Foundation Types: Strip and pad foundations, Surface spread foundations, Piled foundations, Miscellaneous elements and forms.
• Surface spread foundations,
• Piled foundations,
• Miscellaneous elements and forms.
The design of foundations involves the use of many different combinations of structural elements and foundation types which in turn vary to perform a wide variety of functions. It is therefore not surprising that the foundation scene has grown into a jumble of rather poorly deﬁned elements and forms. In addition to providing guidance on the elements and forms available, this chapter suggests a more clearly deﬁned terminology in an attempt to help clarify the issue. It is possible therefore that even the experienced engineer may at ﬁrst ﬁnd some of the terms unfamiliar. However, the authors have found that with use, the terms prove to be of great assistance. Since this chapter covers modern developments in foundation design this has resulted in the introduction of further new terms. Wherever existing terms clearly deﬁne the structural element or foundation form they have been retained, but more vague deﬁnitions such as ‘rigid raft’, etc. have been deliberately omitted, since such terms are in danger of misinterpretation and cover a widely varying group of foundations.
In addition to the design of the foundations to support the applied loads, without excessive settlement and distortion, there is a need to resist or prevent the effects of frost-heave and/or shrinkage and swelling of sub-strata. The many different loads and conditions demand different solutions, however the foundation types can generally be deﬁned and the main types are described in this chapter. Various references are made in the text to relative costs. Appendix M should be consulted for more detailed cost guidance.