Types of foundations

The foundation can be classified into two groups, namely:
a. Shallow foundation, the foundation that supports the load directly, generally has a depth D / B £ 1 but could be more. Shallow foundations include the palm foundations, raft foundations (mats) and extends foundation.
b. The foundation, the foundation to continue building loads to the hard ground or rock that is located relatively far from the surface. Generally has a depth D / B ³  
1 and include pitting foundation and pile foundation.
Some examples of the type of foundation is as follows:
1. The foundations of the palm, which is a stand-alone foundation in support of the column.
2. Elongated foundation, the foundation of which is used to support the longitudinal walls or sederatan adjacent column.
3. Raft foundation (foundation mats), the foundation used to support buildings located on soft soil.
4. Pitting foundation (pier foundation), which is an intermediate form of the shallow foundation and pile foundation. Used when the soil is relatively solid foundation in.
5. Pile (pile foundation) small diameter and longer than the foundation sinks, used when the foundation soil at a depth that is not normally capable of supporting the load and the ground is very hard.

 ELECTION FORM FOUNDATIONÄ
In selecting and designing a foundation to consider the following matters:
1. Intention of making buildings, service life, construction type, soil properties, and its implementation method of construction costs.
2. The needs of the owner.
3. The plan is to make sure that it does not degrade the environment and wear safety factor that results in a level of risk that is acceptable to the public, owners and engineers.

For consideration of shear failure and excessive settlement, it is necessary to be fulfilled two criteria: stability criteria and the criteria of decline. Requirements that must be met in the design of the foundation are:
1. Factor of safety against collapse due to exceeding the carrying capacity must be met and are generally used safety factor 3.
2. Decrease foundation must still within the limits of the tolerated values. Special reduction is not uniform (differential settlement) should certainly not result in damage to the structure.