Volume 45, Issue 4 (2025)
Subgrade Engineering
Settlement Calculation Method for Composite Foundations Reinforced with Geo-Encased Stone Columns
LONG Jun and TAN Jingpeng
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.001
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.
Study on Deformation Characteristics Induced by Deep Foundation Pit Excavation Sharing Diaphragm Wall with Existing Subway Station
LING Tonghua, ZOU Nanwei, ZHOU Kun, FENG Wei, WU Xing, and ZHANG Liang
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.002
To investigate the deformation induced by deep foundation pit excavation sharing a diaphragm wall with an existing subway station,this study took the foundation pit project of Gongming Square Station of Shenzhen Metro as an example.A three-dimensional numerical model was established by FLAC3D software to analyze the deformation characteristics of the surrounding ground surface,retaining structures,and the subway station during the excavation process.In addition,field monitoring was conducted to measure the vertical and horizontal displacements of the pit sidewall and the subway station sharing the diaphragm wall.The results show that after excavation,the ground surface settlement behind the retaining wall exhibits an approximately elliptical distribution,with the affected range being about one time the excavation depth.The retaining wall shows lateral deformation toward the pit,forming an “inward convex ” shape.The excavation mainly causes uplift displacement in the subway station sharing the diaphragm wall,while lateral displacement remains small.The maximum uplift displacement (2.85 mm ) occurs at the center of the sidewall adjacent to the pit,and the maximum lateral displacement (1.44 mm ) occurs at the base slab near the station center.The field monitoring data of the pit sidewall and subway station sharing the diaphragm wall agree well with the numerical simulation results,verifying the reliability of the numerical model.
Application of Grouted Steel Pipe Micropile Composite Structure in Highway Landslide Treatment
WU Bing, LIANG Yao, LI Jie, and ZHAO Honghu
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.003
To optimize the calculation methods and application schemes for reinforcing landslides using grouted steel pipe micropile composite structures,the composition of single-pile composite structures and the combination forms of pile group structures were described.By taking the Bishop method as an example,a stability analysis method and the anti-sliding principle of side (sliding ) slopes reinforced with grouted steel pipe micropile composite structures were proposed,and a calculation formula for the allowable shear resistance of the composite pile was derived.By taking a landslide case from a section of Lijiang‒Panzhihua Expressway as an example,landslide stability analysis and landslide thrust calculation were carried out.The grouted steel pipe micropile composite structure was used to strengthen and treat the landslide in sections,and corresponding design schemes for landslide emergency rescue and permanent treatment were proposed.The original landslide section has operated safely for over three years after treatment,effectively verifying the good treatment effect of this composite structure.Meanwhile,suggestions were given on the calculation principles,design methods,and application schemes for landslide treatment using grouted steel pipe micropile composite structures.
Pavement Structure and Materials
Study on Chloride Ion Diffusion Behavior in Cracked Cement Mortar with High Fly Ash Content
LIU Yang, MAO Shengzhe, and LU Naiwei
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.004
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 FA 50 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.
Research on Crack Identification Technology Based on Sobel + Matched Filter Joint Algorithm
WEN Yan, GUO Xiaoqian, TANG Youzhi, YANG Enhui, and QIU Yanjun
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.005
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.
Relationship between Fractal Characteristics and Shear Strength of Highway Spoil Site Materials
LUO Shixin, LUO Hongming, ZOU Fei, and CAI Lei
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.006
Highway spoil features a wide range of particle sizes and poor gradation,and their strength characteristics serve as key factors affecting the stability of spoil slopes.To explore the relationship between fractal characteristics of particle size and strength,this study examined 21 spoil sites along the Guizhou section of the Duyun ‒ Shangri-La Expressway.Based on the field investigation,particle size analysis tests,and laboratory shear tests,the particle composition and shear strength parameters of spoil were obtained.Based on fractal theory,the fractal characteristics of particle size under different gradation scaling methods were analyzed,and the relationship between shear strength parameters and the fractal dimensions of particle size was discussed.A formula for estimating the shear strength parameters of spoil was established.The results show that the particle composition of spoil varies significantly depending on their source and degree of weathering.Spoil from roadbeds and strongly weathered spoil generally exhibit unimodal distributions,while spoil from tunnels and with moderate weathering tend to exhibit bimodal distributions.The fractal dimension shows a strong correlation with both the internal friction angle and the fine particle content (mass percentage of particles smaller than 5 mm ).When the fine particle content is ≤20%,the fractal dimension increases with the increasing of fine particle content,while the internal friction angle decreases with increasing fractal dimension.When the fine particle content exceeds 20%,the fractal dimension decreases with increasing fine particle content,and the internal friction angle increases with increasing fractal dimension.The proposed estimation formula for shear strength parameters was validated through case studies,and the strength parameters can be estimated based on particle composition,providing a reference for the stability assessment of spoil sites.
