Connected or semi-connected sheet piles are often used to build continuous walls for waterfront structures that range from small waterfront pleasure boat launching facilities to large dock facilities. In contrast to the construction of other types of retaining wall, the building of sheet-pile walls does not usually require dewatering of the site. Sheet piles are also used for some temporary structures, such as braced cuts. Several types of sheet pile are commonly used in construction: (a) wooden sheet piles, (b) precast concrete sheet piles, and (c) steel sheet piles. Aluminum sheet piles are also marketed.
Variation of net pressure diagram and variation of moment versus depth of an anchored sheet pile wall with a granular soil backfill is shown below:
The objective in analysis of sheet pile walls is to get to a depth of embedment (D) sufficient for the wall stability. For this purpose, one needs to know the lateral earth pressure theory first.
Step-by-step procedure for obtaining pressure diagram is given below:
2. Calculate horizontal stress at point "C" and "D" respectively as:
3. Calculate L3
4. At z = L1 + L2 + L3 + L4, the net pressure is given by
5. Summing the forces in the horizontal direction (per unit length of the wall) gives:
Area of the pressure diagram ACDE - area of EBF - F = 0
where F = tension in the tie rod/unit length of the wall perpendicular to the screen
where P = area of the pressure diagram ACDE
6. Calculate the distance of P from point "E" (called z-bar on figure), by taking the moment about point "E" (P has to induce equal moment to the pressure of ACDE area).
7. Solving the following fourth order equation yield L4
this equation can be solved by trial-and-error method.
8. Draw the pressure diagram like the one given above, for which the depth of embedment is
D = L3 + L4