Note: The direct application of the formula for unconstrained pile for lateral support is incorrect.The result of direct application will result in pile embedment depths that are to shallow,over stress on soil bearing and maximum moments on the concrete pile that are to low. S1 needs to be divided by two (2) as the average soil bearing pressure "not" the maximun pressure. Shear and moment diagrams need to be drawn to ascertain the correct result.Sample calculation available by fax upon request.
Older versions( 20 years +/- ) of the UBC have illustrations of the soil pressure diagram which is clear about S1 as maxumum soil pressure.
Has anyone else noticed this issue and what was your experience with Bulding Depts. etc.