Search results
Results from the WOW.Com Content Network
The first modern theoretical models for soil consolidation were proposed in the 1920s by Terzaghi and Fillunger, according to two substantially different approaches. [1] The former was based on diffusion equations in eulerian notation, whereas the latter considered the local Newton’s law for both liquid and solid phases, in which main variables, such as partial pressure, porosity, local ...
Saturated soil samples exhibit the phenomenon of consolidation, whereby the soil's volume changes gradually to give a delayed response to the change in applied confining stresses. This typically takes minutes or hours to complete in an oedometer and the change of sample thickness with time is recorded, providing measurements of the coefficient ...
The name cam clay asserts that the plastic volume change typical of clay soil behaviour is due to mechanical stability of an aggregate of small, rough, frictional, interlocking hard particles. [3] The Original Cam-Clay model is based on the assumption that the soil is isotropic, elasto-plastic, deforms as a continuum, and it is not affected by ...
These equations relate a change in total or water volume (or ) per change in applied stress (effective stress — or pore pressure — ) per unit volume. The compressibilities (and therefore also S s ) can be estimated from laboratory consolidation tests (in an apparatus called a consolidometer), using the consolidation theory of soil mechanics ...
Terzaghi's principle applies well to porous materials whose solid constituents are incompressible - soil, for example, is composed of grains of incompressible silica so that the volume change in soil during consolidation is due solely to the rearrangement of these constituents with respect to one another.
If the soil particles in a sample are predominantly in a relatively narrow range of sizes, the sample is uniformly graded. If a soil sample has distinct gaps in the gradation curve, e.g., a mixture of gravel and fine sand, with no coarse sand, the sample may be gap graded. Uniformly graded and gap graded soils are both considered to be poorly ...
The activity of soil is the ratio of the plasticity index to the clay size fraction. If activity is less than 0.75, the soil is inactive. If activity exceeds 1.4, then the soil is termed active. If activity lies within the above values, then the soil will be moderately active. [10]
K a = Coefficient of active pressure w = weight density of soil h = depth of the section (below top soil) where the pressure is being evaluated. β = angle that the top surface of soil makes with the horizontal. φ = angle of internal friction of soil. The expression for passive pressure is: = where: