Assessment Of Field Permeability

Question 1

Refers to the ability of soil to transmit water or other fluids through its pore spaces.

Answer 1

Soil permeability

Also called Hydraulic Conductivity, is measured using several methods that include constant and falling head laboratory tests on intact or reconstituted specimens.

Permeability may be measure in the field using in-situ borehole permeability testing, and field pumping test.

Question 2

Refers to a hole drilled directly into the ground to collect samples or perform tests at the location where the hole is drilled.

Answer 2

In-situ borehole

Question 3

Consists of pumping out water from a main well and observing the resulting drawdown surface of the original horizontal water table from at least two observation wells.

Answer 3

Field permeability test

• When a steady state of flow is reached, the flow quantity and the levels in the observation wells are noted.

Question 4

The coefficient of permeability can be calculated using?

Answer 4

•Pressure measurements
•The volume of permeated water
•The height
•cross-sectional area of the soil sample.

To ensure accurate results, repeat the test 3 or more time to get average coefficient.

Question 5

The four types of permeability tests:

Answer 5

Pressure tests, constant head gravity tests, falling head gravity tests, and slug tests.

Question 6

In these tests one or two packers are used to isolate the test section in the hole.

Answer 6

Pressure tests and falling head gravity tests.

Question 7

What are the four widely used methods in determining the coefficient of hydraulic conductivity?

Answer 7

•Field tests, such as pumping and borehole permeability tests.
• Empirical correlations with grain size distribution.
• Evaluation from an oedometer test
• Permeability tests on soil specimens in the laboratory

Question 8

Also known as consolidation test, is a laboratory experiment used to determine the compression behavior of soils under applied load.

Answer 8

Oedometer test

Question 9

A hydrogeological test conducted to assess the response of an aquifer to pumping or extraction.

Answer 9

Drawdown test

Question 10

A device used to measure the hydraulic conductivity of the subsurface formations encountered in a borehole

Answer 10

Borehole permeameter