(2) When the initial shear stress exists, the dynamic
pore-water pressure cannot develop to the confining pressure as the cycle time increases.
By assuming the field as a series of independent, vertical soil columns, field-scale mean transport was also analysed in terms of the STM with a stochastic
pore-water velocity, v, and dispersion coefficient, D.
As expected (Passioura and Rose 1971), at a given
pore-water velocity, the dispersion coefficient was greater in the aggregated material than in the solid particles.
The
pore-water pressure distribution in the fault fracture zone under different supporting conditions is shown in Figure 6.
Physical conditions of the flow experiments Textural Water flux Soil-water
Pore-water class (cm/h) content velocity ([cm.sup.3]/ (cm/h) [cm.sup.3]) Coarse sand 0.497 0.143 3.48 Sandy loam 0.219 0.321 0.68 Clay loam 0.149 0.386 0.39 Clay 0.100 0.415 0.24 Table 3.
Mazurek, Borehole DGR-2:
Pore-water investigations, Institute of Geological Sciences University of Bern, Switzerland, 2008.
If a conservative tracer such as [Br.sup.-] is transported continuously throughout the soil profile at the same rate as the
pore-water velocity [v.sub.w], the tracer is said to have moved as piston flow (Jury et al.
Claret et al., "Mineralogical and isotopic record of diagenesis from the Opalinus Clay formation at Benken, Switzerland: Implications for the modeling of
pore-water chemistry in a clay formation," Clays and Clay Minerals, vol.
De Smedt and Wierenga (1984) credited the increase in [alpha] with increased
pore-water velocity to a higher mixing in the mobile phase at high
pore-water velocities, whereas van Genuchten and Wierenga (1977) related it to shorter diffusion path lengths as a result of a decrease in the amount of immobile water.
(1997) on the beneficial effect of intermittent leaching on the removal of solute from a saturated bed of inert spherical aggregates of diameter 2.4 mm at several
pore-water velocities.
Ng, "Analysis of plant root-induced preferential flow and
pore-water pressure variation by a dual-permeability model," Canadian Geotechnical Journal, vol.
During water infiltration the
pore-water pressure is redistributed, on one hand by the hydraulic properties of the partially saturated soil including retention characteristics and permeability and on the other hand by the external loading due to climate conditions (rainfall intensity, duration, and evapotranspiration rate).
