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Model Tests and Numerical Study on hydraulics of Spillway with Variable Slope

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Model Tests and Numerical Study on Hydraulics of Spillway wi...

Particle size spatial distribution in landslide dams

中国水利学会2016学术年会

作者： Li Qiulin Li Lianxia Liao Huasheng Liu Dewei Sheng Huanrong Yi Wenming State Key Laboratory of hydraulics and mountain river development and protection Michigan State University

Spillway is a common discharge structure,for which it is very important to have a reasonable layout and *** on a practical project,physical model tests and three-dimensional numerical simulation of turbulent flow method were conducted to study the rationality and liability of its spillway’s design,includingthe form of entrance,the curve of weir surface,bottom slope and transitional form and the hydraulic characteristics of discharge capacity,water surface,velocity,pressure were *** data and numerical results are in good agreement;both of them show thatthe flow regime of the spillway entrance and body are smooth and stable with a reasonable velocity distribution,and no negative pressure was captured and all the cavitation numbers fall into the range of ***,results from this study enriched the content and methods of the study of spillway hydraulic characteristics,and can provide reference to similar projects.

关键词： Spillway Slope Model tests Numerical simulation

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Journal of Mountain Science 2024年第6期21卷 1886-1903页

作者： ZHANG Jingyi ZHANG Jianmin State Key Laboratory of hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610064China

The particle composition and spatial distribution of landslide-induced dam bodies are critical geotechnical parameters for studying the hazards of dam-break ***,current research often neglects the influence of the initial particle composition and spatial distribution of the landslide on the particle composition and spatial distribution of the landslide *** study investigated the impact of initial particle size distribution,volume,and sliding length on the energy and velocity changes of characteristic particles during the sliding process and the spatial distribution of particle sizes in the landslide dam *** simulations and physical models were employed to examine the effects of sequential gradient arrangements(where particle sizes decrease from top to bottom)and four other different initial particle arrangements on the energy and velocity changes of particles and the spatial distribution of particle sizes in the dam *** study reveals the characteristics of translational and rotational energy of different particles and the laws of mechanical energy conversion,obtaining the spatial distribution patterns of particle sizes in landslide-induced *** results show that under the sequential gradient arrangement,the energy dissipation of the landslide movement is lower,with larger particles mainly distributed at the distal end and smaller particles at the proximal end of the landslide *** contrast,under the reverse gradient arrangement,the energy dissipation of the landslide movement is higher,and the distribution pattern of the dam particles is opposite to that of the sequential gradient *** the other arrangement modes,the spatial distribution of dam particles falls between the aforementioned *** is a positive correlation between particle size and translational kinetic energy within the particle flow during the landslide process,and rotational motion increases energy *** constant slope conditions,sliding

关键词： Particle size distribution Landslide Numerical simulation Discrete element method

Hydrodynamic Characteristics of Undular Tidal Bores in the Qiantang River Based on Field Observations

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China Ocean Engineering 2024年第3期38卷 505-518页

作者： ZHANG Shu-yu PAN Cun-hong ZHANG Shen-yang LI Ruo-hua CHENG Wenlong XIE Dong-feng Zhejiang Tongji Vocational College of Science and Technology Hangzhou 311231China Zhejiang Institute of hydraulics and Estuary Hangzhou 310020China

Understanding the undular tidal bores in the Qiantang River is essential for effective river management and *** breaking tidal bores have been studied extensively, reports on undular tidal bores in the Qiantang Riverremain limited. Furthermore, observed data on undular tidal bores fulfilling the requirements of short measurementtime intervals, and spring, medium, and neap tide coverage, and providing detailed data for the global vertical stratificationof flow velocity are quite limited. Based on field observations at Qige in the Qiantang estuary, we analyzedthe characteristics of undular tidal bores. The results showed that the flooding amplitude (a) of the first wave isalways larger than its ebbing amplitude (b). Moreover, the vertical distribution of the maximum flood velocity exhibitesthree shapes, influenced by the tidal range, while that of the maximum ebb velocity exhibites a single shape. Duringthe initial phase of the flood tide in the spring and medium tides, the upper water body experiences multiple oscillatingchanges along the flow direction, corresponding to the alternating process of the crest and trough of the tide levelupon the arrival of the tidal bore. The tidal range is a crucial parameter in tidal bore hydrodynamics. By establishingthe relationship between hydrodynamic parameters and tidal range, other hydrodynamic parameters, such as the tidalbore height, maximum flood depth–averaged velocity, maximum flood stratified velocity at the measurement points,and duration of the flood tide current, can be effectively predicted, thereby providing an important reference for rivermanagement and maintenance.

