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

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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Risk assessment of high-speed railway CTC system based on improved game theory and cloud model

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railway Sciences 2024年第3期3卷 388-410页

作者： Yanhao Sun Tao Zhang Shuxin Ding Zhiming Yuan Shengliang Yang Signal and Communication Research Institute China Academy of Railway Sciences Corporation LimitedBeijingChina Traffic Management Laboratory for High-Speed railway National Engineering Research Center of System Technology for High-Speed Railway and Urban Rail TransitBeijingChina Signal and Telecommunication Department China Railway Chengdu Group Company LimitedChengduChina Postgraduate Department China Academy of Railway SciencesBeijingChina

Purpose-In order to solve the problem of inaccurate calculation of index weights,subjectivity and uncertainty of index assessment in the risk assessment process,this study aims to propose a scientific and reasonable centralized traffic control(CTC)system risk assessment ***/methodologylapproach-First,system-theoretic process analysis(STPA)is used to conduct risk analysis on the CTC system and constructs risk assessment indexes based on this ***,to enhance the accuracy of weight calculation,the fuzzy analytical hierarchy process(FAHP),fuzzy decision-making trial and evaluation laboratory(FDEMATEL)and entropy weight method are employed to calculate the subjective weight,relative weight and objective weight of each *** three types of weights are combined using game theory to obtain the combined weight for each *** reduce subjectivity and uncertainty in the assessment process,the backward cloud generator method is utilized to obtain the numerical character(NC)of the cloud model for each *** NCs of the indexes are then weighted to derive the comprehensive cloud for risk assessment of the CTC *** cloud model is used to obtain the CTC system's comprehensive risk *** model's similarity measurement method gauges the likeness between the comprehensive risk assessment cloud and the risk standard ***,this process yields the risk assessment results for the CTC ***-The cloud model can handle the subjectivity and fuzziness in the risk assessment process *** cloud model-based risk assessment method was applied to the CTC system risk assessment of a railway group and achieved good ***/value-This study provides a cloud model-based method for risk assessment of CTC systems,which accurately calculates the weight of risk indexes and uses cloud models to reduce uncertainty and subjectivity in the assessment,achieving effective risk assessment of CTC *** can provide a reference and

关键词： High-speed railway Centralized traffic control Risk assessment Game theory Cloud model Paper type Research paper

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Mechanical behaviors of mylonitic granite and granitic protomylonite in a deep ductile shear zone

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2663-2677页

作者： Lanbin Zhang Ru Zhang Li Ren Zhilong Zhang Zetian Zhang Dong Wang Xinzhong Wang Huijun Lu State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China MOE Key Laboratory of Deep Earth Science and Engineering Sichuan UniversityChengdu610065China China railway Eryuan Engineering Group company Ltd.Chengdu610065China School of Architecture and Civil Engineering Xihua UniversityChengdu610065China

For projects near the tectonic belt,mylonite of varying metamorphic degrees may be *** matrix proportion of rock reflects its internal microscopic characteristics,thus it is beneficial for engineering geology to study the effect of the matrix proportion on the mechanical properties and rupture behaviors of *** of mylonitic granite and granitic protomylonite with varying matrix proportions were obtained from a ductile shear zone for a series of uniaxial compression and acoustic emission(AE)*** results showed that with the increase in matrix proportion,the average strength and elastic modulus of the samples increased,and the rock sample with the largest matrix proportion exhibited the maximum peak stress of 244.42 MPa,which was 45.86%greater than the average peak stress of the rock samples with the smallest matrix *** the rock samples with larger matrix proportion,their mechanical parameters exhibited greater dispersion and the large-scale appearance of AE events occurred earlier,showing a relatively gradual failure *** samples had larger accumulated AE parameter values and greater degree of *** contrast,for samples with smaller matrix proportions,the large-scale appearance of AE events occurred close to the peak stress,indicating that the occurrence of damage and fractures was centralized and *** samples had lower accumulated AE parameter values and fewer cracks after ***,for the rock samples with more matrix proportion,the average variance of the b-value was 1.1,which was lower than that of rock samples with the smallest matrix proportion(the average variance of the b-value was 3.7).Furthermore,it can be predicted that under certain stress,the failure depth around a tunnel is generally smaller when the strength of rock samples with larger matrix proportion is greater.

