Civil Engineering - Soil Mechanics and Foundation Engineering - Discussion

It is disadvantageous because :-.

Drainage not controlled.

Shear Stress development is not uniform.

Principle Plane rotates.

Failure plane is predetermined.

All the above are the disadvantage for direct shear test.

The correct answer is all of above.

Yes, All of the above is the correct answer.

Yes, all are the disadvantages.

-> The failure plane is always horizontal in the test, and this may not be the weakest plane in the sample. Failure of the soil occurs progressively from the edges towards the centre of the sample.

-> There is no provision for measuring pore water pressure in the shear box and so it is not possible to determine effective stresses from undrained tests.

->The shear box apparatus cannot give reliable undrained strengths because it is impossible to prevent localised drainage away from the shear plane.

I too think that E) all of these is correct answer.

The correct answer is all of above (E).

Thr correct answer is E) all of above.

All are disadvantages of Direct shear test.