Isolated Foundation and Type

Ø  What is Foundation?

·         Foundation is the basic component of structure through which the whole load of structure is transferred to the soil, the solid ground on which foundation is rested, is called foundation bed.

·         Stability is provided by Foundation to the structure, by distributing the load of superstructure to the earth.

·         Strong and well-designed foundation prevent settlement of structure and increase the stability.

 

Ø  Isolated Foundation

·     Isolated foundation or Individual foundation is the type of shallow foundation, (Types of Foundations) which is used for building construction.

·    This foundation is constructed for single column.

·     It is the most economical types of footing, because the column placed at a particular distance.

·   The shape of footing may be square or rectangular or circular.

·   Material used for it may be reinforced or non-reinforced.

·  The size of footing is depended on the safe bearing capacity of soil and load of superstructure come on column.

·  Simply, the size of footing calculated by dividing the total load at the column base by the allowable bearing capacity of soil.

·  On all sides of concrete bed, 15 cm offset is provided. But in case of brick masonry column, 5 cm offset is provided to all four sides.

·  According to load conditions, and the soil bearing capacity and characteristics, the isolated footing having following types.

 

Ø  Types of Isolated Foundation     

1.      Flat, pad, plain or reinforced isolated foundation

2.      Sloped isolated foundation

       3.    Stepped isolated foundation 

1.      Flat, Pad, Plain Or Reinforced Isolated Foundation

ü  It is constructed by plain or reinforced concrete.

ü  Each footing with column constructed independently of others.

ü   The thickness of base is uniform.

ü  It has different shapes of square, circular, and rectangular which is depend upon the loading condition of structure.

ü  At the critical section, the footing helps to minimize the bending moments, and the shearing forces.

ü  It is economical construction because it needs less excavation.

 

2.      Sloped Isolated Foundation

ü  Slope isolated foundation has trapezoidal.

ü  It is constructed with care to achieve top slope of 45 degree across all directions.

ü  In sloped isolated footing, the requirement of reinforcement and concrete is less than the plain isolated footing.

ü  The concrete mix used in the footing must be stiff so that avoiding sustaining viscous deformation.

  

3.      Stepped Isolated Foundation

ü  It is mostly used in residential building.

ü  In this footing construction is done step by step, each step of footing is depend on the another step of footing.

ü  This type of footing was popular previously, but nowadays it is not used more.

 

Ø  Factor Affecting To The Construction Of  Isolated Foundation

ü  The footing is well-organized, and efficient.

ü  The footing is constructed when the capacity of soil is large.

ü  The load of structure is not more on ground, isolated foundation preferred.

ü   When there is a need of distance between the columns, the isolated foundation is constructed.

 

Ø  Use Of Isolated Foundation

ü  For transferring the concentrated load to the soil, isolated foundation is used as shallow foundation.

ü  When columns are placed at distance.

ü  Load of structure is less.

ü  Bering capacity of soil is high.

 

Ø  Advantages Of Isolated Foundation

1.      It is very economical.

2.      It is easy and simple to construct.

3.      Low skilled lobar required.

4.      It needs a less excavation of soil.

 

Ø  Disadvantages Of Isolated Foundation

1.      Round the base of foundation soil should be stable.

2.      For dealing with heavy loads, the footing made wide.

3.      Separate foundation should make different settlement.