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Journal of Hydrodynamics 2024年第2期36卷 219-231页

作者： Chen Geng Zhao-hui Qian Ke-xin Zheng Wei-xiang Ye Xian-wu Luo State Key Laboratory of hydroscience cand engineering Deparment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China

In the present paper,the unsteady cavitating turbulent flow over the twisted NACA66 hydrofoil is investigated based on an modified shear stress transfer k-ωpartially averaged Navier-Stokes(MSST PANS)model,i.e.,new MSST PANS(NMSST PANS)model,where the production term of kinetic energy in the turbulence model is modified with *** with the experimental data,cavitation evolution and its characteristic frequency are satisfactorily predicted by the proposed NMSST PANS *** is revealed that the interaction among the main flow,the reentrant jets,and sheet cavitation causes the formation of the primary shedding cavity near the mid-span and the secondary shedding cavity at each side of the twisted hydrofoil,and further induces the remarkable pressure gradient around shedding *** with the development of the primary and the secondary shedding cavities,the great pressure gradient associated with large cavity volume variation promotes the vortical flow generation and the spatial deformation of vortex structure during cavitation evolution,and results in the primary and the secondary U-type ***,dynamic mode decomposition(DMD)analysis is utilized to confirm the interaction among the main flow,the main reentrant jet and two side reentrant jets,and *** results indicate that the proposed NMSST PANS model is suitable to simulate the complicated cavitating turbulent flow for various engineering applications.

关键词： Cavitating turbulent flow partially averaged Navier-Stokes(PANS)model hydrofoil numerical simulation

A review of rock macro-indentation:Theories,experiments,simulations,and applications

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Journal of Rock Mechanics and Geotechnical engineering 2024年第6期16卷 2351-2374页

作者： Weiqiang Xie Xiaoli Liu Xiaoping Zhang Xinmei Yang Xiaoxiong Zhou State Key Laboratory of hydroscience and engineering Tsinghua UniversityBeijing100084China Yunlong Lake Laboratory of Deep Underground Science and engineering Xuzhou221116China State Key Laboratory of Water Resources and Hydropower engineering Science Wuhan UniversityWuhan430072China

Rock macro-indentation plays a fundamental role in mechanical rock breaking for various rock engineering application,such as drilling,tunneling,cutting,and *** the past decades,extensive research has been conducted to understand the indentation mechanisms and responses through various *** review aims to provide an overview of the current status and recent advancements in theories,experiments,numerical simulations,and applications of macro-indentation in rock *** starts with elaborating on the mechanisms of macro-indentation,followed by a discussion of the merits and limitations of commonly used *** factors and their effects on indentation test results are then *** numerical simulation methods for rock macro-indentation are highlighted,along with their advantages and ***,the applications of indentation tests and indentation indices in characterizing rock properties are *** reveals that compression-tension,compression-shear,and composite models are widely employed in rock *** the compression-tension model is straightforward to use,it may overlook the anisotropic properties of *** the other hand,the composite model provides a more comprehensive description of rock indentation but requires complex ***,factors,such as indentation rate,indenter geometry,rock type,specimen size,and confining pressure,can significantly influence the indentation *** methods for macro-indentation encompass continuous medium,discontinuous medium,and continuous-discontinuous medium methods,with selection based on their differences in ***,rock macro-indentation can be practically applied to mining engineering,tunneling engineering,and petroleum drilling *** indices serve as valuable tools for characterizing rock strength,brittleness,and *** review sheds light on the development of rock macro-inde

关键词： Rock macro-indentation Indentation test Indentation indices Mechanism Rock breaking

Exploration on electrical resistance tomography in characterizing the slurry spatial distribution in cemented granular materials

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Frontiers of Structural and Civil engineering 2024年第3期18卷 365-379页

作者： Bohao WANG Wei WANG Feng JIN Handong TAN Ning LIU Duruo HUANG State Key Laboratory of hydroscience and engineering Tsinghua UniversityBeijing 100084China Institute of Science and Technology China Three Gorges CorporationBeijing 100038China School of Geophysics and Information Technology China University of GeosciencesBeijing 100083China

This study investigated the application of electrical resistance tomography(ERT)in characterizing the slurry spatial distribution in cemented granular materials(CGMs).For CGM formed by self-flow grouting,the voids in the accumulation are only partially filled and the bond strength is often limited,which results in difficulty in obtaining in situ samples for quality ***,it is usually infeasible to evaluate the grouting effect or monitor the slurry spatial distribution by a mechanical *** this research,the process of grouting cement paste into high alumina ceramic beads(HACB)accumulation is reliably monitored with *** shows that ERT results can be used to calculate the cement paste volume in the HACB accumulation,based on calibrating the saturation exponent n in Archie’s *** results support the feasibility of ERT as an imaging tool in CGM characterization and may provide guidance for engineering applications in the future.

