Volume 46, Issue 1 (2026)
Subgrade Engineering
Review of Research on Ecological Protection Technologies for Highway Subgrade Slopes
ZHANG Rui, LI Wangjun, GAO Qianfeng, CHEN Bo, GONG Yi, HOU Yudong, and ZHANG Xiwei
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.001
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.
Slope Reliability Analysis Based on IWOA-SVM
WANG Jinfeng, FAN Shengtong, and XIE Haibo
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.002
To address the difficulties traditional slope reliability calculation methods face in considering the uncertainty among multiple variables and the large computational burden, this paper proposed a slope reliability analysis method based on the improved whale optimization algorithm (IWOA) and support vector machine (SVM). First, the basic theory of SVM was described. The differential mutation strategy and adaptive weight factor were introduced to improve the whale optimization algorithm (WOA), and the performance of the IWOA was tested. Then, the key parameters of SVM were optimized based on the IWOA, and the slope reliability analysis model was constructed. Finally, by taking a slope with an explicit performance function as Example 1, the reliability index of the slope was calculated based on IWOA-SVM. The results were compared with those of existing reliability methods, and the sensitivity of random variables was analyzed. By taking a general homogeneous slope without an explicit performance function as Example 2, the calculation results of IWOA-SVM, Monte Carlo simulation (MCS), and first order reliability method (FORM) were compared. The results show that the slope reliability analysis model based on IWOA-SVM has good fitting performance in both the global scope and the scope of checking points; especially within the scope of checking points, the fitting accuracy is higher. The slope reliability index obtained by IWOA-SVM is very close to that obtained by MCS, validating the accuracy of this method. IWOA-SVM is also applicable to slopes without explicit performance functions, validating the universality of this method. Compared with the MCS method, the IWOA-SVM method avoids a large number of samplings and significantly improves computational efficiency. Slope reliability is positively correlated with the internal friction angle φ and cohesion c and negatively correlated with the tensile crack depth z, the water-filled depth coefficient of tensile cracks iw, and the horizontal seismic acceleration coefficient α. The random variable with the greatest influence on slope reliability is α, followed by iw, c, and φ, while z has the least influence.
Numerical Simulation Analysis of Stiffness Reduction Effect for Pipe-Combination Piles
CHEN Xiangyi, WANG Yanhua, ZHOU Dequan, WANG Chuangye, and HU Hanqing
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.003
In order to investigate the mechanism of bending stiffness reduction in the pipe-combination (PC) piles, Abaqus was employed to establish a numerical finite element model considering the interaction between lock joints. The variation in bending stiffness of PC piles was analyzed under different factors such as lock joint friction coefficient, pile head constraints, and combination methods, and the influence of neutral axis displacement on the stiffness of PC piles was analyzed through theoretical derivation. The results show that increasing the friction force between lock joints can effectively mitigate the bending stiffness reduction effect of PC piles. When the lock joints are fully welded, the stiffness reduction coefficient of PC piles increases to 0.83. The presence of lateral support at the pile head can significantly reduce the pile's lateral displacement and the stiffness reduction effect. The bending stiffness of PC piles decreases with an increase in the number of steel sheet piles inserted between the pipe piles, resulting in a smaller stiffness reduction coefficient. For engineering applications, it is suggested that the steel sheet piles should be arranged in opposite directions; the lock joints should be welded, and lateral support should be provided. Furthermore, it is recommended to match one steel pipe pile with one steel sheet pile, or use C 9, C-T, or L-T type lock joints to satisfy soil retaining and water isolation requirements while ensuring foundation pit safety.
Stability Analysis of Expansive Soil Slope Excavation in Overlying Rock Layers in Alpine Regions
ZHANG Dawei, MOU Chao, CUI Guangyan, LI Xiaoshuang, DING Yuanyuan, ZHANG Wei, and QIAO Jiachen
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.004
Based on the slope project of Zhangbei‒Shangyi Expressway, indoor tests were conducted to obtain the mechanical parameters of rock and soil layers, variation law of shear strength of expansive soil with different number of cycles in dry-wet-freeze-thaw conditions was studied, and variation characteristics of mechanical parameters were revealed to deeply analyze the stability of expressway cutting slope excavation in the condition of expansive soil in overlying rock layers in alpine regions. By adopting MIDAS/GTS (SRM) software, the original slope excavation and support scheme of increasing the flattened down slope were simulated, and the improvement scheme of reducing the load by eliminating the cubic meter and installing anti-slide piles was put forward, with the stability compared and analyzed. The results show that increasing the cycle number decreases the cohesion and angle of internal friction of expansive soil, with the first cycle having the most prominent reduction effect. Additionally, the cohesion and angle of internal friction are no longer sensitive after five cycles. The dry-wet-freeze-thaw and freeze-thaw effects have the greatest influence on the degradation of cohesion and the angle of internal friction, respectively. Under the overlying rock layers of expansive soil in alpine regions, the excavation unloading, degradation of expansive soil layers in contact with water, and freeze-thaw-dry-wet-coupling effect are the main factors resulting in the reduction of mechanical parameters of soil layers, prominent deformation of side slopes, and side slide collapse. Compared with the measures of slowing down the side slopes and reducing the load by eliminating the cubic meter, anti-slide piles show the most significant effect on controlling the side slope displacement.
