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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 728-737页

作者：何子明申爱琴 WANG Xiaobin WU Jinhua WANG Lusheng School of Civil and Architectural engineering Liaoning University of TechnologyJinzhou 121001China School of Highway Chang’an UniversityXi’an 710064China Department of Road and bridge engineering Liaoning Provincial College of Communica-tionsShenyang 110122China

The modification methods of pozzolan slurry combined with sodium silicate and silicon-based additive were respectively adopted to treat recycled coarse brick-mixed aggregate(RCBA)in this *** compressive strength and chloride permeability resistance of recycled aggregate concrete(RAC)before and after modification treatment were tested,and the microstructure of RAC was analyzed by mercury intrusion porosimetry(MIP)and scanning electron microscopy(SEM).The results show that the physical properties of RCBA strengthened by modification treatment are improved,and the compressive strength and chloride permeability resistance of treated RAC are also significantly *** modification treatment optimizes the pore size distribution of RAC,which increases the number of gel pores and transition pores,and decreases the number of capillary pores and macro *** surface fractal dimension shows a significant correlation with chloride diffusion coefficient,indicating that the variation of chloride permeability of treated RAC is consistent with the microstructure evolution.

关键词： recycled aggregate concrete modification treatment compressive strength chloride permeability resistance microstructure

A Rapid Crack Detection Technique Based on Attention for Intelligent M&O of Cross-Sea bridge

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China Ocean engineering 2024年第5期38卷 866-876页

作者： ZHOU Yong-chuan LI Guang-jun WEI Wei WANG Ya-meng JING Qiang Hong Kong-Zhuhai-Macao bridge Authority National Observation and Research Station of Material Corrosion and Structural Safety of Hong Kong-Zhuhai-Macao bridge in Guangdong Wuhan Maritime Communication Research Institute

Rapid and accurate segmentation of structural cracks is essential for ensuring the quality and safety of engineering projects. In practice, however, this task faces the challenge of finding a balance between detection accuracy and efficiency. To alleviate this problem, a lightweight and efficient real-time crack segmentation framework was ***, in the network model system based on an encoding-decoding structure, the encoding network is equipped with packet convolution and attention mechanisms to capture features of different visual scales in layers,and in the decoding process, we also introduce a fusion module based on spatial attention to effectively aggregate these hierarchical features. Codecs are connected by pyramid pooling model(PPM) filtering. The results show that the crack segmentation accuracy and real-time operation capability larger than 76% and 15 fps, respectively, are validated by three publicly available datasets. These wide-ranging results highlight the potential of the model for the intelligent O&M for cross-sea bridge.

关键词： bridge defect detection crack detection lightweight design

Effects of the Water-Cement Ratio and the Molding Temperature on the Hydration Heat of Cement

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 990-998页

作者：代金鹏 HE Jie WANG Qicai LOU Xuyu National and Provincial Joint engineering Laboratory of Road&bridge Disaster Prevention and Control Lanzhou Jiaotong UniversityLanzhou 730070China Civil engineering Department Lanzhou Jiaotong UniversityLanzhou 730070China

The effects of the water-cement ratio and the molding temperature on the hydration heat of cement were investigated with semi-adiabatic *** specimens were prepared with water-cement ratios of 0.31,0.38,and 0.45,and the molding temperature was specified at 10 and 20℃.The experimental results show that,as the water-binder ratio increases,the value of the second temperature peak on the temperature curve of the cement paste decreases,and the age at which the peak appears is *** higher the water-cement ratio,the higher the hydration heat release in the early period of cement hydration,but this trend reverses in the late *** are intersection points of the total hydration heat curve of the cement pastes under the influence of the water-cement ratio,and this law can be observed at both molding *** the increase in the molding temperature,the age of the second temperature peak on the temperature curve of the cement paste will advance,but the temperature peak will *** higher the molding temperature,the earlier the acceleration period of the cement hydration began,and the larger the hydration heat of the cement in the early stage,but the smaller the total heat in the late period.A subsection function calculation model of the hydration heat,which was based on the existing models,was proposed in order to predict the heat of the hydration of the concrete.

