File Name: on the compressibility and shear strength of natural clays .zip
- Effect of Pore Fluid Salinity on Compressibility and Shear Strength Development of Clayey Soils
- On the compressibility and shear strength of natural clays
- Shear strength and compressibility characteristics of reconstituted clays
- Engineering properties of low to medium overconsolidation ratio offshore clays
In order to investigate the compressibility, particularly the secondary compression behaviour, soil structure and undrained shear strength of Shanghai Clay, a series of one-dimensional consolidation tests some up to 70 d and undrained triaxial tests on high-quality intact and reconstituted soil specimens were carried out. Measured coefficients of secondary compression generally fall in the range of 0. The effect of soil structures on the compressibility of Shanghai Clay is found to reduce with an increase in depth. Soil structure has an important influence on initial soil stiffness, but does not appear to affect undrained shear strength significantly.
Effect of Pore Fluid Salinity on Compressibility and Shear Strength Development of Clayey Soils
Citation: Don J. Jones, Tor Inge Yetginer-Tjelta. Engineering properties of low to medium overconsolidation ratio offshore clays[J]. AIMS Geosciences, , 5 3 : Article views PDF downloads Cited by 3.
On the compressibility and shear strength of natural clays
compressibility of some normally consolidated natural clays followed by their shear strength properties. The corresponding properties of some overconsolidated.
Shear strength and compressibility characteristics of reconstituted clays
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Soil consolidation refers to the mechanical process by which soil changes volume gradually in response to a change in pressure. This happens because soil is a two-phase material, comprising soil grains and pore fluid, usually groundwater. When soil saturated with water is subjected to an increase in pressure, the high volumetric stiffness of water compared to the soil matrix means that the water initially absorbs all the change in pressure without changing volume, creating excess pore water pressure. As water diffuses away from regions of high pressure due to seepage , the soil matrix gradually takes up the pressure change and shrinks in volume. The theoretical framework of consolidation is therefore closely related to the diffusion equation , the concept of effective stress , and hydraulic conductivity.
Investigations of shear strength, compressibility and moisture content of a recent marine clay in the Caspian Sea showed soil profiles with a lower shear strength and higher moisture content, than expected for a normally consolidated soil. Further, measured preconsolidation pressures were lower than the calculated in-situ effective stress, suggesting that the deposit was underconsolidated. The pore fluid salinity was also measured and showed an increase with depth up to saturation concentration.
Engineering properties of low to medium overconsolidation ratio offshore clays
The compressibility and strength characteristics of reconstituted clays are used as a basic frame of reference for interpreting the corresponding characteristics of natural sedimentary clays. The properties of a natural clay differ from its intrinsic properties due to the influence of soil structure fabric and bonding. Thus the intrinsic properties provide a frame of reference for assessing the in situ state of a natural clay and the influence of structure on its in situ properties. A new normalizing parameter called the void index is introduced to aid in correlating the compression characteristics of various clays. The sedimentation compression curves for most, but not all, natural clays lie well above the corresponding intrinsic compression curves. A consequence of this is that such clays are more sensitive and brittle than the reconstituted material and the post-yield compression index Cc is usually much greater than the intrinsic value. This observation has important consequences for stress-path testing of soft clays.
Hyodo, M. Undisturbed clay samples were taken from alluvial deposits at seven different urban coastal locations in Japan. The samples were then triaxially tested in both undisturbed and remoulded states. The cyclic data for normally consolidated samples was used to define the cyclic strength of the clays as an intrinsic function of the plasticity index 4. This was modified to take into account the initial vertical yield stress ratio and degree of aging. A further series of tests were carried out on samples which were anisotropically consolidated by being subjected to an initial drained shear stress. The cyclic strength of the anisotropically consolidated clays at low initial drained shear stress ratios increased with increasing plasticity.
Figures and Tables
The consolidation characteristics of kaolin, bentonite, their mixtures, and natural clays have been widely evaluated. However, the effect of pore fluid on the consolidation characteristics of artificially structured kaolin-bentonite mixtures should be more investigated. The test results show that bentonite greatly affects the consolidation behavior of mixture samples, especially when the pore fluid is distilled water. In the case of distilled water, the addition of bentonite to kaolin clay significantly increased the compression index C c , swelling index C s , and coefficient of volume change. The compressibility of clays is one of the most important aspects in geotechnical engineering, especially regarding the settlement calculation. It has been widely studied in terms of different clay minerals and different pore fluids [ 1 — 8 ].
- На этих таблицах есть числа. Количество протонов. Период полураспада. Что-нибудь, что можно было бы вычесть одно из другого. - Три минуты! - послышался крик.
Третья попытка провалилась. Он помнил, что сказал Клушар: немец нанял девушку на весь уик-энд. Беккер вышел из телефонной будки на перекрестке калле Саладо и авениды Асунсьон. Несмотря на интенсивное движение, воздух был наполнен сладким ароматом севильских апельсиновых деревьев. Спустились сумерки - самое романтическое время суток.