关键词： electrical resistance tomography cemented granular material grouting spatial distribution Archie’s law

Effect of the sloping seabed on 3D soil-spudcan interaction using a material point-finite element(MPM-FEM)model

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Journal of Rock Mechanics and Geotechnical engineering 2024年第4期16卷 1436-1454页

作者： Zhengda Lei Guangtian Zeng Huaihui Ren Bisheng Wu Yuxin Jie State Key Laboratory of hydroscience and engineering Department of Hydraulic EngineeringTsinghua UniversityBeijingChina Key Laboratory of the Hydrosphere Sciences of the Ministry of Water Resources BeijingChina Institute of Ocean engineering Tsinghua UniversityBeijingChina Longyuan (Beijing) Wind Power engineering Technology Co. Ltd.BeijingChina

The sloping seabed affects the bearing capacity and failure mechanism of soil,which may compromise the stability and safety of offshore structures such as jack-up *** paper employs a coupled model combining the material point method and finite element method(MPM-FEM)to analyze the impact of sloping seabeds on the three-dimensional soil-spudcan *** MPM-FEM model implements the B¯approach to solve the challenge of volumetric locking due to the incompressibility constraints imposed by yield *** is validated against the centrifuge *** effects of sloping seabeds on penetration resistance,soil flow pattern,lateral response,stress distribution,and failure mechanism are *** soil mainly undergoes overall failure when the ratio of penetration depth to spudcan diameter(i.e.D P/D)is between 0 and *** the slope angle increases,the soil on the side of lower slope is expelled further,resulting in an asymmetric stress distribution and a larger horizontal sliding force of *** D P/D increases to 0.75,the soil transitions to localized plastic flow failure,and the range of soil flow affected by the spudcan penetration *** results show that,when the slope angle increases,the lateral displacement and stress distribution on the lower slope of a sloping seabed is significantly larger than that of a horizontal seabed,impacting the spudcan and surrounding soil *** study suggests that the seabed slope significantly affects the range of soil flow and failure at shallow penetration,indicating that the slope angle should be taken into account in the design and installation of offshore jack-up rigs,particularly in areas with sloping seabeds.

关键词： Soil-spudcan interaction Centrifuge tests MPM-FEM model B—approach Sloping seabeds Offshore structures

Effect of granular shape on radial segregation in a two-dimensional drum

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Chinese Physics B 2024年第4期33卷 509-514页

作者：徐悦李然迟志鹏修文正孙其诚杨晖 School of Optical-Electrical and Computer engineering University of Shanghai for Science and TechnologyShanghai 200093China School of Electrical and Electronic engineering Shandong University of TechnologyZibo 255049China State Key Laboratory of hydroscience and engineering Tsinghua UniversityBeijing 100084China College of Medical Instruments Shanghai University of Medicine and Health SciencesShanghai 201318China

Granular segregation is widely observed in nature and *** research has focused on segregation caused by differences in the size and density of spherical ***,due to the fact that grains typically have different shapes,the focus is shifting towards shape *** this study,experiments are conducted by mixing cubic and spherical *** results indicate that spherical grains gather at the center and cubic grains are distributed around them,and the degree of segregation is *** experiments,a structured analysis of local regions is conducted to explain the inability to form stable segregation patterns with obviously different geometric ***,through simulations,the reasons for the central and peripheral distributions are explained by comparing velocities and the number of collisions of the grains in the flow layer.

