Figure 8-21. - Floating template for positioning piles.

A pile is at the point of refusal when it has been driven to a depth where deeper penetration is prevented by friction. A pile supported by skin friction alone is called a FRICTION pile. A pile supported by bedrock or an extra dense layer of soil at the tip is called an END-BEARING pile. A pile supported partly by skin friction and partly by substratum of extra dense soil at the tip is called a COMBINATION END-BEARING and FRICTION pile.

It is not always necessary for you to drive a friction pile to refusal; such a pile needs to be driven only to the depth where friction develops the required load-bearing capacity.

When bearing piles are driven on land, the position of each pile is usually located by the Engineering Aid and marked with a stake. A common method of locating the positions of a series of pile bents driven in water is by use of a wire rope long enough to stretch between the abutments and marked with pieces of tape, spaced according to the prescribed or calculated distance between bents.

After the first bent is driven, a floating TEMPLATE is used when driving subsequent bents like the one shown in figure 8-21. Pairs of BATTENS are spaced according to a specified spacing between piles in a bent and are nailed across each pair of timbers. The