Research on Improvement of Adhesive Properties of Asphalt and Granite Gravel
LI Yu, ZHANG Yingxue, QIU Chao, WANG Mo, and LIU Li
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.007
In view of the poor adhesion of acidic granite gravel and asphalt and the shortage of alkaline stone in asphalt pavement in China ’s expressway construction,this study evaluated the improvement effects of schemes,including single use of amine anti-stripping agent DRD-K 1,single use of non-amine anti-stripping agent AMR- 3,single use of cement,and combined use of anti-stripping agent and cement,on the asphalt-aggregate adhesion properties.Through the tests of three major indexes before and after asphalt aging,aggregate adhesion test,and improved water immersion method,the adhesion of asphalt was evaluated,and the optimal amount for use was proposed.The results show that the non-amine anti-stripping agent AMR- 3 exhibits a better improvement effect than the amine anti-stripping agent DRD-K 1,and 0.4% AMR- 3 + 3% cement is the optimal anti-stripping solution.The research results can improve the application performance of acid granite in asphalt pavement,alleviate the shortage of stone resources,and reduce engineering costs.
Effect of Granite Machine-Made Sand Properties on Concrete Performance
WANG Jiliang, WEI Xinyuan, and YU Bo
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.008
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.
Factors Influencing Fatigue Damage in Manufactured Sand-Based Ecological Self-Compacting Concrete Pavement
FU Suanzi and LI Hongyan
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.009
Ecological-self-compacting concrete (Eco-SCC ) pavements offer advantages such as reduced cement consumption,lower carbon emissions,and improved economic performance.However,their durability has not been sufficiently studied.Based on the literature review and fatigue test data,the fatigue parameters of Eco-SCC were determined using the Chaboche damage evolution model.A finite element model of fatigue damage in Eco-SCC pavement structures was established to compare the fatigue damage distribution under different loading positions,identify the unfavorable loading positions,and analyze the influence of slab thickness and modulus on the durability of Eco-SCC pavements.SCC plate thickness and modulus on the durability of Eco-SCC pavement.The results show that fatigue damage under different loading positions is mainly distributed at the bottom of the slab,and controlling the bending and tensile stresses at the slab bottom is key to improving Eco SCC pavement durability.For longitudinal cracking,the most unfavorable loading positions are ranked as slab corner > slab edge > slab center;for transverse cracking,the order is slab edge > slab corner > slab center,which is consistent with the Specifications for Design of Highway Cement Concrete Pavement (JTG D 40—2011 ).Increasing the slab thickness or decreasing the modulus effectively suppresses both transverse and longitudinal cracking of Eco-SCC pavements.To optimize longitudinal cracking control while delaying transverse cracking,it is recommended that,when the modulus is 24 000 MPa,30 000 MPa,and 40 000 MPa,the slab thicknesses be set at 26 cm,28 cm,and 30 cm,respectively.