关键词： Mylonite Matrix proportion Mechanical properties Acoustic emission(AE) Rupture behaviors

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Evaluating the thermal environment of urban land surfaces in Yakutsk,a city located in a region of continuous permafrost

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Advances in Climate Change Research 2024年第1期15卷 113-123页

作者： Xiang-Long LI Ze ZHANG Jin-Xin LU Anatoli BROUCHKOV Qing-Kai YAN Qi-Hao YU Sheng-Rong ZHANG Andrey MELNIKOV School of Civil Engineering and Transportation Institute of Cold Regions Science and EngineeringPermafrost InstituteNortheast Forestry UniversityHarbin150040China China railway Qinghai-Tibet Group company Xining 810000China Department of Geocryology Faculty of GeologyLomonosov Moscow State UniversityMoscow 119234Russian Federation State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco Envi ronment and Re sourcesChinese Academy of SciencesLanzhou 730000China Melnikov Permafrost Institute Siberian BranchRussian Academy of ScienceYakutsk 677010Russian Federation

Rapid urbanization has led to changes in the urban land surface thermal ***,there are still much unknown about the urban land surface thermal conditions in permafrost *** is a unique geological environment,changes in the urban land surface thermal environment may trigger geological disasters caused by permafrost *** study utilized remote sensing data and geographic de-tectors to identify the dynamic changes in land surface temperature(LST)and land use/land cover(LU/LC)in Yakutsk,as well as the potential factors contributing to LST *** 1992 and 2020,the built-up area in Yakutsk increased by 36%,and the annual average LST in Yakutsk has risen by 6.67℃,accompanied by an expansion of high-temperature *** ongoing greening efforts,rapid urbanization poses a threat to these green *** in the normalized difference built-up index(NDBI)and land use transfer(LDT)were identified as the primary drivers of urban LST *** integrating geographic detector technology and artificial neural network models,we optimized the selection of input factors in the prediction model and used it to explore the future changes in LST in *** average LST in Yakutsk is expected to reach 23.4℃ and 25.1℃ in 2030 and 2040,respectively,with a further increase in high-temperature *** study provides a reference for ecological,hydrological,and geological assessments of cities in permafrost regions.

关键词： Remote sensing Land surface temperature Land use/Land cover Permafrost Yakutsk

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Probing dark matter particles from evaporating primordial black holes via electron scattering in the CDEX-10 experiment

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Science China(Physics,Mechanics & Astronomy) 2024年

作者： Zhenhua Zhang Litao Yang Qian Yue Kejun Kang Yuanjing Li Haipeng An Greeshma C. Jianping Chang Yunhua Chen Jianping Cheng Wenhan Dai Zhi Deng Changhao Fang Xinping Geng Hui Gong Qiuju Guo Tao Guo Xuyuan Guo Li He Shengming He Jinwei Hu Hanxiong Huang Tuchen Huang Lin Jiang S.Karmakar Haubin Li Hanyu Li Jianmin Li Jin Li Qianyun Li Renmingjie Li Xueqian Li Yulan Li Yifan Liang Bin Liao FongKay Lin ShinTed Lin Jiaxuan Liu Shukui Liu Yandong Liu Yu Liu Yuanyuan Liu Hao Ma Yucai Mao Qiyuan Nie Jinhua Ning Hui Pan Ningchun Qi Jie Ren Xichao Ruan Monoj Kumar Singh Tianxi Sun Changjian Tang Yang Tian Guangfu Wang Junzheng Wang Li Wang Qing Wang Yufeng Wang Yunxiang Wang Henry Tsz-King Wong Shiyong Wu Yucheng Wu Haoyang Xing Rui Xu Yin Xu Tao Xue Yulu Yan Nan Yi Chunxu Yu Haijun Yu Jianfeng Yue Ming Zeng Zhi Zeng Bingtao Zhang Fengshou Zhang Lei Zhang Zhenyu Zhang Jizhong Zhao Kangkang Zhao Minggang Zhao Jifang Zhou Zuying Zhou Jingjun Zhu Sino-french Institute of Nuclear and Technology Sun Yet-sen University School of Physics Nankai University Department of Physics Banaras Hindu University Department of Physics Beijing Normal University Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of Engineering Physics Tsinghua University Department of Physics Tsinghua University Institute of Physics Academia Sinica Taipei NUCTECH company YaLong River Hydropower Development company College of Nuclear Science and Technology Beijing Normal University College of Physics Sichuan University School of Physics Peking University Department of Nuclear Physics China Institute of Atomic Energy

Dark matter （DM） is a major constituent of the ***,no definite evidence of DM particles （denoted as“χ”） has been found in DM direct detection （DD） experiments to *** is a novel concept of detectingχfrom evaporating primordial black holes （PBHs）.We search forχemitted from PBHs by investigating their interaction with target *** examined PBH masses range from 1×1015to 7×1016g under the current limits of PBH abundance *** 205.4 kg·day data obtained from the CDEX-10 experiment conducted in the China Jinping Underground Laboratory,we exclude theχ-electron （χ-e）elastic-scattering cross sectionσχe～5×10-29cm2forχwith a mass mχ0.1 ke V from our *** the higher radiation background but lower energy threshold （160 eV）,CDEX-10 fills a part of the gap in the previous *** (mχ,σχe) can be determined in the future,DD experiments are expected to impose strong constraints on fPBHfor large MPBHs.

