Pile foundations can be defined as a special type of deep foundation, where piles are used to transfer the loads from the low bearing capacity soil to the high soil bearing capacity strata at depth. Pile foundations are generally used for large structures. It is also used in places where the soil settlement is very high.
Generally, piles are used to serve any structure in 2 ways.
- Pile for shore protection as a construction safety measure.
- Pile for load bearer of main structure as structural pile or service pile.
Read article on: Mat or Raft Foundation
Installation of Piles (Shore / Service Pile)
In pile foundation, pile installation process is very important. This pile installation process differs in many countries due to technology difference. Here is a common pile installation process that is practically used in most developing countries.
Materials Required For Pile Installation
- Stone chips or shingles
- steel bars
- PCC cement
The pile installation steps are described in brief below.
- Give layout of whole building and super impose the pile layout on that layout.
- Mark the level of pile top where it has to cut off depth.
- Check the design data (Pile size, size & nos. of rebar etc).
- Transfer the pile point by coordinating & undisturbed adjacent place.
- Construct a mud tank in a suitable place where there is no pile points are located. Capacity of mud tank should be at least two piles discharged mud.
- Arrangement must be kept to remove the mud from the mud tank in every days cycle.
- Fabricate the rebar for pile as per design specification & maintain the lap, weld etc. as per recommended way.
- Use the block for clear cover with having proper curing otherwise it’ll break in casual stress.
- Locate and set the rig in pile point and start to dig by chiseling and washing out the bore simultaneously.
- Complete the digging and washing of bore as per design length.
- Check the color & concentration of disposed water from bore hole before finishing the washing.
- Use bentonite for separating between mud and concrete at bottom layer.
- Mix the concrete as per design strength will allowable slump and through the trimmie pipe upto the bottom end, do not through the concrete from the top of pile. Trimmie pipe should reach at least 12 inch depth of concrete layer and shake the concrete during placing.
- Check the concrete load by practical and theoretical volume.
- In between nearest (6 ft) pile can be progress after 72 hours.
- Pile head should not be broken after fulfilling 28 days.
Pile Foundation – Safety Measures
- Safety belt
- Safety shoes etc.
Tests Needed For Pile Foundations
- Slump cone test for slump test.
- Cylinder / Cube for compressive strength test.
- Pile integrity test for uniformly concrete medium test.
- Pile load test for pile load bearing capacity.
- Don’t work at dark.
- Don’t work at rain.
- Don’t work if you do not feel safe.