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Application analysis of empirical mode decomposition and phase space reconstruction in dam time-varying characteristic

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Science china(Technological Sciences) 2010年第6期53卷 1711-1716页

作者： zhang ZhiJun1,2.3,GU ChongShi1,2.BAO TengFei1,2.zhang lan1,2.& yu hong1,2.1 state key laboratory of hydrology-water resources and hydraulic engineering,hohai university,nanjing 2.0098,china 2.National engineering Research Center of water {12. Efficient Utilization and engineering Safety,hohai university,nanjing 2.0098,china 3 Department of Civil,Environmental and Geomatic engineering,Swiss Federal Institute of Technology,Zurich 8093,Switzerland state key {2. of {2.-water resources and hydraulic engineering Hohai University Nanjing China National engineering Research Center of water {2. Efficient Utilization and engineering Safety Hohai University Nanjing China Department of Civil Environmental and Geomatic Engineering Swiss Federal Institute of Technology Zurich Switzerland

In view of some courses of the time-varying characteristics processing in the analysis of dam deformation,the paper proposes a new method to analyze the dam time-varying characteristic based on the empirical mode decomposition and phase space reconstruction *** of all,to reduce the influences on the traditional statistical model from human factors and assure the analysis accuracy,response variables of the time-varying characteristic are obtained by the way of the empirical mode decomposition;and then,a phase plane of those variables is reconstructed to investigate their processing *** methods have already been applied to an actual project and the results showed that data interpretation with the assists of empirical mode decomposition and phase space reconstruction is effective in analyzing the perturbations of response variables,explicit in reflecting the entire development process,and valid for obtaining the evolution rules of the time-varying *** methodology is a powerful technical support for people to further master the rules of dam operation.

关键词： dam safety monitoring dam time-varying characteristic empirical mode decomposition phase space reconstruction

Implications for fault reactivation and seismicity induced by hydraulic fracturing

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Petroleum Science 2024年第2期21卷 1081-1098页

作者： Zi-Han Sun Ming-Guang Che Li-hong Zhu Shu-Juan zhang Ji-{2.an Lu Chang-{2. Jin key laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil Engineering and Key Laboratory of Liaoning Province on Deep Engineering and Intelligent TechnologyNortheastern UniversityShenyang110819LiaoningChina Research Institute of Petroleum Exploration&Development PetroChina Company LimitedBeijing100084China The Exploration and Development Research Institute of Daqing Oilfield Limited Company Daqing163458HeilongjiangChina

Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operations. Current understanding supports the overriding role of the effective stress magnitude in triggering earthquakes, while the impact of change rate of effective stress has not been systematically addressed. In this work, a modified critical stiffness was brought up to investigate the likelihood, impact,and mitigation of induced seismicity during and after hydraulic fracturing by developing a poroelastic model based on rate-and-{2. fraction law and linear stability analysis. In the new criterion, the change rate of effective stress was considered a key variable to explore the evolution of this criterion and hence the likelihood of instability slip of fault. A coupled fluid flow-deformation model was used to represent the entire hydraulic fracturing process in COMSOL Multiphysics. The possibility of triggering an earthquake throughout the entire hydraulic fracturing process, from fracturing to cessation, was investigated considering different fault locations, orientations, and positions along the fault. The competition between the effects of the magnitude and change rate of effective stress was notable at each fracturing stage. The effective stress magnitude is a significant controlling factor during fracturing events, with the change rate dominating when fracturing is suddenly started or stopped. Instability dominates when the magnitude of the effective stress increases(constant injection at each fracturing stage) and the change rate of effective stress decreases(the injection process is suddenly stopped). Fracturing with a high injection rate, a fault adjacent to the hydraulic fracturing location and the position of the junction between the reservoir and fault are important to reduce the Coulomb failure stress(CFS) and enhance the critical stiffness as

关键词： hydraulic fracturing Coulomb failure stress Rate-and-state fraction model Linear stability analysis Critical stiffness Seismically induced fault

Effect of incoming sediment on the transport rate of bed load in mountain streams

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International Journal of Sediment Research 2009年第3期24卷 260-273页

