Foundation full details and Advantages and Disadvantages

Foundations are structural components used to support columns and transfer loads to the underlying soi                                                               

There are two types

1. Shallow foundation
2. Deep foundation

                                       Shallow foundation

 hallow foundations are constructed where soil layer at shallow depth (upto 1.5m) is able to support the structural loads. The depth of shallow foundations are generally less than its width.

                                          Deep foundation

 deep foundation is required to carry loads from a structure through weak compressible soils or fills on to stronger and less compressible soils or rocks at depth, or for functional reasons. Deep foundations are founded too deeply below the finished ground surface for their base bearing capacity to be affected by surface conditions, this is usually at depths >3 m below finished ground level.

Types of shallow foundation.

1.    Isolated footing
2.  Combined footing
3.   Strap footing
4.  Wall footing
5.   Raft footing

Types of deep foundation.

6.  Caissons
7. Piles

               

Pile foundation.

1. Our building is rested on a weak soil formation which can not resist the loads coming from our proposed building, so we have to choose pile foundation.
2. Pile are structural members that are made of steel, concrete or timber.

                             Function of piles

         As with other types of foundation, the purpose of a pile foundation is,

       1. To transmit a foundation load to a solid ground

       2. To resist vertical, lateral and uplift load

                       Pile can be,

        1. Timber

        2. Concrete

       3. Steel

      4. Composite

                                                   Concrete piles,

                  General facts.

            1. Usual length: 10m-20m

            2. Usual load: 300kN-3000kN

          Advantages,

           1. Corrosion resistance

           2. Can be easily combined with a concrete superstructure

        Disadvantages

           1. Difficult to achieve proper

           2. Difficult to transport

                                                     Pile foundation

                 Piles con be divided in to two major categories,

1. End Bearing Piles

If the soil-boring records presence of bedrock at the site within a reasonable depth,

Pile can be extended to the rock surface

2. Friction Piles

When np layer of rock is present depth at a site, point bearing piles become very long and uneconomical, in this type of subsoil, piles are driven through the softer material to specified depths.