关键词： tidal bores Qiantang Estuary tidal bore height tidal bore velocity propagation speed

A refined representation method of the particle size distribution curve based on grading entropy

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Particuology 2024年第5期88卷 302-311页

作者： Xing Li Qun Chen Zhaozhao Liu Cheng Zhou Chen Wang Chen Chen State Key Laboratory of hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

The particle size distribution(PSD)curve is an important expression of the basic properties of the *** characteristic parameters such as median particle size D_(50),effective particle size D_(10),and some combinations of characteristic parameters can only represent some points of the PSD curve,failing to represent all information of the PSD *** this paper,a fraction characteristic parameter F that could reflect the fraction size variation of the PSD curve was introduced based on grading *** a new presentation method of the A-B-F three parameters was proposed for a refined representation of the PSD *** was found that the newly constructed model not only better represents the differences in the width of PSD curves but also has a higher sensitivity than the A-B two-parameter model proposed by Lő*** PSD curves with similar distributions,the new presentation method has a higher degree of discrimination than that of the D_(50)-C_(u)-C_(c) three-parameter or the four-parameter combination G_(c) proposed by ***,the application of this new method in describing the spatial nonuniformity distribution of depositions and predicting the soil hydraulic conductivity was *** research results can provide a reference for the refined representation of PSD curves.

关键词： Grading entropy Particle size distribution curve Refined representation

Study of a Hydraulic Jump in an Asymmetric Trapezoidal Channel with Different Sluice Gates

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Fluid Dynamics & Materials Processing 2024年第7期20卷 1499-1516页

作者： Bouthaina Debabeche Sonia Cherhabil Research Laboratory in Civil Engineering HydraulicsSustainable Development and Environment(LARGHYDE)University of BiskraBiskra7000Algeria Faculty of Sciences Applied Sciences Liege UniversityLiege4000Belgium Underground and Surface hydraulics Research Laboratory(LARHYSS) Biskra7000Algeria

In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and *** particular,an asymmetric trapezoidal flume with a length of 7 m and a width of 0.304 m is considered,with the bottom of the flume transversely inclined at an angle of m=0.296 and vertical lateral *** corresponding inflow Froude number is allowed to range in the interval(1.405,the hydraulic jump is found to be more effective than that occurring in triangular and symmetric trapezoidal ***,when■mes>8 and■>5,the hydraulic jump in the asymmetrical trapezoidal channel downstream of a parallelogram sluice gate is completely formed as opposed to the situation where a triangular sluice is considered.

关键词： Asymmetric trapezoidal channel characteristic lengths efficiency Froude hydraulic jump sequent depths sluice gate

Numerical Simulation of the Mass Movement Process of the 2018 Sedongpu Glacial Debris Flow by Using the Fluid-Solid Coupling Method

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Journal of Earth Science 2024年第2期35卷 583-596页

作者： Xing-Yu Long Yu-Xiang Hu Bin-Rui Gan Jia-Wen Zhou State Key Laboratory of hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China College of Water Resource and Hydropower Sichuan UniversityChengdu610065China

In the context of global warming and intensified human activities,glacier instability in plateau regions has increased,and glacier debris flows have become active,which poses a significant threat to the lives and property of people and socioeconomic *** mass movement process of glacier debris flows is extremely complex,so this paper uses the 2018 Sedongpu glacier debris flow event on the Qinghai-Tibet Plateau as an example and applies a numerical simulation method to invert the whole process of mass *** view of the interaction between phases in the process of motion,we use the fluid-solid coupling method to describe the mass *** granular-flow model and drift-flux model are employed in FLOW3D software to study the mass movement process of glacier debris flows and explore their dynamic *** results indicate that the glacier debris flow lasted for 700 s,and the movement process was roughly divided into four stages,including initiation,scraping,surging and deposition;the depositional characteristics calculated by the fluid-solid coupling model are consistent with the actual survey results and have good reliability;strong erosion occurs during the mass movement,the clear volume amplification effect,and the first wave climbs 17.8 m across the *** fluid-solid coupling method can better simulate glacier debris flows in plateau regions,which is helpful for the study of the mechanism and dynamic characteristics of such disasters.