作者： Guo-An yu1, Zhao-Yin WANG2. Kang zhang3, Tung-Chiung CHANG4, and Huaixiang LIU51 Dr., Institute of Geographical Sciences and Natural {2. Research, Chinese Academy of Sciences, Beijing 100101, {2. and Dept. of hydraulic engineering, Tsinghua university, 2.Prof., state key laboratory of Hydroscience and engineering, Tsinghua university, Beijing 100101, {2., 3 Ph.D. candidate, state key laboratory of Hydroscience and engineering, Tsinghua university, Beijing 100084, {2. 4 Ph.D. candidate, Tsinghua university, Beijing 100084, {2. and Prof., Kaoyuan university, Kaohsiung 82.51, Taiwan, {2. 5 Dr., state key laboratory of Hydroscience and engineering, Tsinghua university, Beijing 100084, {2. Dr. Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China and Dept. of Hydraulic Engineering Tsinghua University Prof. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100101 China Ph.D. candidate State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Ph.D. candidate Tsinghua University Beijing 100084 China and Prof. Kaoyuan University Kaohsiung 82151 Taiwan China Dr. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

Field experiments were conducted on bed load transport in the Diaoga River, a mountain stream in southwest china, to study the variation of bed load transport with varying sediment supply. The rate of bed load transport is greatly affected by incoming sediment (load and size). Under the same flow conditions, bed load transport rates may differ by three orders of magnitude depending on whether measurements were taken before or after the first flood of the year. The relation of the "bed load transport rate versus flow intensity" appears to have similar characteristics as a clockwise looped-rating curve. Experiments also were conducted during the non-flood season to study bed load transport processes with different incoming load from an upstream section. Bed load with different sizes can be grouped into two types: traveling bed load and structural bed load. Traveling bed load is composed of sediment finer than a critical size, Dc, and its transport rate depends mainly on the incoming sediment rate. The incoming sediment rate can alter the rate of bed load transport by three orders of magnitude. Structural bed load is composed of coarser sediment and its transport rate closely relies on the flow intensity.

关键词： Mountain streams Bed load transport Sediment supply Sediment size distribution

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基于PSO-WNN的大坝安全监控模型研究

水电能源科学 2010年第6期28卷 61-63页

作者：张煜王建荆凯范磊河海大学水文水资源与水利工程科学国家重点实验室江苏南京210098 河海大学水利水电学院江苏南京210098

针对大坝安全监控中小波神经网络模型(WNN)训练时间较长且易陷入局部极小值的缺陷,提出采用粒子群优化算法(PSO)取代传统的梯度下降法对小波神经网络中的各参数进行优化,建立了PSO-WNN模型并用于大坝安全监测的拟合和预报。实例结果表明... 详细信息

针对大坝安全监控中小波神经网络模型(WNN)训练时间较长且易陷入局部极小值的缺陷,提出采用粒子群优化算法(PSO)取代传统的梯度下降法对小波神经网络中的各参数进行优化,建立了PSO-WNN模型并用于大坝安全监测的拟合和预报。实例结果表明,PSO-WNN模型收敛速度快、预测精度及稳定性高,为大坝变形监测分析提供了一种有效的新型建模方法。

关键词：粒子群优化算法小波神经网络大坝变形监测预报安全监控模型

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裂点发育及其对堰塞坝的稳定性影响

山地学报 2011年第4期29卷 474-482页

作者：张康王兆印刘怀湘余国安清华大学水沙科学与水利水电工程国家重点实验室南京水利科学研究院水文水资源与水利工程科学国家重点实验室中国科学院地理科学与资源研究所

通过野外调查及试验对堰塞坝的稳定和裂点的发育进行研究,发现堰塞坝的稳定性主要取决于泄洪道内阶梯-深潭系统的发育程度Sp和坝体上游洪峰的水流能量p。堰塞坝的保存与溃决情况采用保留的坝高比进行定量描述,对于洪峰流量小于30 m3/s... 详细信息

