry turbidity to a stable value. Upon the removal of dynamic slurry loading, the fine particles quickly settle and fill the gravel pores, forming a muddy interlayer, which significantly reduces the vertical permeability of the gravel-sandy slit column. Based on the engineering practice of treating mud pumping on the G0615 Dema Expressway (Huashixia to Jiuzhi Section) in Qinghai Province, it was found that an important driver for mud pumping formation is the infiltration of rainfall and snowmelt water through the asphalt surface layer, and this water can even form “water pockets” within the subbase. When vehicles pass, the deformation of the pavement structural layers causes the slurry in the pores of the water-stable base layer to be squeezed upward through cracks, leading to continuous erosion and damage to the gravel materials. By considering construction difficulty, economic costs, and the ecological environmental protection requirements of the Qinghai?Xizang Plateau, different treatment methods such as grouting repair and sealing, as well as milling and sealing were adopted, respectively based on the severity and level of the hazard. These methods have played a positive role in sealing and reinforcing the water-stable base layer and reducing pavement permeability. The research provides valuable insights for understanding the development patterns of mud pumping, effectively enhancing the treatment capabilities and promoting high-quality maintenance of plateau highways.

47 Emergency Vehicle Dispatching Model Considering Demand Urgency and Delivery Fairness

LONG Kejun , LIU Jia , GAO Zhibo , CHEN Suqian , ZHANG Zhonggen

2024, 44(6):251-258. DOI: 10.14048/j.issn.1671-2579.2024.06.029

[Abstract](888) [HTML](1684) [PDF 1.25 M](7418)

Abstract:
In emergency vehicle dispatching after unexpected events，it is crucial to prioritize critical nodes with high demand urgency while minimizing excessive delivery delays at other nodes to prevent secondary impacts.On this basis，this study developed an emergency vehicle dispatching model that considered demand urgency and delivery delay fairness.Firstly，the entropy weight-TOPSIS method was used to calculate the demand urgency for each node，and a delivery delay balance index was introduced to minimize disparities in delivery delays between nodes.Secondly，a multi-objective optimization model was established with total delivery time，overall cost，and delivery delay balance as objectives，while considering constraints such as inventory levels at distribution centers and route continuity.Finally，the K-Means algorithm and the Clarke-Wright （CW） saving algorithm were employed to partition the sub-networks，and an improved ant colony algorithm incorporating a variable neighborhood local search was applied.The results indicate that compared with the basic model，the proposed model reduces the average and maximum delivery delays at nodes with high demand urgency by 25.26% and 22.98%，respectively，while increasing the delivery delay variance by 34.30%.Compared with a model considering only demand urgency，the proposed model decreases the average delivery delay，maximum delivery delay，and delivery delay variance at nodes with high demand urgency by 10.79%，20.26%，and 40.57%，respectively.These findings demonstrate that the proposed model effectively balances priority for critical nodes with fairness for standard nodes.

48 Lessons Learned from 60 Years of Pavement Trials in Continental Climate Regions of Canada and Future Perspective

WANG Di , LI Jingxiao , REN Xueyuan , ZHANG Fan , YUAN Dongdong

2024, 44(5):284-300. DOI: 10.14048/j.issn.1671-2579.2024.05.032

[Abstract](1516) [HTML](2855) [PDF 1.53 M](8041)