Pavement Structure and Materials
Review of Study on Performance of Interlayer Bonding of Concrete Bridge Pavements
LYU Songtao, YANG Dingling, LU Weiwei, and DUAN Haihui
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.005
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.
Effect of Calcined Constructio n Spoil on Mechanical and Shrinkage Proper ties of UHPC
CHANG Cheng, WANG Xufu, WANG Yu, ZHONG Yuan, ZHANG Bofa, and TANG Yuxiang
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.006
This study utilized calcined construction spoil from Guangdong as a partial replacement for cement in the preparation of green ultra-high-performance concrete (UHPC). The effects of different calcined construction spoil content levels (0%, 5%, 10%, 15%, and 20%) on the workability, mechanical property, and shrinkage behavior of UHPC were investigated. Additionally, a life cycle assessment (LCA) was performed to quantify carbon emissions. The results indicate that the incorporation of calcined construction spoil improves the fluidity of the UHPC mixture. At the age of 3 days, the effect of calcined construction spoil on the mechanical properties of UHPC is limited. However, at 7 and 28 days, the compressive strength and flexural strength of UHPC show a trend of initially increasing and then decreasing with the increase in calcined construction spoil content, reaching maximum values of approximately 172.5 and 32.7 MPa at a 10% replacement level, respectively. The use of calcined construction spoil reduces the shrinkage of the UHPC matrix, particularly the autogenous shrinkage. Within the range of dosages studied, the partial replacement of cement with calcined construction spoil can reduce the carbon emissions of UHPC by approximately 11.3%.
Influence Mechanism of Admixtures on Strength of High Volume Fly Ash
LIU Yang, YANG Jie, YUAN Heping, LU Naiwei, and LUO Dong
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.007
This paper investigated the effects of nano-silica (NS), metakaolin (MK), and silica fume (SF) as supplementary cementitious materials on the compressive strength of mortar with high volume fly ash. Through a comparative analysis, the study established the influence patterns of single and combined additions of various cementitious materials on the compressive strength of the mortar. The microstructure and reaction mechanisms of the specimens were analyzed using methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TG). The results indicate that when NS or MK is used alone, the compressive strength of fly ash mortar at 28 days increases and then decreases with the increasing dosage. In contrast, when SF is used alone, the compressive strength of the fly ash mortar increases with the increase in SF content. When NS is combined with MK or SF, both exhibit good synergistic effects, and the strength of mortar with various mix ratios shows a certain improvement compared to the single addition groups at the same curing age. Whether used in combination or alone, NS, MK, and SF all effectively enhance the compressive strength of mortars with high volume fly ash. Among them, the combination of 5% NS and 15% SF (N5S15) achieves the highest compressive strength, exceeding that of the pure cement mortar group at 7 days, 14 days, and 28 days, with a maximum strength of 42.32 MPa at 28 days. Microscopic test results indicate that the increase in strength of the mortar specimens is closely related to the hydration products within the specimens, with higher strength specimens containing a richer array of hydration products such as hydrated calcium silicate and hydrated calcium aluminate.