Adhesion Mechanism of Geopolymer-Modified Emulsified Asphalt Slurry at Interface with Aggregate
ZHONG Chao, YANG Hao, LIN Juntao, and XIAO Yue
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.010
In order to investigate the adhesion mechanism at the interface between geopolymer-modified emulsified asphalt slurry and aggregate,the interfacial adhesion performance was studied by the molecular dynamics method and compared with that of cement-modified emulsified asphalt slurry.In addition,macro-scale splitting strength tests were performed for verification.The results indicate that van der Waals forces play a major role in the adhesion at the slurry-aggregate interface.Under equivalent mix ratios,the interfacial binding energy between the geopolymer-modified emulsified asphalt slurry and aggregate is 6.84% ‒19.99% higher than that of the cement system.The adhesion performance is closely related to the diffusion properties and atomic distribution of the slurry.Simulated pull-out tests show that under corresponding mix ratios,the maximum interfacial tensile stress between geopolymer-modified emulsified asphalt slurry and aggregate is 9.06% ‒20.91% higher than that of the cement system.The macro-scale splitting strength tests reveal that the maximum splitting strength of geopolymer-modified cold recycled asphalt mixtures after 28 days of curing reached 1.982 MPa.When the emulsified asphalt-to-geopolymer ratio is 1:1,the result is consistent with the simulation findings,demonstrating that the molecular dynamics method can effectively reveal the adhesion mechanism at the interface between geopolymer-modified emulsified asphalt slurry and aggregate.
Experimental Study on Workability of Alkali-Activated Red Mud-Based Controlled Low-Strength Materials
WU Yun, FANG Mingjing², LIN Zhiyang², LIU Zhengwei³, and BENG Jianping³
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.011
This study aims to optimize the mix design of alkali-activated red mud-based controlled low-strength materials (CLSMs ) to enhance their applicability in road engineering backfilling.The effects of red mud content (20% ‒ 50%),water-to-solid ratio (0.30‒0.36),sand-to-soil ratio (7∶3‒4∶6),polycarboxylate superplasticizer (PEC ) dosage (0%‒2.1%),and fly ash to mineral powder ratio (5∶1‒0.5∶1) on the flowability and bleeding resistance of the materials were systematically investigated.The results are as follows:① The water-to-solid ratio significantly influences flowability.Increasing it to 0.32‒0.34 improves flowability by 39%‒78%,but when the ratio exceeds 0.34,the bleeding rate increases significantly (up to 4.89%);② When the red mud content is 30%‒40%,the high specific surface area adsorption and alkaline hydration synergistic effect balance flowability (200‒300 mm ) and bleeding resistance (bleeding rate ≤5%);③ When the sand-to-soil ratio is optimized to 5∶5,the grading effect of manufactured sand reduces the water absorption impact of fine-grained soil,enhancing slurry stability;④ PEC dosages of 1.4% ‒ 2.1% significantly improve flowability through electrostatic repulsion and free water release mechanisms.However,excessive addition (>2.1%) leads to increased bleeding rate due to insufficient water film thickness;⑤ When the fly ash to mineral powder ratio is ≥ 2∶1,the spherical particle effect of fly ash reduces frictional resistance and suppresses bleeding.Based on the synergistic effects of multiple factors,the optimized mix design is recommended as follows:red mud content of 30%,water-to-solid ratio of 0.32,sand-to-soil ratio of 5∶5,PEC dosage of 1.4%‒2.1%,and fly ash to mineral powder ratio of 2∶1.This mix achieves high flowability (flow diameter of 200‒300 mm ) and low bleeding rate (2-hour bleeding rate ≤ 5%).This study provides key technical parameters for the low-carbon application of red mud-based CLSM and promotes the resource utilization of industrial solid waste and the development of green building materials.
Bridge Engineering & Tunnel Engineering
Damage Localization of Simp ly Supported Beams Based on Deflection Influence Surfaces Calculated by Three-Dimensional Boundary Face Method
YIN Xinfeng, LUO Zonghao, YAN Wanli, and KAIERSAER ∙Tuerdi
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.012
The deflection influence surface (DIS) of a spatial structure is difficult to calculate using the existing two-dimensional boundary element method.To address this issue,a damage localization method based on DIS calculated using the three-dimensional boundary face method (BFM ) was proposed.A custom BFM program with an internal loop was developed,and the internal forces and deformations of a square plate and a supported T-beam structure were calculated using the static method.By specifying the domain of the order of a bivariate polynomial function (BPF ),a secondary optimization program for influence surfaces was established,and the DIS with the minimum mean square error was obtained.The results calculated by BFM were compared with the analytical solutions,showing an error of no more than 1.8‰,which verifies the accuracy and effectiveness of using the BFM to compute DIS.Damage localization was studied based on the high-precision DIS,and a simply supported T-beam experiment was performed to validate the proposed method.The results show that,compared with traditional DIS-based damage localization methods,the proposed method improves damage localization accuracy by 28.6% and 16.7% under single and double damage conditions,respectively.The proposed method offers a more efficient numerical tool for damage diagnosis of bridges and other spatial structures.
Wind Tunnel Test Study on Vortex-Induced Vibration Performance of Cable-Stayed Bridge with Double-Side Box Open Section Composite Main Girder
ZHOU Guohua, DU Guoqiang, PEI Shan, DING Wangxing, and ZHU Zhiwen
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.013
In order to evaluate the vortex-induced vibration (VIV ) performance of a single-tower ground-anchored cable-stayed bridge with a double-side box open section composite main girder,sectional model wind tunnel tests were conducted under different wind angles of attack and wind speeds.The results show that the torsional stiffness of the π-shaped open section main girder is significantly higher than its vertical bending stiffness.The dominant vibration mode of the main girder is the obvious vibration of the main span,while the ground-anchored abutment effectively stabilizes the cable tower through the back stays.At the damping ratio level specified in the code,within the range of prevailing wind speeds at the bridge site and under a wind angle of attack ± 3°,significant VIV occurs on the originally designed main girder in both vertical bending and torsional directions.The vertical VIV amplitude exceeds the code limit,with a maximum value of 0.3 m.Therefore,the VIV performance of the bridge does not meet the code requirements.An economical and feasible lower stabilizing plate,connected to the crossbeam,is designed and installed under the main girder.With this aerodynamic measure applied,the vertical VIV amplitude is significantly reduced,enabling the bridge to meet the code requirements within the ± 3° wind angle of attack.However,under a 5° wind angle of attack,with only the lower stabilizing plate installed,the vertical VIV amplitude still significantly exceeds the code limit,and the torsional VIV amplitude is very large.Therefore,it is necessary to explore other aerodynamic countermeasures to further suppress excessive VIV.The findings of this paper not only provide an important basis for the VIV design of this bridge but also provide a valuable reference for the wind-resistant design of similar bridges.
A Review on Connection Forms between Bridge Guardrails and Bridge Decks
LI Wei, LI Rutao, JIA Ning, and LU Jian
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.014
In recent years,with the continuous expansion of highway bridge construction in China,there has been a growing public demand to enhance road safety and the protective capabilities of highway bridges.To meet the engineering application requirements of various bridge forms and bridge guardrails,diverse connection structures between bridge guardrails and bridge decks have been studied both domestically and internationally.However,in current engineering practice,the selection of these connection forms remains challenging,lacking clear reference criteria.Using the analytic hierarchy process and supported by experimental data,this paper comprehensively analyzed the advantages and disadvantages of these connection forms by considering factors such as guardrail protection effectiveness,load-bearing reliability,construction convenience,and ease of post-collision repair.The results show that for precast concrete guardrails,embedded grouting connections and embedded steel plate connections exhibit superior overall performance;for metal beam-and-post guardrails,the traditional tapping plate connection remains the optimal choice,while other novel connections may be suitable for special protection needs or specific scenarios.These findings provide a reliable reference for further improving the design of connections between bridge guardrails and decks.