通过野外调查及试验对堰塞坝的稳定和裂点的发育进行研究,发现堰塞坝的稳定性主要取决于泄洪道内阶梯-深潭系统的发育程度Sp和坝体上游洪峰的水流能量p。堰塞坝的保存与溃决情况采用保留的坝高比进行定量描述,对于洪峰流量小于30 m3/s山区河流,保留坝高比与Sp呈线性相关;洪峰流量大于30 m3/s(<30 000m3/s)时,河道稳定所需的最小河床结构强度Sp随着单宽水流能量p的增加而增大。堰塞坝泄洪道内不发育阶梯-深潭系统或发育程度较低的坝体,Sp值小于稳定河床最小的阻力强度,将会发生下切、溯源冲刷并引起溃坝。保留的堰塞坝在泥沙淤积和水流的长期作用下会形成裂点,对河床下切起到控制作用,降低再次发生滑坡的风险。大型裂点能改变河床演变和河流地貌,连续堰塞坝形成的裂点能长期保存并形成优美的自然景观,创造良好的河流生态环境。

关键词：堰塞坝阶梯-深潭系统裂点河床下切汶川地震

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设施栽培菠菜需水规律与作物系数研究

节水灌溉 2009年第5期 1-3,8页

作者：叶澜涛彭世彰王仰仁孙书洪徐俊增河海大学水文水资源与水利工程科学国家重点实验室南京210098 天津农学院水利系天津300384

根据设施栽培蔬菜需水量试验资料,分析了设施栽培春菠菜和冬菠菜在全生育期内的需水规律和累积需水规律;采用FAO-56单作物系数法计算了设施栽培春菠菜和冬菠菜的作物系数,分析了2.作物的作物系数在全生育期内的变化规律;引入Logistic... 详细信息

根据设施栽培蔬菜需水量试验资料,分析了设施栽培春菠菜和冬菠菜在全生育期内的需水规律和累积需水规律;采用FAO-56单作物系数法计算了设施栽培春菠菜和冬菠菜的作物系数,分析了2.作物的作物系数在全生育期内的变化规律;引入Logistic曲线划分的生育阶段对设施栽培作物系数进行了进程修正,引入气象修正因子对其进行了数值修正。结果表明,设施栽培春菠菜与冬菠菜作物需水规律随生长发育表现为先增后减变化规律,作物累积需水量表现出符合Logistic曲线的慢—快—慢的累积规律;作物系数呈与需水规律一致的变化规律;进程、数值双重修正后的作物系数值更加接近实测值。

关键词：设施栽培需水规律 Logistic曲线作物系数

Monotonic mechanical behaviour of compacted completely decomposed granite with various inclusion levels of incineration bottom ash

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Journal of Zhejiang university-Science A(Applied Physics & engineering) 2024年第8期25卷 670-679页

作者： Han-Lin WANG Cheng-Shuang YIN Qian-Yi zhang Qi-Wei LIU Zhen-yu YIN Dong-Xing XUAN Askar KHASANOV Research Center for Advanced Underground Space Technologies of Hunan university Changsha 410082China key laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan UniversityChangsha 410082China College of Civil engineering Hunan UniversityChangsha 410082China School of Civil engineering Zhengzhou UniversityZhengzhou 450001China Department of Civil and Environmental engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Department of Applied and Theoretical Mechanics Samarkand State UniversitySamarkandUzbekistan

1 Introduction Completely decomposed granite(CDG)is widely distributed in South china(Xu et al.,2.2.;Wang et al.,2.2.).The parent granite rock mass gradually loses features during the weathering process,and thus needs to be reinforced when used(lan et al.,2.03;Dassekpo et al.,{2.7;Alamanis et al.,2.2.).On the other hand,considering the huge demand for construction materials and limited natural resources,it is increasingly important to fully utilize solid waste(Gruhler et al.,{2.9;Anagnostopoulos et al.,2.2.;Jiang et al.,2.2.,2.2.a,2.2.b).With high strength and environment-friendly characteristics,incineration bottom ash(IBA)seems to be a suitable reinforcement material for CDG(Ahmed and Khalid,{2.1;Alhassan and Tankó,{2.2.Toraldo et al.,{2.3;Lynn et al.,{2.7;Xuan et al.,{2.8;Tang et al.,2.2.).

