Civil and Building Engineering.

A number of authors have made proposals for bearing capacity factors, including Caquot and Ke ´risel (1953), Meyerhof (1963), Hansen and Christensen (1969), Hansen (1970), and Vesic ´ (1973). The basic form of the bearingcapacity equation (Eq. 7.1), proposed by Terzaghi, has been accepted by most subsequent investigators; however, two modifications have been suggested: (1) improved analysis of the model proposed by Terzaghi (Figure 7.2), and (2) an extension of the method to include a number of factors such as inclined loading and a rectangular footing rather than a strip.

In addition, a number of other studies have been undertaken, such as those using FEM, to study the upper- and lower-bound values of the bearing capacity (Ukritchon et al., 2003). Hansen’s method has been selected and is presented in detail because it is comprehensive and because the analytical results agree reasonably well with experimental results.

Figure 7.4 Assumed curves for unit load versus settlement for a footing on dense soil, C1 and on loose soil, C2 (from Terzaghi, 1943, p. 118).