ABSTRACT

This chapter discusses the important and expensive elements, together with some refined methods for the design of the structures. The analysis of footing and raft foundations produces some well-known soil-structure interaction problems, and many methods and computer programmes have evolved to try to deal with them. Total shears, bending moments and torsions are calculated for various sections along the same direction, and the structural design is then carried out accordingly. Generally, the footing has to be analysed in two directions, and the structural design is performed for the two directions independently. In the classical rigid method, it is assumed that a plane section remains plane, and the subgrade is treated as a classical beam under moment and axial force. The stresses acting on a beam generally have a trapezoidal stress distribution. The grillage beam simulation was popularly used before finite element software was popular.