关键词： incineration behaviour utilize

Climate change drives flooding risk increases in the Yellow River Basin

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Geography and Sustainability 2024年第2期5卷 193-199页

作者： Hengxing lan Zheng Zhao langping Li Junhua Li Bojie Fu Naiman Tian Ruixun Lai Sha Zhou Yanbo Zhu Fan{2. zhang Jianbing Peng John J.Clague state key {2. of {2. and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China School of Geological engineering and Geomatics Chang’an UniversityXi’an 710064China university of Chinese Academy of Sciences Beijing 10049China Yellow River Institute of hydraulic Research Yellow River Conservancy CommissionZhengzhou 450003China state key {2. of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China state key {2. of Earth Surface Processes and {2. Ecology Beijing Normal UniversityBeijing 100875China key laboratory of Mechanics on Disaster and Environment in Western {2. The Ministry of Education of ChinaSchool of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China Department of Earth Sciences Simon Fraser UniversityBurnabyCanada

The Yellow River Basin(YRB)has experienced severe floods and continuous riverbed elevation throughout *** climate change has been suggested to be driving a worldwide increase in flooding ***,owing to insufficient evidence,the quantitative correlation between flooding and climate change remains *** present a long time series of maximum flood discharge in the YRB dating back to 1843 compiled from historical documents and instrument *** in yearly maximum flood discharge show distinct periods:a dramatic decreasing period from 1843 to 1950,and an oscillating gentle decreasing from 1950 to 2.2.,with the latter period also showing increasing more extreme floods.A Mann-Kendall test analysis suggests that the latter period can be further split into two distinct sub-periods:an oscillating gentle decreasing period from 1950 to 2.00,and a clear recent increasing period from 2.00 to *** further predict that climate change will cause an ongoing remarkable increase in future flooding risk and an∼44.4 billion US dollars loss of floods in the YRB in 2.00.

关键词： Flooding risk Risk management Climate change Flood discharge Extreme precipitation

Study on Hydrodynamic Characteristics of Wave Turbulent Bottom Boundary Layer Using A Large-Sized Wave Flume

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china Ocean engineering 2021年第5期35卷 759-766页

作者： zhang hong-qian XIE Ming-xiao zhang Chi LI Shao-wu zhang Hua-qing SUN yu-chen state key {2. of {2. engineering Simulation and Safety Tianjin UniversityTianjin 300072China Tianjin Research Institute for water Transport engineering M.O.T..Tianjin 300456China state key {2. of {2.-water resources and hydraulic engineering Hohai UniversityNanjing 210098China

Experimental studies were conducted in a super-large wave flume,aiming at uncovering the hydrodynamic characteristics involved in the turbulent wave boundary layer of full scale *** explicit formula of boundary layer thickness on rough turbulent flow was presented based on the measured velocity data of the present study and collected experimental data on wave boundary *** was found that the bottom wave-associated nominal stresses under the conditions of prototype scale tests suppress the vertical turbulence scattering upward over the boundary layer,which accounts for thickening of the boundary layer under wave *** effect has yet not been reported in the literatures using oscillatory U-tube or small-sized wave *** phase inconsistency in the turbulent boundary layer to the free stream velocity(velocity immediately outside the boundary layer)is within15°,which is remarkably smaller than the results from oscillatory U-tubes,as well as the larger wave flume experiment presented by Xie et al.(2.2.),showing that the coarser bed would further reduce the phase *** intensity of the vertical turbulent component is approximately 1/2.of the horizontal component,which has larger ratio compared with the value of 1/5 reported by previous ***,it was also found that the vertical turbulent energy was approximately 3/4 of the turbulent energy in spanwise directions(y-direction).This means that the turbulent fluctuation has similar order in all three-directions(x,y,z)in a full scale environment and highlights that the turbulent components in all the three directions should not be neglected when calculating the total turbulent energy.

关键词： large wave flume wave boundary layer hydrodynamic mechanism turbulent