Question

Consider the following statements:

Which of these statements is/are correct?

• A. 1 and 2
• B. 1 and 3
• C. 2 and 3
• D. 1, 2 and 3

Answer 1

The correct option is B 1 and 3

The mode of failure of pile groups in cohesive soils depends primarily upon spacing of piles. For smaller spacings 'blocks failure' may occur. In other words the group capacity as a block will be less than sum of individual pile capacities.
For larger spacings failure of individual piles may occur.
For medium dense sand the settlement of pile group is more than settlement of single piles and group settlement ratio (settlement of group to settlement of individual pile) increases with increase in B/d where B is the width of the pile group and d is diameter of the pile.