Question

In a soil sample of a consolidometer test, pore water pressure is

• A. Minimum at the centre
• B. Maximum at the top
• C. Maximum at the bottom
• D. Maximum at the centre

Hint:

For double drainage in an oedometer test, \[ \boxed{ u_{\max} \text{ occurs at the centre of the specimen.} } \] The drainage path is \[ \boxed{\dfrac{H}{2}}. \]

Answer 1

The Correct Option is D

Step 1: Recall the consolidation process. In a consolidometer (oedometer) test, drainage takes place through porous stones at the top and bottom surfaces.

Step 2: Identify the pore pressure distribution. Since water escapes through both boundaries, the excess pore water pressure is highest at the middle of the sample and decreases toward the drainage faces. Thus, \[ \boxed{\text{Maximum pore water pressure occurs at the centre.}} \] Hence, \[ \boxed{(D)} \] is the correct answer.