Research on Construction Monitoring of Continuous Rigid Frame Bridge Based on KNN Algorithm
LIU Jianlin, PAN Kai, YANG Gang, and WANG Junming
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.015
To address common issues in bridge construction monitoring,such as sensor damage and failure in strain and displacement measurements,this study took the Nanliu Jialing River Bridge as a case and proposed a method based on the K-nearest neighbor (KNN ) algorithm to reconstruct missing construction monitoring data.ANSYS Workbench was used to establish a finite element model (FEM ) of the bridge construction process to verify the effectiveness of the KNN algorithm in the presence of missing bridge construction monitoring data.The results show:① KNN algorithm can assist in filling short-term data gaps caused by damage to strain and displacement sensors during bridge construction;② The stress at the root section of the box girder increases with the extension of the cantilever length,and the measured stress of the bottom plate is gradually close to the theoretical value.The stress at the root section of Pier 8# is larger than the theoretical value,and this error may be caused by the initial reading error of the strain gauge;③ The alignment of the main girder at Pier 8# during cantilever construction is in good agreement with expectations and gradually approaches the target line.However,the elevation of the left flange plate of the main girder section of the Qingniu side of Pier 10# is lower than the target elevation.At the same time,the elevation at the center of the top plate of the main girder section on the Hutiao side is also lower than the target,which needs timely adjustment in the subsequent construction process.
Field Measurement and Analysis of Wind Characteristics at Xuefenghu Bridge Site
YU Wenhao and YI Lu
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.016
Wind field parameters at bridge sites serve as an important basis for wind-resistant bridge design.The terrain surrounding the Xuefenghu Bridge is unique-mountains flank both sides in the bridge-aligned direction,and the bridge spans the wide surface of the Zhexi Reservoir.In order to investigate the wind field characteristics under such complex topographic conditions,an observation,acquisition,and wireless data transmission system was established at the bridge site.A one-year in-situ wind measurement campaign was conducted,and the characteristics of average wind and fluctuating wind were deeply analyzed.The results show that the average wind speed at the bridge site generally follows a Weibull distribution,and the average wind direction is mainly eastward.For high wind speed events (10-minute average wind speed exceeding 5 m/s),the wind attack angle ranges from ‒ 6.37° to ‒ 1.72°.Turbulence intensity and gust factor both follow a log-normal distribution,and there is an obvious linear relationship between them.The average turbulence intensities in the downwind direction,crosswind direction,and vertical direction are 0.224 70,0.204 06,and 0.132 29,respectively,yielding a ratio of 1∶0.908∶0.589,which exceeds the recommended value in the Wind-Resistant Design Specification for Highway Bridges (JTG/T 3360 -01—2018 ).The gust factor becomes more concentrated with the increase of wind speed.The measured turbulence integral scales in the downwind direction,crosswind direction,and vertical direction are about 113 m,110 m,and 44 m,respectively and obey a log-normal distribution.For the power spectral density,the measured turbulence spectrum in the downwind direction matches the standard spectrum well in the high-frequency range but exceeds it in the low-frequency range;the vertical spectrum remains consistently higher than the standard across all frequencies.These findings demonstrate that the wind characteristics at this reservoir-mountain terrain bridge site,especiall y in terms of turbulence intensity and power spectral density,significantly deviate from code-recommended values.
Shear Strength Test of UHPC-NC Bonding Surface
ZHANG Shichang, YAN Donghuang, LIU Yun, YUAN Sheng, and WANG Shuo
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.017
As a cement-based composite material with excellent mechanical properties,ultra-high performance concrete (UHPC ) demonstrates outstanding performance in tensile and compressive strength,durability,and impermeability.This material is suitable for the reinforcement and repair of normal concrete (NC) bridge structures.To study the shear behavior of the UHPC-NC bonding interface and its reinforcement effect,this paper conducted interface shear tests using Z-shaped specimens and designed a total of six sets of comparative specimens.The influence of parameters such as the planted bar ratio,implantation depth,and bonding surface size on the shear strength was explored.Through experiments,the load –slip curve and the shear strength data were obtained.The results show that:① An increase in the planted bar ratio leads to an improvement in the shear strength of the bonding surface,with the rate of increase gradually slowing down as the planted bar increases.A planted bar range of 1%‒1.5% is optimal;② An increase in implantation depth increases the shear strength,but when the depth reaches (10‒12)d (d refers to the diameter of the reinforcement ),the enhancement effect begins to weaken;③ The size of the bonding surface has also been proven to have a significant impact on shear performance.