Aggregate Crushing Behavior of Asphalt Mixture Incorporating Waste Glass and Its Effect on Performance
LI Yiming, LI Xinze, CHENG Peifeng, CHEN Xiule, and GUO Shuang
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.008
Utilizing crushed waste glass as a substitute for natural aggregate in asphalt mixtures presents significant economic potential and environmental protection advantages. However, compared with natural aggregates, the low-strength glass aggregates are prone to crushing under load, necessitating an investigation into the crushing behavior of glass aggregates under load and its influence on the performance of asphalt mixture. In this paper, the crushing behavior of the mixture was analyzed through rotational compaction test and digital image processing technology, using the aggregate crushing index of the mixture as an indicator to evaluate its road performance. The results show that as the number of compaction times and the proportion of glass aggregates increase, the aggregate crushing index of the mixture rises, leading to more pronounced crushing phenomena in glass asphalt mixtures, primarily due to the crushing of glass aggregates. By extracting the void information from the cross-section of the glass asphalt mixture specimen, it is found that the void number and the void area in the mixture decrease with an increase in the number of compaction times and the proportion of glass aggregates. Within a certain range of glass content, the crushing behavior of glass aggregates significantly impacts the road performance and durability of the asphalt mixture, while having no noticeable effect on skid resistance. As the aggregate crushing index of the glass asphalt mixture increases, the high-temperature performance of the mixture deteriorates; when the crushing index is greater than 4.45%, its resistance to high-temperature deformation does not meet the specification requirements. Conversely, when the crushing index is below 3.25%, the low-temperature cracking resistance, water stability, and durability of the mixture are improved, but exceeding this threshold adversely affects the mixture's low-temperature cracking resistance, water stability, and durability. Therefore, it is suggested that the glass content in glass asphalt mixture should not exceed 20%, and the number of rotary compaction times should not exceed 150.
Research on Properties of Glass Sand Shotcrete
GAO Qingshui, MA Kaikai, GUO Lingz hi, LIU Hongtian, HUANG Shimei, HAN Song, and HU Peng
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.009
In order to study the effect of glass sand on the properties of shotcrete, shotcrete was prepared by using glass sand instead of natural sand. Through the compressive strength test, splitting tensile strength test, drying shrinkage test, and chloride ion erosion test, the effects of different amounts of glass sand on the strength, shrinkage, and durability of shotcrete were analyzed. The results show that:① The 50% glass sand replacement rate has the least effect on the strength of shotcrete, and its 28-day compressive strength is only reduced by 2.19% compared with the control group; ② Glass sand can improve the drying shrinkage rate of shotcrete. As the replacement rate of glass sand increases from 10% to 50%, the 28-day drying shrinkage rate of shotcrete decreases by 27.7%; ③ When the replacement rate of glass sand is 50%, the compressive strength loss rate of shotcrete after 120 d erosion is reduced by 17.65%. This study provides theoretical support for the application and promotion of glass sand in shotcrete and provides a solution for the resource utilization of waste glass.
Long-Term Performance of Recycled Asphalt Mixtures with Various FRAP Contents
ZHANG Yongyuan, MENG Weihong, YANG Xin, WU Hao, ZHAN Yiqun, and XU Haoda
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.010
At present, in the refined recycling and utilization of asphalt pavement, the utilization rate of fine recycled asphalt aggregates (FRAP) is much lower than that of coarse recycled asphalt aggregates (CRAP). This not only leads to resource waste but also limits the larger-scale application of RAP in recycled asphalt mixtures. Therefore, this study systematically investigated the impact of FRAP content on the long-term performance of recycled asphalt mixtures through the semi-circular tensile (SCT) tests. Based on the energy evolution laws of strain energy (elasticity and plasticity) and surface energy during material fracture processes, corresponding improvement measures were proposed according to the influence patterns identified. Furthermore, the feasibility of applying a large proportion of FRAP in recycled asphalt mixtures was demonstrated. The research results show that at low temperatures, as the FRAP content increased from 0% to 12%, the strain energy of the recycled asphalt mixture decreases by 39.2%. This indicates a sharp decline in the energy required for cracking, making it more susceptible to the formation of cracks. Additionally, the surface energy of the recycled asphalt mixture decreases by 71.3%, resulting in less energy required for crack propagation, which suggests that cracks are more likely to spread to a completely fractured state. Therefore, the maximum allowable FRAP content should be tested before use in extremely cold regions. At medium temperatures, with the increase in FRAP content, the strain energy of the recycled asphalt mixture drops sharply, with the majority of the energy being used for crack propagation. The cracking issue in recycled asphalt mixtures is more serious than that in conventional asphalt mixture. It is recommended to further reduce the grade of new asphalt or increase the content of regenerant while ensuring the high-temperature stability of the recycled asphalt mixture. The increase in FRAP content resulted in a further rise in the content of aged asphalt, leading to a mismatch in the deformation of the recycled asphalt binder and the stress concentration at the interface between the old and new asphalt. As a result, the fatigue life of the recycled asphalt mixture decreases by nearly 53% compared to that of mixtures without FRAP, and the rate of fatigue damage accumulation increases by 26.7%. The deterioration of fatigue performance is directly related to the increase in FRAP content. The use of a stepwise mixing method, where a portion of new asphalt is mixed with FRAP first, enhances the bonding performance between the new and old asphalt within the recycled asphalt mixture, resulting in a certain degree of improvement in the fracture fatigue performance of the recycled asphalt mixture.
