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water level updating model for flow calculation of river networks

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water Science and Engineering 2014年第1期7卷 60-69页

作者： Xiao-ling WU Xiao-hua XIANG Li LI Chuan-hai WANG co.lege of Hydrology and water resources Hohai University State Key Laboratory of Hydrology-water resources and Hydraulic Engineering Hohai University Zhenjiang Engineering survey and design institute co. Ltd.

co.plex water movement and insufficient observation stations are the unfavorable factors in improving the accuracy of flow calculation of river networks. A water level updating model for river networks was set up based on a three-step method at key nodes, and model co.rection values were co.lected from gauge stations. To improve the accuracy of water level and discharge forecasts for the entire network, the discrete co.fficients of the Saint-Venant equations for river sections were regarded as the media carrying the co.rection values from observation locations to other cross-sections of the river network system. To examine the applicability, the updating model was applied to flow calculation of an ideal river network and the Chengtong section of the Yangtze River. co.parison of the forecast results with the observed data demonstrates that this updating model can improve the forecast accuracy in both ideal and real river networks.

关键词： plain river network cyclic looped channel network water level updating model hydrodynamic model, error co.rection

Numerical modeling airflow in soil with impact of groundwater

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Journal of Central South University 2013年第5期20卷 1405-1411页

作者：张晓悦王栋张晓乐陈晓东 Zhejiang water co.servancy and hydropower co.lege hangzhou Branch of the IT Electronics Eleventh design & Research institute Scientific and Technological Engineering Co.Ltd. Zhejiang Huadong Safety Technology Engineering Limited co.pany

In order to simulate the airflow in anhydrous case and the water-air flow in groundwater case, a numerical model of airflow in soil was developed. For the nonlinearity of the governing partial differential equation, the co.responding discretization and linearization methods were given. Due to the mass transfer between air-phase and water-phase, phase states of the model elements were co.stantly changing. Thus, parameters of the model were divided into primary ones and seco.dary ones, and the primary variables changing with phase states and the seco.dary variables can be obtained by their functional relationship with the primary variables. Additionally, the special definite co.dition of this numerical model was illustrated. Two examples were given to simulate the airflow in soil whether there was groundwater or not, and the effectiveness of the numerical model is verified by co.paring the results of simulation with that of exoeriment.

关键词： groundwater water-air flow capillary pressure finite difference method co.pressed air

An Information Entropy-Based Methodology to co.struct the Avulsion Threshold in the Tail Reach of the Estuarine Alluvial Plain

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China Ocean Engineering 2023年第5期37卷 794-806页

作者： YANG Zhuo-yuan XIA Jun-qiang DENG Shan-shan ZHOU Mei-rong JI Zu-wen YU Xin State Key Laboratary of water resources and Management Wuhan UniversityWuhan 430072China Changjiang survey PlanningDesign and Research Co.LtdWuhan 430010China State Key Laboratary of Simulation and Regulation of River Basin water Cycle China Insititute of Water Resources and Hydropower ResearchBeijing 100048China Yellow River institute of Hydraulic Research Yellow River Conservancy CommisionZhengzhou 450003China

Channel avulsion is a natural phenomenon that occurs abruptly on alluvial river deltas,which can affect the channel *** causes for avulsion co.ld be generally categorized as topography-and flood-driven ***,previous studies on avulsion thresholds usually focused on topography-driven factors due to the centurial or millennial avulsion timescales of the world’s most deltas,but neglected the impacts of flood-driven *** the current study,a novel demarcation equation including the two driven factors was proposed,with the decadal timescale of avulsion being co.sidered in the Yellow River Estuary(YRE).In order to quantify the co.tributions of different factors in each category,an entropy-based methodology was used to calculate the co.tributing weights of these *** factor with the highest weight in each category was then used to co.struct the demarcation equation,based on avulsion datasets associated with the *** avulsion threshold was deduced acco.ding to the demarcation *** avulsion threshold was then applied to co.duct the risk assessment of avulsion in the *** results show that:two dominant factors co.er respectively geomorphic co.fficient representing the topography-driven factor and fluvial erosion intensity representing the flood-driven factor,which were thus employed to define a two dimensional mathematical space in which the demarcation equation can be obtained;the avulsion threshold derived from the equation was also applied in the risk assessment of avulsion;and the avulsion threshold proposed in this study is more accurate,as co.pared with the existing thresholds.

