Designing of Piles

Question

Explain the Designing of Piles in case of Vertical and Lateral loads.

Answer 1

In order to support the load over them piles can be arranged in number of ways. To carry vertical loads and lateral loads vertical piles can be used. But if the raking piles are combined with the vertical piles they can support vertical as well as lateral loads.

Arrangement of piles:

Group of piles and pile cap are the two significant parts of the pile foundation. The applied load is distributed by the pile cap on to the individual piles. These individual piles then transfer the load on the bearing ground. The individual piles are spaced and connected to the pile cap or tie beams and trimmed in order to connect the pile to the structure at cut-off level, and depending on the type of structure and eccentricity of the load, they can be arranged in different patterns.

Load distribution:

Nowadays load analysis of the pile foundation is usually done by using computer software as given by (Ascalew Abebe and Dr. Ian G N Smith). To make understand the method let us follow the following formula.
Let us say that there is a rigid pile and it is pinned at the bottom and at the top. The force applied to it is vertical in nature. So the force applied on this particular pile is proportional to the displacement due to the compression.

Pile foundation for vertical piles only:

In this case the vertical compression U is caused by pile cap. The magnitude of this compression will be equal for all the piles in the pile group. Let us say that the vertical force acting on the pile is Q and it is applied at the neutral axis of the pile group, then the force on a single pile will be calculated as

P_V = Q/n