foundation system of burj al arab

Why is Bentonite Required in Bored Piling Operation?

Almost all bored pile construction need a casing or tube to provide support to the side of bore hole that are driven to lower the reinforcement case and consecutive concreting to finish piling operation. Even in case of cohesive soils, casing is desired to counteract the possible fissures. These is the drilling fluid, with the use of which, casing can be avoided. In this post we will discuss bentonite which is the most popular water based fluid all over the world. 

Bentonite is a clay which principally contains montmorillonite. Though montmorillonite is the major fraction, there have a little portion of minerals like feldspar, quartz, volcanic glass, pyrite, gypsum and other organic matter. Bentonite form a gelling compound when it reacts with organic matter. Bentonite has exchangeable sodium cations and when it disperses, it breaks into particles like plate of which negative charges remain on surfaces and positive charges remain in the edges. If there has no agitation, these charged particles form the above discussed, jelly due to weak electrical bonds. When dispersions are disturbed, the electrical bonds, as it is weak, are broken
and free flow condition is established. 
pile boring without casing using bentonite slurry.JPG
This is all about bentonite. Now it’s time to know the operational procedure. This is simple. Slurry containing bentonite is pumped into outer casing of rig and slurry with cutting soil come out and they are allowed to settle to re-circulate soil removed fairly fresh bentonite slurry to the previous process.


  1. If you need to maintain some hydrostatic pressure in non-cohesive soils by not removing the bentonite, but tremie pouring through it, how do you ensure that all of the drill tailings and spoil have been removed from the base of the hole, to ensure good end bearing capacity?

  2. A question from consultant=D.. you shall flush the shaft by cycling bentonite until bottom is cleaned. by taking bottom samples, it is assured to be cleaned. and maybe air-lifting could be used..

  3. Dear friends,

    I'm Saurabh Jain from Mahaveer Ceramic Industries CO. India, Rajasthan.
    We are bulk manufacturers of bentonite for piling.
    Currently supplying also.
    Kindly contact for bentonite all grades.
    mahaveermineral . com

    1. sir any dealers in tamilnadu for marketing Bentonite?

  4. if the bore hole is consist very stiff to hard consistency clay, do we require to use bentonite or not