关键词： semi-adiabatic calorimetry hydration heat water-cement ratio molding temperature modeling

Investigation and measurement of old building response to the overlapped shield tunnel of multiple schemes in the sandy cobble stratum

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Underground Space 2024年第2期15卷 260-274页

作者： Xue Li Aopeng Geng School of Geoscience and Technology Southwest Petroleum UniversityChengduSichuan 610500China China Railway Construction bridge engineering Bureau Group Co. Ltd.Tianjin 300300China

Ground movements due to tunneling are becoming increasingly critical as buildings are located around construction *** study proposes a new combined reinforcement method using a foundation grouting oblique pipe *** former improves the bearing capacity of the subsoil,and the latter blocks the transmission of soil deformation,which weakens the influence of construction during overlapped tunnel *** on this new method,a case study of the shield tunneling response to an old building in Line 6 of China’s Chengdu Metro is ***,three-dimensional numerical models without reinforcement,traditional foundation grouting reinforcement,and the new combined reinforcement schemes were *** numerical simulation performance was verified using a set of field instrumentation data,which demonstrated that the old building response to the overlapped tunnels was under control,and the maximum deformation,angular distortion,and principal tensile strain of the building were 5.25 mm,5.1010–6 rad/m,and 0.0081%,*** with the traditional reinforcement scheme,the deformation,angular distortion,and principal tensile strain in the combined reinforcement scheme were reduced by 54.78%,71.02%,and 70.22%,*** results have important implications for the design and construction of shield tunnels and their response to old buildings.

关键词： Overlapped tunnels Reinforcement schemes Under-crossing Old building Numerical simulation

Comparative analysis between single-train passing and double-train intersection in a tunnel

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第5期25卷 429-442页

作者： Jianming DU Qian FANG Xuan ZHANG Hualao WANG bridge and Tunnel Research Center Research Institute of Highway Ministry of TransportBeijing 100088China Tunnel and Underground engineering Research Center of Ministry of Education Beijing Jiaotong UniversityBeijing 00044China

Aerodynamic pressure significantly impacts the scientific evaluation of tunnel service *** aerodynamic pressure of two trains running in a double-track tunnel is considerably more complicated than that of a single *** used the numerical method to investigate the difference in aerodynamic pressure between a single train and two trains running in a double-track ***,the numerical method was verified by comparing the results of numerical simulation and on-site ***,the characteristics of aerodynamic pressure were ***,the influence of various train-tunnel factors on the characteristics of aerodynamic pressure was *** results show that the aerodynamic pressure variation can be divided into stage I:irregular pressure fluctuations before the train tail leaves the tunnel exit,and stage II:periodic pressure declines after the train tail leaves the tunnel *** addition,the aerodynamic pressure simultaneously jumps positively or drops negatively for a single train or two trains running in double-track tunnel *** pressure amplitude in the two-train case is higher than that for a single *** maximum positive peak pressure difference(P_(STP))and maximum negative peak pressure difference(P_(STN))increase as train speed rises to the power from 2.256 to 2.930 in stage *** P_(STP) and P_(STN) first increase and then decrease with the increase of tunnel length in stage *** P_(STP) and P_(STN) increase as the blockage ratio rises to the power from 2.032 to 2.798 in stages I and II.

关键词： Railway tunnel Aerodynamic effect Pressure characteristic Train speed Tunnel length Blockage ratio

Deformation mechanism and limit support pressure of cutting steel plate during connection between pipes in large spacing using pipe curtain structure method

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Underground Space 2024年第5期18卷 83-96页

作者： Xiang Liu Rui Zhang Jun Huang Guang Zhao Qian Fang Annan Jiang Liaoning Key Laboratory of Marine Environmental bridge and Tunnel engineering Dalian Maritime UniversityDalian 116026China JSTI Group Nanjing 210017China Key Laboratory for Urban Underground engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

The pipe curtain structure method(PSM)is a novel construction method to control ground deformation *** with the traditional pipe-roofing and pipe jacking method,the connection between pipes in large spacings using PSM is widely acknowledged as a unique construction *** study on this connection procedure is needed to resolve similar cases in that the pipes are inevitably constructed on both sides of existing *** the steel plate during the connection procedure is the first step,which is crucial to control the safety and stability of the surrounding environment and existing *** deformation mechanism and limit support pressure of the cutting steel plate during the connection between pipes in large spacings are studied in this paper,relying on the undercrossing Yifeng gate tower project of Jianning West Road River Crossing Channel in Nanjing,China.A modified 3D wedge-prism failure model is proposed using the 3D discrete element *** with Terzaghi loose earth pressure theory and the limit equilibrium theory,the analytical solutions for the limit support pressure of the excavation face of the cutting steel plate are *** modified 3D wedge-prism failure model and corresponding analytical solutions are categorised into two cases:(a)unilateral cutting scheme,and(b)bilateral cutting *** analytical solutions for the two cases are verified from the numerical simulation and in-situ data and compared with the previous *** comparative analysis between the unilateral and bilateral cutting schemes indicates that the bilateral cutting scheme can be adopted as a *** bilateral cutting scheme saves more time and induces less ground deformation than the unilateral one due to the resistance generated from the superimposed *** addition,the parametric sensitivity analysis is carried out using an orthogonal experimental *** main influencing factors arranged from high to low are the pipe sp

