| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 4001 |
| title | Simulation of flood event in a reach of the Nile River using CCHE2D model |
| authors | Abdul A. Khan, Wang S. S. Y. |
| pages | 329 — 341 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem50str329.pdf |
| keywords | river flow simulation, flood stage, stage-discharge relationship |
| affiliations | - Department of Civil Engineering 320 Lowry Hall, Clemson University Clemson, SC 29634-0911, U.S.A., e-mail: abdkhan@clemson.edu
- National Center for Computational Hydroscience and Engineering 102 Carrier Hall, University of Mississippi, MS 38677, U.S.A., e-mail: wang@ncche.olemiss.edu
|
| abstracts | The impact of design flood in terms of water surface level and maximum velocity in a reach on the Nile River is studied, using a depth-averaged two-dimensional model. The reach includes a proposed site for a shipyard maintenance harbour. The CCHE2D model, a depth-averaged two-dimensional model, is selected to perform both the steady state computation, for calibration purposes, and flood routing through the reach to obtain maximum water surface level and velocity information. Manning's coefficient was obtained by matching the computed and measured water surface level in the reach under steady flow conditions. The computed results of velocity and water surface profiles agreed satisfactorily with the measured data. The verified model was then used to simulate a flood event within the same reach. Stage-discharge relationships for various sections within the reach were obtained. The peak water surface level at each section was compared with the flow stage under normal flow conditions. The peak stage was found to be well below the proposed elevation of the construction site. The estimation of the peak velocity and water surface level might be useful for bank protection work. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 4002 |
| title | Simulation and discretization of random field in the slip-line method |
| authors | Jarosław Przewłócki |
| pages | 343 — 358 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem50str343.pdf |
| keywords | bearing capacity, method of characteristics, random field |
| affiliations | - Gdansk University of Technology, Faculty of Architecture, 80-952 Gdańsk, ul. Narutowicza 11/12, Poland, e-mail: jprzew@pg.gda.pl
|
| abstracts | The paper deals with the problem of bearing capacity of a strip footing based on the random subsoil. The solution has been obtained in a framework of the slip-line method. In order to include randomness of the soil medium, a modification of the method of characteristics is proposed. In such an approach, the stochastic finite difference method based on the Monte Carlo technique has been adopted. It enables including a spatial variability of soil properties into the analysis and to determine its influence on the variance of the ultimate collapse load. It is assumed that the soil medium is purely cohesive and only its cohesion can be considered as a random field. The simulation algorithm of multi-dimensional random field, based on the diagonalisation of the covariance matrix by a transformation using a lower-triangle matrix is described. The problems of the medium discretization and stabilization of the solution are discussed. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 4003 |
| title | A non-local hypoplastic constitutive law to describe shear localisation in granular bodies |
| authors | Jacek Tejchman |
| pages | 359 — 379 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem50str359.pdf |
| keywords | characteristic length, finite element method, non-local model, plane strain compression, shear localization |
| affiliations | - Gdańsk University of Technology, Faculty of Civil Engineering, 80-952 Gdańsk, ul. Narutowicza 11/12, Poland, e-mail: tejchmk@pg.gda.pl
|
| abstracts | The paper presents a FE-analysis of shear localisation in granular bodies by a finite element method based on a hypoplastic constitutive law. The law can reproduce essential features of granular bodies depending on the void ratio, pressure level and deformation direction. To realistically simulate the formation of a spontaneous shear zone inside cohesionless sand during plane strain compression, a hypoplastic constitutive law was extended by non-local terms. The effects of initial void ratio, pressure level and a characteristic length on the thickness of an interior shear zone were shown. The numerical results were compared with corresponding laboratory tests. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 3886 |
| title | A simple model of sinking of breakwater due to earthquake-induced subsoil liquefaction |
| authors | Sawicki A. |
| pages | 381 — 400 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem50str381.pdf |
| keywords | liquefaction, marine structures, cyclic loadings, earthquake sinking |
| affiliations | - Institute of Hydro-Engineering of the Polish Academy of Sciences, ul. Kościerska 7, 80-953 Gdańsk, Poland, e-mail: as@ibwpan.gda.pl
|
| tasks | EVK3-CT-2000-00038-LIMAS: Liquefaction around marine structures |
| abstracts | The paper deals with engineering analysis of breakwater behaviour due to earthquake- induced subsoil liquefaction. First, a simple model enabling analysis of pore-pressure generation in saturated granular soils, due to cyclic loading, is outlined. It is also shown how this model can be applied to the analysis of seabed behaviour during earthquakes. Then, a simple model of breakwater resting on saturated subsoil in which the phenomena of pore-pressure generation and liquefaction take place is described. This model enables estimation of changes of seabed effective reaction due to pore-pressure generation, as well as subsequent sinking of the breakwater due to subsoil liquefaction. Numerical examples illustrate theoretical considerations and show links between breakwater behaviour and earthquake characteristics. |
| attributes | [reviewed] [scientific] |
| language | en |
| points | 6 |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 4062 |
| title | Mixing in strongly stratified bottom cavities of estuaries: an experimental study |
| authors | Yarko Niño, Juan Francisco Miranda |
| pages | 401 — 413 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem50str401.pdf |
| keywords | stratified flows, mixing, estuaries, experimental methods, Acoustic Doppler Velocimetry |
| affiliations | - Department of Civil Engineering, University of Chile Casilla 228-3, Santiago, Chile, Principal author email: ynino@ing.uchile.cl
|
| abstracts | Results of an experimental study on the mixing characteristics of the stratified flow inside bottom cavities in salt wedge estuaries are presented and discussed. The experiments were conducted in a laboratory flume where a cavity was formed by placing two consecutive sills over the channel bottom. The cavity was filled with a bottom layer of saline water with a sharp density interface. A constant fresh water discharge was supplied at the upstream end of the flume. An ADV and a fast conductivity probe were used to measure the turbulence and salinity structure inside the cavity. Flow visualizations were made, in addition, to keep track of the position of the density interface inside the cavity. The density interface tilts in the downstream direction with a slope that increases as the local densimetric Froude number, Frd, increases. This slope can be reasonably estimated from a linear analysis of the response of the 2-layer stratified fluid to an interfacial shear stress. The entrainment velocity, or rate of interface deepening due to mixing, decreases as Frd increases, which appears to be the consequence of a decreasing mixing efficiency related to the tilting of the interface. The present entrainment velocity data compares well with existing experimental data and models, validating the latter on an extended range of relevant parameters. By scaling these results to a prototype such as the Valdivia Estuary in Chile, it is concluded that purging of the saline water trapped inside of bottom cavities cannot be completed during a tidal period. |
| attributes | [reviewed] [scientific] |
| language | en |