Permeability of soil

The flow rate data can also be used to estimate the permeability of the subsurface. The required additional parameter is the value of air viscosity, i.e., pa = 1.83 x 10 4 g/(cms). The intrinsic permeability of soil is calculated from equations 14.16 and 14.15 and is found to be K = 1.34 x 10 8cm2. Care should be taken to perform the appropriate unit conversions when using Equation 14.15. 

As noted in Table I, average surface radium concentrations appear to vary by about a factor of 20. This can also be seen from the distributions from the NARR data. Soil permeabilities, on the other hand, have much larger variations, and thus, in principle, may have a greater influence on the spatial variations in average indoor radon concentrations that have been observed. As with the case of surface radium concentrations, the spatial variability of air permeabilities of soils is an important element in developing a predictive capability. 

Information on surface soils is available from a number of sources, including surface soil maps compiled by the U.S. Geological Survey and the geological surveys of various states. At the present time, the coverage of such maps is not complete, nor has any systematic data on air permeability of soils been compiled. However reports issued by the Soil Conservation Service (SCS) of the U.S. Department of Agriculture contain information on most soils on a county-by-county basis. While no direct air permeability information is contained in these reports, the data and descriptive material contained there may be useful in estimating air permeabilities. 

In addition to the house described above, air permeability of soils was measured at several other house sites in the Spokane, WA, vicinity as part of a study of remedial measures for radon (Turk fit al.1986). Soil probes 1-cm-diameter and ranging between 1 and 1.5 m long were placed in the soil at two locations... 

Factors influencing the production and migration of radon in soils have been examined, and various sources of geographic data have been discussed. Two significant soil characteristics include air permeability and, less importantly, radium concentration. While there are, at present, few opportunities to compare the larger-scale data with on-site field measurements, those comparisons that have been made for both surface radium concentrations and air permeability of soils show a reasonable correspondence. Further comparisons between the aerial radiometric data and surface measurements are needed. Additional work and experience with SCS information on soils will improve the confidence in the permeability estimates, as will comparisons between the estimated permeabilities and actual air permeability measurements performed in the field. 

Allison LE. 1947. Effects of microorganisms on the permeability of soils under prolonged submergence. Soil Science 63 439-450. 

Benefits of the technology include avoiding risks to public health and worker safety associated with excavation, surface treatment, transportation, and disposal and gaseous reactants increase permeability of soils to gases thereby allowing gaseous mixtures to invade smaller soil pores to react with soil contaminants. All information has been supplied by the developer and has not been independently verified. 

This relation is approximately valid for unconsolidated sediments of 30 - 80% porosity (Carman 1956). It is used for both geotechnical applications to estimate permeabilities of soil (Lambe and Whitman 1969) and seismic modeling of wave propagation in water-saturated sediments (Biot 1956a, b Hovem and Ingram 1979 Hovem 1980 ... 

Cecil LD, Green JR (2000) Radon-222. In Environmental tracers in subsurface hydrology. Cook P, Herczeg AL (eds) Kluwer Academic Publishers, Boston, p 175-194 Christiansen JE (1944) Effect of entrapped air upon the permeability of soils. Soil Sci 58 355-365 Clark JF, Davisson ML, Hudson GB, Macfarlane PA (1998) Noble gases, stable isotopes, and radiocarbon as tracers of flow in the Dakota aquifer, Colorado and Kansas. J Hydrol 211 151-167 Clark JF, Hudson GB (2001) Quantifying the flux of hydrothermal fluids into Mono Lake by use of helium isotopes. Limnol Oceanogr 46 189-196... 

Song, C. R., Voyiadjis G. Z., Tumay, M. T. 1999. Determination of permeability of soils using the multiple piezo-element penetrometer. International Journal for Numerical and Analytical Methods in Geomechanics. Vol. 23, No. 13. 1,609-1,629. 

For a more complete discussion than can be given here of the factors that influence infiltration rates and permeability of soils, reference should be made to the publication by Parr and Bertrand (1960). They also describe methods used for measuring infUtration and discuss the theoretical considerations involved. 

Tackett and Pearson (1965) compared the effect of simulated rainfall and mechanical compaction of soil on surface crust formation and water permeability. Crusts formed under simulated rainfall were very dense and had a thin skin of well-oriented clay. Mechanical pressure did not produce this surface effect. Water permeability of soil underlying the crusts was about 5 times that of the surface. In compacted soils permeability of the surface and underlying materials was the same. 

Allison, L.E. 1947. Effect of micro-organisms on permeability of soil under prolonged submergence. 

Wei KY, Vigo TL, Goswami BC, Duckett KE. Permeability of soil-geotextUe systems. Textile Research J 1985 55 620-6. 

Factors affecting the corrosion of pipe include soil resistivity, moisture content of the soil, pH, permeability of soil to moisture and air, soluble ion content of the soil, oxygen content, and the presence of corrosion-activating bacteria. 

The values that characterize pervious concrete should be close to the permeability of soil, which is estimated as between approximately 1.2-10 and 10.5 10 m/s for sandy soils and between 5.2-10 and 3.T10 m/s for loam. To compare, the respective value of permeability of ordinary and high performance concretes is usually in the range of 10 - 10 m/s. 

There is little doubt that fertility- and productivity-affecting features of soils, such as liquid and electrolyte household management, i.e. the capacity to take up, hold, and pass liquids, ventilation, sorptional capacity, and the transport of dissolved substances, are highly dependent upon the structure and permeability of soil component colloid aggregates [1, 2]. Accordingly, the structure and permeability of mineral component clays are important factors [3]. 

Permeability of soil to water (hydraulic conductivity) 1x10 m/s 1 X 10 m/s to 1 X 10- m/s Soils described as clayey silty sands. The permeability will be governed by fine content. G N Smith gives ranges of permeability and baseline value is worse case for fine sand or silt at 1 X 10-5 m/s but could be as low as 1 X 10-7 m/s. This will be converted to intrinsic permeability for analysis of gas flow... 

Air flow into system must be sufficient to maintain pressure (depends on permeability of soil and integrity of walls below ground le el... 

Soils vary widely in composition and permeability, but the gas permeability of soils is always much lower than that of activated carbon beds, and as a result, much lower gas velocities must be employed. Typical air flow rates are in the range of 4-10 m /hr m (13-33 ft /hr ft ) with pressure drops of about 2-3 in. of water. 

Grout granular soil or cavities or fissures in soil or rock by injecting cement or other participate grouts to either increase the strength or reduce the permeability of soil or around. 

Evans, J. C., Kugleman, I. J. Fang, H. Y. 1985. Organic fluid effects on the strength, compressibility and permeability of soil-bentonite slurry walls. In Kugleman, I. J. (ed.) Toxic and Hazardous Wastes. Technomic Publishing, Lancaster, PA, 275-291. 

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