Exit Gradient Sheet Pile Wall

For the sheet pile wall this filter is placed over the potentially unstable prism abed in fig.

Exit gradient sheet pile wall.

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. The computed gradient is in essence an average gradient over this distance. Exit gradient at toe of hydraulic structure g usin computer program seep w software. Musa 2014 studied the influence of cavities on seepage under sheet pile wall for hydraulic.

Of significance for later discussions is that the gradient is computed for a head loss over a fairly long distance of 3 3 m. 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. In 1954 terzaghi has suggested a simplified approach for the design of cutoff walls considering average seepage force. The exit gradient is then computed as 0 62 divided by 3 3 making the upward gradient 0 19.

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. It con sists of graded sand and gravel. The flow net for a sheet pile is shown below. The sheet pile penetrates 20 feet into the soil.

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. It is placed at the exit point where the water emerges from the foundation.