Abstract:
During the early 1960 s，Canadian road authorities began using stiffer asphalt to address the issue of early rutting in the wheel track zone of asphalt pavements，which was caused by the growing traffic volumes.Pavements constructed with stiffer asphalt commonly exhibit evenly spaced transverse cracks due to the significant internal stresses caused by low temperatures and the inadequate resistance of the asphalt to cracking under such conditions.Research conducted on asphalt pavements with cracks caused by low temperatures has verified the significant impact of asphalt ’s consistency，temperature sensitivity，phase uniformity，and durability.In order to tackle the difficulties presented by the utilization of modified asphalt in the current asphalt performance evaluation system，the Canadian asphalt pavement test section during the 1990 s was used to examine and assess the dependability of the U.S.Superpave ? specification.The results reveal that blown asphalt exhibits inadequate durability，while polymer modifiers only improve the durability of soft asphalt.In the early 21st century，the Ontario municipality commissioned studies on asphalt pavement test sections to enhance the current asphalt performance test specifications.These studies mainly considered the occurrences of phase separation，phase transformation，and thermally reversible aging （gelation） of asphalt，as well as the impact of polymers and fibers on the durability of asphalt.The results find that using different types of colloids （sol，gel，and sol-gel ） in the same Superpave level can result in asphalt pavements with benefit/cost ratios varying by up to 2?3 times.By assessing and choosing the appropriate type of asphalt，such as Alberta oil sand asphalt （sol），the service life of asphalt pavements can be prolonged.Compared with polymer-modified asphalt with high content，more oxidized recycled asphalt，or asphalt with higher wax content （gel），Alberta oil sand asphalt has lower wax content.The service life of asphalt pavements can be further improved by incorporating small quantities of polymer or fiber modification.Improved test specifications for asphalt cement will help save costs and meet the maintenance needs of 25 million km of asphalt pavements under global climate change.On the basis of summarizing the research of asphalt pavement trials in Canada in the past 60 years，new prospects and suggestions on the future research content and key technical problems of pavements in cold areas are put forward，which can provide a reference for future research.

49 Review of Snow and Ice Melting Techniques for Road and Bridge in Cold Regions

TANG Liyun , SHAO Haitao , TANG Huaming , QIU Peiyong , DU Xiaoqi , ZHANG Lei , PENG Hui

2024, 44(5):25-38. DOI: 10.14048/j.issn.1671-2579.2024.05.003

[Abstract](1566) [HTML](4204) [PDF 1.95 M](9196)

Abstract:
Snow and ice melting of road and bridge surfaces is crucial for traffic safety，but current research on snow and ice melting techniques mainly focuses on engineering effects and technical evaluation，without the analysis and elaboration from the perspective of their mechanisms.To this end，based on the different mechanisms，this study divided snow and ice melting techniques into three types and summarized them：passive deicing，active deicing，and energy utilization deicing.This study systematically evaluated the advantages and disadvantages of traditional deicing methods such as deicing agents and mechanical deicing，analyzed two active deicing techniques，namely inhibitive freezing pavement and phase change material pavement，discussed the environmental-friendly method for road deicing by using phase change materials，and introduced the mechanisms of different energy utilization deicing techniques.This study analyzed the existing road deicing techniques，their actual application effects，and existing problems，to provide foundational support for the research of snow and ice melting on roads and bridges in cold regions.

50 Progress and Prospects of Road Engineering Disease Treatment Technology in Permafrost Regions

GAO Feng , ZENG Xianzhang , ZHONG Wenhua , HUANG Shengyong , ZHANG Junhui

2024, 44(5):1-16. DOI: 10.14048/j.issn.1671-2579.2024.05.001

[Abstract](1807) [HTML](6526) [PDF 2.09 M](9164)

Abstract:
Freeze-thaw disasters are key issues affecting the service performance and operational safety of road projects in permafrost regions.Under the combined influence of warming and humidification of the permafrost environment and engineering thermal effects，the degradation of permafrost is accelerating，exacerbating the risk of road freeze-thaw diseases.Roads in these regions are more frequently maintained and repaired to ensure service performance，with a service life lower than designed.Therefore，deepening the understanding of the disaster mechanism of road geotechnical structures and strengthening the study on engineering disease treatment technology are of great significance in promoting the construction and maintenance of high-quality and high-grade highways in frozen regions.This paper first expounded on typical types of diseases of roads in frozen regions and explored the formation mechanism and evolution mechanism of the diseases based on internal and external factors，such as frozen soil properties，climate and topography，road materials，and structures.Then the current situations and development of disease treatment technology for roads in frozen regions were discussed according to the different treatment principles.Studies have shown that freeze-thaw subsidence，cracking and pitting，and mud pumping are the main diseases on these roads.The causes include frozen soil properties，climate and topography，road materials and structures，and other factors，with subsidence and deformation induced by soaked and softened foundations due to freeze-thaw water particularly significant.Therefore，the line selection should be fully optimized in road planning.According to the different principles of treatment of in-service road diseases，the existing treatment technologies can be divided into three categories：measures of passively cooling subgrade，measures of actively cooling subgrade，and measures of enhancing frozen soil foundation.Among them，the study and application of the former two categories are relatively systematic and comprehensive，and the subsequent focus should be on improving temperature control performance and the combined use of multiple treatment measures.The frozen soil foundation enhancement technology，with good application prospects and promotion value，is currently under exploration and tests，requiring further study in the design method and construction technology.Moreover，as for the disease treatment technology，the performance of in-service roads should be emphasized and the evaluation of the treatment effects should be strengthened.To reduce the risk of road diseases in frozen regions and ensure the safety of plateau transportation，this study points out that the research direction and focus should be an integrated disease treatment technology centered on a comprehensive chain of “foundation enhancement-subgrade temperature control-integrated drainage ”.

