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Deep-Learning-Based Bridge Condition Assessment by Probability Density Distribution Reconstruction of Girder Vertical Deflection and Cable Tension Using Unsupervised Image Transformation Model 10th

Deep-Learning-Based Bridge Condition Assessment by Probabili...

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10th European Workshop on Structural Health Monitoring, EWSHM 2020

作者： Xu, Yang Tian, Yadi Zhang, Yufeng Li, Hui Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Key Lab of Structures Dynamics Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China State Key Laboratory of Safety and Health for Inservice Long Span Bridges Nanjing211112 China

ISBN: (纸本)9783030649074

This study proposes a deep-learning-based condition assessment approach by reconstructing marginal probability density distributions of girder vertical deflection (GVD) and cable tension (CT) using unsupervised image transformation (UNIT) model for a real cable-stayed bridge. 27 and 139 sensors of GVD and CT are distributed along the full bridge, and both the sampling frequencies are 2 Hz. First, vehicle-induced components of GVD and CT are extracted by data pre-processing while the temperature-induced components are removed, a time window of 3 h with a sliding length of 10 min is used to obtain original GVD and CT segments, and the corresponding margin probability density distributions (PDFs) are calculated by kernel density estimation. The training and test sets consist of 2986 and 6236 PDFs, respectively. The proposed UNIT model consists of a series of variational autoencoders (VAEs) and generative adversarial networks (GANs). Both the PDFs of GVD and CT are used as inputs. Then, the proposed UNIT model is updated by solving the mini-max problem of training GANs, in which VAEs act as generative models. Finally, the Wasserstein distance between the predicted and ground-truth PDFs of CT acts as the indicator of bridge condition change. Results show that specific modes of PDF variations induced by SHM system upgrade, cable damage, data anomaly, and traffic jam can be recognized to assess bridge condition. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Deep learning

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The 2022 report of synergetic roadmap on carbon neutrality and clean air for China:Accelerating transition in key sectors

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Environmental Science and Ecotechnology 2024年第3期19卷 4-18页

作者： Yu Lei Zhicong Yin Xi Lu Qiang Zhang Jicheng Gong Bofeng Cai Cilan Cai Qimin Chai Huopo Chen Renjie Chen Shi Chen Wenhui Chen Jing Cheng Xiyuan Chi Hancheng Dai Xiangzhao Feng Guannan Geng Jianlin Hu Shan Hu Cunrui Huang Tiantian Li Wei Li Xiaomei Li Jun Liu Xin Liu Zhu Liu Jinghui Ma Yue Qin Dan Tong Xuhui Wang Xuying Wang Rui Wu Qingyang Xiao Yang Xie Xiaolong Xu Tao Xue Haipeng Yu Da Zhang Ning Zhang Shaohui Zhang Shaojun Zhang Xian Zhang Xin Zhang Zengkai Zhang Bo Zheng Yixuan Zheng Jian Zhou Tong Zhu Jinnan Wang Kebin He Center of Air Quality Simulation and System Analysis Chinese Academy of Environmental PlanningBeijing100041China Center for Carbon Neutrality Chinese Academy of Environmental PlanningBeijing100041China Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing210044China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China Institute for Carbon Neutrality Tsinghua UniversityBeijing100084China Ministry of Education Key Laboratory for Earth System Modelling Department of Earth System ScienceTsinghua UniversityBeijing100084China State Key Joint Laboratory for Environment Simulation and Pollution Control College of Environmental Sciences and Engineering and Center for Environment and HealthPeking UniversityBeijing100871China National Center for Climate Change Strategy and International CooperationBeijing100035China Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029China School of Public Health Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of HealthFudan UniversityShanghai200032China School of Economics and Management Beijing University of Chemical TechnologyBeijing100029China Department of Earth System Science University of CaliforniaIrvineCA92697USA National Meteorological Center China Meteorological AdministrationBeijing100081China College of Environmental Sciences and Engineering Peking UniversityBeijing100871China Policy Research Center for Environment and Economy Ministry of Ecology and Environment of the People's Republic of ChinaBeijing100029China Jiangsu Key Laboratory of Atmospheric Environment Monitoring

