Sheet piles are a temporary structures used to retain a soil or water for aspecific period of time, to build a structure in the other side of this wall.For example; if we want to build a structure with three basement floors (underground) and this structure surrounded by other structures, when the excavation process starts, if the soil under the surrounding structures doesn’t retained by a sheet pile, this soil will fail and will moves to the excavation site, and the structure above this soil may collapse suddenly, so before establishment of excavation process, sheet pile must be constructed to retain his soil and prevent it from fails and after completion of constructed the structure , we can remove this sheet pile because it’s function was end.Another example; if we wanna build a structure in the sea (waterfront structures)we can use sheet piles to retain sea water from flowing to the required area, and then withdraw the water confined between sheet piles and thereby build the required structures, finally remove sheet piles because there functions were end.The following figures are some explanation of the applications of sheet piles and the shape of sheet pile itself:
1. Sheet piles may be made from steel, concrete or wood.
2. As seen in the above pictures, sheet piles must penetrates a specified distance in earth (from both sides) to be stable against applied lateral loads,this depth called depth of penetration, and the following figure explain the main parts of sheet piles:
The line at which the sheet pile starts penetrating in soil from both sides is known by dredge line, and the depth of penetration of sheet pile under this line is D: depth of penetration.
Designing of sheet piles mainly is to calculate the depth of penetration D and determining the section of sheet pile as will be discussed later.
Types of Sheet Piles
There are two main types of sheet piles:
1. Cantilever Sheet Piles.
2. Anchored Sheet piles.