关键词： avulsion threshold threshold co.ditions entropy weight method tail reach Yellow River Estuary

A 2D well-balanced, co.pled model of water flow, sediment transport,and bed evolution based on unstructured grids with efficient variable storage strategy

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International Journal of Sediment Research 2021年第1期36卷 151-160页

作者： Zhiyuan Yue Qingquan Liu Wei Huang Peng Hu Zhixian Cao Department of Mechanics Beijing Institute of Technology Changjiang survey Planning design and Research co. Ltd (CSPDR) Changjiang River Scientific Research institute Department of Ocean Engineering Ocean College Zhejiang University State Key Laboratory of water resources and hydropower Engineering Science Wuhan University

In recent decades,a few Godunov-type,finite volume two-dimensional(2 D) unstructured grid,co.pled flow,and sediment models(GF2 DUCM) have been developed for flows over erodible *** kinds of models are generally analyzed as a Vertex Model(VM) that define topography at the cell vertex,which can lead to the non-co.servation of mass regarding flow,sediment,and bed ***,a full cellcantered variable storage method(Central Model or CM) is applied as the solution of the GF2 *** this method,terrain elevation is defined at the cell centroids;this accurately describes the physical relations between the water depth and topography *** approach can fully eliminate calculation errors in topography deformation at local cells caused by the interpolation of topography deformation at the cell vertex,and reduced uncertainty in the co.putation of the GF2 *** model performance is systematically tested using a series of laboratory experiments,which demonstrate the mass co.servation feature and high accuracy in reproducing hydrodynamic and morphological processes.

关键词： Two-dimensional co.pled model Well-co.served Unstructured grids Finite-volume algorithm Erodible bed Central model

Study on early warning index of spatial deformation for high co.crete dam

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Science China(Technological Sciences) 2011年第6期54卷 1607-1614页

作者： LEI Peng CHANG XiaoLin XIAO Feng ZHANG GuiJin SU HuaiZhi School of Hydraulic Engineering Changsha University of Science and Technology Changsha 410114 China co.lege of water resources and Hydroelectric Engineering Wuhan University. Wuhan 430072 China Mid-south design and Research institute China Hydropower Engineering Consulting Group Co Changsha 410014 China co.lege of water co.servancy and hydropower Engineering Hohai University Nanjing 210098 China

Owing to the deficiency in early warning for high co.crete dam,a formula was established to characterize the deformation behavior of high co.crete dam as a *** early warning index of spatial deformation was calculated by low probability principle on the basis of the deformation entropy formula *** steps were as ***,the probability method was utilized to define the degree of order and degree of chaos for each survey ***,the weight distribution among the survey points was calculated by projection pursuit ***,the formula of holistic deformation entropy,which can represent the degree of order of high co.crete dam,was established on the basis of synergetics and information ***,the early warning index of deformation entropy was co.puted by low probability method based on series of calculated deformation entropy *** example showed that the dynamic property of deformation entropy is in acco.dance with both environmental variables and deflection ***,deformation entropy can be used to improve warning ability and safety management for high co.crete dam.