关键词： Pipe curtain structure method Wedge-prism failure model Limit support pressure Discrete element method Connection between pipes

Flow resistance in the channel-bar landscape of large alluvial rivers

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Frontiers of Earth Science 2024年第2期18卷 412-421页

作者： Yong HU Congcong LIU Jinyun DENG Wei ZHANG Yitian LI State Key Laboratory of Water Resources and Hydropower engineering Science Wuhan UniversityWuhan 430072China CCCC Second Harbor engineering Company Ltd Wuhan 430040China Key Laboratory of Large-span bridge Construction Technology Wuhan 430040China Research and Development Center of Transport Industry of Intelligent Manufacturing Technologies of Transport Infrastructure Wuhan 430040China CCCC Highway bridge National engineering Research Centre Co.Ltd Wuhan 430040China

Accurate approaches for estimating flow resistance in large alluvial rivers are fundamental for simulating discharge,sediment transport,and flood ***,methods for estimating riverbed resistance and additional resistance in the channel-bar landscapes remain poorly *** this study,we used in situ river bathymetry,sediment,and hydraulic data from the Shashi Reach in the Yangtze River to develop a semi-empirical approach for calculating flow *** method quantitatively separates flow resistance into riverbed resistance and additional resistance and shows high accuracy in terms of deviation ratio(~20%),root-mean-square error(~0.008),and geometric standard deviation(~3).Additional resistance plays a dominant role under low-flow conditions but a secondary role under high flows,primarily due to the reduction in momentum exchange in channel-bar regions as discharge *** resistance first decreases and then increases,which might be attributed to bedform changes in the lower and transitional flow regimes as flow velocity ***,our findings further the understanding of dynamic changes in flow resistance in the channel-bar landscapes of large river systems and have important implications for riverine ecology and flood management.

关键词： flow resistance channel-bar landscape interaction region large river bedform

Surrounding rock pressure in the tunnel portal section through moraine under freeze-thaw action

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Journal of Mountain Science 2024年第7期21卷 2480-2493页

作者： CHEN Zhimin LIU Baoli LIU Yaohui XU Jiangtao School of Civil engineering Lanzhou Jiaotong UniversityLanzhou 730070China CSCEC AECOM Consultants Co. ltdLanzhou 730000China National and Local Joint engineering Laboratory of Road and bridge engineering Disaster Prevention Technology Lanzhou Jiaotong UniversityLanzhou 730070China

Moraines,characterized by the accumulation of rock and soil debris transported by glacial activity,present unique challenges for tunnel construction,particularly in portal sections,due to prevailing geographical and climatic conditions that facilitate freeze-thaw *** these challenges,there is a dearth of studies investigating the influence of freeze-thaw action and water content on the mechanical properties of moraines,and no research on calculating surrounding rock pressure in moraine tunnels subjected to freeze-thaw *** this study,direct shear tests under freeze-thaw cycles were conducted to examine the effects of freeze-thaw cycles and water content on the mechanical properties of frozen moraine.A comprehensive parameter K,integrating the number of freeze-thaws and water content,was introduced to model cohesion *** on Terzaghi Theory,we propose an improved algorithm for calculating surrounding rock pressure at the portal section of moraine *** a tunnel as a case study,surrounding rock pressure was calculated under various conditions to validate the Improved Algorithm's *** results show that:(1)Strength loss exhibits a linear trend with the number of freeze-thaw cycles at water content levels of 4%and 8%,while at 12%water content,previous freeze-thaw cycles induce more significant damage to the soil.(2)Moraine saturation peaks between 8%and 12%water *** repeated freeze-thaw cycles,moraine shear strength initially increases before decreasing with varying water content.(3)The internal friction angle of moraine experiences slight reductions with prolonged freeze-thaw cycles,but both freeze-thaw cycles and water content significantly influence cohesion.(4)Vertical surrounding rock pressure increases after the initial freeze-thaw cycle,particularly with higher water content,although freeze-thaw cycles have minimal effect on it.(5)Freeze-thaw cycles lead to a substantial increase in lateral surrounding rock pre

