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Monitoring and detection of steel bridge diseases:A review

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

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A modified back analysis method for deep excavation with multi-objective optimization procedure

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Journal of Rock Mechanics and Geotechnical engineering 2024年第4期16卷 1373-1387页

作者： Chenyang Zhao Le Chen Pengpeng Ni Wenjun Xia Bin Wang State Key Laboratory of Geomechanics and Geotechnical engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Guangdong Research Center for Underground Space Exploitation Technology School of Civil EngineeringSun Yat-sen UniversityGuangzhou510275China Southern Marine Science and engineering Guangdong Laboratory (Zhuhai) Zhuhai519000China jiangsu provincial transportation engineering construction bureau Nanjing210004China

Real-time prediction of excavation-induced displacement of retaining pile during the deep excavation process is crucial for construction *** paper proposes a modified back analysis method with multi-objective optimization procedure,which enables a real-time prediction of horizontal displacement of retaining pile during *** opposed to the traditional stage-by-stage back analysis,time series monitoring data till the current excavation stage are utilized to form a multi-objective ***,the multi-objective particle swarm optimization (MOPSO) algorithm is applied for parameter *** optimized model parameters are immediately adopted to predict the excavation-induced pile deformation in the continuous construction *** achieve efficient parameter optimization and real-time prediction of system behavior,the back propagation neural network (BPNN) is established to substitute the finite element model,which is further implemented together with MOPSO for automatic *** proposed approach is applied in the Taihu tunnel excavation project,where the effectiveness of the method is demonstrated via the comparisons with the site monitoring *** method is reliable with a prediction accuracy of more than 90%.Moreover,different optimization algorithms,including non-dominated sorting genetic algorithm (NSGA-II),Pareto Envelope-based Selection Algorithm II (PESA-II) and MOPSO,are compared,and their influences on the prediction accuracy at different excavation stages are *** results show that MOPSO has the best performance for high dimensional optimization task.

关键词： Multi-objective optimization Back analysis Surrogate model Multi-objective particle swarm optimization(MOPSO) Deep excavation

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A Simplified Method for the Stress Analysis of Underground Transfer Structures Crossing Multiple Subway Tunnels

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Computer Modeling in engineering & Sciences 2024年第6期139卷 2893-2915页

作者： Shen Yan Dajiang Geng Ning Dai Mingjian Long Zhicheng Bai College of Civil engineering Tongji UniversityShanghai200092China China construction 4th engineering bureau 6th Corp. Ltd.Shanghai201199China Department of Civil and Architecture engineering Hubei Polytechnic UniversityHuangshi435003China

According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock *** address this challenge,a subterranean transfer structure spanning multiple subway tunnels was *** on the function of piles in the transfer structure as springs with axial and bending stiffness,and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure,we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam *** resolved established simplifiedmechanicalmodel employed finite difference technology and the Newton-Simpsonmethod,elucidating the mechanical mechanism of the transfer *** research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure,subsequently reaching the deep soil layer and ensuring minimal impact on adjacent *** established simplified analysis method can be used for stress analysis of the transfer structure,concurrently considering soil stratification,pile foundation behavior,and plate *** pile length,pile section size,and beam section size within the transfer structure should account for the characteristics of the upper load,ensuring an even distribution of the beam bending moment.

关键词： Crossing tunnels transfer structure force mechanism simplify analysis layered soil mass

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Automatic Road Tunnel Crack Inspection Based on Crack Area Sensing and Multiscale Semantic Segmentation

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Computers, Materials & Continua 2024年第4期79卷 1679-1703页

作者： Dingping Chen Zhiheng Zhu Jinyang Fu Jilin He College of Mechanical and Electrical engineering Central South UniversityChangsha410083China Department of Geotechnical Guangdong Hualu Transportation Technology Company LimitedGuangzhou510000China National engineering Research Center of High-Speed Railway construction Technology Changsha410075China

