THICKNESS AT THE EDGE OF FOOTING IN REINFORCED AND PLAIN CONCRETE FOOTINGS THICKNESS AT THE EDGE SHALL NOT BE LESS THAN 15 CM FOR FOOTINGS ON THE SOIL NOR LESS THAN 30 CM ABOVE THE TOPS OF PILES FOR FOOTINGS ON THE PILES.

RCC FOOTINGS AND FOUNDATIONS :- RCC footings are provided to transmit the load of the structure supported by columns or walls to the soil.The design is based on assumption that the foundation is rigid so that the variation of pressure under the foundation will be linear .The distribution of pressure will be uniform if the centroid of the footing coincides with the resultant of the applied loads.This conventional method holds good only in case of rigid foundation.Such an assumption becomes less and less accurate as the footing becomes relatively more flexible.The requirements in design of foundations are as under (1) The pressure on the soil does not exceed the bearing capacity of the soil .(2) The settlement of the structure should be with in the permissible limits.Further there should be no differential settlement.Whenever possibility of differential settlement occurs ,the different portions of the structure should be made such as to settle independently of each other. In the case of footings on the piles, computation for moments and shears may be based on the assumption that the reaction from any pile is concentrated at the centre of the pile and for the purpose of computing stresses forces which support a round or octagonal concrete Column or pedestal , the face of the column or pedestal shall be taken as the side of a square inscribed with in the perimeter of the round or octagonal column or pedestal .The bending moment at any section shall be determined by passing through the section a vertical plane which extends completely across the footing, and computing the moment of the forces acting over the entire area of the footing on one side of the said plane 

.The greatest BM to be used in the design of an isolated Concrete footing which support a column, pedestal or a wall ,shall be moment computed in the manner prescribed as follows (1) The face of the column,pedestal or wall for footings Supporting a concrete column,pedestal or wall.(2) Half way between the center line and the edge of the wall for footings under masonry walls .(3) Half way between the face of the column or pedestal and the edge of the gussetted base ,for footings under gussetted base.