China is now confronting the intertwined challenges of air pollution and climate *** the high synergies between air pollution abatement and climate change mitigation,the Chinese government is actively promoting synergetic control of these two *** Synergetic Roadmap project was launched in 2021 to track and analyze the progress of synergetic control in China by developing and monitoring key *** Synergetic Roadmap 2022 report is the first annual update,featuring 20 indicators across five aspects:synergetic governance system and practices,progress in structural transition,air pollution and associated weather-climate interactions,sources,sinks,and mitigation pathway of atmospheric composition,and health impacts and benefits of coordinated *** to the comprehensive review presented in the 2021 report,the Synergetic Roadmap 2022 report places particular emphasis on progress in 2021 with highlights on actions in key sectors and the relevant *** milestones include the proportion of non-fossil power generation capacity surpassing coal-fired capacity for the first time,a decline in the production of crude steel and cement after years of growth,and the surging penetration of electric ***,in 2022,China issued the first national policy that synergizes abatements of pollution and carbon emissions,marking a new era for China's pollution-carbon *** changes highlight China's efforts to reshape its energy,economic,and transportation structures to meet the demand for synergetic control and sustainable ***,the country has witnessed a slowdown in carbon emission growth,improved air quality,and increased health benefits in recent years.

关键词： Synergetic roadmap Carbon neutrality Clean air

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Artificial intelligence for geoscience:Progress,challenges,and perspectives

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The Innovation 2024年第5期5卷 136-160,135页

作者： Tianjie Zhao Sheng Wang Chaojun Ouyang Min Chen Chenying Liu Jin Zhang Long Yu Fei Wang Yong Xie Jun Li Fang Wang Sabine Grunwald Bryan MWong Fan Zhang Zhen Qian Yongjun Xu Chengqing Yu Wei Han Tao Sun Zezhi Shao Tangwen Qian Zhao Chen Jiangyuan Zeng Huai Zhang Husi Letu Bing Zhang Li Wang Lei Luo Chong Shi Hongjun Su Hongsheng Zhang Shuai Yin Ni Huang Wei Zhao Nan Li Chaolei Zheng Yang Zhou Changping Huang Defeng Feng Qingsong Xu Yan Wu Danfeng Hong Zhenyu Wang Yinyi Lin Tangtang Zhang Prashant Kumar Antonio Plaza Jocelyn Chanussot Jiabao Zhang Jiancheng Shi Lizhe Wang Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China School of Computer Science China University of GeosciencesWuhan 430078China State Key Laboratory of Mountain Hazards and Engineering Resilience Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610299China Key Laboratory of Virtual Geographic Environment(Ministry of Education of PRC) Nanjing Normal UniversityNanjing 210023China Data Science in Earth Observation Technical University of Munich80333 MunichGermany The National Key Laboratory of Water Disaster Prevention Yangtze Institute for Conservation and DevelopmentHohai UniversityNanjing 210098China Institute of Computing Technology Chinese Academy of SciencesBeijing 100190China School of Geographical Sciences Nanjing University of Information Science and TechnologyNanjing 210044China State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China Soil Water and Ecosystem Sciences DepartmentUniversity of FloridaPO Box 110290GainesvilleFLUSA Materials Science Engineering Program Cooperating Faculty Member in the Department of Chemistry and Department of Physics Astronomy University of CaliforniaCaliforniaRiversideCA 92521USA Institute of Remote Sensing and Geographical Information System School of Earth and Space SciencesPeking UniversityBeijing 100871China Key Laboratory of Computational Geodynamics University of Chinese Academy of SciencesBeijing 100049China International Research Center of Big Data for Sustainable Development Goals Beijing 100094China College of Geography and Remote Sensing Hohai UniversityNanjing 211100China Department of Geography The University of Hong KongHong Kong 999077SARChina Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Nanjing 210044China School of Environmental Science and Engineering Nanjing University of Information Science&TechnologyNanjing 210044China Collaborative Inno

