DIFFERENT TYPES OF MAT FOUNDATION
Mat foundation alias raft foundation stands for a continuous solid concrete slab that is provided on the soil to expand the whole footprint of the building and enhance the bearing strength of the soil. Mat foundation mainly provides support to bear the whole building loads as well as securely transmit it to the ground. Raft/Mat foundation is suitable for those areas where the soil contains less bearing strength. The purpose of using mat foundation is to allocate the entire loads of the structure to the soil (If the area of the footing is raised, the bearing strength of the soil is also enhanced) to minimize the stress on the soil at the similar area. Mat foundation defines the stress in civil engineering. To find out the stress, divide weight with per unit area. Suppose, a building measure 10 m x 7 m and weight on it is 130 Tons so the result will be as follow :Stress = Weight / Area = 130 / 70 = 1.85 tons weight per m2. This foundation is ideal for basement structures. There should be a water-resistant membrane sheet over the ground surface and then 4″ PCC is poured to develop a level base for the Mat/raft foundation. Once the PCC is completed, reinforcement steel bars are attached (cage) in place and then the required thickness of the concrete(According to the design) is poured.
REASON FOR USING MAT FOUNDATION It is used for the following purposes :1.
The bearing strength of the soil is weak and fails to transmit the load of building to the ground. 2. A column is provided adjacent to the property line and walls are very close that lead to the overlapping of the individual footing. 3. When the cost of a deep foundation (Pile foundation) exceeds the raft foundation in use to make the structure cost-effective. 4. If a spread footing column has the ability to cover up to 50% of the foundation area.