关键词： deformation entropy early warning index synergetics dam monitoring co.crete dam

Influence Mechanism of Curing Regimes on Interfacial Transition Zone of Lightweight Ultra-High Performance co.crete

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Journal of Wuhan University of Technology(Materials Science) 2023年第3期38卷 591-603页

作者：李洋张高展 YANG Jun ZHANG Jian DING Qingjun ZHAO Mingyu Advanced Building Materials Key Laboratory of Anhui Province Anhui Jianzhu UniversityHefei 230022China Anhui co.struction Engineering Building Materials co. LtdHefei 230001China State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Anhui survey&design institute of water resources&hydropower co.Ltd Hefei 230001China School of Materials Science and Engineering Shenyang Jianzhu UniversityShenyang 110168China

This study aims to clarify the effects of curing regimes and lightweight aggregate(LWA)on the morphology, width and mechanical properties of the interfacial transition zone(ITZ) of ultra-high performance co.crete(UHPC), and provide reference for the selection of lightweight ultra-high performance co.crete(L-UHPC) curing regimes and the pre-wetting degree LWA. The results show that, under the three curing regimes(standard curing, steam curing and autoclaved curing), LWA is tightly bound to the matrix without obvious boundaries. ITZ width increases with the water absorption of LWA and decreases with increasing curing temperature. The ITZ microhardness is the highest when water absorption is 3%, and the microhardness value is more stable with the distance from LWA. Steam and autoclaved curing increase ITZ microhardness co.pared to standard curing. As LWA pre-wetting and curing temperatures increase, the degree of hydration at the ITZ increases, generating high-density CSH(HD CSH) and ultra-high-density CSH(UHD CSH), and reducing unhydrated particles in ITZ. ITZ micro-mechanical properties are optimized due to hydration products being denser.

关键词： curing regime ultra-high performance co.crete lightweight aggregate interfacial transition zone meso-mechanical properties micro-mechanical properties

Eco.ogical risk assessment and early warning of heavy metal cumulation in the soils near the Luanchuan molybdenum polymetallic mine co.centration area,Henan Province,central China

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China Geology 2023年第1期6卷 15-26页

作者： Zhen-yu Chen Yuan-yi Zhao Dan-li Chen Hai-tao Huang Yu Zhao Yu-jing Wu Xi’an Center of China Geological survey Xi’an 710119China School of Earth Science and resources China University of GeosciencesBeijing 100083China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China No.3 Geological Exploration institute Henan Provincial Bureau of Geo-exploration and Mineral DevelopmentZhengzhou 450014China Fujian water resources and hydropower survey Design and Research Institute Co.Ltd.Fuzhou 350001China

The Luanchuan molybdenum polymetallic mine co.centration area is rich in mineral resources and has a long history of *** environmental impact of long-term mining activities cannot be *** is of great significance to study the eco.ogical risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and co.trol of heavy metal *** the Taowanbeigou River Basin in the mine co.centration area as the research object,the eco.ogical pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the co.prehensive pollution index method,potential eco.ogical risk assessment method and geoaccumulation index *** this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning *** co.prehensive potential eco.ogical risk of heavy metals in the soil near the Luanchuan mine co.centration area is moderate,and the single element Cd is the main eco.ogical risk factor,with a co.tribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>*** to the current accumulation rate and taking the risk screening values for soil co.tamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 *** cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the eco.ogical *** activities will accelerate the accumulation of heavy metals in *** the co.tinuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will

关键词： Soil Heavy metals Mining impact Cumulative effect Potential eco.ogical risk Cumulation early warning Luanchuan mine co.centration area Environmental geological survey engineering

co.stitutive model for Ya'an mudstone based on mesosco.ic breakage mechanism

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Journal of Mountain Science 2023年第4期20卷 1159-1169页

作者： HE Yun-yong CHEN co.g WANG Fu-ming GUO Cheng-chao XIANG Bo YU Di LIU En-long DING Chun School of Civil Engineering Southwest Jiaotong UniversityChengdu610031China Sichuan Highway Planning SurveyDesign and Research Institute LtdChengdu610041China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resources and HydropowerSichuan UniversityChengdu610065China School of Civil Engineering Sun Yat-sen UniversityGuangzhou510275China Ya’an Transportation co.struction Group co. Ltd.Ya’an625000China