关键词： glacial debris flow Qinghai-Tibet Plateau fluid-solid coupling FLOW3D mass movement depositional characteristics disasters engineering geology

GIS-based prediction method of shallow landslides induced by heavy rainfall in large mountainous areas

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Journal of Mountain Science 2024年第5期21卷 1534-1548页

作者： LUO Xiaoxiong LI Congjiang ZHOU Jiawen State Key Laboratory of hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China College of Water Resource and Hydropower Sichuan UniversityChengdu 610065China

Rainwater runoff that does not infiltrate the soil during heavy rainfall may increase slope instability. The effect of runoff is usually neglected in conventional rainfall-induced slope failure analysis to simplify the model. To analyze the effect of runoff on slope stability, this study simultaneously simulated the effects of surface runoff and rainfall infiltration on bank slopes in the Three Gorges Reservoir Area. A shallow slope failure method that can be used to analyze runoff was proposed based on the modified Green-Ampt model, the simplified Saint-Venant model, and the infinite slope model. In this model, the modified Green–Ampt model was used to estimate the rainfall infiltration capacity and the wetting front depth. The eight-flow(D8) method and the simplified Saint-Venant model were selected to estimate the distribution of runoff. By considering the wetting front depth as the slip surface depth, the factor of safety of the slope could be determined using the infinite slope stability model. A comparison of the different models reveals that runoff can escalate the instability of certain slopes, causing stable slopes to become unstable. Comparison of the unstable areas obtained from the simulation with the actual landslide sites shows that the model proposed in this study can successfully predict landslides at these sites. The slope instability assessment model proposed in this study offers an alternative approach for estimating high-risk areas in large mountainous regions.

关键词： Rainfall-induced landslide Surface runoff Infiltration Geographic Information System Landslide susceptibility

Blast damage zone strength reduction method for deep cavern excavation and its application

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Frontiers of Structural and Civil Engineering 2024年第2期18卷 236-251页

作者： Tianzhi YAO Zuguo MO Li QIAN Yunpeng GAO Jianhai ZHANG Xianglin XING Enlong LIU Ru ZHANG State Key Laboratory of hydraulics and Mountain River Engineering College of Water Resources and HydropowerSichuan UniversityChengdu 610065China Power China Chengdu Engineering Corporation Limited Chengdu 610072China

The drill and blast(D&B)method is widely used to excavate underground spaces,but explosions generally cause damage to the ***,no blast simulation method can provide computational accuracy and *** this paper,a blast equivalent simulation method called the blast damage zone strength reduction(BDZSR)method is *** method first calculates the range of the blast-induced damage zone(BDZ)by formulae,then reduces the strength and deformation parameters of the rock within the BDZ ahead of excavation,and finally calculates the excavation damage zone(EDZ)for the D&B method by numerical *** method combines stress wave attenuation,rock damage criteria and stress path variation to derive the BDZ depth calculation *** formulae consider the initial geo-stress,and the reliability is verified by numerical *** calculation of BDZ depth with these formulae allows the corresponding numerical simulation to avoid the time-consuming dynamic calculation process,thus greatly enhancing the calculation *** method was applied to the excavation in Jinping Class II hydropower station to verify its *** results show that the BDZSR method can be applied to blast simulation of underground caverns and provide a new way to study blast-induced damage.

关键词： attenuation of stress wave deep-buried underground building drill and blast in situ stress

A macro-mesoscopic constitutive model for porous and cracked rock under true triaxial conditions

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3080-3098页

作者： Li Qian Zuguo Mo Jianhai Zhang Xianglin Xing Ru Zhang Tianzhi Yao Yunpeng Gao State Key Laboratory of hydraulics and Mountain River Engineering College of Water Resources and HydropowerSichuan UniversityChengdu610065China Power China Chengdu Engineering Corporation Limited Chengdu610072China

The complex mechanical and damage mechanisms of rocks are intricately tied to their diverse mineral compositions and the formation of pores and cracks under external *** rock tests reveal a complex interplay between the closure of porous defects and the propagation of induced cracks,presenting challenges in accurately representing their mechanical properties,especially under true triaxial stress *** paper proposes a conceptualization of rock at the mesoscopic level as a two-phase composite,consisting of a bonded medium matrix and frictional medium *** bonded medium is characterized as a mesoscopic elastic material,encompassing various minerals surrounding porous *** mechanical properties are determined using the mixed multi-inclusion *** of the bonded medium into the frictional medium occurs through crack extension,with its elastoplastic properties defined by the DruckerePrager yield criterion,accounting for hardening,softening,and *** and Eshelby’s equivalent inclusion methods are applied to the bonded and frictional media,*** macroscopic mechanical properties of the rock are derived from these mesoscopic ***,a True Triaxial Macro-Mesoscopic(TTMM)constitutive model is *** model effectively captures the competitive effect and accurately describes the stress-deformation characteristics of *** the TTMM model,the strains resulting from porous defect closure and induced crack extension are differentiated,enabling quantitative determination of the associated damage evolution.

关键词： Micromechanics Macroemesoscopic Homogenization Constitutive model Competitive effect