Analysis and Control of Impact of Wide Waterway Excavation on Adjacent Bridge Pile Foundations
ZHANG Peisheng, QIAO Lyu, SHENG Jianchao, SHENG Haoxiang, LIU Hanchen, and WANG Zhe
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.018
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.
Experimental Study on Shear Resistance of Existing Prestressed Concrete Hollow Slabs
LU Youfu, DI Jin, QIN Fengjiang, and SUN Yifei
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.019
Prestressed concrete hollow slabs are widely used in small- and medium-sized span highway bridges in China.With the increase in load ratings,many hollow slab bridges built in early periods fail to meet the current specifications for shear bearing capacity.Nevertheless,these hollow slabs continue to function adequately under existing vehicle loads,making it essential to conduct an in-depth investigation into their shear bearing capacity.Shear bearing capacity tests were conducted on five 16 m-span hollow slabs dismantled from a renovation and expansion project,including three top slabs with a 15 cm cast-in-place concrete structural layer.Various parameters,such as load-displacement curves,web concrete strain,cracking loads,crack development patterns,failure modes,and ultimate loads of the hollow slabs,were determined.The findings reveal that the 16 m hollow slabs without the added concrete layer developed diagonal cracks followed by shear compression failure.For 16 m hollow slabs with the added concrete layer,the cracking load increased by 32%,and the shear bearing capacity increased by 22%.A comparison between the experimental results and the results according to the design code highlights the overly conservative nature of the current method for calculating the shear bearing capacity of hollow slabs.
Analysis of Flexural Bearin g Ca pacity of Concrete Box Girders Reinforced with
CFRP Mesh End AnchorsHU Guihua
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.020
Carb on fiber reinforced polymer (CFRP ) composite s have significant advantages in the reinforcement of concrete structures.It is worth systematically studying the effect and mechanism of applying this material in embedded end-anchored reinforcement of concrete box girders on improving the load-bearing capacity of the component.Based on the Abaqus finite element analysis (FEA ) platform,two numerical analysis models considering slip contact and full bonding contact between CFRP mesh and polymer mortar were established.A full-scale concrete box girder model test was conducted for validation.The results show that the FEA results are in good agreement with the experimental results.The FEA model that disregards interfacial slip within reinforcement layers prior to steel reinforcement yielding aligns more closely with experimental results,while the model accounting for slip after yielding demonstrates greater consistency with experimental findings.The influences of the bonding position,bonding width,number of bottom mesh layers,and crossing angle of the U-shaped hoop on the flexural capacity of the reinforced concrete box girder were analyzed.The results show that the anchoring position and anchoring width have a certain impact on the deflection and failure mode of the component,and the anchoring amount and the number of bottom mesh layers should be proportional,while the variations in the crossing angle of the anchoring strips have little effect on the flexural performance of the girder.The numerical modeling method and parameter optimization results proposed in this paper can provide a scientific basis for the design of CFRP mesh-reinforced concrete box girders.The conclusions have been validated through model tests and offer engineering reference values.
Wind Tunnel Test on Wind-Resistant Performance of Suspended Monorail Cable-Stayed Bridge
CHEN Yujiang
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.021
To investigate the wind-induced vibration of a suspended monorail bridge,a full-bridge aeroelastic model at a 1∶40 scale was designed and fabricated according to the geometrical parameters and dynamic characteristics of the real bridge.Wind tunnel tests on the bridge in both the completed state and the maximum cantilever state were conducted under different conditions,including uniform flow and turbulent flow,yaw angles of ± 45°,±30°,±15°,and 0°,and wind attack angles of ‒ 3°,0°,and + 3°.Both vertical and torsional displacements of the structure under different wind speeds were measured.The test results show that the vertical displacements and torsional responses of the cable-stayed bridge increase when the wind speed increases from 1 m/s to 12 m/s (equivalent to 6.3‒76.0 m/s for the real bridge ).No flutter,galloping,or vortex-induced vibration was observed,and the critical flutter wind speed exceeds 76 m/s.In addition,the yaw angle has little effect on the structural response of the completed bridge but has an obvious effect on that in the maximum cantilever state.In both states,the structural response under a wind attack angle of + 3° is the largest,making it the most unfavorable wind attack condition.The results verify that the suspended monorail cable-stayed bridge offers good wind-resistance performance.