The detection of crack defects on the walls of road tunnels is a crucial step in the process of ensuring travel safetyand performing routine tunnel maintenance. The automatic and accurate detection of cracks on the surface of roadtunnels is the key to improving the maintenance efficiency of road tunnels. Machine vision technology combinedwith a deep neural network model is an effective means to realize the localization and identification of crackdefects on the surface of road *** propose a complete set of automatic inspection methods for identifyingcracks on the walls of road tunnels as a solution to the problem of difficulty in identifying cracks during manualmaintenance. First, a set of equipment applied to the real-time acquisition of high-definition images of walls inroad tunnels is designed. Images of walls in road tunnels are acquired based on the designed equipment, whereimages containing crack defects are manually identified and selected. Subsequently, the training and validationsets used to construct the crack inspection model are obtained based on the acquired images, whereas the regionscontaining cracks and the pixels of the cracks are finely labeled. After that, a crack area sensing module is designedbased on the proposed you only look once version 7 model combined with coordinate attention mechanism (CAYOLOV7) network to locate the crack regions in the road tunnel surface images. Only subimages containingcracks are acquired and sent to the multiscale semantic segmentation module for extraction of the pixels to whichthe cracks belong based on the DeepLab V3+ network. The precision and recall of the crack region localizationon the surface of a road tunnel based on our proposed method are 82.4% and 93.8%, respectively. Moreover, themean intersection over union (MIoU) and pixel accuracy (PA) values for achieving pixel-level detection accuracyare 76.84% and 78.29%, respectively. The experimental results on the dataset show that our proposed two-staged

关键词： Road tunnel crack inspection crack area sensing multiscale semantic segmentation CA-YOLO V7 DeepLab V3+

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3D digital-image correlation insight into generalized relaxation behavior of sandstone under stress and pore pressure coupling

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Journal of Rock Mechanics and Geotechnical engineering 2024年第7期16卷 2516-2536页

作者： Cancan Chen Heping Xie Jiang Xu Seisuke Okubo Shoujian Peng Cunbao Li Minghui Li State Key Laboratory of Intelligent construction and Healthy Operation and Maintenance of Deep Underground engineering Shenzhen UniversityShenzhen518060China Guangdong provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and GreenEnergyCollege of Civil and Transportation EngineeringShenzhen UniversityShenzhen518060China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing400044China

The occurrence of geological hazards and the instability of geotechnical engineering structures are closely related to the time-dependent behavior of ***,the idealization boundary condition for constant stress in creep or constant strain in relaxation is not usually attained in natural geological ***,generalized relaxation tests that explore the simultaneous changes of stress and strain with time under different stress levels with constant pore-water pressure are conducted in this *** results show that in area I,area II,and area III,the stress and strain both change synchronously with time and show similar evolutionary laws as the strain-time curve for creep or the stress-time curve for *** the applied stress level surpasses the sci or scd threshold,the variations in stress and strain and their respective rates of change exhibit a significant *** radial deformation and its rate of change exhibit greater sensitivity in response to stress *** apparent strain deforms homogeneously at the primary stage,and subsequently,gradually localizes due to the microcrack development at the secondary ***,interconnection of the microcracks causes the formation of a shear-localization zone at the tertiary *** strain-time responses inside and outside the localization zone are characterized by local strain accumulation and inelastic unloading during the secondary and tertiary stages,*** width of the shear-localization zone is found to range from 4.43 mm to 7.08 mm and increased with a longer *** electron microscopy(SEM)reveals a dominant coalescence of intergranular cracks on the fracture surface,and the degree of physiochemical deterioration caused by water-rock interaction is more severe under a longer *** brittle sandstone’s time-dependent deformation is essentially controlled by microcrack development during generalized relaxation,and its expectancy-life is determi

关键词： Generalized relaxation Stress level Direction coefficient Major-strain field Microcrack damage Stress threshold

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Cause analysis of expressway traffic accidents based on accident statistics of Hunan provincial expressway in 2012-2018

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transportation Safety and Environment 2024年第1期6卷 83-92页

