Exercise 14 1 derive relationship between the critical hydraulic gradient icr and porosity solution 14 1 cr also cr gs gs exercise 14 2 sheet pile wall.
Exit gradient sheet pile wall.
Musa 2014 studied the influence of cavities on seepage under sheet pile wall for hydraulic.
It con sists of graded sand and gravel.
In 1954 terzaghi has suggested a simplified approach for the design of cutoff walls considering average seepage force.
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.
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 observed that the best location of sheet pile to reduce seepage flow is at the downstream end.
The exit gradient is then computed as 0 62 divided by 3 3 making the upward gradient 0 19.
Exit gradient at toe of hydraulic structure g usin computer program seep w software.
The flow net for a sheet pile is shown below.
It is placed at the exit point where the water emerges from the foundation.
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.
Shayan and tokaldany 2014 studied the effects of upstream blanket and sheet pile on reducing seepage flow exit gradient and uplift force.
For the sheet pile wall this filter is placed over the potentially unstable prism abed in fig.