4(a)Describe the following types of piles: (i) end bearing piles; (ii) friction piles; (iii) compaction piles.(6marks)Oct./Nov. 2021

1. Support: The foundation provides a stable base for the building, distributing the weight of the structure evenly across the soil.
2. Load Transfer: The foundation helps to transfer the load of the building from the upper structure to the soil, ensuring that the building does not sink or settle unevenly.
3. Protection from moisture: Foundation helps to keep the building dry by preventing water from seeping into the lower levels of the structure. This can be done by using materials that are water-resistant and by installing drainage systems around the foundation.
4. Protection from natural hazards: Foundation help in protecting the building from natural hazards such as earthquakes, floods and soil movement. This can be done by using specific types of foundation and by reinforcing the foundation with materials that can withstand these forces.

(i) End bearing piles: End bearing piles are piles that transfer the load of a building to a layer of soil or rock that is capable of bearing the load. They are typically driven into the ground until they reach a solid layer of soil or rock, and the load is then transferred to this layer through the end of the pile. These piles are commonly used in areas where the soil is not suitable to support the structure on its own. Examples include sandy soils and rocky terrain.

(ii) Friction piles: Friction piles are piles that transfer the load of a building to the soil through friction between the pile and the soil. They are typically driven into the ground until they reach a stable layer of soil and the load is then transferred to this layer through the friction between the pile and the soil. These piles are commonly used in areas where the soil is suitable to support the structure, but additional support is needed to increase the stability of the structure. Examples include clay soils and silty soils.

(iii) Compaction piles: Compaction piles are piles that are used to compact the soil around the foundation of a building. They are typically driven into the ground in a specific pattern and at a specific depth. The weight of the pile compacts the soil around it, increasing the density of the soil and improving its ability to support the load of the building. These piles are commonly used in areas where the soil is loose or poorly compacted. Examples include sandy soils and soil with a high organic content.