EFFECTS OF EXISTENCE OF SEDIMENT PARTICLES ON THE ENERGY LOSS OF FLOW

ＥＦＦＥＣＴＯＦＥＸＩＳＴＥＮＣＥＯＦＳＥＤＩＭＥＮＴＰＡＲＴＩＣＬＥＳＯＮＴＨＥＥＮＥＲＧＹＬＯＳＳＯＦＦＬＯＷ￥ＬＩＵＱｉｎｇｑｕａｎ；ＣＨＥＮＬｉａｎｄＬＩＵＤａｙｏｕ（Ａｓｓｏｃ．ＲｅｓｅａｒｃｈＦｅｌｌｏｗ，ＩｎｓｔｉｔｕｔｅｏｆＭｅｃｈａ...     

NUMERICAL ANALYSIS OF THE MECHANICS OF SOIL REINFORCEMENT

1 INTRODUCTION China is rich in mountains. The mountainous area occupies 69% of the total land of the country. Thus, landslides frequently occur in the mountain areas of China. Landslides originating in subsurface soils are typical, and constitute approxi…     

BED CONDITIONS OF NON-EQUILIBRIUM TRANSPORT OF SUSPENDED SEDIMENT

I.INTRODUCTIONSuspendedsedimenttransportissaidbeinanycaseaphenomenaofa3Dprocess.Becauseofthelimitationsincomputercapacity,mostoftheexistingmodelstreateditasatlvoorevenonedimensionalproblem.WiththerapidadvancesofcomputersinbothCPUandmemorycapacity,andbecauseoftheavailabilityof3Dmodelsforturbulentflowsimulationsinpracticalapplications,thefully3Dsimulationofsuspendedsedimentbecomesafeasibleandurgenttaskforhydraulicengineers.TheprocessofsuspendedsedimenttransportisdescribedbytheadVection-d…     

MODELING OF THE HIGH CONCENTRATION LAYER OF COHESIVE SEDIMENT UNDER THE ACTION OF WAVES AND CURRENTS

MODELING OF THE HIGH CONCENTRATION LAYEROF COIIESIVE SEDMNT UNDER Tus ACTIONOF WAVES AND CURRENTSQinghe ZHANG', Yongsheng WU', Jiian LIAN1 and Pingxing DING3Abstract:High concenhation layer of cohesive sediment frequenhy occurs in muddy estUaries and coastalzones, and causes raPid siltation of the waterways. A one dimensional vertical coupled modeldescribing the interactions betWeen waves, currentS and suspended cohesive sediment is develoPed inthe pre…     

DELINEATION OF THE FOCAL AREAS OF CHINA''''S HISTORICAL MAJOR EARTHQUAKES AND DETERMINATION OF POTENTIAL SEISMIC FOCUSES USING DATA OF MODERN SMALL SHOCKS

Delineation of the focal area of historical major earthquake is important because only when the location and dimensions of the focal area and the strike of the earthquake—triggering structure are definitely known will we be able to carry out calculation on the influence field of major earthquake. At the same time, in order to predict whether a new potential major earthquake is likely to occur again in the historical focal area, we must in the first place know the location and the     

DELINEATION OF THE FOCAL AREAS OF CHINA''S HISTORICAL MAJOR EARTHQUAKES AND DETERMINATION OF POTENTIAL SEISMIC FOCUSES USING DATA OF MODERN SMALL SHOCKS

Delineation of the focal area of historical major earthquake is important because only when the location and dimensions of the focal area and the strike of the earthquake-triggering structure are definitely known will we be able to carry out calculation on the influence field of major earthquake.     

ZONAL CHARACTERISTICS OF SEDIMENT YIELD OF RIVER BASINS CHINA

ＺＯＮＡＬＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＳＥＤＩＭＥＮＴＹＩＥＬＤＯＦＲＩＶＥＲＢＡＳＩＮＳＣＨＩＮＡＸＵＪｉｏｎｇｘｉｎ（Ｐｒｏｆｅｓｓｏｒ，ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｇｒａｐｈｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉ...     

