Geotechnical Engineering ch.2

One main advantage of a ring sampler over a split barrel (split spoon) is:

• gradation tests can be performed only on the ring sample.

• A consolidation test can be performed on a ring sample without having to remold the sample.

• a moisture test is more accurate when performed on a ring sample.

Which exploration technique is the best method to observe shallow geologic strata?

• Backhoe trenching

• split barrel sampling

• tube sampling

Choose the two best methods for determining excavatability of rock.

• Backhoe trench

• split barrel sampling

• tube sampling

• Seismic investigation

A blow count of 23 for an SPT sampler driven into a sandy soil would indicate:

• A relative density of “medium dense”

• refusal

• a relative consistency of “stiff"

A seismic velocity of 2100 ft/s would indicate to the contractor that blasting is necessary.

• true

• False

During removal of rings from the ring sampler barrel it is best to hit the barrel with a hammer to loosen the rings.

• true

• False