Research on Autonomous Deviation Correction of Tunnel Boring Machines and Parameters Based on Machine Learning
ZHANG Jun and LI Maopeng
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.022
In order to solve the problem of realizing the autonomous deviation correction of tunnel boring machines (TBMs ), a TBM deviation correction control method that integrated the random forest (RF) algorithm with the genetic algorithm (GA) was proposed based on actual engineering data.The method combined a prediction model with an optimization model,using target deviation values as input to invert and output the required TBM deviation correction parameter values,thereby further improving the automation level of TBM deviation correction.By comparing it with the actual data,the feasibility of the model was verified.The results show that the RF algorithm-based prediction model achieves an R2 value of 0.875,an EMSE of 6.287,and an EMAE of 2.03,demonstrating that the accuracy control can meet the requirements of the construction specification.The RF-GA-based TBM deviation correction model can control deviations within 7 mm in real time,and the average accuracy of the output TBM tunneling parameters compared with actual data is above 90%.In the comparative experiment,the variation pattern of TBM parameters output by the control model is consistent with the actual pattern.This paper provides a new approach for achieving TBM attitude control and studying the variation pattern of TBM parameters in practical engineering.
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, and LIU Jiansong
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.023
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 C 15 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.
Smart Road and Intelligent Transportation
Research on Automatic Review Method of Highway BIM Based on Knowledge Graph
WANG Wuyu, SHAO Kebo, and ZHANG Feng
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.024
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.
Research on Multi-Classification Prediction of Traffic Accident Severity on Mountainous Expressways
WANG Hao, YAN Jie, GUO Jianmin, ZHANG Yu, and SUN Chengji
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.025
To enhance the safety level of mountainous expressways and establish an accurate and effective prediction model for traffic accident severity,this study analyzed 2 484 traffic accidents on mountainous expressways in Chongqing from 2010 to 2016.A total of 17 influencing factors were selected from four aspects:human,vehicle,road,and environment,to serve as explanatory variables.Partial proportional odds model,random forest algorithm,and XGBoost algorithm were used to construct multi-class prediction models for traffic accident severity.The model performance was evaluated using the confusion matrix,accuracy,and minority class recall rate.The results show that the XGBoost model achieves the highest prediction accuracy in multi-class prediction of traffic accident severity on mountainous highways.The overall accuracy rate of the XGBoost model is 69.58%,with a recall rate for severe accidents of 61.11%.These figures are significantly higher than those of the partial proportional odds model and the random forest algorithm.Furthermore,the absence of nighttime lighting,involvement of large vehicles,and bridge segments were identified as strong contributing factors in both the partial proportional odds model and the XGBoost model.Specifically,the probability of severe accidents occurring on bridge segments is 2.649 times higher than on other road segments.
Research on Prefabrication Scheme of Concrete Barrier Based on Anchorage in Cast-in-situ Layer
LIANG Xiaochong, KANG Hanjing, LUO Yongchuan, WEN Zhiquan, and DENG Bao
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.026
In order to improve the on-site construction efficiency of bridge concrete barriers,a prefabrication scheme for bridge concrete barrier installation was proposed.A structure scheme was developed by anchoring transverse steel bars at the bottom of prefabricated wall panels into the integrated cast-in-situ layer,adopting tongue-and-groove connections between adjacent wall panels,and optimizing the structural configuration and reinforcement of the panels.According to the requirements of the Level VI protection standard,full-scale impact tests using a large bus and a large truck were organized in turn.The results show that the prefabricated concrete bridge barrier can effectively withstand continuous impacts from both large buses and trucks.Its structural integrity and connection reliability meet the safety performance indexes,thereby verifying the feasibility of the prefabricated concrete bridge barrier scheme.