This paper explores the evolution of geoscientific inquiry,tracing the progression from traditional physics-based models to modern data-driven approaches facilitated by significant advancements in artificial intelligence(AI)and data collection *** models,which are grounded in physical and numerical frameworks,provide robust explanations by explicitly reconstructing underlying physical ***,their limitations in comprehensively capturing Earth’s complexities and uncertainties pose challenges in optimization and real-world *** contrast,contemporary data-driven models,particularly those utilizing machine learning(ML)and deep learning(DL),leverage extensive geoscience data to glean insights without requiring exhaustive theoretical *** techniques have shown promise in addressing Earth science-related ***,challenges such as data scarcity,computational demands,data privacy concerns,and the“black-box”nature of AI models hinder their seamless integration into *** integration of physics-based and data-driven methodologies into hybrid models presents an alternative *** models,which incorporate domain knowledge to guide AI methodologies,demonstrate enhanced efficiency and performance with reduced training data *** review provides a comprehensive overview of geoscientific research paradigms,emphasizing untapped opportunities at the intersection of advanced AI techniques and *** examines major methodologies,showcases advances in large-scale models,and discusses the challenges and prospects that will shape the future landscape of AI in *** paper outlines a dynamic field ripe with possibilities,poised to unlock new understandings of Earth’s complexities and further advance geoscience exploration.

关键词： Earth utilizing landscape

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Research on Ventilation and Cooling Technology of Shield Tunnel Based on Cfd

SSRN

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SSRN 2022年

作者： Liu, Changqi Bao, Qiu Nie, Wen Wang, Dan Liu, Qingming State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing100081 China State Key Laboratory of Mining Disaster Prevention and Control Co-found by Shandong Province The Ministry of Science and Technology Shandong University of Science and Technology Qingdao266590 China College of Safety and Environmental Engineering Shandong University of Science and Technology Qingdao266590 China Beijing Key Laboratory of Metro Fire and Passenger Transportation Safety China Academy of Safety Science and Technology Beijing100012 China

There are many heat sources in the shield tunnel, and the power of the shield machine is high. During the high temperature weather in summer, the average temperature in shield tunnel (Ta) will exceed 28°C, which will bring serious harm to the health of construction workers and the safety of equipment. In this study, the ventilation and cooling system of the shield tunnel was studied by the method of combining field measurement and numerical simulation. Firstly, the heat source in the shield tunnel is studied, and the total thermal power in the shield tunnel is calculated. The effects of primary ventilation velocity (V1) and inlet air temperature (T1) on the temperature of shield tunnel were studied by numerical simulation. The results show that the V1 and the T1 have a great influence on the temperature field in the tunnel, and the Ta in the shield tunnel has a linear relationship with the T1. When the V1 is 55 m/s, it can not only ensure the ventilation requirements in the tunnel, but also achieve the highest cooling efficiency. When the T1 exceeds 25°C, ventilation alone cannot achieve the purpose of cooling, and the inlet air needs to be cooled to ensure that the ambient temperature of the tunnel is lower than 28°C. © 2022, The Authors. All rights reserved.

关键词： Cooling

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Early-Age Hydration Heat Evolution and Kinetics of Portland Cement Containing Nano-Silica at Different Temperatures

SSRN

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SSRN 2022年

作者： Bai, Shuai Guan, Xinchun Li, Guoyu Key Lab of Structures Dynamic Behavior and Control The Ministry of Education Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters The Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Harbin Institute of Technology Harbin150090 China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou730000 China

This study investigated the influence of nano-silica dosages and hydration temperatures on the early-age hydration heat of cement using isothermal calorimetry, and a hydration kinetics model was used to analyze the nucleation and growth rates of hydrates. The calorimetry results show that the addition of nano-silica and the increase of hydration temperature can accelerate the process of hydration reaction. As the dosage of nano-silica increases, the induction period decreases, the acceleration period and exothermic rate peak value increase. The fast pozzolanic effect of nano-silica is responsible for accelerating the hydration reaction. However, the excessive addition (5%) of nano-silica may form many agglomerations, thereby inhibiting the modification effect of nano-silica on the cement hydration. The simulating results of kinetic parameters show that, at three hydration temperatures, the nucleation rate of hydrates increase with the increasing of nano-silica dosages, which indirectly confirms the nucleation effect of nano-silica in the early-age hydration. At 20 °C and 30 °C, the growth rate of hydrates also increases with the increasing of nano-silica dosages. At 40 °C, the growth rate of hydrates is decreased gradually, possibly due to the lack of sufficient Ca2+ and H2SiO42-. In addition, the nucleation rate is more sensitive and the growth rate is less sensitive to the hydration temperature. © 2022, The Authors. All rights reserved.

