| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 7344 |
| title | Size effect in centrifuge cone penetration tests |
| authors | Lech Bałachowski |
| pages | 161 — 181 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem54str161.pdf |
| keywords | centrifuge, CPT, quartz sands, grain size |
| affiliations | - Civil and Environmental Engineering Faculty, Gdańsk University of Technology, ul. Narutowicza 11/12, 80-952 Gdańsk, Poland, e-mail: abal@pg.gda.pl
|
| abstracts | In-flight penetration tests with 12 mm mini-cone, were performed in the centrifuge ofL.C.P.C. in Nantes, in two uniform quartz sands of different grain size. Stress level effectand particle size effect on the cone resistance were analyzed. Geometry and particle sizeeffects were found for cone penetration in coarse sand especially at a penetration less thanthe critical depth. The irregularities on the profile of the mini-cone penetration in coarsesand can be attributed to the particle size effect. The evidence of the geometry size effectwas not very marked for the relatively narrow range of accelerations applied. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 6692 |
| title | A study on pre-failure deformations of granular soils |
| authors | Sawicki A. |
| pages | 183 — 206 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem54str183.pdf |
| keywords | granular soils, pre-failure deformations, instability line |
| affiliations | - Institute of Hydro-Engineering Polish Academy of Sciences, ul. Kościerska 7, 80-328 Gdańsk, Poland, e-mail: as@ibwpan.gda.pl
|
| tasks | 4 T07A 028 39 |
| abstracts | A simple model describing pre-failure deformations of granular soils is derived on the basisof a wide range of experimental data. The model is defined by two incremental equationsdescribing the volumetric and deviatoric strains. Functions appearing in governing equationswere determined from experiments performed in the triaxial apparatus, with additional measurementsof lateral strains for some simple stress paths. These functions are different forloading and unloading, and have different shapes for contractive and dilative soil samples.The instability line is built into the structure of the model. The incremental equations wereapplied to predict the soil behaviour during anisotropic compression, including determinationof the K0 -line. Some basic statistical characteristics of the initial density index of investigatedsoils and deformations during isotropic compression are presented. |
| attributes | [reviewed] [scientific] |
| language | en |
| points | 4 |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 6689 |
| title | Drained against undrained behaviour of sand |
| authors | Sawicki A., Świdziński W. |
| pages | 207 — 222 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem54str207.pdf |
| keywords | granular soils, stress-strain characteristics, instability line, dilative and contractive behaviour, static liquefaction |
| affiliations | - Institute of Hydro-Engineering, Polish Academy of Sciences, ul. Kościerska 7, 80-328 Gdańsk, Poland, e-mails: as@ibwpan.gda.pl, waldek@ibwpan.gda.pl
|
| tasks | 4 T07A 028 39 |
| abstracts | The incremental constitutive equations describing the pre-failure deformations of sand arepresented. These equations were calibrated on the basis of extensive experimental data,obtained from investigations performed in a triaxial apparatus. Incremental equations werecalibrated separately for initially contractive and dilative soil samples. Then, they wereapplied to predict the undrained behaviour of saturated soil samples. In the case of contractive soils, the constitutive equations describe the effective stress paths leading to thestatic liquefaction. In the case of dilative soils, the effective stress path is different, as themean effective stress initially decreases, and after passing the instability line, it starts toincrease, asymptotically reaching the failure envelope. Theoretical predictions of undrainedbehaviour are supported by experimental data. The original feature of this paper is that onecan predict the undrained behaviour of saturated granular soils on the basis of stress-straincharacteristics of the same soil but dry or tested in drained conditions. |
| attributes | [reviewed] [scientific] |
| language | en |
| points | 4 |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 7345 |
| title | Grain kinematics in weak linear transport |
| authors | Francesco Ballio, Alessio Radice |
| pages | 223 — 242 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem54str223.pdf |
| keywords | sediment transport, grain concentration and velocity, solid discharge |
| affiliations | - Politecnico di Milano, Dept. I.I.A.R., Piazza Leonardo da Vinci, 32, 20133 Milano, Italy, e-mails: francesco.ballio@polimi.it, alessio.radice@polimi.it
|
| abstracts | Some preliminary results of measurements of one-dimensional sediment transport on a flatbed are presented. Image processing was applied to measure the time evolution of the arealconcentration and the velocity of transported grains in a series of bed-load tests with valuesof the bed shear stress up to twice the threshold for incipient motion. The concentrationand velocity data were used to compute the time evolution of the solid discharge per unitwidth. It was found, as expected, that the sediment transport is an episodic phenomenon,particularly at low shear stress; visualization of the moving particles allows recognition of theexistence of longitudinal streaks, that can be more clearly observed when the sediment rate isweaker. The first and second order statistics of sediment concentration and velocity and soliddischarge have been analyzed; the mean and standard deviation of the quantities increase asthe transport intensity increases, while the coefficient of variation decreases. The ranges ofvariation of all the time-averaged quantities with the mean sediment rate are narrower if thezero values of the samples are disregarded prior to calculating the statistics; the coefficient ofvariation is almost constant. The solid discharge data samples were analyzed in the amplitudedomain, by calculating the Cumulative Frequency Distributions; it was found that the shapeof the CFDs computed with reference to the non-zero values of the sediment rate alone isself-similar regardless of the transport intensity. |
| attributes | [reviewed] [scientific] |
| language | en |