作者： Xinyu Liu Shengjun Huang Qun Chen Business school Foshan UniversityFoshan 528225GuangdongChina School of Traffic and transportation engineering Central South UniversityChangsha 410075HunanChina Hunan provincial Expressway Traffic Police Station Law Enforcement DepartmentChangsha 410007HunanChina

Based on the 2012–2018 accident statistics on the Hunan provincial Expressway in China,this paper analyses the proportion to which various factors contribute to accidents,as well as the trends over *** 2012 to 2018,the total number of general procedure handling accidents(*** accidents)increased first and then decreased,while the number of accidents and deaths per 1000 kilometres decreased year by *** total number of simple procedure handling accidents(*** accidents)increased year by year,but the number of accidents per 1000 kilometres remained relatively ***,fatigued driving,improper driving operation,failure to maintain a safe distance from the preceding vehicle and pedestrians entering the expressway are the main causes of general procedure handling *** to maintain a safe distance from the preceding vehicle as required and improper driving operation accounted for approximately 2/3 of the simple procedure handling *** view of the accidents caused by these factors,how to use law enforcement,education,science and technology and facilities construction to further reduce the occurrence of expressway traffic accidents is discussed.

关键词： expressway traffic accident cause analysis

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Track Defects Recognition Based on Axle-Box Vibration Acceleration and Deep- Learning Techniques

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Structural Durability & Health Monitoring 2024年第5期18卷 623-640页

作者： Xianxian Yin Shimin Yin Yiming Bu Xiukun Wei School of transportation engineering Shandong Jianzhu UniversityJinan250101China China construction Eighth bureau(Shandong)Design Consulting Co. Ltd.Jinan250100China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing100044China

As an important component of load transfer,various fatigue damages occur in the track as the rail service life and train trafﬁc increase gradually,such as rail corrugation,rail joint damage,uneven thermite welds,rail squats fas-tener defects,***-time recognition of track defects plays a vital role in ensuring the safe and stable operation of rail *** this paper,an intelligent and innovative method is proposed to detect the track defects by using axle-box vibration acceleration and deep learning network,and the coexistence of the above-mentioned typical track defects in the track system is ***,the dynamic relationship between the track defects(using the example of the fastening defects)and the axle-box vibration acceleration(ABVA)is investigated using the dynamic vehicle-track ***,a simulation model for the coupled dynamics of the vehicle and track with different track defects is established,and the wavelet power spectrum(WPS)analysis is performed for the vibra-tion acceleration signals of the axle box to extract the characteristic ***,using wavelet spectrum photos as input,an automatic detection technique based on the deep convolution neural network(DCNN)is sug-gested to realize the real-time intelligent detection and identiﬁcation of various track ***ﬁndings demonstrate that the suggested approach achieves a 96.72%classiﬁcation accuracy.

关键词： Track defects intelligent detection deep convolution neural network acceleration of axle-box vibration

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Local Climate Change Induced by Urbanization on a South China Sea Island

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Journal of Tropical Meteorology 2024年第1期30卷 11-19页

作者：郝宇李磊陈柏纬孙伟戴永久 School of Atmospheric Sciences Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Sun Yatsen UniversityZhuhaiGuangdong 519082 China Guangdong provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary ZhuhaiGuangdong 519082 China Key Laboratory of Tropical Atmosphere-Ocean System Ministry of EducationSun Yat-sen UniversityZhuhaiGuangdong 519082 China Guangdong provincial Marine Meteorology Science Data Center Guangzhou 510640 China Hong Kong Observatory KowloonHongkong 999077 China Meteorological bureau of Sansha City SanshaHainan 573199 China

