Chapter 9: Pile foundations

This chapter

Piles are a particular type of deep foundation generally chosen for use at a construction site where the soils at shallow depths are weak and therefore have very low bearing capacity. It is not an overstatement to say that piles are used in most heavily loaded structures such as multi-storey buildings, bridges, flyovers and oil platforms. Piles are also used in seismic-prone zones having loose to medium-dense sandy soil or soft clay. As noted in Chapters 6 and 7, if loose to medium-dense sands are saturated due to a shallow water table, they lose their strength and stiffness during earthquake shaking – a process is known as liquefaction. In other words, these soil deposits momentarily become a fluid-like material, affecting the foundations.