Changes

Jump to navigation Jump to search
m
no edit summary
Line 9: Line 9:

===Data Analysis===
===Data Analysis===
# As the Soil Grain Size Analysis method is only approved for soils with d<sub>10</sub> between 0.1 and 2.5 millimeters, the Hazen formula <ref>Hazen, A. (1893). Some physical properties of sand and gravel with special reference to the use in filtration. 4th Annual Report, State Board of Health, Boston.</ref> may be used to calculate the soil permeability:
# As the Soil Grain Size Analysis method is only approved for soils with d<sub>10</sub> between 0.1 and 2.5 millimeters, the Hazen formula <ref>Hazen, A. (1893). Some physical properties of sand and gravel with special reference to the use in filtration. 4th Annual Report, State Board of Health, Boston.</ref> may be used to calculate the soil permeability. The calculated soil permeability shall be considered to be the measured infiltration rate:
 
# Soil permeability shall be considered to be the measured infiltration rate:
<math>K=C\cdot {\left (d_{10}\right )^{2}}</math>
<math>K=C\cdot {\left (d_{10}\right )^{2}}</math>
{{plainlist|Where:
{{plainlist|Where:
''d<sub>10</sub>'' = the soil particle diameter for which 10% of all soil particles are finer (smaller) by weight (mm),
''d<sub>10</sub>'' = the soil particle diameter for which 10% of all soil particles are finer (smaller) by weight (mm),
''C'' = is a shape fitting parameters (see below), and
''C'' = is a shape factor (see below), and
''K'' = permeability (mm/hr)
''K'' = permeability (mm/hr)
{| class="wikitable"
|+ Shape factors to yield K in mm/hr
|-
|Very fine to fine sand
|144000
|-
|Medium to coarse sand
|288000
|}


==Safety Correction Factor==
==Safety Correction Factor==

Navigation menu