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Investigation of the hydro-mechanical behaviour of fouled ballast

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第4期14卷 244-255页

作者： Yu-jun CUI Trong Vinh DUONG Anh Minh TANG Jean-Claude DUPLA Nicolas CALON Alain ROBINET Laboratoire Navier/CERMES Ecole des Ponts ParisTechBlaise PascalCité DescartesChamps-sur-Marne 77455 Marne-la-Vallée Cedex-France french national railway company 93574La Plaine St DenisFrance

In this study,a fouled ballast taken from the site of Sénissiat,France,was *** the hydraulic behaviour,a large-scale cell was developed allowing drainage and evaporation tests to be carried out with monitoring of both suction and volumetric water content at various positions of the *** was observed that the hydraulic conductivity of fouled ballast is decreasing with suction increase,as for common unsaturated *** effect of fines content was found to be *** the mechanical behaviour,both monotonic and cyclic triaxial tests were carried out using a large-scale triaxial *** water contents were *** results were interpreted in terms of shear strength and permanent axial *** appeared that the water content is an important factor to be accounted for since any increase of water content or degree of saturation significantly decreases the shear strength and increases the permanent *** modelling has been attempted based on the experimental *** model in its current state is capable of describing the effects of stress level,cycle number and water content.

关键词： Fouled ballast Degree of saturation Hydraulic behaviour Mechanical behaviour Fines content Constitutive modelling

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A novel diffusion model considering curvature radius at the bonding interface in a titanium/steel explosive clad plate

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International Journal of Minerals,Metallurgy and Materials 2015年第9期22卷 956-965页

作者： Hai-tao Jiang Qiang Kang Xiao-qian Yan national Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing China railway Materials Technologies company Limited

This article introduces an element diffusion behavior model for a titanium/steel explosive clad plate characterized by a typical curved interface during the heat-treatment process. A series of heat-treatment experiments were conducted in the temperature range from 750℃ to 950℃, and the effects of heat-treatment parameters on the microstructural evolution and diffusion behavior were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and electron-probe microanalysis. Carbon atoms within the steel matrix were observed to diffuse toward the titanium matrix and to aggregate at the bonding interface at 850℃ or lower; in contrast, when the temperature exceeded 850℃, the mutual diffusion of Ti and Fe occurred, along with the diffusion of C atoms, resulting in the for- marion of Ti-Fe intermetallics （Fe2Ti/FeTi）. The diffusion distances of C, Ti, and Fe atoms increased with increasing heating temperature and/or holding time. On the basis of this diffusion behavior, a novel diffusion model was proposed. This model considers the effects of various factors, including the curvature radius of the curved interface, the diffusion coefficient, the heating temperature, and the holding rime. The experimental results show good agreement with the calculated values. The proposed model could clearly provide a general prediction of the elements＇ diffusion at both straight and curved interfaces.

关键词： explosive bonding metal cladding diffusion models interfaces heat treatment

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Diffusion and catalyst efficiency in hierarchical zeolite catalysts

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national Science Review 2020年第11期7卷 1726-1742页

作者： Peng Peng Xiong-Hou Gao Zi-Feng Yan Svetlana Mintova State Key Laboratory of Heavy Oil Processing China University of Petroleum Laboratory of Catalysis and Spectrochemistry (LCS) Normandy University National Graduate School of Engineering of Caen (ENSICAEN)University of Caen (UNICAEN) French National Center for Scientific Research (CNRS) Petrochemical Research Institute China National Petroleum Company