The slope stability of Ya’an expressway in Sichuan dominated by mudstone strata,is influenced greatly by both the mechanical properties and stressstrain relationship of *** this paper,the mechanical properties of the Ya’an mudstone samples under triaxial co.pression co.ditions were studied,based on an established co.stitutive model under the framework of breakage mechanics to simulate the mechanical properties of ***,triaxial co.pression tests and SEM tests at the co.fining pressures of 0.5 MPa,1.0 MPa,and 2.0 MPa were carried out on the mudstone samples,and it was found that the mudstone sample undergoes strain softening and dilatancy followed by the volumetric ***,based on analysis on the breakage mechanism of the above test results,we idealized the mudstone sample as a binary medium material co.sisting of the bonded elements and frictional elements,of which the bonded elements are co.posed of solid matrix and pores,and the frictional elements are co.posed of broken *** the loading process,the cementation between clay minerals and non-clay minerals in the mudstone sample is first destroyed,leading to the formation of micro-cracks within the particle aggregate,that is,the bonded elements are gradually damaged during the loading process and gradually turned into the frictional elements,and the two jointly bear the external *** bonded elements are co.posed of mudstone matrix and pores,which have the cementitious characteristics of mudstone,and the frictional elements are co.posed of the broken aggregate with the frictional characteristics of the broken *** on the homogenization theory,the co.stitutive model for the mudstone is established,and the determining method for model parameters is also ***,the results of the triaxial co.pression tests of the mudstone samples are predicted by the co.stitutive model proposed here,which can reflect the main mechanical properties of the mudstone samples.

关键词： Mudstone Breakage mechanism co.stitutive model Strain softening Binary medium model

Experimental study on instability mechanism and critical intensity of rainfall of high-steep rock slopes under unsaturated co.ditions

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International Journal of Mining Science and Technology 2023年第10期33卷 1243-1260页

作者： Xiaoshuang Li Qihang Li Yunmin Wang Wei Liu Di Hou Wenbo Zheng Xiong Zhang School of Urban co.struction Changzhou UniversityChangzhou 213164China co.lege of Civil Engineering Qilu Institute of TechnologyJinan 250200China Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province Shaoxing 312000China School of resources and Safety Engineering Chongqing UniversityChongqing 400044China Sinosteel Maanshan General institute of Mining Research co.LTD. Maanshan 243000China Guizhou survey and design Research institute for water resources and hydropower Guiyang 550001China School of Engineering University of Northern British ColumbiaPrince George V2K3V3Canada

Two critical factors,namely intense precipitation and intricate excavation,can trigger rock mass disasters in mining *** this study,an indoor rainfall system was developed to precisely regulate the flow and intensity of precipitation.A large-scale model experiment was co.ducted on a self-designed physical simulation experiment platform to investigate the failure and instability of high-steep rock slopes under unsaturated *** real-time reproduction of the progressive failure process in high-steep rock slopes enabled the determination of the critical rainfall intensity and revealed the mechanism underlying slope *** results indicated that rainfall may be the primary factor co.tributing to rock mass instability,while co.tinuous pillar mining exacerbates the extent of rock mass *** critical failure stage of high-steep rock slopes occurs at a rainfall intensity of 40 mm/h,whereas a rainfall exceeding 50 mm can induce critical instability and precipitation reaching up to 60 mm will result in slope *** improved region growing segmentation method(IRGSM)was subsequently employed for image reco.nition of rock mass deformation in underground *** an error co.parison with the simple linear iterative cluster(SLIC)superpixel method and the original region growing segmentation method(ORGSM)showed that the average identification error in the X and Y directions by the method was reduced significantly(1.82%and 1.80%in IRGSM;4.70%and 6.26%in SLIC;9.45%and 12.40%in ORGSM).Ultimately,the relationship between rainfall intensity and failure probability was analyzed using the Monte Carlo ***,the stability assessment criteria of rock slope under unsaturated co.dition were quantitatively and accurately evaluated.

关键词： Open-pit to underground mining Rock slope Rainfall infiltration Excavation unloading Similar physical model Image reco.nition