关键词： Moraines Freeze-thaw cycles Direct shear test Surrounding rock pressure

Performance evaluation of new epoxy resin-based composite phase change materials and their asphalt mixture

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Journal of Traffic and Transportation engineering(English Edition) 2024年第3期11卷 507-522页

作者： Yuchao Gao Jiao Jin Shuai Liu Yinfei Du Guoping Qian Jie Mao Yongqiang Zhu School of Traffic and Transportation engineering Changsha University of Science and TechnologyChangsha 410114China School of Civil engineering Central South UniversityChangsha 410075China Guangdong Guanyue Highway and bridge Co. Ltd.Guangzhou 511452China

In recent years,the temperature-adjusted asphalt pavement has been an extensive concern by scholars in various countries,and this pavement can reduce temperaturerelated *** this study,the shaped composite phase change materials(CPCMs)were successfully synthesized by two processes,which are vacuum impregnation and epoxy ***,the applicability of CPCMs in asphalt mixtures was evaluated by microscopic characterization,chemical compatibility,thermal properties,durability,and leakage ***,CPCMs were applied to the asphalt mixture to evaluate its temperatureadjusted characteristics and pavement ***,the performance of the temperature-adjusted asphalt mixture was analyzed by integrating all *** research shows that the prepared CPCMs have excellent thermal properties and durability,the phase transition temperature is 48.93℃,and the phase transition enthalpy is 106.5 J/g,which fully meets the requirements for use in *** temperature-adjusted asphalt mixture could alleviate the occurrence of extreme temperature,which was 4.9℃lower than the conventional *** pavement performance of the temperatureadjusted asphalt mixture can meet the specified standards for humid *** the factors,the recommended amount of CPCMs is 1.5%.The research results provide a basis for the promotion of temperature-adjusted asphalt pavement and effectively support the development of pavement engineering technology.

关键词： Pavement engineering Temperature-adjusted asphalt mixture Phase change materials Thermal performance

Monitoring and detection of steel bridge diseases:A review

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Journal of Traffic and Transportation engineering(English Edition) 2024年第2期11卷 188-208页

作者： Chuang Cui Qinghua Zhang Dengke Zhang Wulve Lao Lemou Wu Zhenxiong Jiang National Key Laboratory of bridge Intelligent and Green Construction Southwest Jiaotong UniversityChengdu 610031China School of Civil engineering Southwest Jiaotong UniversityChengdu 610031China Jiangsu Provincial Transportation engineering Construction Bureau Nanjing 210004China

Fatigue,corrosion,and bolt loosening are the main causes of structural performance degradation and collapse in steel *** monitoring of steel bridge diseases is a basic premise for ensuring high-quality operation and maintenance of steel *** this regard,a summary and analysis were conducted on the classification of steel bridge diseases,monitoring and detection methods,application statuses,and major *** main causes,research status,and development trends of steel bridge diseases are *** results showed that,for fatigue crack problems,fatigue crack initiation has a small scale,high difficulty in monitoring and detection,few methods,and low *** the cracks grow,the difficulty of monitoring and detection decreases,the number of methods increases,and the accuracy *** crack monitoring and detection are affected by the environmental and vehicular *** corrosion features are evident in steel bridges,and corrosion identification methods and technologies are rapidly *** and detecting corrosion in concealed areas is difficult and requires further improvements in monitoring and detection technologies and their *** and detection methods and supporting equipment for bolt loosening in steel bridges are rapidly *** development of intelligent monitoring and detection technologies and supporting equipment is an important research topic that urgently needs to be addressed for the full-lifecycle operation and maintenance of steel bridges and the sustainable development of bridge *** new intelligent sensing components based on high-performance materials and sensing element design theory to improve the monitoring and detection perception ability is an important development direction for steel bridge monitoring and *** on intelligent monitoring and detection technologies,standardized indicators,and related topics based on intelligent oper

关键词： Steel bridge Diseases Fatigue crack Corrosion Bolt loosening Monitoring and detection