The preparation of hierarchical zeolites with reduced diffusion limitation and enhanced catalyst efficiency has become a vital focus in the field of zeolites and porous materials chemistry within the past decades. This review will focus on the diffusion and catalyst efficiency of hierarchical zeolites and industrial catalysts. The benefits of diffusion and catalyst efficiency at two levels of hierarchies (zeolitic component level and industrial catalyst level) from a chemical reaction engineering point of view will be analysed. At zeolitic component level, three types of mesopores based on the strategies applied toward enhancing the catalyst effectiveness factor are presented:(i)‘functional mesopores’(raising effective diffusivity);(ii)‘auxiliary mesopores’(decreasing diffusion length); and (iii)‘integrated mesopores’(a combination thereof). At industrial catalyst level, location and interconnectivity among the constitutive components are *** hierarchical pore interconnectivity in multi-component zeolite based industrial catalysts is exemplified by fluid catalytic cracking and bi-functional hydroisomerization catalysts. The rational design of industrial zeolite catalysts at both hierarchical zeolitic component and catalyst body levels can be fully comprehended using the advanced in situ and/or operando spectroscopic, microscopic and diffraction techniques.

关键词： diffusion effectiveness factor pore connectivity hierarchical zeolite industrial catalyst advanced characterization

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Microscopic damage evolution of anisotropic rocks under indirect tensile conditions: Insights from acoustic emission and digital image correlation techniques

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International Journal of Minerals,Metallurgy and Materials 2023年第9期30卷 1680-1691页

作者： Chaoqun Chu Shunchuan Wu Chaojun Zhang Yongle Zhang School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Department of Civil&Mineral Engineering University of TorontoToronto ON M5S 1A4Canada Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunmiing 650093China China railway Sixth Group Limited company Beijing 100036China

The anisotropy induced by rock bedding structures is usually manifested in the mechanical behaviors and failure modes of *** tests are conducted for seven groups of shale specimens featuring different bedding angles. Acoustic emission (AE) and digital image correlation (DIC) technologies are used to monitor the in-situ failure of the specimens. Furthermore, the crack morphology of damaged samples is observed through scanning electron microscopy (SEM). Results reveal the structural dependence on the tensile mechanical behavior of shales. The shale disk exhibits compression in the early stage of the experiment with varying locations and durations. The location of the compression area moves downward and gradually disappears when the bedding angle increases. The macroscopic failure is well characterized by AE event location results, and the dominant frequency distribution is related to the bedding angle. The b-value is found to be *** crack turning angle between layers and the number of cracks crossing the bedding both increase with the bedding angle, indicating competition between crack propagations. SEM results revealed that the failure modes of the samples can be classified into three types:tensile failure along beddings with shear failure of the matrix, ladder shear failure along beddings with tensile failure of the matrix, and shear failure along multiple beddings with tensile failure of the matrix.

关键词： anisotropic rock failure mechanism acoustic emission digital image correlation Brazilian test

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Optimization of anchorage support parameters for soft rock tunnel based on displacement control theory

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Journal of Mountain Science 2023年第7期20卷 2076-2092页

作者： LI Gan MA Wei-bin YU Chang-yi TAO Zhi-gang WANG Feng-nian School of Civil&Environmental Engineering and Geography Science Rock mechanics Research InstituteNingbo UniversityNingbo 315000China railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China CCCC First Harbor Engineering company Co.Ltd.Tianjin 300461 CCCC-Tianjin Port Engineering Institute Co.Ltd.Tianjin 300222 State Key Laboratory for Geomechanics&Deep Underground Engineering Beijing 100083China Shanxi Transportation Technology Research and Development Co. LTDTaiyuan 030032China

In the construction of a soft rock tunnel,it is critical to accurately estimate the pre-stressed anchor support parameters for surrounding rock reinforcement;otherwise,engineering disasters may *** paper presents a support parameter selection method that aims to allow deformation as a control objective,which was applied to the tunnel located in Muzailing Highway,Min County,Dingxi City,Gansu Province,*** theoretical analysis,we have identified five factors that influence pre-stressing *** selection of mechanical parameters for the rock mass was carried out using an inverse analysis *** with the measured data,the maximum displacement error of the numerical simulation results was only 0.07 *** length of anchor cable,circumferential spacing of anchor cable,longitudinal spacing,and pre-stress index are adopted as the input parameters for the support vector machine neural network model based on particle swarm optimization(PSO-LSSVM).Besides,the vault subsidence and the maximum deformation of surrounding rock are considered as output values(performance indices).The goodness of fit between the predicted values and the simulated values exceeds ***,all support parameters within the acceptable deformation range are *** optimal support variables are derived by considering the construction cost and *** field application results show that it is feasible to construct the sample database utilizing the numerical simulation approach by taking the displacement as the control target and using the neural network to specify the appropriate support parameters.

关键词： Displacement control theory Anchorage support parameters Numerical simulation PSOLSSVM Tunnel construction

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