Research on Compaction Characteristics and High Compaction Paving Technology of AC-13 Steel Slag Asphalt Concrete
WANG Yaping, YI Long, ZHENG Wenzhang, GU Meng, and WANG Juyang
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.011
To solve the problems of difficult compaction and high porosity of steel slag asphalt concrete, a rotary compactor was used to analyze the compaction characteristics of steel slag asphalt concrete from the aspects of gradation, compaction temperature, and compaction energy index. By conducting orthogonal experiments in the test section, the influence of paving speed, vibration frequency of the screed, and vibration compaction rate of the hammer on the compaction degree of paving was analyzed, and the paving construction parameters of steel slag asphalt concrete were optimized. Research shows that the use of a median finer gradation can accelerate compaction rate, and it is recommended to control the percent passing the 2.36 mm sieve between 37% and 50% to reduce compaction energy consumption. An appropriate increase in the compaction temperature can improve both the compaction speed and degree, and a compaction temperature of 165 °C is recommended. During the paving process, the vibration frequency and paving speed of the screed have the greatest impact on the compaction degree of paving. The optimal combined parameters for paving construction of steel slag asphalt concrete are a vibration compaction rate of 12 Hz, a vibration frequency of 35 Hz, and a paving speed of 2 m/min.
Experimental Analysis of High- and Low-Temperature Rheological Properties of Revulcanized Rubber Powder-SBS Composite Modified Asphalt
FENG Hao, YANG Zhaodong, FENG Xuran, LIN Bin, YAO Ailing, and WANG Kang
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.012
This paper aims to explore the performance recovery of desulfurized rubber powder in the desulfurized rubber powder-SBS composite modified asphalt after revulcanization treatment. By using 18% rubber powder-2% SBS composite modified asphalt, a desulfurized rubber powder-SBS composite modified asphalt was first prepared via a microwave pyrolysis desulfurization process. Subsequently, a vulcanizing agent was added to the system to prepare the revulcanized rubber powder-SBS composite modified asphalt. Experiments determined the optimal microwave pyrolysis desulfurization duration for rubber powder to be 5 min, and the optimal sulfur dosage was 6% by mass of the desulfurized rubber powder. A comparative analysis of the high- and low-temperature rheological properties of three composite modified asphalts (non-desulfurized, desulfurized, and revulcanized) shows that compared to the desulfurized rubber powder composite modified asphalt, the revulcanized rubber powder composite modified asphalt exhibits significantly improved viscoelasticity, deformation recovery rate, and deformation resistance under high-temperature conditions. Meanwhile, its deformation resistance and durability in low-temperature environments are also significantly improved, with all performance indicators restored to the levels of the non-desulfurized rubber powder-SBS composite modified asphalt. Infrared spectroscopy tests indicate that the addition of the vulcanizing agent restores C‒S bonds and partially restores S‒S bonds in the desulfurized rubber powder. These results confirm the effectiveness of revulcanization treatment in recovering the performance of desulfurized rubber powder-SBS composite modified asphalt, providing a theoretical basis and practical reference for related research and engineering applications.
Bridge Engineering & Tunnel Engineering
Influence Mechanism of Maintenance Rails on Vortex-Induced Vibration of Twin Steel Box Girders
SUN Hongxin, HU Lei, CHEN Wei, and HUANG Wenjun
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.013
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.
Study on Structural Schemes of Comb-Type Steel-Concrete Composite Girder Bridges
XIONG Zhihua, PAN Zhenhua, DI Di, LI Jun, CHENG Litao, and LIU Hongyu
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.014
To investigate the structural performance of novel comb-type steel-concrete composite girder bridges (with a span of 8‒40 m) and optimize their design schemes, this paper took the live load structural efficiency index as the indicator and comprehensively considered factors such as structural mechanical performance, engineering economy, and construction convenience. It also studied the mechanical performance of the negative bending moment zone and the seamless joint of the integral abutment using numerical simulation. The results show that ① for comb-type steel-concrete composite girder bridges with a span of 8‒20 m, the three-girder scheme is recommended; for those with a medium span of 30‒40 m, the four-girder scheme possesses structural and economic advantages, while the five-girder scheme offers advantages in construction convenience and transportation; ② The reasonable range of girder height for the novel composite girders is clarified; in the four-girder scheme, it is recommended that the height of the steel web for a 30 m span should be 600‒800 mm; ③ The structural scheme of the negative bending moment zone using small-sized CL connectors exhibits excellent mechanical performance; ④ The force transmission path of the seamless joint in the integral abutment is clarified, and specific engineering design schemes are proposed.
