751.39 Pile Footings

Water elevation to be determined for site conditions by preliminary Design Section. Generally less than the average of high and low water.

Determine uplift force per pile by deducting weight of seal course and friction between seal course and sheet piling of cofferdam from uplift produced by hydrostatic head “$\,h$”.

Use friction value between seal course and sheet piling of $\,2lbs./in.^{2}$ acting on $\,(perimeter\times depth)$ of seal course.

Allowable uplift force per pile shall be determined by minimum of:

1.	$\,10lbs./in.^{2}$ frictional force to $\,(perimeter\ of\ pile\times depth\ of\ seal\ course)$ .
2.	Pullout capacity of pile;
	In saturated SAND $\,(F=5.0PL^{2})$
	Where:
	$\,P$ = perimeter pile in feet
	$\,L$ = embedded length of pile in sand (ft.)
	In saturated CLAY $\,(1.75lbs./in.^{2}$ frictional force to $\,(perimeter\ of\ pile\times embedment\ length\ of\ pile\ in\ clay)$ .
3.	Maximum pullout of 12 kips or 20% of maximum friction pile load.