51 Comparison of Chinese ， Ame rican， and Bangladeshi Criteria for Liquefaction Judgment o f Fine‑Grained Soil

WU Zi

2024, 44(4):263-268. DOI: 10.14048/j.issn.1671-2579.2024.04.031

[Abstract](1051) [HTML](2062) [PDF 1.30 M](9172)

Abstract:
The criteria for liquefaction judgment of fi ne-grained soil in current seismic design codes of China，the United States，and Bangladesh are quite different.In order to propose the judgment criteria for engineering application and Chinese code revision，this paper compared the judgment processes and criteria of the three countries.After analyzing the formation process，based on the application of the criteria for liquefaction judgment of 168 fine-grained soil samples collected in Dhaka，Bangladesh and surrounding cities，the rationality of each judgment process and criteria was evaluated comprehensively.Finally，a set of judgment processes and result criteria for fine-grained soil liquefaction integrating all criteria were put forward.

52 Construction of Carbon Emission Monitoring and Management System for Commercial Vehicles

CHANG Zheng , SONG Yan , JI Meichen , LIU Yuqing , WANG Jing

2024, 44(4):255-262. DOI: 10.14048/j.issn.1671-2579.2024.04.030

[Abstract](588) [HTML](1019) [PDF 1.12 M](9036)

Abstract:
To construct a comprehensive carbon emission monitoring and management system for commercial vehicles，firstly，this article described the background and significance of carbon emission monitoring and management of commercial vehicles and summarized the research in relevant fields in China and abroad.Then，this article expounded on the carbon emission monitoring system for commercial vehicles，which covered three major levels：monitoring target layer，monitoring implementation layer，and monitoring summary layer，so as to achieve comprehensive and accurate carbon emission monitoring.Finally，combined with the carbon emission monitoring data of commercial vehicles，this article put forward a carbon emission management system for commercial vehicles based on data information，including carbon emission data sharing and opening，data management and analysis，management strategies and measures，as well as evaluation and optimization，so as to enhance the effective carbon emission management of commercial vehicles.

53 Fume Emission and Environmental Impact Assessment in Fresh Asphalt Tunnel Construction Site

DENG Wenti , ZOU Guilian , ZHANG Yuan , YU Liang , XIE Huiduan

2024, 44(4):210-216. DOI: 10.14048/j.issn.1671-2579.2024.04.025

[Abstract](1105) [HTML](1651) [PDF 1.50 M](9053)

Abstract:
In view of the random monitori ng of fum e emission in asphalt pavement construction sites，combined with the engineering application of fresh asphalt in the construction of hot-mixed and hot-spread asphalt pavement in large and long tunnels for fume emission reduction，the fume collection and evaluation method of asphalt pavement construction sites were studied，and the emission reduction effect of fresh asphalt was evaluated.The Summa tanks were used to collect the asphalt fume at different positions of the paver，and the asphalt fume was quantitatively analyzed by gas chromatograph-mass spectrometer （GC-MS）.The results show that compared with the non-fresh asphalt from the same source，the fresh asphalt reduces the total mass concentration of volatile organic compounds （VOCs） in the asphalt fume at the edge of the paver，the middle of the paver flank，and the upper position of the paver by 57.0%，22.6%，and 27.4% during pavement construction，respectively.The fresh asphalt mixture reduces the total mass concentration of class 1 and 2 carcinogens by 62.3% at the edge of the paver during construction，and the odor intensity is only about 1/3 of the non-fresh asphalt mixture.The study suggests that the total mass concentration of VOCs，the total mass concentration of carcinogens exceeding class 2，and the odor intensity at the edge of the paver should be used as the key environmental impact assessment indexes for fume emission monitoring in the asphalt pavement construction site.