Matching Analysis of Cantilever Assembly for Wide Steel-UHPC Composite Girder in Cable-Stayed Bridge
CHEN Changsong, WANG Cong, and HUANG Gen
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.015
To control the deformation difference bet ween the to-be-installed and installed segments during the cantilever assembly of wide steel-UHPC composite girders in cable-stayed bridges and achieve precise matching, this paper first introduced a matching method combining pre-hanging cables with crane unloading. Then, by taking the Guanyin Temple Yangtze River Bridge (a super-kilometer-span cable-stayed bridge with wide steel-UHPC composite girders) as the engineering background, a locally refined finite element model was established to analyze the vertical deformation laws of the matching sections during the cantilever assembly construction phase. Finally, the effects of matching sequence, pre-hanging cable force, and crane unloading ratio on the deformation and stress of the girder segments were discussed. Calculation methods for pre-tensioning cable force and unloading ratio were proposed, and the optimal unloading scheme was determined. The results show that the method of pre-hanging cables with crane unloading can effectively reduce the vertical deformation difference between the to-be-installed and installed segments during the cantilever assembly of wide steel-UHPC composite girders, creating favorable conditions for the precise matching of the splicing between to-be-installed and installed segments.
Study on Maximum Vertical Prestress Spacing of PC Continuous Box Girder Bridges
WANG Fan and LU Xiaolei
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.016
To clarify the distribution pattern of the stress field between vertical prestresses in large-span PC continuous box girder bridges and the layout criteria for the maximum vertical prestress spacing, an analytical solution for the web stress field under the action of two prestressed tendons was derived. On this basis, the distribution patterns of the vertical stress field under various prestress spacings and sectional heights were analyzed. Under the premise of ensuring a high-stress state in the web, this study proposed recommendations for the maximum prestress spacing by introducing the sectional stress uniformity index, addressing the blind zone of prestress induced by the vertical prestress diffusion angle. The specific results are as follows:① The analytical solution of the stress field effectively reflects the distribution pattern of vertical normal stress in the web; ② The stress distribution among the vertical prestress tendons varies correspondingly with changes in the prestress spacing:When the vertical prestress spacing is relatively small, the diffusion effect is pronounced; as the vertical prestress spacing increases, the diffusion effect gradually transitions to a superposition effect; ③ For the control of vertical normal stress levels near the L/4 position of continuous box girder bridges, the maximum vertical prestress spacing should ensure that the stress uniformity level at the control section exceeds 0.95.
Refined Finite Element Analysis of Shrinkage and Creep in External Prestressed Reinforced Concrete Beams
LI Xianyang, DENG Jihua, LIANG Luyi, and PENG Jianxin
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.017
To accurately analyze the shrinkage and creep effects in external prestressed reinforced concrete beams, a method was proposed for analyzing the shrinkage and creep of such beams based on refined finite element analysis. First, considering the force characteristics of the external prestressed tendons as constant-strain components, a differential treatment was performed on the geometric and nodal displacement relationships between the external prestressed tendons at the anchorage and deviation points and the concrete beam. Using the principle of virtual work, the element stiffness matrix that needed to be iteratively solved was derived for the external prestressed tendons. Second, based on the assumption that there was good bond between the reinforcement and the surrounding concrete under the action of shrinkage and creep, and that both materials exhibited coordinated strains, a finite element model was established for analyzing the shrinkage and creep of reinforced concrete beams that incorporated the effects of the reinforcements, utilizing the initial strain method in shrinkage and creep analysis. Finally, based on the aforementioned results, a method for analyzing shrinkage and creep in external prestressed reinforced concrete beams was established, along with the development of the corresponding programs. An analysis of the shrinkage and creep of two external prestressed reinforced concrete beams was conducted, and the results were compared with relevant literature. The findings indicate that the method established in this paper for analyzing the shrinkage and creep of external prestressed concrete beams is accurate. It was observed that in the computational model, treating the external prestressed tendons as if they were bonded internal tendons, or neglecting the influence of ordinary steel reinforcement in the concrete beam, can lead to significant errors in the calculated results.
