Thanks Ron,
Until now I have been calculating the I value of both the concrete (35N)and the steel casing (100yr residual thickness), and calculating Pcrit seperately for each, summing the values to give a Pcrit for the whole pile.
The Piles will be driven through 18m of Alluvial Silt, into...
I am currently in the process of designing a number of steel cased bottom driven piles, for Axial Loads of up to 500kN (@273mm diamter) and 350kN (@220mm diameter). The piles will be driven through alluvial silts (SPT N values 0-1), through a medium dense layer of sand at 18m, before end bearing...