Water Science and the Environment - HWR 201 - Fall 2016
Homework 6
Distributed: 18 November 2016Due:1 December April 2016, in class
Class experiment using soil columns
Problem 1. Measuring hydraulic conductivity.
We conduct falling-head column experiments to measure hydraulic conductivity of two soils (“soilA”and “soil B”). For details of experimental setup, please refer to file “measuring-soil-properties.pdf” that is on the D2L site insectioncalled “Experiments”, and it is also included here as “Appendix”.
Here are the experimental data:
Soil A:
Experimentconducted on November 22, 2016.
Grain size: 0.125 mm - 0.25 mm
d10 = 0.15 mm
t1 = _____ s
t2 = _____ s
Soil B:
Experiment conducted on November 29, 2016.
Grain size: 0.25 mm - 0.5 mm
d10 = 0.27 mm
t1 = _____ s
t2 = _____ s
Required
(a)Compute hydraulic conductivity K for the two soils (call them KA and KB) using the falling- head equation given in the description of the experiment. Comment on the results.
(b)Compute intrinsic permeability k for the two soils. Are the results consistent with expectations based on grain size?
Problem 2. Measuring specific yield.
We conduct draining experiments to measure specific yield of the two soils (A and B). For details, please refer to file “measuring-soil-properties.pdf” that is on the D2L site in section called “Experiments”, and it is also included here as “Appendix”.
Here are the experimental data:
Soil A:
Experiment conducted on November 22, 2016.
Mass of water drained: _____ g
This value is the same as the volume drained, under the assumption of water density of 1 g/cm3.
Soil B:
Experiment conducted on November 29, 2016.
Mass of water drained: _____ g
This is equal to the volume drained.
Required
(a)Compute specific yield Sy for the two soils (call them Sy,A and Sy,B) using the definition of specific yield given in the description of the experiment.
(b)Comment on the difference between the two values of specific yield. Are the results consistent with expectations based on grain size?
Compute hydraulic conductivity K for the two soils (call them KA and KB) using the falling- head equation given in the description of the experiment. Comment on the results.