关键词： Hydration

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Blast Responses of Bfrp-Bar Reinforced Aac Panels

SSRN

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SSRN 2022年

作者： Li, Sensen He, Huguang Yang, Dapeng Zhang, Bei Fan, Hualin Henan International Joint Laboratory of Dynamics of Impact and Disaster of Engineering Structures Department of Civil Engineering Nanyang Institute of Technology Nanyang473004 China State Key Laboratory for Disaster Prevention & Mitigation of Explosion & Impact Army Engineering University of PLA Nanjing210007 China Institute of Defense Engineering AMS PLA Beijing100850 China Institute of Defense Engineering AMS PLA Luoyang471023 China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Nanjing210016 China

Basalt ﬁber reinforced polymer (BFRP) bars can replace steel bars in concrete protective structures and have advantages in corrosion resistance and high load-bearing capacity. In this paper, the BFRP-bar reinforced autoclaved aerated concrete (AAC) panels (BFRP-AACPs) were designed and prepared. Based on close-in explosion experiments, the dynamic responses and failure modes of the BFRP-AACPs were revealed. Through quasi-static four-point-bending experiments, the residual load capacity of each BFRP-AACP was evaluated, which quantitatively reveals the damage degree of the exploded BFRP-AACP. Combined with the equivalent static load method, the critical scaled distance of the designed panel is 2.08 m/kg 1/3 , which provides a basis for the application of the BFRP-AACP. © 2022, The Authors. All rights reserved.

关键词： Corrosion resistance

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Fabrication and Mechanical Testing of Ultralight Folded Lattice-CoreSandwich Cylinders

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Engineering 2020年第2期6卷 196-204页

作者： Wanxin Li Qing Zheng Hualin Fan Bin Ji State Key Laboratory for Disaster Prevention and Mitigation of Explosion and Impact Army Engineering University of PLANanjing 210007China Research Center of Lightweight Structures and Intelligent Manufacturing State Key Laboratory of Mechanics and Control of Mechanical StructuresNanjing University of Aeronautics and AstronauticsNanjing 210016China Aerospace System Engineering Shanghai Shanghai 2011089China

In this research,two novel folded lattice-core sandwich cylinders were designed,manufactured,and *** lattice core has periodic zigzag corrugations,whose ridges and valleys are directed axially or *** vibration and axial compression experiments were performed to reveal the fundamental frequency,free vibration modes,bearing capacity,and failure mode of the cylinder.A folded lattice core effectively restricts local buckling by reducing the dimension of the local skin periodic cell,and improves the global buckling resistance by enhancing the shear stiffness of the sandwich *** cylinders fail at the mode of material failure and possess excellent load-carrying *** axially directed folded sandwich cylinder has greater load-carrying capacity,while a circumferentially directed folded sandwich cylinder has higher fundamental *** two types of folded lattices provide a selection for engineers when designing a sandwich cylinder requiring strength or *** research also presents a feasible way to fabricate a large-dimensional folded structure and promote its engineering application.

关键词： Folded lattice-core sandwich cylinder Fabrication Mechanical testing

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Post-buckling behaviour of concrete-filled circular steel tube stub columns under axial compression 9

Post-buckling behaviour of concrete-filled circular steel tu...

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9th International Conference on Advances in Steel Structures, ICASS 2018

作者： Yang, Chang Yu, Zhixiang Zhao, Shichun Sun, Yuping Zhao, Hua Xu, Hu School of Civil Engineering Southwest Jiaotong University Chengdu China National Engineering Laboratory for Prevention and Control of Geological Disasters in Land Transportation Chengdu China China-Japan Resilient and Sustainable Concrete Structure Research Center Chengdu China Department of Architecture Graduate School of Engineering Kobe University Kobe Japan State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu China

