By Aravind Babu S R , 3rd year , Civil Engineering

Have you ever wondered how a building or a bridge stabilizes itself ? obviously you might have . but how? This is where the picture of piling comes into play . The term piling may look complicated , actually it is complicated because it involves a series of activities like drilling , inserting the reinforcement , casting the concrete  etc. 

Let’s understand this in an easier way , consider your home / any other ongoing construction site . There you might have noticed a large volume of fresh concrete being poured into wooden planks/ steel boxes thus forming / casting a column for raising your home or any other construction site . The column inserted in our homes gives us a better stability and also helps to raise floors likewise piling is done for mega structures and public projects. It is done so that a mega structure or any other construction site is highly stable .After installing the piles a column is raised in case of Bridges (Pile -Pile caps – Columns-Decks ) .Moreover the process of piling is very expensive and is generally noticed for the construction of mega-structures . Since we now know what piling is , let’s now look at the procedure of piling .

At the beginning a pile driver is used for drilling . A pile driver is a heavy machinery  that is handled by well experienced operators.

A pile driving machinery

The pile driver pictured above is just one form of pile driver , there are many pile drivers available in the market . The pile driver is brought to the site and according to reference points obtained by using total station the operators are instructed to drill and excavate the earth fillings. The piles are hammered into the ground until the refusal point is reached , a point where no more soil can be excavated .

To be specific, piling is done at  places with weak soil density , hard rock strata etc. Usually this is called as cast-in situ piles since fresh concrete is made to pour at the spot itself . After this a prefabricated reinforcement is made and inserted into the driven pile . Usually the cylindrical reinforcements are made and implanted on-site. 

A pile reinforcement

After a steady reinforcement ,a good volume of fresh concrete is poured into the borehole. Fresh concrete is generally supplied by the concrete trucks / transit mixers . Usually fresh concrete is poured using a pipe and to serve this purpose a tremie pipe is used .This is how a pile is generally casted .

There are different materials of piles namely timber piles , concrete piles , sand piles and steel piles . The above content is purely a concrete pile , which is most widely used in the industry . 

Apart from materials there are different piles depending upon their functions like bearing piles , friction piles , batter piles , glide piles etc.

First let’s see what’s a bearing pile ? . A bearing pile is generally installed in such places where the top soil surface is considered to be weak and the bottom one to be hard whereas a friction pile is established in soft soils where there are no hard strata .Another one is a batter pile it is purposely casted inclined to resist the lateral forces .The last one is a guide pile used for underwater construction and piling. The process may look simple while reading but on-site situations may be different and hectic. Anything can happen reinforcements could have gone wrong , Transit mixtures may arrive late and other factors make this look complicated.  Believe it or not, piling could even happen underwater and that’s totally different from the normal ones casted in land. 

A pile driven construction site ( pile breaking process is done for the required cutoff level )
The yellow colored ones are temporary support for secant piles