EngineeringExtract

           I. Pile Foundation

              Pile foundations are the part of a structure used to carry and transfer the load of the structure to the bearing ground located at some depth below ground surface. The main components of the foundation are the pile cap and the piles. Piles are long and slender members which transfer the load to deeper soil or rock of high bearing capacity avoiding shallow soil of low bearing capacity The main types of materials used for piles are Wood, steel and concrete. Piles made from these materials are driven, drilled or jacked into the ground and connected to pile caps. Depending upon type of soil, pile material and load transmitting characteristic piles are classified accordingly. In the following chapter we learn about, classifications, functions and pros and cons of piles. 

             II. Types of Piles

                             1. End bearing piles

            These piles transfer their load on to a firm stratum located at a considerable depth below the base of the structure and they derive most of their carrying capacity from the penetration resistance of the soil at the toe of the pile (see figure 1.1). The pile behaves as an ordinary column and should be designed as such. Even in weak soil a pile will not fail by buckling and this effect need only be considered if part of the pile is unsupported, i.e. if it is in either air or water. Load is transmitted to the soil through friction or cohesion. But sometimes, the soil surrounding the pile may adhere to the surface of the pile and causes "Negative Skin Friction" on the pile. This, sometimes have considerable effect on the capacity of the pile. Negative skin friction is caused by the drainage of the ground water and consolidation of the soil. The founding depth of the pile is influenced by the results of the site investigate on and soil test.

                                    2. Friction or cohesion piles
                           3. Cohesion piles
                           4. Friction piles
                           5. Combination of friction piles and cohesion piles
                           6. Classification of pile with respect to type of material
                            7. Timber piles
                           8. Concrete pile
                           9. Driven and cast in place Concrete piles 
                          10.Steel piles
                          11. Composite piles
                          12. Classification of pile with respect to effect on the soil
                          13. Driven piles

                             14. Bored piles