Awarded as the best online publication by CIDC

In Hiley’s formula for driven piles, why is a coefficient of 0.5 applied for the term elastic deformation of piles and soil?

Hiley’s formula R=E/(s+0.5c) is based on the principle of energy conservation in which the energy brought about by hammers during the action of hitting are transferred to piles in ground. When the hammer force and displacement is plotted, the energy absorbed by piles is the area under the curve.

Since the curve of elastic component is linear with a positive slope, the area i.e. energy should be the area of triangle (0.5xRxc) where R is reaction force and c is elastic compression due to helmet, piles and soil system. For settlement, it is of horizontal line in force-displacement diagram and hence the energy transferred to pile-soil system is (Rxs).

pile-soil system


This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.

Share this post

Kanwarjot Singh

Kanwarjot Singh is the founder of Civil Engineering Portal, a leading civil engineering website which has been awarded as the best online publication by CIDC. He did his BE civil from Thapar University, Patiala and has been working on this website with his team of Civil Engineers.

If you have a query, you can ask a question here.

Leave a Reply

Your email address will not be published. Required fields are marked *

Ask a question