Pile Foundation

 Foundation is the component which transfers loads from the substructure to the bearing layer. Depending on the geotechnical properties of the bearing layer, shallow or deep foundations are adopted. Usually, piles and wall foundations are adopted for bridge foundations. The foundation constructed sufficiently below ground level such as piles, walls etc., at their base are called deep foundations. Deep foundations are the one which are used to transmit the load to a deeper layer. The load transfer in this type of foundation is either by end bearing, friction or in combinations of both. Pile Foundation Piles are used to transfer the loads from the superstructure to a competent sub-surface layer, where the required bearing capacity is available.

 Usage of Pile Foundation 

The selection of type of pile foundation is based on site investigation report. Site investigation report suggests the need of pile foundation, type of pile foundation to be used, depth of pile foundation to be provided. Unless the ground condition is rocks, for heavy construction and multi-storey buildings, the bearing capacity of soil at shallow depth may not be satisfactory for the loads on the foundation. In such cases, pile foundation has to be provided. The number of piles in a required pile group is calculated from the pile capacity of single pile and the loads on the foundation. Piles are a convenient method of foundation for works over water, such as jetties or bridge piers. Generally, piles are used, if the soil at shallow depth does not have adequate bearing capacity and when the estimated settlement values are greater than the allowable limits. Pile foundations are also preferred where expansive and collapsible soils are found. 

Types of Pile Foundation

 Types of pile foundation can be classified under various heads. In this discussion we limit ourselves under the following listed categories.

 1) Materials Used 

2) Construction Method 

3) Installation Type 

4) Load Transmission and Functional Behavior