The bearing capacity of vibro-pile can be increased by ________
(a) Increasing its diameter
(b) Elongation of the pile
(c) By using cone-shape base at the bottom
(d) By adding more load
This question was posed to me during a job interview.
The above asked question is from Uncased Cast-in-Situ Concrete Piles topic in chapter Pile Foundations of Geotechnical Engineering II