Shayan and tokaldany 2014 studied the effects of upstream blanket and sheet pile on reducing seepage flow exit gradient and uplift force.
Exit gradient sheet pile wall.
It is observed that the best location of sheet pile to reduce seepage flow is at the downstream end.
The flow net for a sheet pile is shown below.
The computed gradient is in essence an average gradient over this distance.
The 7 saturated unit weight of the soil is 130 pcf and the hydraulic conductivity is 3x10 ft sec.
Musa 2014 studied the influence of cavities on seepage under sheet pile wall for hydraulic.
In 1954 terzaghi has suggested a simplified approach for the design of cutoff walls considering average seepage force.
A sheet pile cutoff wall simply called cutoff wall is used in almost all types of water retaining structures to reduce the exit gradient at the downstream toe and prevent the chances of sand boiling and piping.
Of significance for later discussions is that the gradient is computed for a head loss over a fairly long distance of 3 3 m.
The sheet pile penetrates 20 feet into the soil.
10 20 such that the factor of safety against heave piping is improved as shown in f w w f f s 10 47.
A compute the total quantity of seepage in units of ft through the soil over a 24 hour b compute the critical hydraulic gradient and factor of safety against quick sand given this.
It is placed at the exit point where the water emerges from the foundation.
For the sheet pile wall this filter is placed over the potentially unstable prism abed in fig.
Depended on the software program tests were carried out with three different value of each following parameter upstream sheet pile depth downstream sheet pile depth permeability for first and second soil layer depth of first and.
The exit gradient is then computed as 0 62 divided by 3 3 making the upward gradient 0 19.