Wind Tunnel Test on Shielding Effect of Arch Ribs for Irregular Bent Arch Bridges
HOU Xu, WANG Xuejun, LIU Yaokun, LONG Hang, WEN Qing, and HUA Xugang
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.018
Bent arch bridges are a kind of novel structural form, and the components for spatial rod structures with densely arranged components exert significant shielding effects on wind load. By taking an irregular bent arch with densely arranged arch rib components as the engineering background, wind tunnel tests of the sectional model of two square arch ribs and two rectangular arch ribs with and without flanges were conducted to obtain the influence of center distance on the aerodynamic drag and aerodynamic lift coefficient of arch ribs within the wind direction angles of 0°‒90°. Meanwhile, the characteristics of the shielding effect of arch rib components on wind load were analyzed. The results of wind tunnel tests show that the shielding effect of windward arch ribs will significantly reduce the drag coefficient of leeward arch ribs. The smaller center-to-center distance ratio leads to the smaller drag of leeward arch ribs. As the wind direction angle increases, the shielding effect of windward arch ribs is weakened, with the shielding effect basically disappearing at the wind direction angle of more than 30°. The influence of flanges on the aerodynamic drag of leeward arch ribs is related to the center-to-center distance ratio and wind direction angle. In the wind direction angle of 0°‒30°, the flanges have almost no influence on the aerodynamic drag of leeward arch ribs. In the wind direction angle of 30°‒90°, the flanges lead to difference in the aerodynamic drag of leeward arch ribs, with the difference related to the center-to-center distance ratio.
Identification of Cable-Stayed Bridge Damage Based on Anchor Point Vibrations Caused by Moving Vehicle Loads and Through Machine Learning
ZENG Youyi, DU Jiarui, ZHANG Jiabin, WANG Jinhao, and FAN Jirong
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.019
The vibration response data on the bridge deck under the load of moving vehicles contains a wealth of information about the geometric parameters of the bridge, enabling effective identification of structural damage. Machine learning can extract key information from the response data and capture linear relationships within it. Taking the Shaozhou Bridge as the research background, this study established a finite element model for a cable-stayed bridge and applied loads from two-axle trucks with various vehicle parameters to the cable-stayed bridge model under different small damage conditions to simulate the vibration response of the cable-stayed bridge model under moving load. Principal component analysis (PCA) was employed for dimensionality reduction and compression of acceleration data, and Bayesian-optimized least squares support vector machine (BO-LSSVM) was used to analyze both damage localization and quantification of the cable-stayed bridge under different load combinations. Additionally, in response to inaccuracies in predicting damage for multiple cables, a method was proposed to integrate localization labels into the damage data. The results indicate that, through a substantial amount of damage response data, the BO-LSSVM model can identify the optimal hyperparameter combinations, effectively analyzing complex response data and monitoring cable damage levels using moving vehicle loads. Utilizing PCA for dimensionality reduction and compression of acceleration response data maintains predictive accuracy while enhancing the computational efficiency of machine learning, thus conserving computational resources. Furthermore, the method of adding localization labels to multiple damage feature data can improve damage identification accuracy. This study provides a model reference and theoretical basis for real-time monitoring of damage in practical engineering.
Cantilever Construction and Control of Long-Span Steel-Concrete Hybrid Continuous Box Girder Bridges with Variable Sections
LYU Haijun, TANG Liang, ZHOU Ye, and QI Le
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.020
This study aims to solve the overall lifting difficulty of mid-span steel box girders in steel-concrete hybrid continuous box girder bridges with variable sections under special environments, providing guidance for the design and construction control of such bridges. By analyzing the external measures adopted by different construction methods and their influence on the bridge-building state of the structure, theoretical research and real bridge calculations were conducted on the key influencing factors and control points of the sub-segment cantilever assembly method. The results indicate that the effect of temporary load and temporary external prestressing cannot be offset after the system transformation, and will affect the bridge-building state of the structure. Additionally, it is found that by conducting construction measures, the sub-segment cantilever assembly method can achieve the bridge-building state corresponding to the overall lifting method, and the efficiency of adjusting closure state by adopting upper external prestressing is 2. 4 times that of adopting the lower external prestressing and can substantially reduce axial force on steel girders. Furthermore, in the sub-segment cantilever assembly method, crane weight has a greater influence on internal forces than the overall lifting method. Based on this, a process-oriented design method considering construction processes was developed for this type of bridge, and a key technology of designing temporary hinged devices at the closure was proposed, which can eliminate the adverse influence of bridge deck cranes on the bending moment at the steel girder root.
