In site investigation, significant depth is generally taken as the depth corresponding to what percentage of the vertical stress?

• 5%

• 10%

• 20%

• 25%

Which boring method is NOT suitable for gravelly soil due to circulation loss of drilling mud?

• Percussion

• Auger boring

• Rotary boring

• None

The SPT sampler collects soil samples which are:

• Undisturbed

• Completely undisturbed

• Highly disturbed

• Partially undisturbed

The area ratio (AR) of a thin-walled undisturbed sampler should be:

• > 30%

• < 10%

• < 25%

• 15–20%

Toe failure in slopes is most common when:

• Slope is flat with weak soil below

• Slope is steep and homogeneous

• Soil at toe is strong

• Slip surface non-circular

Critical void ratio refers to:

• Volume ratio at failure

• Void ratio at zero shear

• Void ratio when loose and dense sand reach same volume after shear

• Ratio of dry and moist voids

In vane shear test, drainage condition is controlled and therefore Mohr circle can be drawn.

• True

• False

Assertion (A): In SCPT, Dutch cone gives point resistance of soil. Reason (R): Cone is driven dynamically using repeated blows of a hammer.

• A true, R true and R is correct explanation

• A true, R true but R not correct explanation

• A true, R false

• A false, R true

In Mohr–Coulomb failure criterion, the shear strength S = __________.

In unconfined compression test, undrained shear strength Cu = __________.