6.2 Rectangular combined footings In actual practice it is very difficult to make a rigid footing,for the thickness would have to be great. In recognition of the over-design using the conventional (or "rigid")method,current practice tends to modify the design by a beam-on- elastic-foundation analysis. ■ The conventional (or rigid)design of a rectangular combined footing consists in determining the location of the center of footing area.Next the length and width can be found. 6.2 Rectangular combined footings ▪ In actual practice it is very difficult to make a rigid footing, for the thickness would have to be great. ▪ In recognition of the over-design using the conventional (or “rigid”) method, current practice tends to modify the design by a beam-on￾elastic-foundation analysis. ▪ The conventional (or rigid) design of a rectangular combined footing consists in determining the location of the center of footing area. Next the length and width can be found