Stress Analysis of Cable-Girder Anchorage Structure During Construction Phase of a Hybrid Girder Cable-Stayed Bridge
WANG Zhiguo, XIONG Zhancheng, LIU Yuxiong, and SHI Jialin
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.021
The delayed casting technology of wet joints can significantly shorten the construction period of hybrid girder cable-stayed bridges. To ensure the safety of the stress in the cable-girder anchorage structure of the steel anchor box type under this new process, this paper took a large-span hybrid girder cable-stayed bridge as the research object. It studied the stress distribution pattern and the sensitivity of component parameters in the anchorage zone during construction. Firstly, the construction cable forces were obtained by establishing a full-bridge grid model using the finite element software Midas Civil. Combined with the Abaqus software, a detailed local model of the cable-girder anchorage structure was built. Based on the delayed casting technology of wet joints for the hybrid girder cable-stayed bridge, the weld force transfer under different cable force conditions was calculated. Finally, a parameter analysis was conducted considering the variations in the thickness of the anchorage structure plates and the angles of the pre-embedded sleeves. The results indicate that under the delayed two-section casting scheme, the stress in each component of the steel anchor box structure is within safe limits. Influenced by the angle of the pre-embedded sleeves, the stress on the welds tends to be higher on the lower side than on the upper and more significant on the inner side of the bridge centerline than on the outer. The effective stress distribution along the length of the welds typically exhibits a saddle-shaped pattern. The top plate anchor stiffening and the thickness of the pre-embedded sleeves have the most significant impact on weld stress. The maximum weld stress is directly proportional to the horizontal and vertical angles of the pre-embedded sleeves.
Smoke Control Wind Speed of Transversal Double-Source Fire in Road Tunnel Sections
GAO Hengchao, TAO Jiaqing, CHEN Xun, and WANG Feng
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.022
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.
Study on Pit Corner Effect of Open-Cut Foundation Pit Considering Coupling Action of Internal and External Corners
FENG Wei, ZHOU Kun, LI Hailong, WU Xing, and HUANG Fu
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.023
At present, most studies on the spatial effect of open-cut foundation pits focus only on the influence of either internal corners or external corners on the supporting structure, while the coupling effect of internal corners or external corners on the deformation characteristics of the retaining structure and surrounding soil has not been thoroughly investigated. Based on the Gongming Square open-cut foundation pit project of Shenzhen Metro Line 13, this study constructed a three-dimensional numerical model. The influence of the coupling action between the internal and external corners during excavation on the deformation of the retaining structure was analyzed. The deformation pattern of lateral displacement of the diaphragm wall under different relative positions of the internal and external corners was obtained, and a calculation formula for the influence coefficients of the internal and external corners was proposed. The results show that an increase in the wall length of the external corner parallel to the long side of the pit only affects the lateral displacement of the diaphragm wall on the pit side where the external corner is located. Increasing the wall length of the external corner is beneficial to control the horizontal displacement along the long side but is unfavorable for controlling displacement along the short side. Surface settlement at 1 m behind the diaphragm wall increases with the wall length of the external corner (parallel to the long side), and the point of maximum displacement shifts from the central part of the pit toward the location of the external corner.
Analysis of Cooling Effect of Tunnel Surrounding Rock Construction Based on Spray Cooling
MENG Lingchen
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.024
To study the cooling effect of spray cooling on the surrounding rock during the construction of an extra-long tunnel, based on the Zhongliangshan Tunnel Project, numerical simulations were performed to analyze the characteristics of average temperature variation in the tunnel under different spray rates, the evaporation efficiency and temperature drop characteristics of spray under different humidity levels, and the average temperature variation characteristics of the tunnel section under different spray positions. The measured values of the air temperature in the tunnel section were compared with the simulated values. The results indicate that:① With the increase of the spray rate, the average temperature in the tunnel decreases gradually; when the spray rate is 0.038 kg/s, the temperature drops by 2.75 ℃ compared with the initial temperature of the tunnel; ② As air humidity increases, the droplet evaporation rate decreases gradually; when air humidity is 12 g/kg, the droplet evaporation rate is the highest compared to other humidity levels; ③ At the same distance from the tunnel face, when the air moisture content is 12 g/kg, the temperature drop after spraying is the largest compared with other moisture contents, with a maximum temperature drop of 7.06 ℃; ④ There is no significant difference between the average measured air temperature and the average simulated value, suggesting that the measured and simulated air temperatures are basically consistent. In actual tunnel spray cooling projects, the spray cooling system should be closely combined with the tunnel ventilation system. The position and air volume of the vents should be reasonably set to promote good air convection, while controlling the humidity in the tunnel to improve the cooling effect.
Smart Road and Intelligent Transportation
Research on Multi-Object Detection Algorithm for Routine Highway Inspection Based on UAV
MA Tao, TIAN Meijuan, WANG Zhipeng, DONG Jiazhi, and ZHU Junqing
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.025
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 YOLOv 11n, YOLOv 11-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 C 3k2, reducing the model parameter volume and computational complexity while enhancing feature extraction capability. Experimental results show that the YOLOv 11-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 (RP) and mean average precision (mAP) 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.