EFFECTS OF SEDIMENT GRADATION ON THE GEOMETRY OF RIVER DELTAS

l INTRODUCTlONIn this study, formation of alluvial deltas was treated as a river-dominated type of topograPhy process,caused simply by sediment deposition from a channel into a wide basin. The influences of waves, tides,and density differences related to coastal effects were excluded. There have been numerous experimentalstUdies on river delta problems. For examPle, Shieh et al. (1988, 1997) used coarse sediment asexperimental material and revealed the development and the geometric simil…     

ANALYSIS OF SETTLING CHARACTERISTICS OF SPHERICAL PARTICLES IN BINGHAM FLUID

Based on the dimensional analysis, resistance coefficients of spherical particles to Bingham fluid in laminar flow region, transition region and fully developed turbulent flow regions are derived respectively. A systematical experimental study on settling velocity of steel balls in slurry with different sediment concentrations is conducted and comprehensive discussions are presented. Formulae proposed by the authors are checked with experimental data from various sources.     

SHEAR STRESS FOR INITIATION OF MOTION OF NON-UNIFORM SEDIMENT MIXTURES

Experiments on initiation of motion of different fractions of non-uniform sediment mixtures are reported. Four sediment mixes and reference transport method to define the threshold of bed particle movement are used in this analysis. Factors controlling the initiation of motion are analyzed. It is found that relative size of different grains with respect to a median size greatly affects the initiation of movement. The incipient motion of non-uniform sediment is very much dependent on the absolute size for coarser fractions. Considering the factors controlling the initiation of motion the experimental data sets along with the other available data yield a new relationship for the calculation of critical shear stress of non-uniform sediments. A set of equations have found that all the data points fall into a single line for the finer and for coarser fractions.     

RECENT UNDERTHRUSTS OF TIANSHAN AND POSSIBLE MECHANISM OF THEIR ORIGIN

ＲＥＣＥＮＴＵＮＤＥＲＴＨＲＵＳＴＳＯＦＴＩＡＮＳＨＡＮＡＮＤＰＯＳＳＩＢＬＥＭＥＣＨＡＮＩＳＭＯＦＴＨＥＩＲＯＲＩＧＩＮ￥Ｏ．Ｋ．Ｃｈｅｄｉａ（ＩｎｓｔｉｔｕｔｅｏｆＳｅｉｓｍｏｌｏｇｙＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓＲｅｐｕｂｌｉｃｏｆＫｉｒｇ...     

NUMERICAL SIMULATION OF 1998 RED TIDE OF THE BOHAI SEA

1 INTRODUCTION The Bohai Sea, located in East China, consists of five parts: Bohai Bay, Liaodong Bay, Laizhou Bay, Central Bohai and the Bohai Strait, as shown in Fig.1. The average water depth of the semi-enclosed sea is only 17 m. The maximum water depth is 70 m, measured in the Bohai Strait. Surrounding the Bohai Sea are 17 industrial cities, including Beiijing, Tangshan, Tianjin, Dalian, Huanghua and Dongying. More than 50 rivers, including the Haihe, Liaohe, Yellow, and …     

STUDY OF METHODOLOGY FOR PHYSICAL MODELING OF SEDIMENTATION IN RESERVOIR

ＳＴＵＤＹＯＦＭＥＴＨＯＤＯＬＯＧＹＦＯＲＰＨＹＳＩＣＡＬＭＯＤＥＬＩＮＧＯＦＳＥＤＩＭＥＮＴＡＴＩＯＮＩＮＲＥＳＥＲＶＯＩＲＹＡＮＧＧｕｏｗｅｉ（ＴｈｅＥｎｇｌｉｓｈｔｅｘｔｈａｓｂｅｅｎｒｅｖｉｅｗｅｄｂｙＭｒ．ＣＡＩＸｉａｏｙｏｎｇａｎｄｅｄｉ...     

