Concrete pi Woodpile Lowest ground b) Figure 1-7 Protecting timber piles from decay: a)by pre-cast concrete upper section above water level b)by extending pile cap below water level 1.4.13 Classification of pile with respect to effect on the soil A simplified division into driven or bored piles is often employed 1.4.14 Driven piles Driven piles are considered to be displacement piles.In the process of driving the pile into the ground,soil is moved radially as the pile shaft enters the gechdnhemeyalsobeacomponentotnmo,ementoithesalnheueted Figure 1-7 Protecting timber piles from decay: a) by pre-cast concrete upper section above water level. b) by extending pile cap below water level 1.4.13 Classification of pile with respect to effect on the soil A simplified division into driven or bored piles is often employed. 1.4.14 Driven piles Driven piles are considered to be displacement piles. In the process of driving the pile into the ground, soil is moved radially as the pile shaft enters the ground. There may also be a component of movement of the soil in the vertical direction