The South China Sea is a hotspot for regional climate *** the past 40 years,considerable improvement has been made in the development and utilization of the islands in the South China Sea,leading to a substantial change in the land-use of the ***,research on the impact of human development on the local climate of these islands is *** study analyzed the characteristics of local climate changes on the islands in the South China Sea based on data from the Yongxing Island Observation Station and ERA5 ***,the influence of urbanization on the local climate of the South China Sea islands was explored in this *** findings revealed that the 10-year average temperature in Yongxing Island increased by approximately 1.11℃from 1961 to 2020,and the contribution of island development and urbanization to the local warming rate over 60 years was approximately 36.2%.The linear increasing trend of the annual hot days from 1961–2020 was approximately 14.84 days per *** diurnal temperature range exhibited an increasing trend of 0.05℃per decade,whereas the number of cold days decreased by 1.06days per *** rapid increase in construction on Yongxing Island from 2005 to 2021 led to a decrease in observed surface wind speed by 0.32 m s^(-1)per ***,the number of days with strong winds decreased,whereas the number of days with weak winds ***,relative humidity exhibited a rapid decline from 2001 to 2016 and then *** study also found substantial differences between the ERA5 re-analysis and observation data,particularly in wind speed and relative humidity,indicating that the use of re-analysis data for climate resource assessment and climate change evaluation on island areas may not be feasible.

关键词： local climate climate change Yongxing Island a South China Sea island climate change induced by urbanization

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Review on frost resistance and anti-clogging of pervious concrete

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Journal of Traffic and transportation engineering(English Edition) 2024年第3期11卷 481-496页

作者： Zhuo Wang Zhichen Liu Feng Zeng Kun He Shuaicheng Guo China Railway construction Group Co. Ltd.Beijing 100040China State Key Laboratory of Bridge Safety and Resilience College of Civil EngineeringHunan UniversityChangsha 410082China

Pervious concrete is a special type of concrete that is of high porosity and contains no or a small amount of fine aggregate,and it is an important basic material for sponge city *** presence of a large number of connected pores inside pervious concrete leads to a marked difference in durability failure mechanism compared with that of ordinary *** this study,the frost resistance and anti-clogging of pervious concrete were introduced in detail,and the methods to improve their performance were summarized *** cracking pattern of pervious concrete is influenced by geometric characteristics and three-dimensional morphological features of pores,resulting in its crack generation,development,and geometry being significantly different from those of ordinary concrete,thus leading to different freeze-thaw cycle *** addition,due to its different pore structure compared to ordinary concrete,three types of clogging mechanisms,affecting the long-term permeability of pervious concrete were elaborated systematically(i.e.,physical clogging,biological clogging,and chemical clogging).And the ways to improve the anti-clogging of pervious concrete are systematically presented from multiple ***,in order to broaden the engineering applications of pervious concrete,some research proposals are presented in this study.

关键词： Pervious concrete Connected pore Frost resistance Clogging mechanism

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Stability behavior of the Lanxi ancient flood control levee after reinforcement with upside-down hanging wells and grouting curtain

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Journal of Mountain Science 2024年第1期21卷 84-99页

作者： QIN Zipeng TIAN Yan GAO Siyuan ZHOU Jianfen HE Xiaohui HE Weizhong GAO Jingquan School of Water Conservancy and Environment engineering Zhejiang University of Water Resources and Electric PowerHangzhou 310018China Department of Civil engineering Imperial College LondonLondonSW71BFEngland Lanxi Water Affairs bureau Lanxi 321102China Zhejiang Water Conservancy engineering Consulting Co. LtdHangzhou 310051China

The stability of the ancient flood control levees is mainly influenced by water level fluctuations, groundwater concentration and rainfalls. This paper takes the Lanxi ancient levee as a research object to study the evolution laws of its seepage, displacement and stability before and after reinforcement with the upside-down hanging wells and grouting curtain through numerical simulation methods combined with experiments and observations. The study results indicate that the filled soil is less affected by water level fluctuations and groundwater concentration after reinforcement. A high groundwater level is detrimental to the levee's long-term stability, and the drainage issues need to be fully considered. The deformation of the reinforced levee is effectively controlled since the fill deformation is mainly borne by the upside-down hanging wells. The safety factors of the levee before reinforcement vary significantly with the water level. The minimum value of the safety factors is 0.886 during the water level decreasing period, indicating a very high risk of the instability. While it reached 1.478 after reinforcement, the stability of the ancient levee is improved by a large margin.

关键词： Stability analysis Multiple factors Antiseepage reinforcement Upside-down hanging well Grouting curtain Ancient levee

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