Comparative Study on Visual Recognition Distances of Chinese and British Symbolic Traffic Signs and Guide Signs for Chinese Drivers
WANG Heng, YUAN Wanfu, REN Jiaming, PEI Weihao, LI Weidong, and YANG Zhen
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.026
To reveal the differences in drivers' visual recognition of traffic signs in a transnational context and provide a methodological reference for research on visual recognition distance differences, this study, based on the SILAB driving simulation platform, used triangular slippery road signs, circular end-of-speed-limit signs, and guide signs as examples to compare and analyze the differences in the relationship between sign size and visual recognition distance for Chinese drivers regarding Chinese and British traffic signs. In the experiment, the information content and location of the same types of Chinese and British traffic signs were kept consistent, and the sign sizes were set according to the current traffic sign design standards of the two countries. Combined with data regression characteristics, the slopes of the relationship equations between visual recognition distance for Chinese drivers and sign size for Chinese and British signs were compared and analyzed. The research data show that the slopes of the relationship equations between visual recognition distance for Chinese drivers and traffic sign size regarding Chinese and British signs are similar. Under the same road design speed, the design size ranges of the end-of-speed-limit signs in China and the UK differ significantly. Under the condition of identical sign size and information content, the visual recognition distance for Chinese guide signs is greater than that for British guide signs, and the slope of the relationship equation between visual recognition distance and sign size is higher for Chinese guide signs. In view of the differences in Chinese drivers' visual recognition of traffic signs in a transnational context, it is suggested to strengthen adaptive training for local traffic signs. The research results can provide a reference for international driving safety education and road traffic sign design.
Technical Framework Design for Unmanned Roller Cluster Operations
JIN Yongquan, WU Difei, FU Yingli, and LIANG Wenyao
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.027
To improve the efficiency and safety of road construction and address problems such as harsh environments, unstable construction quality, and high labor costs in traditional road construction, a technical framework for unmanned roller cluster operations was proposed. The framework consists of three modules:underlying hardware control, trajectory planning calculation, and cooperative operation scheduling, realizing unmanned compaction operations for the roller cluster. Specifically, the underlying hardware control module achieves unmanned control, positioning, and communication by retrofitting active rollers; the trajectory planning calculation module is used to plan the operation trajectories of unmanned rollers; the cooperative operation scheduling module coordinates the operation process of the roller cluster. Field test results indicate that the average trajectory error of the unmanned single-drum roller based on this framework is 6.3 cm, and that of the unmanned double-drum roller is 14.3 cm. The study shows that the framework can effectively ensure the precise path-tracking operations of unmanned rollers, maintain the stable execution of cooperative operation schemes, effectively improve construction efficiency, reduce labor costs, and provide strong support for smart road construction.
Road Maintenance and Environmental Protection
Multi-Objective Maintenance Strategy Optimization of Deteriorated Bridges Considering Carbon Emissions
WEI Yonghua and TIAN Zhongchu
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.028
In order to realize the new situation of safe, economic, and low-carbon bridge maintenance and ensure the efficient operation of the bridge during the maintenance period, the reliability evaluation model of the deteriorated bridge was obtained based on the reliability theory. According to the carbon emission factor method, the carbon emission calculation model of the bridge maintenance stage was established. An objective function considering bridge reliability, maintenance cost, and carbon emission was constructed. Based on the objective function and bridge reliability constraints, a multi-objective optimization model of bridge maintenance strategy considering carbon emission was formed. By taking a bridge as an engineering example, the optimal maintenance strategies considering different weights were obtained, and the single maintenance behavior and the combined maintenance behavior were compared. The results show that decision-makers can choose bridge maintenance strategies according to different needs. In the case of emphasizing economic benefits, the maintenance cost is the lowest, but the reliability is small. When the environmental impact is emphasized, its carbon emission is the lowest, but its reliability is the lowest. When the overall performance is emphasized, its reliability is the highest, but its carbon emissions and maintenance costs are the highest. With the same weight, its carbon emission, maintenance cost, and reliability are more balanced. The carbon emission of combined maintenance behavior is similar to that of pasted steel plate and external prestressing method, but the maintenance cost of combined maintenance behavior is smaller. The increased section method produces the most carbon emissions, and the pasted FRP has the least carbon emissions, but the total maintenance cost is the highest.
Research on Carbon Emission Accounting for Road Engineering Foundation Reinforcement
YANG Penghui, LIU Rui, WAN Ch uanfeng, ZHANG Haixiao, ZHOU Yefei, and LU Chunying
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.029
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.
Foreign Highway
Environmental and Economic Benefits of Brick Aggregate for Road Applications in Bangladesh
LIU Zhifang, LIU Gang, XU Jinlong, and ZHANG Jingbo
Date posted: 2-5-2026
DOI: https://doi.org/10.14048/j.issn.1671-2579.2026.01.030
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.