THE VARIATION WITH TIME OF GRAVITATIONAL FIELD OF KUNMING AREA

This paper deals with the work for obtaining the gravitational value G on the basis of gravitational observation for 5 years at Kunming Observatory using the Birchaiv method in which the zero drift is removed and the theoretical value of earth tides corrected.The gravitational daily mean value G obtained after corrections of zero drift and theoretical values of earth tides shows obvious variations with periods of 15 days and one month respectively and the maximum amplitude of variation reaches approximately to 8μgal.The obtained gravitational monthly mean value Gmonth,also after corrections of zero drift and theoretical value of earth tide shows variation with periods of 6 months and one year respectively.This value tends to be greater in spring and fall and smaller in winter and summer,the maximum variation amplitude of which is about 4 μgal.No clear mutations in the gravitational field in Kunming area have been detected.It is therefore believed that the gravitational field of Kunming area is compara     

ON THE INFLUENCE OF TURBULENCE ON THE INITIATION OF SEDIMENT MOTION

1 PROBLEM DEFINITION Owing to the practical importance of the initiation of motion many researchers began to tackle this problem even at the beginning of the last century (e.g. Kramer (1932, 1935), Casey (1935)). Shields (1936, Fig. 1) developed a non-dimensional representation based on the measured data of Casey, Kramer, USWES and Gilbert, together with his own data based on investigations with succinite sand, lignite, granite chips and heavy spar. Despite the different material p…     

《INTERNATIONAL JOURNAL OF SEDIMENT RESEARCH》 SUBJECT INDEX OF 2006

3D movement 272 Gullied land area 62Alluvial stream 123 Headcuts 101Alternate bars 1 High gradient 220Antecedent precipitation 261 Hydrograph recession 50Barge-tow 249 Hydrological condition 13Bed evolution 74 Hydraulics 166Bed scour 321 Hysteresis 101Bra…     

NALYSIS OF CHANNEL SCOURING AND DEPOSITION OF THE LOWER YELLOW RIVER

ＡＮＡＬＹＳＩＳＯＦＣＨＡＮＮＥＬＳＣＯＵＲＩＮＧＡＮＤＤＥＰＯＳＩＴＩＯＮＯＦＴＨＥＬＯＷＥＲＹＥＬＬＯＷＲＩＶＥＲＱＩＰｕａｎｄＳＵＮＺａｎｙｉｎｇ（ＴｈｅＥｎｇｌｉｓｈＴｅｘｔｉｓｔｒａｎｓｌａｔｅｄｂｙＤｒ．ＬＩ，Ｗｅｎｘｕｅ，ａｌｔｅｒｅｄ...     

ON THE NUMBER OF FRACTIONS TO COMPUTE TRANSPORT OF SEDIMENT MIXTURES

1 INTRODUCTIONMany hydro-momhological mathematical models neglect the innuence of river bed maerialheterogeneity and its time and space changes during transport and related erosion/dePosition processes. Inthese models a rePresentative diameter of the river bed grain-size distribution (for examPle d5o) isspecified as initial data in each comPutational point of the modeled domain. Different d5o can be assignedto each ghd point but temPoral changes in bed material gradation cannot be simula…     

EFFECT OF FLOW CONDITIONS ON 3D MOVEMENT CHARACTERISTICS OF PARTICLES

1 INTRODUCTION The mechanism of particle movement in the flow is one of basic problems of sediment transport research. The conventional measurement approaches usually disturb the structure of the flow, consequently inducing errors. With the development of…     

SPECIFIC DEGRADATION OF WATERSHEDS

An extensive database of reservoir sedimentation surveys throughout continental United States is compiled and analyzed to determine specific degradation SD relationships as function of mean annual rainfall R, drainage area A, and watershed slope S. The database contains 1463 field measurements and specific degradation relationships are defined as function of A, R and S. Weak trends and significant variability in the data are noticeable. Specific degradation measurements are log normally distributed with respect to R, A, and S and 95% confidence intervals are determined accordingly. The accuracy of the predictions does not significantly increase as more independent variables are added to the regression analyses.