54 Deformation and Damage Characteristics of a Newly Operated Tunnel Caused by above Foundation Pit Construction

LIU Jiqiang , ZHU Min , HAO Kun , CHEN Dengwei , CHEN Xiangsheng

2024, 44(3):202-210. DOI: 10.14048/j.issn.1671-2579.2024.03.023

[Abstract](1031) [HTML](921) [PDF 1.97 M](8862)

Abstract:
The construction of foundation pits in granite residual soil layers is prone to causing upheaval deformation and structural damage in shield tunnels below.Based on the engineering case of a newly operated metro tunnel collinear with the above long-distance deep foundation pit in Shenzhen,a three-dimensional finite element model was established to investigate the variation law of the heave and horizontal convergence of the shield tunnel caused by the deep foundation pit excavation.The correlation between the longitudinal stress of the lining structure and the damage was analyzed.The results indicate that the tunnel deformation caused by foundation pit unloading is primarily vertical heave,accompanied by slight section deformation.After adopting the jump excavation method and the stripped soil reinforcement above the tunnel crown,the average tunnel heave is reduced by 14.4%,and the lateral displacement of the envelop enclosure is reduced by 49.1%.The shield tunnel damage caused by the above unloading is mainly the spalling at the circumferential joints of the tunnel crown.The reason is that the compressive shear cracks occur and expand on the intrados of the circumferential joints of the tunnel crown under the combined action of bending moment and shear.

55 Experimental Study on Road Performance of Resin Elastomer for Seamless Expansion Joints of Bridges

ZHOU Wei , SHENG Liang , GAO Qin , ZHANG Hui , ZHAO Menglong

2024, 44(3):123-128. DOI: 10.14048/j.issn.1671-2579.2024.03.014

[Abstract](841) [HTML](1474) [PDF 1.24 M](8722)

Abstract:
Seamless expansion joint is a new type of bridge expansion joint.In order to study the road performance of resin elastomer for seamless expansion joints,the feasibility of applying resin elastomer to small and medium displacement expansion joints of bridges was explored.Through the rutting test at 60 ℃, low-temperature beam bending test at ?10 ℃,dynamic modulus test,Poisson's ratio test,and overlay test (OT),the high and low temperature stability,deformation performance,and fatigue crack resistance of the resin elastomer were compared.The test results show that the dynamic stability of the resin elastomer at 60 ℃ is more than 31 000 times/mm,and the bending strain at low temperature of ?10 ℃ exceeds 43 000 × 10?6.Under different temperatures and load conditions,the dynamic modulus is 10?12 MPa,and the Poisson's ratio of tension/compression is 0.03?0.05.The fracture energy of OT is 59% higher than that of the TST elastoplastic body.The resin elastomer for seamless expansion joints of bridges has excellent high and low temperature performance,and it is insensitive to temperature and load frequency.Therefore,it is a material with a low Poisson ’s ratio and strong fatigue crack resistance and can better meet the driving and deformation requirements of small and medium displacement expansion joints of bridges.

56 Review on LCCA and LCA Methods for Pavement Based on BIM

YOU Shengjie , HU Yonggang , LIU Xinsuo , ZHENG Xiaoyan

2024, 44(3):85-94,103. DOI: 10.14048/j.issn.1671-2579.2024.03.010

[Abstract](1410) [HTML](1832) [PDF 1.21 M](9012)

Abstract:
Currently,life cycle cost analysis (LCCA ) and life cycle assessment (LCA ) methods are commonly used to assess the economic and environmental impacts of pavement during the whole life cycle.However,there are drawbacks in the application of LCCA and LCA methods,such as a large amount of data and multiple data categories,which lead to a tedious evaluation process.In view of this,some scholars have tried to combine building information modeling (BIM ) with LCCA and LCA methods to optimize the evaluation process.In the pavement field,the combination of LCCA and LCA with BIM is still in its infancy,lacking a summary of relevant research results.Therefore,this paper summarized the research on LCCA,LCA,and LCCA-LCA methods for pavement,as well as their combination with BIM to explore the existing problems and challenges.It is found that the application of BIM can optimize the LCCA and LCA processes and realize the dynamic coordination of design and evaluation.However,the low integration degree and the lack of unified data format standards between modeling software and evaluation software hinder the application and development of BIM.