Ground Motions and Structures - Earthquake Engineering for Structural Design - page 304

304 Earthquake Engineering for Structural Design

Figure 8.7 Mat foundations (Gioncu and Mazzolani, 2002)

Figure 8.8 Condition of foundation-soil contact (after Savidis et al, 2000)

the foundation and the soil beneath. Tensile contact stresses are basically excluded and
a partial or full uplift becomes possible (Fig. 8.8). Therefore, the so-called condition of
partial contact is allowed for mat foundations (Savidis et al, 2000).

8.2.4 Pile Foundations

Pile foundation is used when firm soil is at a considerable distance below the natural
level of the site, in order to transfer building loads down to a suitable bearing layer,
when the soil immediately below a construction is unsuitable for direct bearing of
footing (Fig. 8.9). Piles support loads either by bearing directly on rock or suitable soil
and/or by developing friction along their very long length.