ISBN: (纸本)9889914093

Based on 151 experimental data sets from available tests, the post-buckling behaviour of concrete-filled circular steel tube stub columns (CFSTs) in compression is comprehensively analysed to confirm the composite responses, such as failure mode and residual bearing capacity. The development characteristics with initial mechanical parameters of CFSTs are discussed in detail, and a procedure for deriving the reasonable upper limit of residual capacity is proposed by using the superposition method, based on interaction of steel tubes and concrete core in the post-buckling stage, as validated by comparison with the test results from the literature. The mechanical behavior of steel tube in CFSTs is confirmed to be consistent with the circular hollow section steel tube stub columns (CHSs) in compression according to the experimental data. Based on the maximum utilization of material strength and the confinement relationship between steel tubes and concrete core, a higher extreme compressive strength of concrete core may be obtained in the axial strain of 0.04, unless the effective confinement from the tubes is hardly exerted, resulting in the severe damage of the concrete core before stress redistribution in the post-buckling stage. Copyright © 2018 by The Hong Kong Institute of Steel Construction.

关键词： Axial compression

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Crushing Behaviors of Frac tai Hexagonal Tubular Structures: Experiments and Plastic Analysis

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Acta Mechanica Solida Sinica 2019年第6期32卷 713-724页

作者： Weiwei Li Bei Zhang Hualin Fan Research Center of Lightweight Structures and Intelligent Manufacturing State Key Laboratory of Mechanics and Control of Mechanical StructuresNanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory for Disaster Prevention&Mitigation of Explosion&Impact PLA Army Engineering UniversityNanjing 210007China Department of Civil Engineering Nanyang Institute of TechnologyNanyang 473004China Research Institute for National Defense Engineering of Academy of Military Science PLA Luoyang 471023China

Fractal tubular structures(FTSs)can greatly increase the anti-crushing and energy absorption capacity of the *** reveal this mechanism,fractal hexagonal tubes(FHTs)with self-similar fractal structure were designed and *** experiments were carried out to verify the crushing modes of structures with different scale *** with the single-cell structure,FHTs have much greater mean crushing force(MCF).According to the experiments and the numerical simulations,when the side length of the second-order hexagon is 0.3 times of the length of the first-order primary hexagon,the FTS has the greatest peak force(PF)and MCF as well as the most excellent energy-absorbing *** folding styles were revealed by the experiments and the numerical simulation when changing the scale factor,including the overall folding mode,the local foaling mode and the hybrid folding *** plastic models were built,which consistently predicted the MCF.

关键词： Fractal structure Crushing Energy absorption Plastic analysis

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Gap effects on the aerodynamic characteristics and flow patterns of a long-span rail-cum-road bridge girder with three separated boxes

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Journal of Wind Engineering and Industrial Aerodynamics 2025年 264卷

作者： Yize Ran Wen-Li Chen Hui Li Donglai Gao Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin 150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace Engineering Xi’an Jiaotong University Xi’an 710049 China

Separated box girder configurations enhance flutter stability in long-span bridges but introduce more complex flow interactions within the gaps, potentially inducing vortex-induced vibrations (VIV) at lower wind velocities. This study investigates the effects of gap ratios ( G / H ) on the aerodynamic characteristics and flow patterns of a long-span rail-cum-road bridge girder with three separated boxes. Stationary wind tunnel tests were conducted for G / H ranging from 0.000 to 7.752. Combined time–frequency analysis, pressure measurements, and smoke–wire visualizations revealed distinct flow characteristics for various gap ratio cases. As G / H increased, the upstream and middle box girders successively influenced the flow through vortex impingement on the windward sides of the downstream box girders. When G / H exceeded a critical threshold, the dominant frequency of the wake flow behind the downstream box girder became pronounced, indicating a general reduction in the influence of the upstream wake. The surface pressure distributions corroborated the observed vortex dynamics. Four distinct gap flow patterns were categorized: Pattern A exhibited overshoot flows in both upstream and downstream gaps for G / H = 0 . 000 to 0.678; Pattern B featured shear layer impingement in the upstream gap combined with vortex impingement in the downstream gap for G / H = 0 . 775 to 1.260; Pattern C displayed vortex impingement in the upstream gap and a secondary vortex street in the downstream gap for G / H = 1 . 357 to 1.841; Pattern D demonstrated alternate vortex shedding in both upstream and downstream gaps for G / H = 1 . 938 to 7.752. The phase lag between the fluctuating lift coefficients of adjacent box girders and the spanwise coherence coefficient elucidated the aerodynamic characteristics of the three-box girder under different gap flow patterns.

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