Road Maintenance and Environmental Protection
Application and Analysis of Energy-Conservation and Carbon-Reduction Technologies in Green Highways
HUANG Xuewen, WANG Kai, HUANG Shanqian, XIONG Xinzhu, and FU Jinsheng
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.027
To improve the low-carbon development level of highway engineering,this study relied on a typical green highway in Anhui Province and established a calculation model for energy-conservation and carbon-reduction in highway engineering based on the emission factor method.A combination of quantitative and qualitative approaches was adopted to evaluate the benefits of 33 energy-conservation and carbon-reduction technologies in reducing life cycle energy consumption and carbon emissions,based on life cycle assessment (LCA ) theory.The results show that during the material production stage,through channel resource coordination and the application of low-carbon,energy-saving materials,comprehensive reductions in the embodied carbon can be achieved.During the construction stage,energy consumption is reduced by optimizing construction organization and the energy consumption structure of temporary facilities and on-site operations.In the operation and maintenance stage,the construction of near-zero-carbon service areas helps reduce operational carbon emissions,improve project durability,and lower maintenance energy consumption.Based on the evaluation of energy conservation and carbon reduction benefits,an inventory of life cycle energy-conservation and carbon-reduction technologies for green highways is established,providing practical experience for the implementation of green and low-carbon development requirements in highway construction.
Influence of Horizontal Curve Radius on Vehicle Fuel Consumption and Pollutant Emissions on Tw o-Lane Highways
TU Shengwen, LEI Meimei, and GUO Wenyu
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.028
To investigate the influence of horizontal curve radius on vehicle fuel consumption and pollutant emissions on two-lane highways,this study developed a model based on running speed theory,vehicle driving dynamics,and a fuel consumption and emission analysis system.Fuel consumption and emissions of CO2,CO,HC,and NOx were calculated for a passenger car traveling along horizontal curves under three design speeds:40 km/h,60 km/h,and 80 km/h.The results show that the horizontal curve radius has a significant effect on vehicle fuel consumption and pollutant emissions.The trends of fuel consumption,CO2,and NOx emissions vary consistently with curve radius,while CO and HC emissions follow a similar but different trend.At the three design speeds,the maximum values of fuel consumption,CO2,and NOx emissions occur at radii of 80 m,125 m,and 450‒700 m,respectively.The maximum CO and HC emissions occur at the minimum allowable curve radius corresponding to each design speed.The lowest values of fuel consumption and all four pollutant emissions are observed at or beyond the critical curve radius where the vehicle ’s mid-curve speed reaches the desired operating speed.In addition,changes in the curve radius have the greatest impact on CO emissions,while their influence on fuel consumption,CO2,and NOx emissions is relatively smaller.
Foreign Highway
Reference and Inspi ration from Low-Carbon Development Experience of Foreign Highway Infrastructure
LU Chunying, GAO Shuohan, DU Xueyua n, JIAN Li, WANG Xinjun, and KONG Yaping
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.029
In order to provide supp ort for the scie ntific 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.
Traffic Consulting Research for Overseas Toll Road Investment and Mergers & Acquisition Projects
WU Lei and YAN Feng
Date posted: 8-15-2025
DOI: https://doi.org/10.14048/j.issn.1671-2579.2025.04.030
In recent years,the “investment,construction and operation integration ” model has gradually become the mainstream for overseas infrastructure projects.This paper aims to provide a reference for traffic consulting in overseas toll road investment and merger & acquisition projects.Taking the traffic assessment of a project in Indonesia as an example,this study evaluated and revised the forecast results in the Traffic Volume Forecast Report.In the absence of base-year OD (origin-destination ) matrix data,the evaluation was conducted based on field survey results and the forecasted future-year OD data of toll station entrances and exits in the report,combined with economic forecasts from international financial institutions.Three traffic volume scenarios,namely low,medium,and high were developed.The research indicates that,based on field survey data and considering the design capacity and influencing factors of toll stations,the conclusions from the evaluation are objective and reasonable.The assessment approach and methodology applied in this study are suitable for scenarios in which foundational OD matrix data,current traffic volume and related planning documents are insufficient.It provides a reference for traffic consulting during the investment and M&A stage of toll road enterprises in Indonesia and other overseas countries.