关键词： granular materials cubic grains shape segregation segregation mechanism

Fiber optic monitoring of an anti-slide pile in a retrogressive landslide

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Journal of Rock Mechanics and Geotechnical engineering 2024年第1期16卷 333-343页

作者： Lei Zhang Honghu Zhu Heming Han Bin Shi School of Water Resources and Environment China University of GeosciencesBeijing100084China State Key Laboratory of hydroscience and engineering Tsinghua UniversityBeijing100084China School of Earth Sciences and engineering Nanjing UniversityNanjing210023China School of Civil and Environmental engineering Nanyang Technological University639798Singapore

Anti-slide piles are one of the most important reinforcement structures against landslides,and evalu-ating the working conditions is of great significance for landslide *** widely adopted analytical methods of pile internal forces include cantilever beam method and elastic foundation beam ***,due to many assumptions involved in calculation,the analytical models cannot be fully applicable to complex site situations,*** with multi-sliding surfaces and pile-soil interface separation as discussed *** view of this,the combination of distributed fiber optic sensing(DFOS)and strain-internal force conversion methods was proposed to evaluate the working conditions of an anti-sliding pile in a typical retrogressive landslide in the Three Gorges reservoir area,*** optical time domain reflectometry(BOTDR)was utilized to monitor the strain distri-bution along the ***,by analyzing the relative deformation between the pile and its adjacent inclinometer,the pile-soil interface separation was ***,the internal forces of the anti-slide pile were derived based on the strain-internal force conversion *** to the ratio of calculated internal forces to the design values,the working conditions of the anti-slide pile could be *** results demonstrated that the proposed method could reveal the deformation pattern of the anti-slide pile system,and can quantitatively evaluate its working conditions.

关键词： Anti-slide pile Multi-sliding surface Pile-soil interface Brillouin optical time domain reflectometry (BOTDR) Geotechnical monitoring Reservoir landslide

Pixel-level crack segmentation of tunnel lining segments based on an encoder–decoder network

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Frontiers of Structural and Civil engineering 2024年第5期18卷 681-698页

作者： Shaokang HOU Zhigang OU Yuequn HUANG Yaoru LIU State Key Laboratory of hydroscience and engineering Tsinghua UniversityBeijing 100084China China Renewable Energy engineering Institute Beijing 100120China State Key Laboratory of Stimulation and Regulation of Water Cycles in River Basins China Institute of Water Resources and Hydropower ResearchBeijing 100038China Hunan Provincial Water Resources Development&Investment Co. Ltd.Changsha 410007China

Regular detection and repair for lining cracks are necessary to guarantee the safety and stability of *** development of computer vision has greatly promoted structural health *** study proposes a novel encoder–decoder structure,CrackRecNet,for semantic segmentation of lining segment cracks by integrating improved VGG-19 into the U-Net *** image acquisition equipment is designed based on a camera,3-dimensional printing(3DP)bracket and two laser rangefinders.A tunnel concrete structure crack(TCSC)image data set,containing images collected from a double-shield tunnel boring machines(TBM)tunnel in China,was *** data preprocessing operations,such as brightness adjustment,pixel resolution adjustment,flipping,splitting and annotation,2880 image samples with pixel resolution of 448×448 were *** model was implemented by Pytorch in PyCharm processed with 4 NVIDIA TITAN V *** the experiments,the proposed CrackRecNet showed better prediction performance than U-Net,TernausNet,and *** paper also discusses GPU parallel acceleration effect and the crack maximum width quantification.

关键词： tunnel lining segment crack detection semantic segmentation convolutional neural network encoder-decoder structure

Numerical study on local scour characteristics around submarine pipelines in the Yellow River Delta silty sandy soil under waves and currents

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Deep Underground Science and engineering 2024年第2期3卷 182-196页

作者： Peng Yu Ruigeng Hu Jike Zhang Qi Yang Jieru Zhao Lei Cao Chenghao Zhu Key Laboratory of Geological Safety of Coastal Urban Underground Space Ministry of Natural ResourcesQingdaoChina Qingdao Geo-engineering Surveying Institute(Qingdao Geological Exploration Development Bureau) QingdaoChina Sinopec Petroleum engineering Corporation DongyingChina State Key Laboratory of hydroscience and engineering Tsinghua UniversityBeijingChina Department Civil and Environmental engineering Politecnico di MilanoMilanItaly College of Environmental Science and engineering Ocean University of ChinaQingdaoChina

Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource *** to the interaction of waves,currents,seabed,and pipeline structures,the soil around submarine pipelines is prone to local scour,severely affecting their operational *** the Yellow River Delta as the research area and based on the renormalized group(RNG)k-εturbulence model and Stokes fifth-order wave theory,this study solves the Navier-Stokes(N-S)equation using the finite difference *** volume of fluid(VOF)method is used to describe the fluid-free surface,and a threedimensional numerical model of currents and waves-submarine pipeline-silty sandy seabed is *** rationality of the numerical model is verified using a self-built waveflow *** this basis,in this study,the local scour development and characteristics of submarine pipelines in the Yellow River Delta silty sandy seabed in the prototype environment are explored and the influence of the presence of pipelines on hydrodynamic features such as surrounding flow field,shear stress,and turbulence intensity is *** results indicate that(1)local scour around submarine pipelines can be divided into three stages:rapid scour,slow scour,and stable *** maximum scour depth occurs directly below the pipeline,and the shape of the scour pits is asymmetric.(2)As the water depth decreases and the pipeline suspension height increases,the scour becomes more intense.(3)When currents go through a pipeline,a clear stagnation point is formed in front of the pipeline,and the flow velocity is positively correlated with the depth of *** study can provide a valuable reference for the protection of submarine pipelines in this area.

关键词： local scour numerical simulation submarine pipelines Yellow River Delta

Agricultural drought vulnerability in the middle reaches of Yangtze River Basin under environmental change

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Journal of Earth Science 2024年

作者： Peng Yang Fei Xu Jun Xia Jiang Li Libo Zhou Cai Fu State Key Laboratory of hydroscience and engineering Tsinghua University School of Geography and Information engineering China University of Geosciences Information Center of Department of Natural Resources of Hubei Province School of Water Resources and Hydropower engineering Wuhan University Wuhan C-Geo Clouds Science and Tech Co. Ltd

Climate change and economic development impact the population expansion and water shortage in the middle reaches of the Yangtze River Basin (MYRB)， leading directly to drought aggravation-expansion and impacting agricultural production in the MYRB. Therefore， this study quantitatively evaluated agricultural drought vulnerability in the MYRB based on the variable fuzzy evaluation model (VFEM). The main conclusions are as follows: (1) The arable land in the MYRB gradually decreased between 2005 and 2020， whereas the forest cover decreased and then increased; (2) precipitation and evapotranspiration were the key factors affecting the agricultural drought vulnerability (e.g.， weights of 0.24 and 0.21)， whereas arable land density and gross domestic product (GDP) per capita played less significant roles; and (3) the agricultural drought vulnerability in the MYRB during 2005–2020 was mainly at level 3 and below， with higher drought vulnerability in the western and northern regions， which had a higher drought risk potential.

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Frequency and size change of ice–snow avalanches in the central Himalaya:A case from the Annapurna II glacier

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Advances in Climate Change Research 2024年第3期15卷 464-475页

作者： Yao LI Yi-Fei CUI Jian-Sheng HAO Zheng-Tao ZHANG Hao WANG Jian GUO Shuo-Fan WANG State Key Laboratory of hydroscience and engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China Key Laboratory of Hydrosphere Sciences of the Ministry of Water Resources Beijing 100084China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China School of National Safety and Emergency Management Beijing Normal UniversityBeijing 100875China Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

Glaciers have retreated and shrunk in High Mountain Asia since the mid-20th century because of global warming,leading to glacier instability and hazardous iceesnow ***,the complex relationship between iceesnow avalanches and factors such as climate and potential triggers are difficult to understand because of the lack of observational ***,we addressed iceesnow avalanches on the Annapurna II glacier in Nepal,Central *** constructed an iceesnow avalanche history using long-term multi-source remote sensing images(1988-2021)and mapped the velocity fields of glaciers using cross-correlation analysis on SAR and optical ***,we investigated the impact of climate change and earthquakes on the frequency and size of iceesnow *** results demonstrate that the frequency of iceesnow avalanches has increased from 10 in 1988 to 27 in 2020,but the average area of iceesnow avalanche deposits has decreased by approximately 70%,from 3.4×10^(5) m^(2) in 1988 to 1.2×10^(5) m^(2) in *** evolutionary characteristic of ice avalanches is linked to the impact of glacier retreat(reduction in ice material supply)and increased activity under climate *** glacier movement velocity controls the size of iceesnow avalanches and can be set as an indicator for iceesnow avalanche *** the Annapurna Ⅱ glacier,an iceesnow avalanche occurred when the glacier velocities were greater than 1.5 m d^(-1).These results offer insights into iceesnow avalanche risk assessment and prediction in high-mountain areas,particularly in regions characterised by dense glacier distribution.

关键词： Iceesnow avalanche Glacier instability Climate change Central Himalaya Remote sensing