Pile foundation

A lot depends upon soil and nature of land where you intend to construct house especially for foundation work of your house.

In places like Cochin where majority of land is marshy in nature which is filled with laterite soil  to get a feel of land,there is no other alternative other than going for concrete pile foundation even when you construct an ordinary house.

Scientific procedure to ascertain the nature of foundation required will be like this

1.Conduct soil test at the plot

If the plot is small a soil test at center of the plot will be sufficient using rig which goes down to something like 40-45 feet taking samples of soil or whatever you have down the line as the rig goes down.Samples thus taken will be tested in soil test laboratory and the results obtained will be given along with plan of the house to be built to a structural consultant.

2.Structural Engineering design of foundation

A structural consultant is an Engineer specialised in Structural Engineering at post graduate study level after his basic Engineering graduation.He will study soil test results and  architectural plan of the building and suggest foundation details for the house.This structural design for foundation of the building will tell you about what exactly you have to do to obtain a safe foundation in your plot which has weak soil conditions

3.Options possible

Exact nature of foundation will be decided by the structural consultant.But I can tell you about various possibilities that may be suggested by the structural consultant

1.Sand piling

If sand is available in your plot at depth not more than 20 feet,you can go for sand piling in the excavated area for foundation which is basically ramming the  foundation area with pile filled with sand and 1/4 inch metal up to a depth of 20 feet or where you can find sand.This is the cheapest option of pile foundation only if you are lucky to have sand at a depth of 20 feet

2.Manual concrete piling

You may not be lucky to get sand at 20 feet at most places in Cochin.Even if you dig down to 45 feet or more,in most places you will find only mud(clay) with absolute no trace of sand.So you will have to bore holes at places in foundation as per suggestions of structural consultant  and fill concrete of a richer variety after putting in place reinforcement as designed by consultant preferably with welded tying of round stirrups.

3.Compaction concrete piling

This is better option technically and cost wise.Here you bore holes to desired depths,fill concrete and then by force ram down reinforcement as per design.But this compaction may cause slight vibrations nearby and your neighbor may object to it.So you will have no other option other than going for costlier manual method.In places where your neighbour do not object you can go for compaction method

Sometimes your structural consultant may suggest doing sand piling in the entire area where the house comes in addition to concrete piling at corner points and other places where he finds it essential .This will be much more safer as it will strengthen entire area and chances of floor going down after flooring  work can be avoided.

After the concrete piling you will have to do so many other works to complete your foundation work. See pictures of compaction piling.

Even in hilly terrain like Nedumkandom in Iduki district even though land may be quite strong with laterite,there will be big slope in land terrain.Some times it may not be possible to level the land.So there also foundation cost can go up trying to level foundation.